BR112019002676B1 - RACH CONVERSION OF INFORMATION ABOUT THE DL SYNC BEAM TO VARIOUS DL-UL MATCHING STATES - Google Patents

Abstract

Methods, systems and devices for wireless communication are described. A user equipment (UE) may receive a downlink (DL) signal from a base station on one or more DL beams. The UE may identify a nature of correspondence between one or more receive beams in the UE and one or more transmit beams in the UE. The UE may identify a DL beam selected from one or more DL beam(s) for communications from the base station to the UE. The UE may transmit a random access channel (RACH) message to the base station using a selected RACH resource and/or waveform based on the selected DL beam based, at least in part, on the selected DL beam and the nature of the correspondence.

Description

CROSS REFERENCE

[0001] The present patent application claims priority to U.S. Patent Application No. 15/674,214 of Islam et al., Entitled "RACH Conveyance of DL Synchronization Beam Information for Multiple States of DL-UL Correspondence", filed on August 10 2017; and to provisional patent application US62/374,735 by Islam et al., entitled "RACH Conveyance of DL Synchronization Beam Information for Various States of DL-UL Reciprocity," filed August 12, 2016; and to U.S. Provisional Patent Application No. 62/379,209 to Islam et al., entitled "RACH Conveyance of DL Synchronization Beam Information for Multiple DL-UL Reciprocity States," filed August 24, 2016; and to provisional patent application US 62/406,377 by Islam et al., entitled "RACH Conveyance of DL Synchronization Beam Information for Multiple States of DL-UL Reciprocity", filed October 10, 2016; and to U.S. Provisional Patent Application No. 62/407,423 of Islam et al., entitled "RACH Conveyance of DL Synchronization Beam Information for Multiple DLUL Reciprocity States" filed on October 12, 2016; and to U.S. Provisional Patent Application No. 62/418,072 of Islam et al., entitled "RACH Conveyance of DL Synchronization Beam Information for Multiple States of DL-UL Reciprocity", filed November 4, 2016; each of which is assigned to the assignee.

BACKGROUND

[0002] The following relates generally to wireless communication, and more specifically to random access channel (RACH) transmission of downlink (DL) synchronization Beam information for various downlink (DL) matching states -UL).

[0003] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcasting, and so on. Such systems may be able to support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such multiple access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and frequency division multiple access systems. orthogonal frequency control (OFDMA). Long Term Evolution (LTE). A wireless multiple access communications system may include a number of base stations, each simultaneously supporting communication for multiple communication devices, which may also be known as user equipment (UE).

[0004] Wireless communication systems can operate in millimeter wave (mmW) frequency bands (e.g., 28 GHz, 40 GHz, 60 GHz, etc.). Wireless communications at these frequencies may be associated with increased signal attenuation (e.g., path loss), which may be influenced by various factors such as temperature, barometric pressure, diffraction, etc. As a result, signal processing techniques such as beamforming can be used to coherently combine energy and overcome path losses at these frequencies. Due to the greater amount of path loss in mmW communication systems, base station and/or UE transmissions may be configured in Beam.

[0005] Wireless communications between two wireless nodes, (e.g., between a base station and a UE), may use Beam signals or Beam-formed signals for transmission and/or reception. A base station can transmit Beam-shaped sync signals into Downlink Sync Beams (DL). A UE may receive a synchronization signal on one or more DL Sync Beams, and thus be enabled to initiate a RACH procedure with the base station. In some cases, the UE may send a message to the base station as part of the RACH procedure, and the base station may assume that the Uplink Beam (UL) on which the RACH message is received is representative of a DL Beam that the base station must use when communicating with the UE. In other words, the base station assumes DL-UL correspondence. However, the correspondence between the DL channel and the UL channel may be absent for several reasons. Therefore, the base station's assumption may be incorrect, meaning that the DL Beam selected by the base station may not be the most appropriate Beam for communications with the UE.

SUMMARY

[0006] The described techniques refer to improved methods, systems, devices or devices that support RACH transport of DL Beam information to various DL-UL correspondence states. Generally, the described techniques provide a base station for transmitting DL signals to a UE. DL signals can be transmitted on DL Beam(s). The UE may use the DL Beam of the DL Beam(s) that may be used to communicate with the base station (e.g., DL communications). The UE may select a resource waveform and/or a random access channel (RACH) for transmitting a RACH message, (e.g., RACH msgl or RACH msg3, to the base station). In some aspects, the UE may select the RACH feature and/or waveform based on the Beam DL. The UE may transmit the RACH message to the base station on the selected resource and/or RACH waveform. The base station can receive the RACH message on the resource and/or RACH waveform and identify the Beam DL selected by the UE based on the resource and/or RACH waveform. The base station can use the selected Beam DL for subsequent communications with the UE.

[0007] A wireless communication method is described. The method may include receiving a downlink (DL) signal from a base station on one or more DL Beam, identifying a nature of correspondence between one or more receive Beams in the UE and one or more transmit Beams in the UE, identifying a Beam DL selected from one or more Beam DL for communications from the base station to the UE and transmitting a random access channel (RACH) message to the base station using at least one of a resource or a selected RACH waveform based at least in part on the selected Beam DL and the nature of the match.

[0008] A device for wireless communication is described. The device may include means for receiving a downlink (DL) signal from a base station in one or more DL Beam, means for identifying a nature of correspondence between one or more receive Beams in the UE and one or more transmit Beams in the UE, means for identifying a Beam DL selected from one or more Beam DLs for communications from the base station to the UE, and means for transmitting a random access channel (RACH) message to the base station using at least one of a resource or a RACH selected waveform based, at least in part, on the selected Beam DL and the nature of the correspondence.

[0009] Another device for wireless communication is described. The device may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be operable to cause the processor to receive a downlink (DL) signal from a base station on one or more DL Beams, identify a nature of correspondence between one or more receive Beams in the UE and one or more Beams transmitter in the UE, identifies a Beam DL selected from one or more Beam DL for communications from the base station to the UE, and transmits a random access channel (RACH) message to the base station using at least one of a resource or a form selected RACH waveform based, at least in part, on the selected Beam DL and the nature of the correspondence.

[0010] A non-transitory computer readable medium for wireless communication is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to receive a downlink (DL) signal from a base station in one or more DL Beam, identify a nature of correspondence between one or more receive Beams in the UE and one or more Transmit Beams in the UE, identify a Beam DL selected from one or more Beam DL for communications from the base station to the UE, and transmit a random access channel (RACH) message to the base station using at least one a feature or selected RACH waveform based, at least in part, on the selected Beam DL and the nature of the correspondence.

[0011] In some examples of the method, device, and non-transitory computer-readable medium described above, the resource comprises a time resource, a frequency resource, or a time-frequency resource.

[0012] In some examples of the method, device and non-transitory computer readable medium described above, the RACH message comprises a RACH 1 message (msgl).

[0013] In some examples of the method, device, and non-transitory computer-readable medium described above, the nature of the correspondence comprises at least one of: complete correspondence, partial correspondence, or correspondence may be absent.

[0014] Some examples of the method, device and non-transitory computer-readable medium described above may further include processes, features, means or instructions for determining that there may be complete correspondence. Some examples of the method, device and non-transitory computer-readable medium described above may further include processes, features, means or instructions for selecting the RACH resource or waveform to transmit the RACH message to the base station based on complete matching, where a DL Beam is mapped to the RACH feature or waveform.

[0015] Some examples of the method, device and non-transitory computer-readable means described above may further include processes, features, means or instructions for determining that there may be partial or null correspondence. Some examples of the method, device and non-transitory computer-readable medium described above may further include processes, features, means or instructions for selecting a transmission time of the RACH waveform to transmit the RACH message to the base station based on partial matching. or unmatched, where the transmission time comprises a symbol from a corresponding random access subframe.

[0016] Some examples of the method, device and non-transitory computer-readable means described above may further include processes, features, means or instructions for determining that there may be partial correspondence. Some examples of the method, device and non-transitory computer-readable medium described above may further include processes, features, means or instructions for selecting a transmission time for transmitting the RACH message to the base station based on partial matching, wherein the time transmission frame comprises multiple symbols of a corresponding random access subframe.

[0017] Some examples of the method, device and non-transitory computer-readable means described above may further include processes, features, means or instructions for determining that there may be partial or null correspondence. Some examples of the method, device and non-transitory computer-readable medium described above may further include processes, facilities, means or instructions for transmitting multiple instances of the RACH message to the base station based, at least in part, on partial or without correspondence, in which multiple instances of the RACH message are transmitted before receiving a subsequent message from the base station.

[0018] Some examples of the method, device and non-transitory computer readable medium described above may further include processes, features, means or instructions for selecting the RACH feature or waveform based, at least in part, on an associated symbol to the DL signal and the nature of the correspondence.

[0019] Some examples of the method, device and non-transitory computer-readable medium described above may further include processes, resources, means or instructions for selecting one or more of a transmission time, a frequency range or a RACH preamble to transmit the RACH message based on the nature of the correspondence.

[0020] In some examples of the method, device and non-transitory computer readable medium described above, the selected feature or RACH waveform comprises: selecting the feature or RACH waveform based, at least in part, on an index of the Beam DL selected.

[0021] Some examples of the method, device and non-transitory computer readable medium described above may further include processes, features, means or instructions for when correspondence may be absent between one or more receive Beams in the UE and one or more transmit Beams in the UE, the missing match is associated with one or more receive Beams having a different channel propagation characteristic than one or more transmit Beams.

[0022] Some examples of the method, device and non-transitory computer readable medium described above may further include processes, features, means or instructions for transmitting an indication of the nature of the correspondence, comprising transmitting on a physical uplink control channel (PUCCH ) or a physical uplink shared channel (PUSCH) during a first symbol of a first random access subframe and a second symbol of a second random access subframe.

[0023] Some examples of the method, device and non-transitory computer-readable medium described above may further include processes, features, means or instructions for mapping Receive Beams used to transmit Channel State Information Reference Signals (CSI-RSs) to transmit Beams used to transmit polling reference signals (SRSs) or map transmit Beams used to transmit SRSs to receive Beams used to transmit CSI-RSs.

[0024] Some examples of the method, device and non-transitory computer-readable medium described above may further include processes, resources, means or instructions for mapping receive Beams used in a DL Beam training to UL Beams used in a training or mapping from UL Beams the UL Beams used in UL Beams training to the DL Beams used in DL Beam training.

[0025] Some examples of the method, device and non-transitory computer readable medium described above, the DL signal comprises a synchronization signal or a reference signal.

[0026] A wireless communication method is described. The method may include identifying a nature of correspondence between one or more receive Beams on the UE and one or more transmit Beams on the UE and transmitting a random access channel (RACH) message to a base station based at least partly in the nature of the correspondence.

[0027] A device for wireless communication is described. The device may include means for identifying a nature of correspondence between one or more receive Beams on the UE and one or more transmit Beams on the UE and means for transmitting a random access channel (RACH) message to a base station based at least in part, about the nature of the correspondence.

[0028] Another device for wireless communication is described. The device may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be operable to cause the processor to identify a nature of correspondence between one or more Receive Beams on the UE and one or more Transmit Beams on the UE and transmit a Random Access Channel (RACH) message to a base station. based at least in part on the nature of the correspondence.

[0029] A non-transitory computer readable medium for wireless communication is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to identify a nature of correspondence between one or more Receive Beams on the UE and one or more Transmit Beams on the UE and transmit a random access channel message ( RACH), to a base station based, at least in part, on the nature of the correspondence.

[0030] In some examples of the method, device and non-transitory computer readable medium described above, the RACH message comprises a RACH 1 message (msgl) or a RACH 3 message (msg3) of a RACH procedure.

[0031] In some examples of the method, device, and non-transitory computer-readable medium described above, the RACH message conveys the nature of the correspondence.

[0032] In some examples of the method, device, and non-transitory computer-readable medium described above, the nature of the correspondence comprises at least one of a complete correspondence, a partial correspondence, or correspondence may be absent.

[0033] In some examples of the method, device and non-transitory computer readable medium described above, transmitting the RACH message comprises: transmitting the RACH message for the entire duration of a corresponding random access subframe.

[0034] A wireless communication method is described. The method may include transmitting a downlink (DL) signal on one or more DL Beam, receiving at least one resource waveform or random access channel (RACH), a RACH message from a user equipment (UE) into a series of Uplink (UL) Beams, identifying, based at least in part on the RACH feature or waveform, a DL Beam selected from one or more DL Beams for base station communications to the UE and transmitting one or more subsequent messages to the UE using the selected Beam DL.

[0035] A device for wireless communication is described. The device may include means for transmitting a downlink (DL) signal on one or more Beam DL, means for receiving, on at least one of a resource or random access channel (RACH) waveform, a RACH message. of a user equipment (UE) into a series of uplink (UL) Beams, means for identifying, based at least in part on the feature or RACH waveform, a DL Beam selected from one or more Beam DL for base station to UE communications; means for transmitting one or more subsequent messages to the UE using the selected Beam DL.

[0036] Another device for wireless communication is described. The device may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be operable to cause the processor to transmit a downlink (DL) signal on one or more Beam DL, receive, at least one of a resource waveform or random access channel (RACH), a RACH message from a user equipment (UE) into a series of uplink (UL) Beams, based, at least in part, on the RACH feature or waveform, a DL Beam selected from one or more DL Beams for network communications base station to the UE, and transmit one or more subsequent messages to the UE using the selected Beam DL.

