WO2018201958A1

WO2018201958A1 - User equipment, base station, and related method

Info

Publication number: WO2018201958A1
Application number: PCT/CN2018/084585
Authority: WO
Inventors: 常宁娟; 山田升平; 张萌
Original assignee: 夏普株式会社; 常宁娟
Priority date: 2017-05-04
Filing date: 2018-04-26
Publication date: 2018-11-08
Also published as: CN108811072A

Abstract

Provided by the present disclosure is a method in a user equipment (UE), comprising: selecting the downlink beam having the best signal quality from a plurality of downlink beams to serve as a downlink reference; and performing uplink transmission on the basis of the downlink reference.

Description

User equipment, base station and related methods

Technical field

The present disclosure relates to the field of wireless communication technologies, and more particularly, to user equipment, base stations, and related methods.

Background technique

In March 2016, at the RAN#71 plenary session of the 3rd Generation Partnership Project (3GPP), NTT DOCOMO proposed a new research project on 5G technology standards (see Non-patent literature: RP-160671) :New SID Proposal: Study on New Radio Access Technology), and approved. The goal of the research project is to develop a new wireless (New Radio: NR) access technology to meet all 5G application scenarios, requirements and deployment environments. NR mainly has three application scenarios: Enhanced Mobile Broadband (eMBB), Massive Machine Type Communication (mMTC) and Ultra Reliable and Low Latency Communications (URLLC). According to the planning of the research project, the standardization of NR is carried out in two phases: the first phase of standardization will be completed in mid-2018; the second phase of standardization will be completed by the end of 2019. The first-stage standard specification is forward-compatible with the second-stage standard specification, while the second-stage standard specification is based on the first-stage standard specification and meets all the requirements of the 5G NR technical standard.

In NR, a beam is widely used for information transmission. In a multi-beam transmission system, multiple beams can be used to serve the same user equipment (User Equipment, UE), whether uplink or downlink. When using multiple beam transmissions, how to handle the uplink transmission timing becomes a problem to be solved.

In addition, when multiple beam transmissions are used, like the existing mechanism, the UE acquires the timing advance of an uplink transmission by performing random access. Generally, the UE transmits a random access preamble to the base station on an uplink beam with a downlink reference as a starting point for transmitting a random access preamble. The base station calculates the timing advance of the uplink beam based on the received time of the random access preamble of the UE, and notifies the UE of the advance amount in a random access response (Random Access Response). The UE uses the timing advance to adjust the uplink transmission time on subsequent uplink transmissions of the uplink beam. During subsequent transmissions, the base station may cause the UE to update the timing advance by a time advance command.

When the uplink beam of the UE is switched (for example, the uplink beam signal of the original configuration is degraded due to the geographical location of the UE, a new uplink beam needs to be replaced), because the UE cannot determine whether the source uplink beam and the target uplink beam are available. The same amount of time advance, so the UE cannot judge whether to acquire a new timing advance through random access. Therefore, how to obtain the timing advance when beam switching is also a problem to be solved.

Summary of the invention

According to a first aspect of the present disclosure, a method in a user equipment UE is provided, comprising: selecting a downlink beam with the best signal quality from a plurality of downlink beams as a downlink reference; and performing uplink transmission based on the downlink reference.

In an embodiment, the downlink beam comprises: a broadcast beam, and/or a UE-specific beam, wherein the one or more are selected when the UE is configured with one or more active beams and one or more inactive beams One of the active beams is used as a downlink reference.

According to a second aspect of the present disclosure, there is provided a method in a user equipment UE, comprising: configuring a set of uplink beams, the uplink beams in the group having the same time advance TA value; receiving from the base station for the group a TA command; and determining the same TA value of the uplink beam in the group based on the TA command.

In an embodiment, the configuring comprises: configuring a plurality of uplink beams associated with the same sounding reference signal SRS resource or SRS resource indication as a set of uplink beams, or receiving uplink beam group configuration information from the base station, the configuration The information indicates that a plurality of uplink beams associated with the same sounding reference signal SRS resource or SRS resource indication are configured as a set of uplink beams, and the TA command includes the SRS resource indication.