[0037] A non-transitory computer readable medium for wireless communication is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to transmit a downlink (DL) signal on one or more Beam DL, receive at least one waveform from a resource or random access channel (RACH), a RACH message from a user equipment (UE) in a series of uplink (UL) Beams, identifies, based at least in part on the RACH feature or waveform, a selected DL Beam of one or more Beam DL for communications from the base station to the UE and transmitting one or more subsequent messages to the UE using the selected Beam DL.

[0038] In some examples of the method, device and non-transitory computer readable medium described above, the RACH message comprises a RACH 1 message (msgl).

[0039] In some examples of the method, device, and non-transitory computer-readable medium described above, receiving the RACH message comprises: receiving the RACH message for the entire duration of a corresponding random access subframe.

[0040] Some examples of the method, device and non-transitory computer readable medium described above may further include processes, features, means or instructions for measuring a quality of the RACH message received on the UL Beam array. Some examples of the method, device and non-transitory computer-readable medium described above may further include processes, features, means or instructions for determining a selected UL Beam for UE-to-base station communications based, at least in part, on the quality .

[0041] A wireless communication method is described. The method may include receiving a RACH message from a user equipment (UE) on a series of uplink (UL) Beams, measuring a quality of the RACH message received on the series of UL Beams, identifying, based on at least in part , as the RACH message received on the UL Beam array, a preferred UL Beam of the UL Beam array for communications from the UE to the base station, and transmit one or more subsequent messages to the UE, transmitting an indication of the preferred UL Beam.

[0042] A device for wireless communication is described. The device may include means for receiving a RACH message from a user equipment (UE) on a series of uplink (UL) Beams, means for measuring a quality of the RACH message received on the series of UL Beams, means for identifying, with based at least in part on the quality of the RACH message received on the UL Beam array, a preferred UL Beam of the UL Beam array for communications from the UE to the base station, and means for transmitting one or more subsequent messages to the UE carrying a indication of the preferred Beam UL.

[0043] Another device for wireless communication is described. The device may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be operable to cause the processor to receive a RACH message from a user equipment (UE) on a series of uplink (UL) Beams, measure a quality of the RACH message received on the series of UL Beams, identify, with based, at least in part, on the quality of the RACH message received on the UL Beam array, a preferred UL Beam of the UL Beam array for communications from the UE to the base station, and transmit one or more subsequent messages to the UE transmitting an indication of the preferred Beam UL.

[0044] A non-transitory computer readable medium for wireless communication is described. The non-transitory computer readable medium may include instructions operable to cause a processor to receive a RACH message from a user equipment (UE) on a series of Uplink Beams (UL), measure a quality of the RACH message received on the series of UL Beams, identify, based at least in part on the quality of the RACH message received on the UL Beam array, a preferred UL Beam from the UL Beam array for communications from the UE to the base station, and transmit one or more subsequent messages to the UE, transmitting an indication of the preferred UL Beam.

[0045] Some examples of the method, device and non-transitory computer readable medium described above may further include processes, features, means or instructions for transmitting one or more subsequent messages to the UE, comprising a RACH message 2 (msg2) transmission.

[0046] In some examples of the method, device and non-transitory computer-readable medium described above, receiving the RACH message from the UE comprises: receiving the RACH message during multiple symbols in the series of UL Beams.

[0047] In some examples of the method, device and non-transitory computer readable medium described above, the one or more subsequent messages to the UE comprise an identification or index of the preferred UL Beam.

[0048] In some examples of the method, device and non-transitory computer readable medium described above, identifying the preferred UL Beam comprises: associating the RACH feature or waveform with an index of the preferred UL Beam.

[0049] In some examples of the method, device and non-transitory computer readable medium described above, the preferred UL Beam index comprises an orthogonal coverage code (OCC) index.

[0050] Some examples of the method, device and non-transitory computer-readable means described above may further include processes, features, means or instructions for identifying the preferred UL Beam, may be based, at least in part, on a signal strength of the UL signal, on one or more UL Beams, a signal quality of the UL signal on one or more UL Beams, or combinations thereof.

[0051] In some examples of the method, device, and non-transitory computer-readable medium described above, receiving the RACH message comprises: receiving the RACH message for the entire duration of a corresponding random access subframe.

BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 illustrates an example of a system for wireless communication that supports RACH transport of DL Synchronization Beam information to various DLUL reciprocity states in accordance with aspects of the present invention;

[0053] Figure 2 illustrates an example of a process flow that supports RACH transport of DL Synchronization Beam information to various DL-UL reciprocity states in accordance with aspects of the present invention;

[0054] Figure 3 illustrates an example of a system for wireless communication that supports RACH transport of DL Synchronization Beam information to various DLUL reciprocity states in accordance with aspects of the present invention;

[0055] Figures 4A and 4B illustrate exemplary aspects of a Beam subframe mapping configuration that supports RACH transport of DL synchronization Beam information to various DL-UL reciprocity states in accordance with aspects of the present invention ;

[0056] Figures 5A and 5B illustrate examples of a Beam subframe mapping configuration that supports RACH transport of DL synchronization Beam information to various DL-UL reciprocity states in accordance with aspects of the present invention;

[0057] Figures 6A and 6B illustrate examples of a Beam subframe mapping configuration that supports RACH transport of DL synchronization Beam information to various DL-UL reciprocity states in accordance with aspects of the present invention;

[0058] Figures 7A and 7B illustrate examples of a Beam subframe mapping configuration that supports RACH transport of DL synchronization Beam information to various DL-UL reciprocity states in accordance with aspects of the present invention;

[0059] Figures 8 to 10 show block diagrams of a device that supports RACH transport of DL Synchronization Beam information for various DL-UL reciprocity states in accordance with aspects of the present invention;

[0060] [0060] Figure 11 illustrates a block diagram of a system including a UE that supports RACH transport of DL Synchronization Beam information for various DL-UL reciprocity states in accordance with aspects of the present invention;

[0061] Figures 12 to 14 show block diagrams of a device that supports RACH transport of DL Synchronization Beam information for various DL-UL reciprocity states in accordance with aspects of the present invention;

[0062] Figure 15 illustrates a block diagram of a system including a base station that supports RACH transmission of DL Synchronization Beam information for various DL-UL reciprocity states in accordance with aspects of the present invention; It is

[0063] Figures 16 to 19 illustrate methods for transporting DL RACH synchronization Beam information to various DL-UL reciprocity states in accordance with aspects of the present invention.

DETAILED DESCRIPTION

[0064] Free space path loss may increase with carrier frequency. Transmission in millimeter wave (mmW) systems can also be influenced by additional non-linear vision losses (e.g. diffraction loss, penetration loss, oxygen absorption loss, foliage loss, etc.). During initial access, the base station and user equipment (UE) may attempt to overcome these high trajectory losses to discover or detect each other. Aspects of the present invention provide improved initial access in a mmW system.

[0065] Aspects of the present invention are initially described in the context of a wireless communications system. Generally, the techniques described provide for a UE to transmit an indication to a base station of a Downlink Beam selected by the waveform of a corresponding resource and/or random access channel (RACH) for transmission of a scheduling request message. /RACH message. / Beam recovery or Beam trace message. For example, the base station can transmit DL signal(s) on DL Beam(s). The UE may select a DL Beam from the DL signal(s) that may be used for DL communications e.g. from the base station to the UE. The UE may select a resource and/or a waveform (e.g., a RACH waveform or a schedule request waveform) for transmitting the RACH message/schedule request message/Beam recovery or Beam tracking to the base station on the selected Beam DL. The UE may then transmit the RACH request message/Beam scheduling/recovery request message or Beam tracking message to the base station using the selected resource and/or the RACH waveform. The base station receives the RACH Beam Message/Schedule/Retrieve Request Message or Beam Tracking Message on the selected resource and/or RACH waveform and uses the resource and/or the RACH waveform to identify the Beam DL selected. In a non-limiting example, the UE may select a resource (e.g., channel) that corresponds to the timing characteristic of the DL signal(s) (e.g., symbol). The base station may then use the selected DL Beam for communications from the base station to the UE (e.g., for subsequent DL communications). In some aspects, a resource may refer to a time resource, a frequency resource, a time-frequency resource, and the like.

[0066] Aspects of the present invention are further illustrated and described with reference to device diagrams, system diagrams and flow charts that relate to the RACH transport of DL Sync Beam information to various DL-UL correspondence states. In some respects, the term correspondence can refer to reciprocity.

[0067] Figure 1 illustrates an example of a wireless communications system 100 in accordance with various aspects of the present invention. The wireless communications system 100 includes base stations 105, UEs 115, and a core network 130. In some examples, the wireless communications system 100 may be an LTE (or LTE Advanced) network.

[0068] Base stations 105 may communicate wirelessly with UEs 115 via one or more base station antennas. Each base station 105 may provide communication coverage for a respective geographic coverage area 110. The communication links 125 shown in the wireless communications system 100 may include UL transmissions from a UE 115 to a base station 105, or DL transmissions, from a base station 105 to a UE 115. The UE 115 may be dispersed throughout the wireless communications system 100, and each UE 115 may be stationary or mobile. A UE 115 may also be referred to as a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device , a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a telephone device, a user agent, a mobile client, a client, or some other suitable terminology. A UE 115 may also be a cellular telephone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a portable device, a tablet, a laptop, a cordless telephone, a personal electronic device, a handheld, a device, a personal computer, a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, a machine-type communications (MTC) device, a device, a car or like.

[0069] The base stations 105 can communicate with the core network 130 and with each other. For example, base stations 105 may interact with the core network 130 via backlinks 132 (e.g., SI, etc.). The base stations 105 may communicate with each other via return links 134 (e.g., X2, etc.), directly or indirectly (e.g., via the core network 130). Base stations 105 may perform radio configuration and programming for communication with UEs 115, or may operate under the control of a base station controller (not shown). In some examples, the base stations 105 may be macro cells, small cells, hot spots, or the like. Base stations 105 may also be referred to as Signal/Sinai and Bs 105.

[0070] During an initial access procedure, also referred to as a RACH procedure, the UE 115 may transmit a RACH preamble to a base station 105. This may be known as a RACH 1 message. For example, the RACH preamble may be randomly selected from a set of 64 predetermined sequences. This may allow the base station 105 to distinguish between multiple UEs 115 that attempt to access the system simultaneously. The base station 105 may respond with a random access response (RAR), or RACH 2 message, which provides a UL resource grant, a timing advance, and a temporary cellular radio network identity (C-RNTI). The UE 115 may then transmit a Radio Resource Control Connection (RRC) request, or RACH 3 message, along with a Temporary Mobile Subscriber Identity (TMSI) (if the UE 115 has previously been connected to the same wireless network ) or a random identifier. The Radio Resource Control (RRC) connection request may also indicate the reason why the UE 115 is connecting to the network (e.g., emergency, signaling, data exchange, etc.). The base station 105 may respond to the connection request with a contention resolution message, or RACH 4 message, addressed to the UE 115, which may provide a new C-RNTI. If the UE 115 receives a contention resolution message with the correct identification, the UE 115 may proceed with RRC configuration. If the UE 115 does not receive a contention resolution message (e.g., if there is a conflict with another UE 115), the UE 115 may repeat the RACH process by transmitting a new RACH preamble.

[0071] The wireless communications system 100 may operate in an ultra-high frequency (UHF) frequency region utilizing frequency bands from 700 MHz to 2600 MHz (2.6 GHz), although in some cases WLAN networks may use high frequencies such as 4 GHz. This region can also be known as the decimeter band, since wavelengths range from approximately one decimeter to one meter in length. UHF waves can propagate primarily by line of sight, and can be blocked by buildings and environmental features. However, the waves can penetrate walls enough to provide service to UE 115s located indoors. Transmission of UHF waves is characterized by smaller antennas and shorter range (e.g. less than 100 km) compared to transmission using the lower frequencies (and longer waves) of the high frequency (HF) or very high frequency part (VHF). In some cases, the wireless communication system 100 may also utilize extremely high frequency (EHF) portions of the spectrum (e.g., from 30 GHz to 300 GHz). This region may also be known as the millimeter range, since wavelengths range from approximately one millimeter to one centimeter in length. Thus, EHF antennas can be even smaller and spaced further apart than UHF antennas. In some cases, this may facilitate the use of antenna arrays within a UE 115 (e.g., for directional beam formation). However, EHF transmissions may be subject to even greater atmospheric attenuation and shorter range than UHF transmissions.

[0072] Specifically, the wireless communication system 100 may operate in mmW frequency bands (e.g., 28 GHz, 40 GHz, 60 GHz, etc.). Wireless communication at these frequencies may be associated with increased signal attenuation (e.g. path loss), which may be influenced by various factors such as temperature, barometric pressure, diffraction, etc. As a result, signal processing techniques such as beamforming (i.e., directional transmission) can be used to coherently combine signal energy and overcome trajectory loss in specific beam directions. In some cases, a device, such as a UE 115, may select a Beam direction to communicate with a network by selecting the strongest Beam among a number of signals transmitted by a base station 105. In one example, the signals may be DL synchronization signals (e.g., primary or secondary synchronization signals) or DL reference signals (e.g., channel state information reference signals (CSI-RS)) transmitted from the base station 105 during discovery. The discovery procedure may be cell specific, for example, it may be directed in incremental directions around the coverage area 110 of the base station 105. The discovery procedure may be used, at least in certain aspects, to identify and select Beam (s) to be used for Beam transmissions between the base station 105 and a UE 115.

[0073] In some cases, base station antennas may be located in one or more antenna arrays. One or more base station antennas or antenna arrays may be placed in an antenna array such as an antenna tower. In some cases, the antennas or antenna arrays associated with a base station 105 may be located in multiple geographic locations. A base station 105 may utilize multiple antennas or arrays of antennas to conduct beam forming operations for directional communications with a UE 115.

[0074] Wireless communication system 100 may be or include a mmW multicarrier wireless communication system. Broadly speaking, aspects of the wireless communication system 100 may include a UE 115 and a base station 105 configured to support RACH transport of DL Synchronization Beam information for various DL-UL correspondence states. For example, base station 105 may transmit DL signal(s) on DL beam(s). The UE 115 may select a DL Beam from the DL signal(s) that may be used for DL communications (e.g., from the base station 105 to the UE 115). The UE 115 may select a resource and/or a RACH waveform for transmitting the RACH message to the base station 105, where the selection is based on the selected Beam DL. The UE 115 may then transmit the RACH message to the base station 105 using the selected resource and/or the RACH waveform. Base station 105 receives the RACH message on the selected resource and/or RACH waveform and uses the resource and/or RACH waveform to identify the selected Beam DL. In a non-limiting example, the UE 115 may select a resource (e.g., channel) that corresponds to the timing characteristic of the DL synchronization signal(s) (e.g., symbol). The base station 105 may then use the selected DL Beam for communications from the base station 105 to the UE 115 (e.g., for subsequent DL communications).

[0075] Figure 2 illustrates an example of a process flow 200 for RACH transport of DL Sync Beam information to various DL-UL correspondence states. Process flow 200 may implement aspects of the wireless communication system 100 of Figure 1. Process flow 200 may include a UEl-15a and a base station 105-a, which may be examples of the corresponding devices of Figure 1. The station base 105-a may be a mmW base station and a serving base station for the UE 115-a.

[0076] At 205, base station 105-a may transmit a match indication associated with Beam DL on the base station side. In some aspects, the base station 105-a may explicitly indicate correspondence with the UE 115-a. For example, some may be devoted to conveying the correspondence indication. In other aspects, base station 105-a may implicitly indicate correspondence. For example, UE 115-a may deduce that the match is present or absent at base station 105-a from a Beam DL mapping to the RACH or waveform resources. In an example, if the DL Beams and RACH resources are configured using time division duplexing (TDD), this may indicate that base station 105-a may be matched.

[0077] In some cases, base station 105-a may include the match indication in a main information block (MIB) (e.g., bits reserved for indicating match) or a system information block (SIB) (e.g. example, bits reserved to indicate correspondence) transmitted to the UE 115-a. In some examples, the base station may transmit the MIB over a physical transmission channel (PBCH), and the base station may transmit the SIB over an extended PBCH. In some examples, the indication may be based on a preamble format where one preamble format may convey a non-match indication, a second preamble format may convey a partial match indication, and a third preamble format may convey an indication of complete correspondence. Based on the match indication, the UE 115-a may determine whether there is a complete match, no match, or partial match (e.g., with the 2 * N + 1 uncertainty region, where N represents a number of subarrays in the UE 115- a or with uncertainty 2 * M + 1, where M represents a number of Beams transmitted by the base station 105-a). If the UE 115-a determines that the match is missing, the UE 115-a may select a UL Beam (e.g., for communication with the base station 105-a) that is different from the DL Beam used by the base station 105-a .

[0078] Additionally or alternatively, at 205, the UE 115-a may transmit a correspondence indication associated with UL Beams on the UE side. For example, the UE 115-a may transmit a correspondence nature between one or more receive DL Sync Beams on the UE and one or more transmit Uplink (UL) Beams on the UE, the correspondence indication in a RACH message (for example, RACH msg 1 or RACH msg 3) or through a physical uplink control channel (PUCCH) or a physical shared uplink channel (PUSCH). The base station 105-a may receive the matching indication on the UE side, and based on the indication, the base station 105-a may determine the mapping of Beams used to transmit channel status information reference signals (CSI-RS ) a Beams used to transmit sounding reference signals (SRSs) or vice versa. Additionally, base station 105-a may determine to map Beams used in Beam DL training to Beams used in Beam UL training or vice versa, based on the indication.

[0079] At 210, the base station 105-a may transmit (and the UE 115-0 may receive) a DL synchronization signal to the UE 115-a. The DL sync signal may be a Beam-formed signal transmitted from the base station 105-a on DL sync Beam(s). The DL synchronization signal can be associated with an index and/or a symbol of a subframe. The DL synchronization signal may be associated with a transmit power condition.

[0080] In some aspects, base station 105-a transmits a series of DL synchronization signals during a synchronization subframe. Each DL synchronization signal can be transmitted in a symbol of the synchronization subframe (e.g., DL synchronization signal 1 can be transmitted during symbol 1, Dl synchronization signal 2 can be transmitted during symbol 2, etc.) .

[0081] At 215, the UE 115-a may identify a DL Beam selected from the DL Sync Beams to use for communications from the base station 105-a to the UE 115-a. The UE 115-a may identify the selected DL Beam by identifying a preferred DL Beam based on the signal strength and/or signal quality of the DL sync signal (e.g., high received signal strength and/or low level of interference) . In some aspects, the UE 115-a may identify the selected DL Beam by identifying a transmit power condition of the DL sync signal in the DL Sync Beams (e.g., a transmit power above a threshold).

[0082] At 220, the UE 115-a may select a RACH resource and/or waveform for transmitting the RACH message to the base station 105-a. The RACH feature and/or waveform may be selected based, at least in certain respects, on the selected Beam DL (e.g., based on the index of the selected Beam DL, based on the symbol of a subframe of the DL sync signal of the selected Beam DL, etc.). The RACH feature and/or waveform may be associated with tone(s) on a component carrier and/or associated with a component carrier.

[0083] At 225, the UE 115-a may transmit a RACH message to the base station 105-a. The RACH message can be transmitted on the selected RACH resource and/or RACH waveform. The RACH message may be transmitted for the entire duration of a corresponding random access subframe, for example, during each symbol of the random access subframe. In some aspects, the RACH message may be transmitted for the entire duration of a corresponding random access slot, subframe, occasion, timing, timing set, and the like. Generally, these terms can refer to a duration of time in which the gNB scans some or all of its Receive Beams to receive RACH messages. In some aspects, the UE 115-a may select a RACH waveform for transmitting the RACH message. The RACH waveform can be selected based on the selected Beam DL and can include a RACH preamble, a cyclic offset, etc. In some aspects, the UE 115-a may transmit the RACH message on a series of UL Beams.

[0084] At 230, base station 105-a can identify the selected Beam DL. The base station 105-a may identify the selected Beam DL based on the RACH resource and/or waveform used for transmitting RACH messages. In some aspects, base station 105-a may identify the selected Beam DL by associating the RACH feature and/or waveform with an index of the selected Beam DL. In some aspects, base station 105-a may identify the selected Beam DL by associating the feature and/or RACH waveform with a symbol of a subframe of the DL sync signal of the selected Beam DL.

[0085] In some aspects, base station 105-a may identify the selected Beam DL based on the RACH waveform of the RACH message. For example, base station 105-a may identify the selected Beam DL based on the RACH preamble of the RACH message, a cyclic offset of the RACH message, etc.

[0086] At 235, the base station 105-a may transmit subsequent messages to the UE 115-a using the selected Beam DL. In some cases, the selected Beam DL is a preferred Beam DL. Furthermore, in some aspects, the base station 105-a may utilize the RACH message received from the UE 115-a to determine a selected UL Beam for communications from the UE 115-a to the base station 105-a. For example, base station 105-a may measure a quality of the RACH message that is received on a series of UL Beams and determine the selected UL Beam based on the measured quality. Measuring RACH message quality may include measuring a reference signal received power (RSRP), a received signal strength indicator (RSSI), a reference received signal quality (RSRQ), a signal-to-noise ratio ( SNR), a signal to noise interference ratio (SINR), etc.

[0087] In some cases, the UE 115-a may measure an RSRP of a received signal transmitted in a synchronization signal block (e.g., where a combination of one or more synchronization signals is transmitted together in a certain direction ) to identify the best signal. In cases where the UE 115-a is unable to determine a stronger port associated with a particular symbol, the UE 115-a may indicate or transmit a better SS block index or the preferred Beam DL to the base station 105-a using different scatter codes (e.g. orthogonal coverage codes (OCCs)). In some examples, base station 105-a may transmit one or more additional reference signals (e.g., a Beam Reference Signal (BRS), a Mobility Reference Signal (MRS), etc.) within symbols used for synchronization signals 205 and UE 115 -a can identify a best transmission port (e.g., best downlink transmission Beam ID). As a result, the UE 115-a can feed back the best downlink transmission Beam ID using different spreading codes.

[0088] If base station 105-a does not obtain a Beam match, base station 105-a may request UE 115-a to transmit RACH on all symbols in the RACH slot. The base station 105-a can then find the best uplink receive beam based on the quality of the received RACH signals. In some examples, when the base station 105-a does not have a matching transmit/receive beam, the base station 105-a may configure an association between a downlink signal or a downlink channel and a subset of RACH and/or resources. or a subset of preamble indices (e.g., RACH preamble indices), which may be used to determine a Downstream Beam (e.g., to send Msg2). Based on a downlink measurement of received signals and the corresponding association, the UE 115-a may select the RACH resource subset and/or the RACH preamble index subset. In such cases, a preamble index may comprise a preamble sequence index and an OCC index, such as in cases where OCC is supported. In some examples, a subset of preambles may be indicated by OCC indices.

[0089] In some aspects, correspondence may be absent between the DL Sync Beams of the base station 105-a and the UL Beams of the UE 115-a. Therefore, in some examples, the selected Beam DL may be different from the selected Beam UL. Aspects of the present invention may support partial or no-Beam matching between DL transmit Beams and UL receive Beams. In the case of partial matching, the RACH message transmitted at 225 may be transmitted over a transmission time with a center symbol matching the best (e.g., strongest received signal strength), DL Sync Beam, or with a center symbol corresponding to the symbol associated with the best sync DL Beam. Likewise, the UE 115-a may determine the RACH preamble of the RACH message at 225 based on the best DL Synchronization Beam, and the UE 115-a may determine the subcarrier region used for transmission of the RACH message at 225 with based on the best DL Beam synchronization. This may apply to the frequency division duplexing (FDD) system, in which full Beam correspondence may not be present between the DL and UL. The amount of partial Beam matching can vary from one scenario to the next. In some examples, the missing match may be associated with different channel propagation characteristics for the DL and UL Beam (e.g., different transmit power levels, different departure and/or arrival angles, etc.).

[0090] In some cases, correspondence may be present at base station 105-a. In this case, the base station 105-a can transmit different DL synchronization signals at different times, and the base station 05-a can receive the corresponding RACH resources simultaneously from the UE 115-a through a digital receiver subsystem, the which may not suffer from analog Beam restrictions. In this case, a base station 105-a may request the UE 115-a to map DL synchronization signals to the RACH resources or waveforms. The base station 105-a can then analyze each receiving beam path with a RACH detector.

[0091] Embodiments of the present invention can also support Beam matching between DL transmit Beams and UL receive Beams. In the case where the match is present, the RACH message transmitted at 225 may be transmitted over a transmission time that corresponds to the best DL Sync Beam or the symbol corresponding to the best DL Sync Beam.

[0092] Figure 3 illustrates an example of a system 300 for wireless communications that supports RACH transport of DL Synchronization Beam information for various DL-UL correspondence states. System 300 may be an example of aspects of the wireless communication system 100 of Figure 1. System 300 may be a mmW wireless communication system. System 300 may include a UE 115-b and a base station 105-b, which may be examples of the corresponding devices of Figures 1 and 2. In general terms, system 300 illustrates aspects of a discovery procedure where the UE 115-b discovers the 105-b base station based on the DL sync signals transmitted on DL Sync Beams.

[0093] In some examples, the base station 105-b may be a mmW base station that transmits Beam transmissions on an active Beam to the UE 115-b. Transmissions from base stations 105-b may be beam-form or directional transmissions that are directed to the UE 115-b.

[0094] For example, the base station 105-b may transmit the DL synchronization signal on DL Sync Beams 305. The base station 105-b may transmit DL synchronization signals (e.g., for random access) in a manner in Beam shape and swept through the angular coverage region (e.g. in azimuth and/or elevation). Each DL 305 Sync Beam can be transmitted in a Beam sweep operation in different directions so as to cover the coverage area of the base station 105-b. For example, DL Sync Beam 305-a can be transmitted in a first direction, DL Sync Beam 305-b can be transmitted in a second direction, DL Sync Beam 305-c can be transmitted in a third direction and DL the 305-d Sync Beam can be transmitted in a fourth direction. Although system 300 displays four DL 305 Sync Beams, it should be understood that fewer and/or more DL 305 Sync Beams may be transmitted. Furthermore, DL 305 Sync Beams can be transmitted at different Beam widths, at different elevation angles, etc. In some aspects, DL 305 Sync Beams may be associated with a Beam index, for example, an indicator that identifies the Beam.

[0095] In some aspects, the DL 305 Sync Beams may also be transmitted during different symbol periods of a synchronization subframe. For example, DL Sync Beam 305-a may be transmitted during a first symbol period (e.g., symbol 0), DL Sync Beam 305-b may be transmitted during a second symbol period (e.g., symbol 1), the DL 305-c Sync Beam may be transmitted during a third symbol period (e.g., symbol 2) and DL 305-d Sync Beam transmitted during a fourth symbol period (e.g., symbol 3). Additional DL Sync Beams 305 may be transmitted during other symbol periods of the synchronization subframe.