In an embodiment, the method further comprises applying the same time alignment timer to the uplink beams in the group.

According to a third aspect of the present disclosure, there is provided a method in a user equipment UE, the UE to switch from a source uplink beam to a target uplink beam, the method comprising: receiving random access indication information from a base station, the indication The information indicates that the UE performs random access for the target uplink beam to obtain a time advance TA value; transmits a random access preamble on the uplink beam indicated in the indication information; and on the downlink beam indicated in the indication information, or A random access signal is received on the downlink beam with the best signal quality.

According to a fourth aspect of the present disclosure, a user equipment UE is provided, including a transceiver, a processor, and a memory, the processor storing instructions executable by the processor, such that the user equipment performs according to the first, The method of the second or third aspect.

According to a fifth aspect of the present disclosure, there is provided a method in a base station, comprising: transmitting uplink beam group configuration information to a user equipment UE, the configuration information indication to be associated with a same sounding reference signal SRS resource or SRS resource indication The plurality of uplink beams are configured as a set of uplink beams, the uplink beams in the group have the same time advance TA value; and the TA command for the group is sent to the user equipment UE, the TA command including the SRS resource Instructions.

According to a sixth aspect of the present disclosure, there is provided a method in a base station, comprising: determining that a user equipment UE is to be handed over from a source uplink beam to a target uplink beam; and transmitting random access indication information to the UE, the indication information indicating the UE Performing random access for the target uplink beam to obtain a time advance TA value, the indication information further indicating that the UE is configured to send an uplink beam that transmits a random access preamble and/or a downlink beam that the UE uses to receive a random access response.

According to a seventh aspect of the present disclosure, there is provided a base station comprising a transceiver, a processor and a memory, the processor storing instructions executable by the processor such that the base station performs the fifth or sixth aspect according to the above Methods.

DRAWINGS

For a more complete understanding of the present disclosure and its advantages, reference will now be made to the following description

Figure 1 shows a schematic diagram of time advancement.

2 shows a flow diagram of a method in a user equipment in accordance with an embodiment of the disclosure.

FIG. 3 illustrates a flow chart of a method in a user equipment in accordance with another embodiment of the present disclosure.

4 shows a flow chart of a method in a base station in accordance with another embodiment of the present disclosure.

FIG. 5 shows a flow chart of a method in a user equipment in accordance with another embodiment of the present disclosure.

FIG. 6 shows a flow chart of a method in a base station in accordance with another embodiment of the present disclosure.

FIG. 7 shows a block diagram of a user equipment in accordance with an embodiment of the present disclosure.

FIG. 8 shows a block diagram of a base station in accordance with an embodiment of the present disclosure.

detailed description

Other aspects, advantages and salient features of the present disclosure will become apparent to those skilled in the <

In the present disclosure, the terms "include" and "including" and their derivatives are meant to be inclusive and not limiting; the term "or" is inclusive, meaning and/or.

In the present specification, the following various embodiments for describing the principles of the present disclosure are merely illustrative and should not be construed as limiting the scope of the disclosure. The following description with reference to the drawings is intended to be a The description below includes numerous specific details to assist the understanding, but these details should be considered as merely exemplary. Accordingly, it will be appreciated by those skilled in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the disclosure. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness. In addition, the same reference numerals are used throughout the drawings for similar functions and operations.

The embodiments of the present disclosure are specifically described below with the LTE mobile communication system and its subsequent evolved versions as example application environments. However, it should be noted that the present disclosure is not limited to the following embodiments, but is applicable to more other wireless communication systems.

Some concepts related to the present invention will be described first. It is worth noting that the name is not limited here, and other names can be used.

The primary cell: works on the primary frequency, and the UE performs an initial connection establishment or initiates a connection re-establishment procedure on the cell, or a primary cell indicated in the handover command. In the present invention, it may also refer to a primary and secondary cell, that is, a secondary cell group cell in which an initial PUSCH transmission is performed when a UE is instructed to perform random access or when a random access procedure is ignored when a secondary cell group is switched.

A secondary cell: a cell for providing additional radio resources, configured to the UE after the RRC (Radio Resource Control) connection is established.