[0096] Generally, performing the Beam scanning operation supports the base station 105-b, which determines the direction in which UE 115-b is located (e.g., after receiving response messages from UE 115b). This supports transmission of the RACH 2 message from the base station 105-b. Additionally, Beam sweep operation improves communications when correspondence does not maintain between DL and UL channels, the UE 115-b can select the frequency region and/or waveform configuration (e.g., shape RACH waveform and resources) to transmit the random access signal (e.g., RACH message, RACH msgl, or RACH msg3) based on the index of the best or preferred DL sync signal on the DL Sync Beam 305. In some cases, the UE 115-a may transmit the best or preferred Beam DL using an index or identification in a RACH msgl. During the random access period, the base station 105-a can find the suitable Beam UL by receiving the random access signal in a comprehensive manner. The base station 105-b may identify the UE 115 - a Beam DL selected from the RACH resource and/or waveform used (e.g., the frequency region and/or waveform configuration used) that contains the RACH message ( for example, RACH msgl or RACH msg3) of the random access signal.

[0097] Thus, the UEs within the coverage area of the base station 105-b can receive the DL sync signals on the DL Sync Beams 305. The UE 115-b can identify which DL sync signal is the best (e.g. , stronger received signal strength, better channel quality, etc.), and identify this as the selected Beam DL. The UE 115-b may then select a RACH resource and/or waveform to use for transmitting the RACH message based on the selected Beam DL, e.g., the preferred Beam DL. In an example, the resource and/or RACH waveform used for transmitting the RACH message may correspond to the selected Beam DL symbol. In another example, the RACH message may include an identification or index of the preferred Beam DL.

[0098] As a non-limiting example, there may be 16 different Beam DL available. Thus, the UE 115-b can use four bits to transmit the Beam DL information to the base station 105-b. There may be four subcarrier regions (e.g., resources) and four different RACH waveforms available for use by the UE 115-b. Therefore, the UE 115-b can transmit the four bits by selecting one of four different RACH waveforms and one of four subcarriers. Thus, the UE 115-b may select a combination of the resource and the RACH waveform to transmit the RACH message to the base station 105-b.

[0099] Thus, in certain aspects, the system 300 may support the UE 115-b selecting a combination of a RACH waveform and/or the resource used for its transmission of RACH messages based on one or more combinations of the index of a DL Sync Beam or in a symbol of the DL Sync Subframe. The UE 115-b may transmit random access signal (e.g., RACH message, RACH msgl or RACH msg3) during the entire duration of the random access subframe and/or during a portion of the random access subframe.

[0100] In some aspects, the base station 105-b may determine the selected Beam DL of the UE 115-b from the frequency region used and/or the RACH waveform containing message 1 of the random access signal. The 105-b base station can determine the best UL receiving beam by measuring the quality of the signal received on different uplink receiving beams. Signal quality can denote one or more combinations of RSRP, RSSI, RSRQ, SNR, SINR, etc.

[0101] In some aspects, the UE 115-b may select the best DL sync signal and the frequency region of the RACH and/or RACH waveform based on the index of the best DL sync signal. The UE 115-b may select a DL 305 Sync Beam that satisfies a transmit power condition. The UE 115-b may select a RACH preamble and cyclic offset partially based on the index of a DL 305 Sync Beam.

[0102] The lack of correspondence may indicate that the best Beam DL and the best Beam UL are not the same.

[0103] In some aspects, the UE 115-b may select a combination of RACH and the resource used for its transmission based on a DL synchronization subframe symbol if the base station 105-b transmits multiple modules using multiple ports. antenna in each subframe synchronization symbol. In some aspects, the feature may denote the tones on a component carrier and/or on a component carrier.

[0104] Although the example described with reference to Figure 3 is directed to transmitting a RACH message in a RACH subframe, this example is also applicable to transmitting a scheduling request message, Beam recovery message or Beam tracking message in a RACH subframe. In some cases, the UE 115 may find that the best synchronization Beam was transmitted during a specific symbol, and the UE 115 may transmit a schedule request message, Beam recovery message or Beam trace message in a region of frequency that corresponds to the specific symbol. The frequency region can be in a different resource (or block of resources) in a subframe of the RACH. That is, a first portion of the resources in a RACH subframe may be allocated for RACH message transmissions, a second portion of the resources in a RACH subframe may be allocated for scheduling request message transmissions, and a third portion of the resources in a RACH subframe can be allocated for Beam retrieval or Beam tracking message transmissions.

[0105] The UE 115-b may receive a subcarrier region indication for a schedule request message transmission or a Beam recovery or Beam follow message transmission via RRC signaling. In some cases, there may be eight (8) possible subcarrier regions. The UE 115-b may also receive the desired cyclic offset for the schedule request message transmission or the Beam recovery or Beam tracking message transmission via RRC signaling. In some examples, the UE 115-b may use twelve (12) of various different cycles to generate a sequence for transmitting the schedule request message or Beam recovery or transmitting Beam trace messages. The number of cyclic shifts available for programming request message transmission or Beam recovery or Beam tracking message transmission may be greater than the number of cyclic offsets available for a RACH message transmission, as a timing may be corrected before the UE 115-b transmits the transmission of the scheduling request message or the Beam recovery or Beam tracking message. Additionally, the transmission of the schedule request message transmission or the Beam retrieval or Beam tracking message may encompass two (2) symbols that may provide additional degrees of freedom (e.g., 192 degrees of freedom in each pair of symbols).

[0106] Figures 4A and 4B illustrate examples of a Beam 400 subframe mapping configuration for RACH transport of DL synchronization Beam information for various DL-UL correspondence states. Configuration 400 may implement aspects of the wireless communication system 100, process flow 200, and/or system 300 if Figures 1 to 3. In some aspects, aspects of configuration 400 may be implemented by a base station 105 and/or a UE 115, as described with reference to figures 1 to 3.

[0107] Referring to Figure 4A, Beam subtraction mapping configuration 400 may include a series of DL sync signals transmitted on DL Sync Beams 405. A base station 105 may transmit DL sync signals (e.g., to random access) in a Beam-shaped manner and scanned through the angular coverage region (e.g., in azimuth and/or elevation). Each DL 405 Sync Beam may be transmitted in a Beam sweep operation in different directions to cover the coverage area of the base station 105. For example, the DL 405-a Sync Beam may be transmitted in a first direction, the DL 405-b sync beam can be transmitted in a second direction, and so on. In some aspects, DL 405 Sync Beams may be associated with a Beam index, for example, an indicator that identifies the Beam.

[0108] In some aspects, DL Sync Beams 405 may also be transmitted during different symbol periods of a sync subframe 410. Sync subframe 410 may be associated with a time feature along the horizontal axis (e.g. , symbols) and a frequency characteristic along the vertical axis (e.g. frequencies or tones). For example, Sync Beam DL 405-a may be transmitted during a first symbol period (e.g., symbol 0), Sync Beam DL 405-b may be transmitted during a second symbol period (e.g., symbol 1). ) and so on until DL The 405-h Sync Beam is transmitted during an eighth symbol period (e.g. symbol 7).

[0109] In some aspects, each DL sync signal transmitted on a DL Sync Beam 405 may be transmitted on some or all of the frequencies during the symbol. For example, the DL 405-a Sync Beam may be transmitted on frequency or tones 0 - 7 during symbol 0, the DL 405-b Sync Beam may be transmitted on frequency or tones 0 - 7 during symbol 1, and so on.

[0110] Thus, the base station 105 can sweep the DL Sync Beams 405 in eight directions during eight symbols of the synchronization subframe 410.

[0111] Referring to Figure 4B, the UE 115 within the coverage area of the base station 105 can receive the DL sync signals on the DL Sync Beams 405. The UE 115 can identify which DL sync signal is the best (e.g. example, stronger received signal strength, better channel quality, etc.), and identify this as the selected Beam DL. In the example of Figure 4B, the UE 115 identified the DL sync signal transmitted in DL Sync Beam 405-b as the selected DL Beam. As indicated, the DL 405-b Sync Beam was transmitted during the second symbol.

[0112] In some aspects, the UE 115 may then select a resource to use for transmitting the RACH message based on the selected Beam DL and during the RACH subframe 415 . In one example, the resource used to transmit the RACH message may correspond to the selected Beam DL symbol. Thus, the UE 115 may select the second resource 420 (e.g., frequency or tone 1) as the resource for transmitting the RACH message. That is, the UE 115 may select the second resource 420 to transmit an indication of the DL Sync Beam transmitted during the second symbol as being the selected DL Beam. As discussed above, the UE 115 may also select a RACH waveform to transmit the RACH message.

[0113] Thus, UE 115 may find that the best synchronization beam was transmitted during the second symbol. The UE 115 may transmit a RACH message in the second frequency region for all time slots (e.g., during all symbols of RACH subframe 415). The base station 105 may find the best DL transmission beam of the used frequency region (e.g., second resource 420) of the random access signal (e.g., RACH message). In some examples, RACH message transmission time units may be larger than synchronization subframe time units due to DL-UL power differences, for example.

[0114] In some aspects, base station 105 may scan the same eight directions during the same eight symbols during RACH subframe 415. For example, the base station 105 may configure one or more antenna arrays to receive the RACH message according to the same scan pattern used to transmit the DL sync signal on the DL Sync Beams 405 during the RACH subframe 415.

[0115] The example described above with reference to Figure 4 may apply to cases where there is no match at base station 105 for the selected Beam DL. Additionally, the example may apply to cases where there is no match at both the base station 105 and the UE 115. In such cases, the UE 115 may identify a method to transmit using the selected DL Beam based on a link gain. associated with transmissions from UE 115. In some cases, UE 115 may determine its link gain based on synchronization signals received from base station 105. If UE 115 obtains sufficient link gain to satisfy a link budget, the UE 115 may transmit the RACH message in a single RACH subframe. However, if the UE 115 does not obtain sufficient link gain to satisfy a link budget, the UE 115 may transmit the RACH message in several RACH subframes.

[0116] Although the example described with reference to Figures 4A and 4B is directed to transmitting the RACH message in RACH subframe 415, this example is also applicable to transmitting a scheduling request message, Beam recovery message or tracking message of Beam in RACH subframe 415. In some cases, the UE 115 may find that the best synchronization Beam was transmitted during the second symbol, and the UE 115 may transmit a schedule request message, Beam recovery message, or Beam follow message in a region second frequency for all time intervals. The second frequency region may be in a different resource (or resource block) in RACH subframe 415. That is, a first portion of the resources in the RACH subframe 415 may be allocated to RACH message transmissions, a second portion of the resources in the RACH subframe 415 may be allocated to scheduling request message transmissions, and a third portion of the resources in the RACH subframe 415 may be allocated to scheduling request message transmissions. RACH 415 may be allocated for Beam recovery or Beam tracking message transmissions.

[0117] Figures 5A and 5B illustrate an example of a Beam subframe mapping configuration 500 for RACH transport of DL synchronization Beam information for various DL-UL correspondence states. Configuration 500 may implement aspects of the wireless communication system 100, process flow 200, and/or system 300 of Figures 1 to 3. In some aspects, aspects of configuration 500 may be implemented by a base station 105 and/or a UE 115, as described with reference to figures 1 to 3.

[0118] Referring to Figure 5, a Beam subframe mapping configuration 500 may include a series of DL sync signals transmitted on DL Sync Beams 505. A base station 105 may transmit DL sync signals (e.g., for access random) in a Beam shape fashion and swept through the angular coverage region (e.g., in azimuth and/or elevation). Each DL 505 Sync Beam may be transmitted in a Beam sweep operation in a different direction so as to cover the coverage area of the base station 105. For example, the DL 505-a Sync Beam may be transmitted in a first direction, the DL 505-b Sync Beam can be transmitted in a second direction, and so on. In some aspects, DL 505 Sync Beams may be associated with a Beam index, for example, an indicator that identifies the Beam.

[0119] In some aspects, DL Sync Beams 505 may also be transmitted during different symbol periods of a sync subframe 510. Sync subframe 510 may be associated with a time feature along the horizontal axis (e.g. , symbols) and with a frequency characteristic along the vertical axis (e.g. frequencies or tones). In the example of Figure 5A, base station 105 can be configured with four antenna arrays in which base station 105 scans four directions in each symbol. For example, antenna ports 0-3 may be grouped into subgroup 510 and used to transmit DL Sync Beams 505-a through 505-d during the first symbol (e.g., symbol 0) of synchronization subframe 510. Additionally Additionally, antenna ports 0-3 may be grouped into subgroup 515 and used to transmit Sync Beams DL 505-e to 505-h during the second symbol (e.g., symbol 1) of synchronization subframe 510. Thus, base station 105 may scan eight directions during two symbols of synchronization subframe 510.

[0120] In some aspects, each DL sync signal transmitted on a DL Sync Beam 505 may be transmitted on some or all of the frequencies during the symbol. For example, the DL 505-a Sync Beam can be transmitted on any frequency or tones 0 - 7 during symbol 0, the DL 505-b Sync Beam can be transmitted on any frequency or tones 0 - 7 during symbol 1 , and so on . In some aspects, DL 505 Sync Beams transmitted during a symbol may not be transmitted on overlapping frequencies.

[0121] Thus, the base station 105 can sweep the DL Sync Beams 505 in eight directions during eight symbols of the sync subframe 510.

[0122] Referring to Figures 5B, the UE 115 within the coverage area of the base station 105 can receive the DL sync signals on the DL Sync Beams 505. The UE 115 can identify which DL sync signal is the best (e.g. example, stronger received signal strength, better channel quality, etc.), and identify this as the selected Beam DL. In the example of Figure 5B, the UE 115 identified the DL sync signal transmitted in DL Sync Beam 505-a as the selected DL Beam. As indicated, the DL 505-a Sync Beam was transmitted during the first symbol (for example, during symbol 0).

[0123] In some aspects, the UE 115 may then select a resource to use for transmitting the RACH message based on the selected Beam DL and during RACH subframe 515. In one example, the resource used to transmit the RACH message may correspond to the selected Beam DL symbol. Thus, the UE 115 may select the first resource 520 (e.g., frequency or tone 0) as the resource for transmitting the RACH message. That is, the UE 115 may select the first resource 520 to transmit an indication of the DL Sync Beam transmitted during the first symbol as being the selected DL Beam.

[0124] Thus, the UE 115 may find that the best Sync Beam was transmitted during the first symbol. The UE 115 may transmit a RACH message in the first frequency region for all time slots (e.g., during all symbols of RACH subframe 515). The base station 105 can find the best UL-received Beam by measuring the quality of the received signal during different time intervals (e.g., during different symbols). In some aspects, the base station 105 may find the best Beam DL course of the utilized frequency region (e.g., first resource 520) of the random access signal (e.g., RACH message).

[0125] In some aspects, base station 105 may scan the same eight directions during the same eight symbols during RACH subframe 515. For example, the base station 105 may configure one or more antenna arrays to receive the RACH message according to the same scan pattern used to transmit the DL sync signal on the DL Sync Beams 505 during the sync subframe 510.

[0126] Figures 6A and 6B illustrate examples of a Beam subframe mapping configuration 600 for RACH transport of DL synchronization Beam information for various DL-UL correspondence states. Configuration 600 may implement aspects of wireless communication system 100, process flow 200, and/or system 300 if Figures 1 to 3. In some aspects, aspects of configuration 600 may be implemented by a base station 105 and/or a UE 115, as described with reference to figures 1 to 3.

[0127] Referring to Figure 6A, Beam subframe mapping configuration 600 may include a series of DL sync signals transmitted on DL Sync Beams 605. A base station 105 may transmit DL sync signals (e.g., for random access) in a Beam-shaped fashion and scanned through the angular coverage region (e.g., in azimuth and/or elevation). Each DL 605 Sync Beam may be transmitted in a Beam sweep operation in different directions to cover the coverage area of the base station 105. For example, the DL 605-a Sync Beam may be transmitted in a first direction, the DL 605-b sync beam can be transmitted in a second direction, and so on. In some aspects, DL 605 Sync Beams may be associated with a Beam index (e.g., an indicator that identifies the Beam).

[0128] In some aspects, DL sync beams 605 may also be transmitted during different symbol periods of a sync subframe 610. Sync subframe 610 may be associated with a time feature along the horizontal axis (e.g. , symbols) and with a frequency characteristic along the vertical axis (e.g. frequencies or tones). For example, Sync Beam DL 605-a may be transmitted during a first symbol period (e.g., symbol 0), Sync Beam DL 605-b may be transmitted during a second symbol period (e.g., symbol 1 ) and so on until DL 605-h Sync Beam is transmitted during an eighth symbol period (e.g. symbol 7).

[0129] In some aspects, each DL sync signal transmitted on a DL Sync Beam 605 may be transmitted on some or all of the frequencies during the symbol. For example, the DL 605-a Sync Beam may be transmitted on frequency or tones 0 - 7 during symbol 0, the DL 605-b Sync Beam may be transmitted on frequency or tones 0 - 7 during symbol 1, and so on.

[0130] Thus, the base station 105 can sweep the DL Sync Beams 605 in eight directions during eight symbols of the sync subframe 610.

[0131] Referring to Figure 6B, the UE 115 within the coverage area of the base station 105 can receive the DL sync signals on the DL Sync Beams 605. The UE 115 can identify which DL sync signal is the best (e.g. example, stronger received signal strength, better channel quality, etc.), and identify this as the selected Beam DL. In the example of Figure 6B, the UE 115 identified the DL sync signal transmitted in DL Sync Beam 605-b as the selected DL Beam. As indicated, the DL 605-b Sync Beam was transmitted during the second symbol.

[0132] In some aspects, the DL 605-b Sync Beam can be completely matched at the base station 105 and the UE 115. That is, the DL 605-b Sync Beam can be used for transmission and reception at both the base station 105 as in the UE 115. Thus, the UE 115 may select the DL Sync Beam 605-b to transmit a RACH message to the base station 105. In some cases, the UE 115 may randomly select the subcarrier region for transmitting the message RACH to provide diversity in the presence of multiple UEs. In the example of Figure 6B, UE 115 selected subcarrier 3 for transmission of the RACH message.

[0133] In other aspects, the DL 605-b Sync Beam may be fully matched at the base station 105 and unmatched at the UE 115. That is, the DL 605-b Sync Beam may be used for transmission and reception at the base station 105, but a transmission from the UE 115 on the DL 605-b Sync Beam may be noisy. In such cases, the UE 115 may identify a method to transmit using the selected Beam DL based on a link gain associated with transmissions from the UE 115. In some cases, the UE 115 may determine its link gain based on signals synchronization signals received from base station 105. If the UE 115 obtains sufficient link gain to satisfy a link budget, the UE 115 may transmit the RACH message in a single RACH subframe. However, if the UE 115 does not obtain sufficient link gain to satisfy a link budget, the UE 115 may transmit the RACH message in several RACH subframes.

[0134] Although the example described with reference to Figures 6A and 6B is directed to transmitting the RACH message in RACH subframe 615, this example is also applicable to transmitting a schedule request message, Beam recovery message or beam tracking message. Beam in subplot 615 of RACH. In some cases, the UE 115 may find that the best synchronization Beam was transmitted during the second symbol, and the UE 115 may transmit a schedule request message, Beam recovery message or Beam follow message in a region of second frequency for all time slots. The second frequency region may be in a different resource (or block of resources) in the second symbol. That is, a first portion of the resources in RACH subframe 615 may be allocated for RACH message transmissions, a second portion of the resources in RACH subframe 615 may be allocated for scheduling request message transmissions, and/or a third portion of the resources in RACH subframe 615 may be allocated for Beam recovery or Beam tracking message transmissions.

[0135] Figures 7A and 7B illustrate examples of a Beam subframe mapping configuration 700 for RACH transport of DL synchronization Beam information for various DL-UL correspondence states. Configuration 700 may implement aspects of wireless communication system 100, process flow 200, and/or system 300 if Figures 1 to 3. In some aspects, aspects of configuration 700 may be implemented by a base station 105 and/or a UE 115, as described with reference to figures 1 to 3.

[0136] Referring to Figure 7A, Beam subtraction mapping configuration 700 may include a series of DL sync signals transmitted on DL Sync Beams 705. A base station 105 may transmit DL sync signals (e.g., to random access) in a Beam-shaped manner and scanned through the angular coverage region (e.g., in azimuth and/or elevation). Each Sync Beam 705 may be transmitted in a Beam sweep operation in different directions to cover the coverage area of the base station 105. For example, the DL Sync Beam 705-a may be transmitted in a first direction, the Beam DL 705-b synchronization signal can be transmitted in a second direction, and so on. In some aspects, DL 705 Sync Beams may be associated with a Beam index, for example, an indicator that identifies the Beam.

[0137] In some aspects, DL Sync Beams 705 may also be transmitted during different symbol periods of a sync subframe 710. Sync subframe 710 may be associated with a time feature along the horizontal axis (e.g. , symbols) and with a frequency characteristic along the vertical axis (e.g. frequencies or tones). For example, the DL 705-a Sync Beam may be transmitted during a first symbol period (e.g., symbol 0), the DL 705-b Sync Beam may be transmitted during a second symbol period (e.g., symbol 1) and so on until DL 705-h Sync Beam is transmitted during an eighth symbol period (e.g. symbol 7).

[0138] In some aspects, each DL sync signal transmitted on a Sync Beam 705 may be transmitted on some or all frequencies during the symbol. For example, the DL 705-a Sync Beam may be transmitted on frequency or tones 0 - 7 during symbol 0, the DL 705-b Sync Beam may be transmitted on frequency or tones 0 - 7 during symbol 1, and so on.

[0139] Thus, the base station 105 can sweep the DL Sync Beams 705 in eight directions during eight symbols of the sync subframe 710.

[0140] Referring to Figure 7B, the UE 115 within the coverage area of the base station 105 can receive the DL sync signals on the DL Sync Beams 705. The UE 115 can identify which DL sync signal is the best (e.g. example, stronger received signal strength, better channel quality, etc.), and identify this as the selected Beam DL. In the example of Figure 7B, the UE 115 identified the DL sync signal transmitted in DL Sync Beam 705-b as the selected DL Beam. As indicated, the DL 705-b Sync Beam was transmitted during the second symbol.

[0141] In some aspects, the DL 705-b Sync Beam may be matched at the base station 105 and UE 115. That is, the DL 705-b Sync Beam may be used for transmission and reception at the base station 105 and UE 115 with little noise. However, it may be desirable for the UE 115 to identify a better Beam (e.g., stronger signal strength) for uplink transmission. Thus, the UE 115 can transmit the RACH message on the selected DL Beam symbol and adjacent DL Beam symbols (e.g., synchronization DL Beams 705-a and 705-c). In order to receive the uplink transmission, the base station 105 may scan a portion of the eight directions during symbols 0, 1, and 2 in RACH subframe 715.

[0142] The UE 115 may then select a resource to use for transmitting the RACH message based on the selected Beam DL and during the RACH subframe 415 . In one example, the resource used to transmit the RACH message may correspond to the selected Beam DL symbol. Thus, the UE 115 may select the second resource 720 (e.g., frequency or tone 1) as the resource for transmitting the RACH message. That is, the UE 115 may select the second resource 720 to transmit an indication of the DL Sync Beam transmitted during the second symbol as being the selected DL Beam. As discussed above, the UE 115 may also select a RACH waveform to transmit the RACH message.

[0143] Thus, the UE 115 may find that the best synchronization beam was transmitted during the second symbol. The UE 115 may transmit a RACH message in the second frequency region for a portion of the time slots (e.g., during a portion of the RACH subframe 715 symbols). The base station 105 may find the best DL transmission beam of the utilized frequency region (e.g., second resource 720) of the random access signal (e.g., RACH message). In some examples, RACH message transmission time units may be larger than synchronization subframe time units due to DL-UL power differences, for example.

[0144] Although the example described with reference to Figures 7A and 7B is directed to transmitting RACH message in RACH subframe 715, this example is also applicable to transmitting a schedule request message, Beam recovery message or Beam tracking message in subplot 715 of RACH. In some cases, the UE 115 may find that the best synchronization Beam was transmitted during the second symbol, and the UE 115 may transmit a schedule request message, Beam recovery message or Beam follow message in a second frequency region for a portion of the symbols. The second frequency region may be in a different resource (or block of resources) in subframe 715 of the RACH. That is, a first portion of the resources in RACH subframe 715 may be allocated to RACH message transmissions, a second portion of the resources in RACH subframe 715 may be allocated to scheduling request message transmissions, and/or a third portion of the resources in RACH subframe 715 may be allocated for Beam recovery or Beam tracking message transmissions.

[0145] Figure 8 shows a block diagram 800 of a wireless device 805 that supports RACH transfer of DL Sync Beam information to various DL-UL correspondence states in accordance with various aspects of the present invention. The wireless device 805 may be an example of aspects of a UE 115 as described with reference to FIG. 1. The wireless device 805 may include the receiver 810, the UE synchronization manager 815, and the transmitter 820. The wireless device 805 also may include a processor. Each of these components can be in communication with each other (for example, through one or more buses).

[0146] Receiver 810 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and RACH routing-related information of Synchronization Beam Information DL for various states of DL-UL correspondence, etc.). The information can be passed to other components of the device. Receiver 810 may be an example of aspects of transceiver 1135 described with reference to Figure 11.

[0147] The UE synchronization manager 815 may be an example of aspects of the UE synchronization manager 1115 described with reference to Figure 11. The UE synchronization manager 815 may receive a DL synchronization signal from a base station at one or more DL Sync Beams and identify a DL Beam selected from one or more DL sync signals for communications from the base station to the UE.

[0148] Transmitter 820 can transmit signals generated by other components of the device. In some examples, the transmitter 820 may be co-located with a receiver 810 in a transceiver module. For example, transmitter 820 may be an example of aspects of transceiver 1135 described with reference to Figure 11. Transmitter 820 may include a single antenna or may include an array of antennas. The transmitter 820 may also transmit the RACH request/schedule/Beam recovery message or the Beam tracking message to the base station using at least one RACH resource or waveform selected based, at least in part, on the Beam DL selected. In some cases, transmission of the RACH message/schedule request/Beam recovery message or Beam tracking message includes: transmitting the RACH message/scheduling request/Beam recovery message or Beam tracking message throughout the duration of a corresponding random access subframe.

[0149] Figure 9 shows a block diagram 900 of a wireless device 905 that supports RACH routing of DL Synchronization Beam information to various DL-UL correspondence states in accordance with various aspects of the present invention. The wireless device 905 may be an example of aspects of a wireless device 805 or a UE 115 as described with reference to FIGS. 1 and 8. The wireless device 905 may include the receiver 910, the synchronization manager 915 of the UE and transmitter 920. Wireless device 905 may also include a processor. Each of these components can be in communication with each other (for example, through one or more buses).

[0150] Receiver 910 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and RACH routing-related information of Synchronization Beam Information DL for various states of DL-UL correspondence, etc.). The information can be passed to other components of the device. Receiver 910 may be an example of aspects of transceiver 1135 described with reference to Figure 11.

[0151] The UE synchronization manager 915 may be an example of aspects of the UE synchronization manager 1115 described with reference to FIG. 11. The UE synchronization manager 915 may also include the synchronization signal component 925, the Beam selection 930 and the feature selection component 935.

[0152] Sync signal component 925 may receive a DL sync signal from a base station on one or more DL Sync Beams. In some cases, a correspondence is missing between one or more DL Sync Beams on the base station and one or more UL Receive Beams on the base station. In some cases, one or more DL Sync Beams are within a single symbol of a synchronization subframe, where selecting the RACH resource and/or waveform for transmission of the RACH message/scheduling request message/Beam recovery or Beam tracking message includes: selecting the RACH feature and/or waveform based on the selected Beam DL symbol.

[0153] Beam selection component 930 may identify a DL Beam selected from one or more DL Synchronization Beams for base station to UE communications. In some cases, identification of the selected DL Beam includes: identification of the DL Beam based on the DL sync signal on one or more DL Sync Beams that meet a transmit power condition. In some cases, the DL Beam selected from the base station is different from a UL Beam selected from the UE. In some cases, a base station may identify a preferred UL Beam based on the quality of a received RACH message. The base station may also transmit one or more subsequent messages to the UE, transmitting an indication of the preferred UL Beam.

[0154] The resource selection component 935 may select a resource and/or RACH waveform for transmission of a RACH message/Beam schedule/recovery request message or Beam follow message to the base station, being selected feature waveform and/or RACH based on the selected Beam DL. In some cases, selecting the RACH feature and/or waveform includes: selecting the RACH feature and/or waveform based on an index of the selected Beam DL. In some cases, selecting the RACH feature and/or waveform includes: selecting the RACH feature and/or waveform based on a symbol of a subframe of the DL sync signal of the selected DL Beam. In some cases, the resource is associated with one or more tones on a component carrier. In some cases, the resource is associated with a component carrier.

[0155] Transmitter 920 can transmit signals generated by other components of the device. In some examples, the transmitter 920 may be co-located with a receiver 910 in a transceiver module. For example, transmitter 920 may be an example of aspects of transceiver 1135 described with reference to FIG. 11. Transmitter 920 may include a single antenna or may include an array of antennas.

[0156] Figure 10 shows a block diagram 1000 of a UE synchronization manager 1015 that supports RACH transport of DL Synchronization Beam information for various DL-UL correspondence states in accordance with various aspects of the present invention. The UE synchronization manager 1015 may be an example of aspects of a UE synchronization manager 815, a UE synchronization manager 915 or a UE synchronization manager 1115 described with reference to figures 8, 9 and 11. UE synchronization manager 1015 may include synchronization signal component 1020, Beam selection component 1025, resource selection component 1030, preferred Beam component 1035, RACH waveform component 1040, and correspondence management component 1045. Each of these modules can communicate, directly or indirectly, with each other (for example, through one or more buses).

[0157] Sync signal component 1020 may receive a DL sync signal from a base station on one or more DL Sync Beams. The Beam selection component 1025 may identify a DL Beam selected from one or more DL Synchronization Beams for base station to UE communications. The resource selection component 1030 may select a resource and/or RACH waveform for transmitting a RACH message/Beam schedule/recovery request message or Beam tracking message to the base station, the resource being selected and /or RACH waveform based on the selected Beam DL. In some cases, the resource selection component 1030 may select a resource and/or RACH waveform for transmitting a RACH message/Beam schedule/recovery request message or Beam tracking message to the base station based on on an indication of a mismatch between one or more DL Sync Beams on the base station and one or more UL Receive Beams on the base station.

[0158] Preferred Beam component 1035 may identify a preferred Beam from a number of Beams transmitted by a base station. In some cases, identification of the selected DL Beam includes: identification of a preferred DL Beam based on the signal strength of the DL sync signal on one or more DL Sync Beams, a signal quality of the DL sync signal on one or more plus DL Sync Beams, or combinations thereof. The RACH waveform component 1040 may select a RACH waveform for transmitting the RACH request message/schedule recovery/Beam recovery message or Beam follow message to the base station, with the RACH waveform being selected. based on the selected Beam DL. In some cases, RACH waveform selection includes: selecting a RACH preamble, a cyclic offset, or combinations thereof based on a selected Beam DL index.

[0159] The correspondence management component 1045 may receive an indication that there is a mismatch between one or more DL Sync Beams of the base station and one or more UL Receive Beams at the base station. In some cases, the correspondence management component 1045 may transmit the Beam RACH request/recovery schedule/track message message to the base station for the entire duration of a RACH subframe based, at least in part, on the indication of missing correspondence. In some cases, the correspondence management component 1045 may receive the indication in a MIB or a SIB. In some cases, the correspondence management component 1045 may transmit an indication that there is no correspondence between one or more DL Sync Beams of the base station and one or more UL Receive Beams at the base station. In some cases, the correspondence management component 1045 may transmit the Beam RACH request/recovery schedule message/trace message to the base station during a first symbol of a first random access subframe and a second symbol of a second random access subframe. random access subframe. In some cases, the correspondence management component 1045 may transmit the indication of a UE's missing correspondence in a RACH 3, PUCCH, or a PUSCH message.

[0160] In some cases, the correspondence management component 1045 may receive an indication of a nature of correspondence between one or more DL Sync Beams of the base station and one or more UL Beams of the UE. In some cases, the nature of the match is one of the following: complete match, partial match, or no match. In some cases, the mail management component 1045 may determine that the mail is present and select a transmission time to transmit the RACH scheduling request/Beam retrieval message or Beam tracking message to the base station with based on current correspondence. In some cases, the transmission time includes a symbol for a corresponding random access subframe. In some cases, the match management component 1045 may determine that a partial match exists and select a transmission time for transmitting the RACH, Beam message/recovery message/schedule request, or Beam trace message to the base station. based on partial matching. In some cases, the transmission time includes multiple symbols from a corresponding random access subframe. In some cases, a UE may transmit multiple RACH messages if there is no Beam match on the UE.

[0161] In some cases, the correspondence management component 1045 may select a transmission time, frequency range, and RACH preamble to transmit the RACH message based on the nature of the correspondence. In some cases, the correspondence management component 1045 may select the RACH feature or waveform based, at least in part, on a symbol associated with the DL synchronization signal and indicating the nature of the correspondence. In some cases, the correspondence management component 1045 may receive an indication of the nature of the correspondence through a PBCH or an ePBCH. In some cases, the correspondence management component 1045 may receive an indication of the nature of correspondence in a MIB or a SIB.

[0162] Figure 11 shows a diagram of a system 1100 including a device 1105 that supports RACH transport of DL Synchronization Beam information to multiple DL-UL correspondence relates to various aspects of the present invention. Device 1105 may be an example of or include the components of wireless device 805, wireless device 905, or a UE 115 as described above, for example, with reference to FIGS. 1, 8, and 9. Device 1105 may include components for bidirectional voice and data communications, including components for transmitting and receiving communications, including UE synchronization manager 1115, processor 1120, memory 1125, software 1130, transceiver 1135, antenna 1140, and I/O controller 1145. These components may be in electronic communication via one or more buses (e.g., 1110 bus). The device 1105 may communicate wirelessly with one or more base stations 105.

[0163] Processor 1120 may include an intelligent hardware device (e.g., a general purpose processor, a digital signal processor (DSP), a central processing unit (CPU), a microcontroller, a specific integrated circuit application (ASIC), a field - FPGA (programmable gate array), a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof. In some cases, the processor 1120 may be. configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into the processor 1120. The processor 1120 may be configured to execute computer-readable instructions stored in a memory to perform various functions (e.g. For example, functions or tasks that support RACH transport of DL Synchronization Beam information to various DL-UL correspondence states).

[0164] Memory 1125 may include random access memory (RAM) and read-only memory (ROM). Memory 1125 may store computer-readable, computer-executable software 1130, including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, memory 1125 may contain, among other things, a basic input/output system (BIOS) that may control basic hardware and/or software operation, such as interaction with peripheral components or devices.

[0165] Software 1130 may include code to implement aspects of the present invention, including code to support RACH transport of DL Sync Beam information to various DL-UL correspondence states. The software 1130 may be stored on a non-transitory computer-readable medium, such as system memory or other memory. In some cases, software 1130 may not be directly executable by the processor, but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

[0166] Transceiver 1135 may communicate bidirectionally, via one or more antennas, wired or wireless links, as described above. For example, transceiver 1135 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. Transceiver 1135 may also include a modem to modulate packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.

[0167] In some cases, the wireless device may include a single antenna 1140. However, in some cases, the device may have more than one antenna 1140, which may be capable of simultaneously transmitting or receiving multiple wireless transmissions.

[0168] The I/O controller 1145 may manage input and output signals for the device 1105. The I/O controller 1145 may also manage peripherals not integrated with the device 1105. In some cases, the I/O controller 1145 may represent a physical connection or port to an external peripheral. In some cases, the 1145 I/O Controller may utilize an operating system such as iOS®, ANDROID®, MS-DOS®, MS-WINDOWS®, OS/2®, UNIX®, LINUX® or another known operating system.

[0169] Figure 12 shows a block diagram 1200 of a wireless device 1205 that supports RACH transport of DL Synchronization Beam information to various DL-UL correspondence relates to various aspects of the present invention. The wireless device 1205 may be an example of aspects of a base station 105, as described with reference to Figure 1. The wireless device 1205 may include the receiver 1210, the base station synchronization manager 1215, and the transmitter 1220. wireless device 1205 may also include a processor. Each of these components can be in communication with each other (for example, through one or more buses).

[0170] Receiver 1210 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and RACH routing-related information of Synchronization Beam Information DL for various states of DL-UL correspondence, etc.). The information can be passed to other components of the device. Receiver 1210 may be an example of aspects of transceiver 1535 described with reference to Figure 15.

[0171] The base station synchronization manager 1215 may be an example of aspects of the base station synchronization manager 1515 described with reference to Figure 15. The base station synchronization manager 1215 may transmit a DL synchronization signal on one or more Beams of DL synchronization, receive at least one of a RACH waveform or resource, a RACH request/schedule/Beam recovery message, or a Beam follow message, and identify, based on the resource and/or the RACH waveform, a DL Beam selected from one or more DL Sync Beams for base station to UE communications.

[0172] Transmitter 1220 can transmit signals generated by other components of the device. In some examples, the transmitter 1220 may be co-located with a receiver 1210 in a transceiver module. For example, transmitter 1220 may be an example of aspects of transceiver 1535 described with reference to Figure 15. Transmitter 1220 may include a single antenna or may include an array of antennas. The transmitter 1220 may also transmit one or more subsequent messages to the UE using the selected Beam DL.

[0173] Figure 13 shows a block diagram 1300 of a wireless device 1305 that supports RACH transport of DL Synchronization Beam information to various DL-UL correspondence relates to various aspects of the present invention. The wireless device 1305 may be an example of aspects of a wireless device 1205 or a base station 105 as described with reference to FIGS. 1 and 12. The wireless device 1305 may include the receiver 1310, the base station synchronization manager 1315 and the transmitter 1320. The wireless device 1305 may also include a processor. Each of these components can be in communication with each other (for example, through one or more buses).

[0174] Receiver 1310 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and RACH routing-related information of Synchronization Beam Information DL for various states of DL-UL correspondence, etc.). The information can be passed to other components of the device. Receiver 1310 may be an example of aspects of transceiver 1535 described with reference to Figure 15.

[0175] The base station synchronization manager 1315 may be an example of aspects of the base station synchronization manager 1515 described with reference to FIG. 15. The base station synchronization manager 1315 may also include the synchronization signal component 1325, the RACH component 1330 and the selected Beam component 1335.

[0176] Sync signal component 1325 may transmit a DL sync signal on one or more DL Sync Beams. In some cases, a match is missing between one or more DL Sync Beams on the base station and one or more UL Receive Beams on the base station.

[0177] The RACH component 1330 may receive, in a resource and/or RACH waveform, a RACH message/scheduling/Beam recovery request message or Beam tracking message from a UE. In some cases, receipt of the RACH message/Beam schedule/retrieve request message or Beam trace message includes: receipt of the RACH message/Beam schedule/retrieve request message or Beam trace message during the entire duration of a message, corresponding random access subframe. In some cases, receiving the RACH message/scheduling request/Beam recovery message or Beam tracking message includes: receiving the RACH request/scheduling message/Beam recovery request message or Beam tracking message in a set of UL Beams. In some cases, the resource is associated with one or more tones on a component carrier. In some cases, the resource is associated with a component carrier.

[0178] The selected Beam component 1335 may identify, based on the resource and/or the RACH waveform, a DL Beam selected from one or more DL Synchronization Beams for communications from the base station to the UE. In some cases, identification of the selected Beam DL includes: association of the RACH feature and/or waveform with an index of the selected Beam DL. In some cases, identifying the selected Beam DL includes: associating the RACH feature and/or waveform with a symbol of a subframe of the DL sync signal of the selected Beam DL. In some cases, identification of the selected Beam DL further includes: identification of the selected Beam DL based on a RACH waveform of the RACH schedule request/Beam retrieval message or Beam trace message. In some cases, identification of the selected Beam DL includes: identification of the selected Beam DL based on a RACH preamble of the RACH message, a cyclic offset of the RACH message, or combinations thereof. In some cases, the DL Beam selected from the base station is different from a UL Beam selected from the UE.

[0179] Transmitter 1320 can transmit signals generated by other components of the device. In some examples, the transmitter 1320 may be co-located with a receiver 1310 in a transceiver module. For example, transmitter 1320 may be an example of aspects of transceiver 1535 described with reference to FIG. 15. Transmitter 1320 may include a single antenna or may include an array of antennas.

[0180] Figure 14 shows a block diagram 1400 of a base station synchronization manager 1415 that supports RACH transfer of DL Sync Beam information to various DL-UL correspondence states in accordance with various aspects of the present invention. The base station synchronization manager 1415 may be an example of aspects of a base station synchronization manager 1515 described with reference to FIGS. 12, 13 and 15. The base station synchronization manager 1415 may include synchronization signal component 1420, RACH component 1425, selected Beam component 1430, quality measurement component 1435, UL Beam component 1440, and correspondence management component 1445. Each of these modules can communicate, directly or indirectly, with each other (e.g., by through one or more buses).

[0181] Sync signal component 1420 may transmit a DL sync signal on one or more DL Sync Beams. The RACH component 1425 may receive, in at least one of a resource or a RACH waveform, a RACH scheduling request/Beam retrieval message or a Beam tracking message from a UE. The selected Beam component 1430 may identify, based on the resource waveform and/or RACH, a DL Beam selected from one or more DL Synchronization Beams for communications from the base station to the UE.

[0182] The quality measurement component 1435 may measure a quality of the RACH request message/Beam schedule/recovery request message or Beam tracking message received on the UL Beam pool. In some cases, measurement of the RACH message/ Beam retrieval/schedule request message or Beam tracking message includes: measuring one or more of a reference signal received power (RSRP), a signal strength indicator received quality (RSSI), a reference signal received quality (RSRQ), a signal-to-noise ratio (signal-to-noise ratio (SNR)) or a signal to interference plus noise (SINR). The UL Beam component 1440 can determine a selected UL Beam for UE-to-base station communications based on quality.

[0183] The correspondence management component 1445 may transmit an indication that there is no correspondence between one or more DL Sync Beams of the base station and one or more UL Receive Beams at the base station. In some cases, the correspondence management component 1445 may transmit the indication in a MIB or a SIB. In some cases, the correspondence management component 1445 may receive an indication of a mismatch between one or more base station DL Sync Beams and one or more base station UL Receive Beams and DL Map Beams used to transmit CSI. -RSs UL Beams used to transmit SRSs or map UL Beams used to transmit SRSs to DL Beam used to transmit CSI-RSs. In some cases, the correspondence management component 1445 may receive an indication that a mismatch between one or more base station Sync DL Beams and one or more UL Receive Beams at the base station and Map DL Beam used in the Beam DL training for UL Beams used in UL Beams training or Map UL Beams used in Beam DL training for Beam DL used in Beam DL Training.

[0184] Figure 15 shows a diagram of a system 1500 including a device 1505 that supports RACH transport of DL Synchronization Beam information to multiple DL-UL correspondence relates to various aspects of the present invention. Device 1505 may be an example of or include components of base station 105 as described above, for example, with reference to Figure 1. Device 1505 may include components for bidirectional voice and data communications, including components for transmitting and receiving communications. , including base station synchronization manager 1515, processor 1520, memory 1525, software 1530, transceiver 1535, antenna 1540, network communications manager 1545, and base station communications manager 1550. These components may be in electronic communication via one or more buses (e.g. bus 1510). The device 1505 may communicate wirelessly with one or more UE 115.

[0185] Processor 1520 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a gate logic component, or discrete transistor, a discrete hardware component, or any combination thereof). In some cases, the processor 1520 may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated with the processor 1520. The processor 1520 may be configured to execute computer-readable instructions stored in a memory to perform various functions (e.g., functions or tasks that support RACH transmission of information DL sync beam for various DL-UL match states).

[0186] Memory 1525 may include RAM and ROM. Memory 1525 may store computer-readable, computer-executable software 1530, including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, memory 1525 may contain, among other things, a BIOS that may control basic hardware and/or software operation, such as interaction with peripheral components or devices.

[0187] Software 1530 may include code to implement aspects of the present invention, including code to support RACH transport of DL Sync Beam information to various DL-UL correspondence states. The software 1530 may be stored on a non-transitory computer-readable medium, such as system memory or other memory. In some cases, software 1530 may not be directly executable by the processor, but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

[0188] Transceiver 1535 may communicate bidirectionally, via one or more antennas, wired or wirelessly, as described above. For example, transceiver 1535 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. The transceiver 1535 may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission and to demodulate the packets received from the antennas.

[0189] In some cases, the wireless device may include a single antenna 1540. However, in some cases, the device may have more than one antenna 1540, which may be capable of simultaneously transmitting or receiving multiple wireless transmissions.

[0190] Network communications manager 1545 may manage communications with the core network (e.g., via one or more wired backhaul links). For example, network communications manager 1545 may manage the transfer of data communications to client devices, such as one or more UEs 115.

[0191] The communications manager of the base station 1550 may manage communications with another base station 105, and may include a controller or a task manager for controlling communications with UEs 115 in cooperation with other base stations 105. For example, the communications manager of the base station 1550 may manage communications with another base station 105. base station communications 1550 may coordinate the scheduling of transmissions to the UEs 115 for various interference mitigation techniques such as beam formation or joint transmission. In some examples, the base station communications manager 1550 may provide an X2 interface within a Long Term Evolution (LTE)/LTE-A wireless communications network technology to provide communication between the base stations 105.

[0192] Figure 16 shows a flowchart illustrating a method 1600 for transporting RACH of DL Synchronization Beam information to various DL-UL correspondence states in accordance with various aspects of the present invention. The operations of method 1600 may be implemented by a UE 115 or components thereof as described herein. For example, the operations of method 1600 may be performed by a UE synchronization manager as described with reference to FIGS. 8 to 11. In some examples, a UE 115 may execute a set of codes to control functional elements of the device to perform the functions described below. Additionally or alternatively, the UE 115 may perform aspects of the functions described below using special purpose hardware.

[0193] In block 1605, the UE 115 may receive a DL sync signal from a base station on one or more DL Sync Beams. The operations of block 1605 may be performed in accordance with the methods described with reference to Figures 1 to 5. In certain examples, aspects of the operations of block 1605 may be performed by a synchronization signal component as described with reference to Figures 8 to 11.

[0194] In block 1610, the UE 115 may identify a DL Beam selected from one or more DL Synchronization Beams for communications from the base station to the UE. The operations of block 1610 may be performed in accordance with the methods described with reference to Figures 1 to 5. In certain examples, aspects of the operations of block 1610 may be performed by a Beam selection component, as described with reference to Figures 8. to 11.

[0195] In block 1615, the UE 115 may transmit the RACH request/schedule/Beam recovery message or Beam tracking message to the base station using at least one of a resource or a selected RACH waveform based on the least in part in the selected Beam DL. Block 1615 operations may be performed in accordance with methods described with reference to Figures 1 to 5. In certain examples, aspects of block 1615 operations may be performed by a transmitter as described with reference to Figures 8 to 11.

[0196] Figure 17 shows a flowchart illustrating a method 1700 for transporting RACH of DL Synchronization Beam information to various DL-UL correspondence states in accordance with various aspects of the present invention. The operations of method 1700 may be implemented by a UE 115 or components thereof as described herein. For example, the operations of method 1700 may be performed by a UE synchronization manager, as described with reference to FIGS. 8 to 11. In some examples, a UE 115 may execute a set of codes to control functional elements of the device to perform the functions described below. Additionally or alternatively, the UE 115 may perform aspects of the functions described below using special purpose hardware.

[0197] In block 1705, the UE 115 may receive a DL sync signal from a base station on one or more DL Sync Beams. The operations of block 1705 may be performed in accordance with the methods described with reference to Figures 1 to 5. In certain examples, aspects of the operations of block 1705 may be performed by a synchronization signal component, as described with reference to Figures 8. to 11.

[0198] In block 1710, the UE 115 may identify a DL Beam selected from one or more DL Synchronization Beams for communications from the base station to the UE. The operations of block 1710 may be performed in accordance with the methods described with reference to Figures 1 to 5. In certain examples, aspects of the operations of block 1710 may be performed by a Beam selection component, as described with reference to Figures 8. to 11.

[0199] In block 1715, the UE 115 may transmit the RACH request/schedule/Beam recovery message or Beam tracking message to the base station using at least one of a resource or a selected RACH waveform based on the least in part on the selected Beam DL, feature or RACH waveform can also be selected based on an index of the selected Beam DL. Block 1715 operations may be performed in accordance with methods described with reference to Figures 1 to 5. In certain examples, aspects of block 1715 operations may be performed by a transmitter as described with reference to Figures 8 to 11.

[0200] Figure 18 shows a flowchart illustrating a method 1800 for transporting RACH of DL Synchronization Beam information to various DL-UL correspondence states in accordance with various aspects of the present invention. The operations of method 1800 may be implemented by a base station 105 or components thereof as described herein. For example, operations of method 1800 may be performed by a base station synchronization manager, as described with reference to FIGS. 12 to 15. In some examples, a base station 105 may execute a set of codes to control functional elements of the device to perform the functions described below. Additionally or alternatively, base station 105 may perform aspects of the functions described below using special purpose hardware.

[0201] In block 1805, base station 105 may transmit a DL sync signal on one or more DL Sync Beams. The operations of block 1805 may be performed in accordance with the methods described with reference to Figures 1 to 5. In certain examples, aspects of the operations of block 1805 may be performed by a synchronization signal component as described with reference to Figures 12 to 15.

[0202] In block 1810, base station 105 may receive, in at least one of a resource or RACH waveform, a RACH message/scheduling request message or a Beam tracking message from a UE. Block 1810 operations may be performed in accordance with methods described with reference to Figures 1 to 5. In certain examples, aspects of block 1810 operations may be performed by a RACH component as described with reference to Figures 12 to 15.

[0203] In block 1815, base station 105 may identify, based at least in part on the RACH resource or waveform, a DL Beam selected from one or more DL Sync Beams for base station to base station communications. HUH. The operations of block 1815 may be performed in accordance with the methods described with reference to Figures 1 to 5. In certain examples, aspects of the operations of block 1815 may be performed by a selected Beam component, as described with reference to Figures 12 to 15.

[0204] In block 1820, the base station 105 may transmit one or more subsequent messages to the UE using the selected Beam DL. Block 1820 operations may be performed in accordance with methods described with reference to Figures 1 to 5. In certain examples, aspects of block 1820 operations may be performed by a transmitter as described with reference to Figures 12 to 15.

[0205] Figures 19 shows a flowchart illustrating a method 1900 for transporting RACH of DL Synchronization Beam information to various DL-UL correspondence states in accordance with various aspects of the present invention. The operations of method 1900 may be implemented by a base station 105 or components thereof, as described herein. For example, the operations of method 1900 may be performed by a base station synchronization manager, as described with reference to FIGS. 12 to 15. In some examples, a base station 105 may execute a set of codes to control functional elements of the device to perform the functions described below. Additionally or alternatively, base station 105 may perform aspects of the functions described below using special purpose hardware.

[0206] In block 1905, the base station 105 may receive, in at least one of a resource or RACH waveform, a RACH request message/scheduling request message or Beam follow message from a UE in a UL Beam series. Block 1905 operations may be performed in accordance with methods described with reference to Figures 1 to 5. In certain examples, aspects of block 1905 operations may be performed by a RACH component as described with reference to Figures 12 to 15.

[0207] In block 1910, base station 105 may measure a quality of the RACH request message/Beam schedule/recovery request message or Beam tracking message received on the UL Beam array. Block 1910 operations may be performed in accordance with methods described with reference to Figures 1 to 5. In certain examples, aspects of block 1910 operations may be performed by a quality measurement component as described with reference to Figures 12. to 15.

[0208] In block 1915, the base station 105 may determine or identify a selected UL Beam, e.g., a preferred UL Beam, for communications from the UE to the base station based, at least in part, on the measured quality of a RACH message. . The base station may also transmit one or more subsequent messages to the UE, transmitting an indication of the preferred UL Beam, for example, in a RACH msg2. The one or more subsequent messages to the UE may include an identification or index of the preferred UL Beam, for example, an OCC index. Block 1915 operations may be performed in accordance with methods described with reference to Figures 1 to 5. In certain examples, aspects of block 1915 operations may be performed by a Beam UL component, as described with reference to Figures 12 to 15.

[0209] In some cases, receiving the RACH request/scheduling/Beam recovery message or Beam tracking message comprises: receiving the RACH request/message request/Beam recovery message or Beam tracking message in a series of UL Beams.

[0210] It should be noted that the methods described above describe possible implementations, and that the operations and steps can be rearranged or otherwise modified and that other implementations are possible. Furthermore, aspects of two or more of the methods can be combined.

[0211] The techniques described herein can be used for various wireless communications systems such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), access orthogonal frequency division multiple (OFDMA), single carrier frequency division multiple access (SCFDMA) and other systems. The terms "system" and "network" are often used interchangeably. A code division multiple access (CDMA) system can implement radio technology such as CDMA2000, UTRA (Universal Terrestrial Radio Access), etc. CDMA2000 covers IS-2000, IS-95 and IS-856 standards. Versions of IS-2000 may be commonly called CDMA2000 IX, IX, etc. IS-856 (TIA-856) is commonly called CDMA 2000 lx EV-DO, High Rate Packet Data (HRPD), etc. UTRA includes wideband CDMA (WCDMA) and other CDMA variants. A time division multiple access (TDMA) system can implement a radio technology such as the Global System for Mobile Communications (GSM).

[0212] An orthogonal frequency division multiple access (OFDMA) system may implement a radio technology such as Ultra Mobile Broadband (UMB), Evolved UTRA (E-UTRA), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi -Fi), IEEE 802.16. (WiMAX), IEEE 802.20, Flash-OFDM, etc. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS). 3GPP Long Term Evolution (LTE) and LTE-Advanced (LTE-A) are new releases of the Universal Mobile Telecommunications System (UMTS) that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A and the Global System for Mobile Communications (GSM) are described in documents from the organization called "3rd Generation Partnership Project" (3 GPP). CDMA2000 and UMB are described in documents from an organization called "3rd Generation Partnership Project 2" (3GPP2). The techniques described here can be used for the radio systems and technologies mentioned above, as well as for other radio systems and technologies. Although aspects of an LTE system may be described for example purposes, and LTE terminology may be used throughout much of the description, the techniques described here are applicable beyond LTE applications.

[0213] In LTE/LTE-A networks, including the networks described here, the term evolved node B (eNB) may generally be used to describe base stations. The wireless communications system or systems described herein may include a heterogeneous LTE/LTE-A network in which different types of EBs provide coverage for various geographic regions. For example, each eNB or base station can provide communications coverage for a macro cell, a small cell, or other cell types. The term "cell" may be used to describe a base station, a carrier or component carrier associated with a base station, or a coverage area (e.g., sector, etc.) of a carrier or base station, depending on the context .

[0214] Base stations may include or be referred to by those skilled in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a Node B, eNode B (eNB), Home Node B, a Residential eNode B or some other suitable terminology. The geographic coverage area of a base station can be divided into sectors, making up only a part of the coverage area. The wireless communications system or systems described herein may include base stations of different types (e.g., macro or small cell base stations). The UEs described herein may be capable of communicating with various types of base stations and network equipment, including macro eNBs, small cell eNBs, relay base stations, and the like. There may be overlapping geographic coverage areas for different technologies.

[0215] A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscriptions with the network provider. A small cell is a lower power base station, compared to a macro cell, which can operate in the same or different (e.g. licensed, unlicensed, etc.) frequency bands as macro cells. Small cells may include pico cells, femto cells and micro cells according to various examples. A peak cell, for example, may cover a small geographic area and may allow unrestricted access by UEs with service subscriptions with the network provider. A femto cell may also cover a small geographic area (e.g., a house) and may provide restricted access by UEs that have an association with the femto cell (e.g., UEs in a closed subscriber group (CSG), UEs for users at home, and similar). An eNB for a macro cell can be referred to as a macro eNB. An eNB for a small cell may be referred to as a small cell eNB, a pico eNB, a femto eNB, or a home eNB. An eNB may support one or multiple (e.g., two, three, four, and the like) cells (e.g., component carriers). A UE may be capable of communicating with various types of base stations and network equipment, including macro eNBs, small cell eNBs, relay base stations, and the like.

[0216] The wireless communications system or systems described herein may support synchronous or asynchronous operation. For synchronous operation, base stations may have similar frame timing, and transmissions from different stations approximately aligned in time. For asynchronous operation, base stations may have different frame timings, and transmissions from different base stations may not be aligned in time. The techniques described here can be used for synchronous or asynchronous operations.

[0217] The downlink transmissions described herein may also be called forward link transactions, while the uplink transmissions may also be called reverse link transactions. Each communication link described herein - including, for example, wireless communications system 100 and 200 of Figures 1 and 2 - may include one or more carriers, where each carrier may be a signal composed of multiple subcarriers (e.g., signals waveform of different frequencies).

[0218] The description presented here, in connection with the attached drawings, describes example configurations and does not represent all examples that can be implemented or that are within the scope of the claims. The term "exemplary" as used herein means "to serve as an example, example, or illustration" and not "preferred" or "advantageous over other examples." The detailed description includes specific details for the purpose of providing an understanding of the techniques described. These techniques, however, can be practiced without these specific details. In some cases, well-known structures and devices are shown in block diagram form to avoid obscuring the concepts of the examples described.

[0219] In the attached figures, similar components or features may have the same reference label. Furthermore, multiple components of the same type can be distinguished by following the reference label by a dash and a second label that distinguishes between similar components. If only the first reference tag is used in the specification, the description is applicable to any of the similar components that have the same first reference tag, regardless of the second reference tag.

[0220] The information and signals described herein can be represented using any of several different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination of these.

[0221] The various illustrative blocks and modules described in connection with the present invention may be implemented or executed with a general purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, components of discrete hardware or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but alternatively, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other configuration).

[0222] The functions described here can be implemented in hardware, software executed by a processor, firmware or any combination thereof. If implemented in software executed by a processor, functions may be stored or transmitted as one or more instructions or code in a computer-readable medium. Other examples and implementations are within the scope of the present invention and appended claims. For example, due to the nature of software, the functions described above may be implemented using software running by a processor, hardware, firmware, hardwiring, or combinations of any of these. Resources that implement functions can also be physically located in multiple positions, including being distributed so that parts of functions are implemented in different physical locations. Furthermore, as used herein, including in the claims, "or" as used in a list of items (e.g., a list of items preceded by a phrase such as "at least one or" one or more of) indicates an inclusive list such that, for example, a list of at least one of A, B or C means A or B or C or AB or AC or BC or ABC (that is, A and B and C). Also, as used here, the phrase "based on" should not be interpreted as referring to a closed set of conditions. For example, an exemplary step that is described as "based on condition A" may be based on both condition A and condition B without departing from the scope of the present invention. In other words, as used here, the phrase "based on" should be interpreted in the same way as the phrase "based, at least in part."

[0223] Computer-readable media includes non-transitory computer storage media and communications media, including any medium that facilitates the transfer of a computer program from one place to another. A non-transitory storage medium can be any available medium that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, non-transitory computer-readable media may comprise RAM, ROM, EEPROM memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic device, storage devices, or any other non-transitory medium that can be used to transport or store desired program codes in the form of instructions or data structures and that can be accessed by a general purpose or special purpose computer, or a special purpose or special purpose processor . Furthermore, any connection is properly called computer-readable media. For example, if the software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disc and disc, as used here, include CD, laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray disc, where discs generally reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included in the scope of computer-readable media.

[0224] The description here is provided to enable a person skilled in the art to make or use the present invention. Various modifications of the present invention will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the present invention. Thus, the present invention is not limited to the examples and designs described herein, but must be given the broadest scope consistent with the principles and innovative features described herein.

Claims (15)

1. Method for wireless communication in a user equipment, UE, (115), characterized by: receiving (210; 1605; 1705) a downlink signal, DL, from a base station (105) in a plurality of DL beams (305), wherein each DL beam of the plurality of DL beams is transmitted in different symbols of a random access subframe, each symbol associated with a different beam direction; identifying (205) a beam-matching nature between one or more receive beams in the UE and one or more transmit beams in the UE (115), wherein the beam-matching nature is identified by determining whether there is total matching, matching partial or no correspondence; identifying (215; 1610; 1710) a DL beam selected from the plurality of DL beams (305) for communications from the base station (105) to the UE (115); and transmitting (225; 1615; 1715), for a number of symbols of a corresponding random access subframe, wherein each symbol of the corresponding random access subframe is associated with a corresponding beam direction of the base station, a channel message random access, RACH, to the base station (105) using at least one of a frequency resource or a selected RACH waveform (220) based, at least in part, on the DL signal subframe symbol of the selected DL beam , where the number of symbols in the corresponding random access subframe is determined based on whether there is a full match, partial match, or no match. 2. Method, according to claim 1, characterized by additionally comprising: determining that there is total correspondence; select the RACH resource or waveform to transmit the RACH message to the base station based on total matching, where a DL beam is mapped to the RACH resource or waveform. 3. Method, according to claim 1, characterized by additionally comprising: determining that there is partial correspondence or no correspondence; and selecting a transmission time or RACH waveform for transmitting the RACH message to the base station based on partial matching or no matching, wherein the transmission time comprises a symbol of a corresponding random access subframe. 4. Method according to claim 1, characterized by additionally comprising: determining that there is partial correspondence; and selecting a transmission time for transmitting the RACH message to the base station based on partial matching, wherein the transmission time comprises multiple symbols of a corresponding random access subframe. 5. Method, according to claim 1, characterized by additionally comprising: determining that there is partial correspondence or no correspondence; and transmitting multiple instances of the RACH message to the base station based, at least in part, on partial matching or no matching, wherein the multiple instances of the RACH message are transmitted prior to receiving a subsequent message from the base station. 6. The method of claim 1, further comprising: selecting one or more of a transmission time, a frequency range or a RACH preamble to transmit the RACH message based on the nature of correspondence. 7. The method of claim 1, further comprising: selecting the RACH frequency or waveform feature based, at least in part, on an index of the selected DL beam. 8. Method according to claim 1, characterized in that when correspondence is absent between the plurality of receiving beams in the UE and the plurality of transmitting beams in the UE, the absent correspondence is associated with the plurality of receiving beams having a characteristic of channel propagation other than the plurality of transmission beams. 9. The method of claim 1, further comprising: mapping receive beams used to transmit channel state information reference signals, CSI-RSs, to transmit beams used to transmit polling reference signals, SRS, or mapping transmit beams used to transmit SRSs to receive beams used to transmit CSI-RSs. 10. Method according to claim 1, characterized by additionally comprising: mapping receive beams used in a DL beam training to UL beams used in a UL beam training or mapping the UL beams used in UL beam training to the beams DL used in DL beam training. 11. Method according to claim 1, characterized in that transmitting the RACH message comprises: transmitting the RACH message for the entire duration of a corresponding random access subframe. 12. Method for wireless communication at a base station (105), characterized by: transmitting (210; 1805) a downlink signal, DL, in a plurality of DL beams (305), wherein each DL beam of the plurality of DL beams is transmitted in different symbols of a random access subframe, each symbol associated with a different beam direction; receive (225; 1810), on at least one of a frequency resource or a random access channel waveform, RACH, for a number of symbols of a corresponding random access subframe, wherein each symbol of the access subframe corresponding random beam direction is associated with a corresponding base station beam direction, a RACH message from a user equipment (115) in a plurality of UL uplink beams, based, at least in part, on the subframe symbol of the DL signal of the selected DL beam, the number of symbols of the corresponding random access subframe determined based on whether there is a full match, partial match, or no match; identify (230; 1815), based at least in part on the frequency resource or RACH waveform, a DL beam selected from the plurality of DL beams (305) for communications from the base station (105) to the EU (115); and transmitting (235; 1820) one or more subsequent messages to the UE using the selected DL beam. 13. The method of claim 12, further comprising: measuring a quality of the RACH message received in the plurality of UL beams; and determining a selected UL beam for communications from the UE to the base station based, at least in part, on quality. 14. Device for wireless communication in a user equipment, UE, (115), characterized by comprising: means (810; 910) for receiving (210; 1605; 1705) a downlink signal, DL, from a base station (105) in a plurality of DL beams (305), wherein each DL beam of the plurality of DL beams is transmitted in different symbols of a random access subframe, each symbol associated with a different beam direction; means (815; 1045) for identifying a beam-matching nature between one or more receive beams in the UE and one or more transmit beams in the UE, wherein the means for identifying is configured to identify the beam-matching nature of the determine whether there is a full match, partial match, or no match; means (815; 930) for identifying (230; 1815) a DL beam selected from the plurality of DL beams (305) for communications from the base station (105) to the UE (115); and means (820; 920) for transmitting (225; 1615; 1715), for a number of symbols of a corresponding random access subframe, wherein each symbol of the corresponding random access subframe is associated with a corresponding beam direction of the station base, a random access channel, RACH, message to the base station (105) using at least one of a frequency resource or a RACH waveform selected based, at least in part, on the subframe symbol of the DL signal of the selected DL beam, the number of symbols from the corresponding random access subframe determined based on whether there is a full match, partial match, or no match. 15. Device for wireless communication at a base station (105), characterized by comprising: means (1220; 1320) for transmitting (210; 1805) a downlink signal, DL, in a plurality of DL beams (305), wherein each DL beam of the plurality of DL beams is transmitted in different symbols of a random access subframe, each symbol associated with a different beam direction; means (1220, 1320) for receiving (225; 1810), in at least one of a frequency resource or a random access channel waveform, RACH, for a number of symbols of a corresponding random access subframe, in that each corresponding random access subframe symbol is associated with a corresponding base station beam direction, a RACH message, from a user equipment (115) in a plurality of UL uplink beams, based on at least in part, in the DL signal subframe symbol of the selected DL beam, the number of corresponding random access subframe symbols determined based on whether there is a full match, partial match, or no match; means (1215, 1335) for identifying (230; 1815), based at least in part on the frequency feature or RACH waveform, a DL beam selected from the plurality of DL beams (305) for communications from the base station (105) for the UE (115); and means (1220, 1320) for transmitting (235; 1820) one or more subsequent messages to the UE using the selected DL beam.