A serving cell: refers to a primary cell in a non-carrier aggregation or non-dual-connection scenario, and refers to all cells serving the UE in a carrier aggregation or dual connectivity scenario.

NR-PDCCH: refers to the PDCCH (New Radio Physical Downlink Control Channel) for transmitting downlink control information, or simply PDCCH.

NR-PDSCH: refers to the New Radio Physical Downlink Shared Channel in the NR for transmitting downlink data. It can also be simplified as PDSCH.

NR-PUCCH: refers to the New Radio Physical Uplink Control Channel in the NR, used to transmit uplink control information, or simply as PUCCH.

NR-PUSCH: refers to the New Radio Physical Uplink Shared Channel in the NR for transmitting uplink data, and in some cases, for transmitting uplink control information such as aperiodic channel status indication. It can also be simplified as PUSCH.

Beam: beam refers to a transmission with a specific direction formed by beamforming in a multi-antenna system. It may be considered to be determined by a specific codeword in a PMI (precoding matrix indicator) codebook; or determined by a reference signal resource or a reference signal resource indication (eg, a beam is determined by a reference signal resource or a reference signal resource indication) Or determined by a synchronization block (SS block) (such as a synchronization signal block can determine a beam); or can be considered as a beam is determined by a set of time-frequency resources (such as a set of time-frequency resources can correspond to a Beam); or jointly determined by the reference signal resource and the precoding matrix indication (as determined by the reference signal resource and the precoding matrix indication together); or jointly determined by the reference signal resource indication and the precoding matrix indication (eg, by reference signal) The resource indication and the precoding matrix indication jointly determine a beam), and the reference signal may be a channel state information reference signal CSI-RS (Channel state Information-Reference Signal), a sounding reference signal SRS (Sounding Reference Signal), a mobility reference signal MRS (Mobility Reference Signal), used as mobility such as layer 3 mobility Or a radio frequency resource management RRM (Radio Resource Management) measured mobility reference signal), a demodulation reference signal DMRS (Demodulation Reference Signal), and the like.

Time advance: For the uplink alignment at the base station, different UEs need to start transmitting uplink transmissions from different time points, that is, the UE needs to know the time advance value of its uplink transmission.

Downlink reference: In the present invention, the downlink reference refers to a reference time point used by the UE for uplink transmission. That is, the UE uses its downlink reception time as a reference, and adds its timing advance to obtain the time point of its uplink transmission.

The time advance command is: a media access control MAC (Media Access Control) control element that is sent by the base station and includes time advance information, and is used by the UE to calculate an uplink time advance amount.

Taking the LTE system as an example, referring to FIG. 1, the UE transmits the uplink radio frame i by the start time of the corresponding downlink radio frame i (N _TA + N _TAoffest ) × T _S . Where (N _TA + N _TAoffest ) × T _S is the amount of time advancement. This results in frame alignment at the base station.

In NR, the UE will use multiple beam transmission or reception in some cases. For example, in order to improve reliability based on beam transfer information, a method of transmitting one channel (such as NR-PDCCH, NR-PDSCH, NR-PUCCH, NR-PUSCH) based on a plurality of beams is employed. Taking the NR-PDCCH as an example, one or more of the multiple beams may be referred to as an active beam for transmitting downlink control information to the UE in real time, and the other beams are referred to as backup beams (backup A beam or a non-active beam is used to transmit a copy of the downlink control information. In another case, the network side may configure the UE to use different beams to transmit different physical channels such as NR-PUCCH and NR-PUSCH. In addition, more than one antenna array may be provided on the UE, and transmission of different antenna arrays may be implemented using different beams. In the present invention, the backup beam and the inactive beam are used interchangeably.

In NR systems where high frequencies are widely used, the transmission of broadcast information is also transmitted by beams using beamforming techniques. In general, considering resource/signaling overhead and system coverage, broadcast information is transmitted using a wide coverage beam; while UE unicast transmission may use a narrower beam. At present, in the NR system discussed in the 3GPP, a broadcast signal is transmitted by using a SS block. In the coverage of the cell, the sync block is covered by a beam sweeping method to cover the entire cell, that is, a synchronization signal. The block may transmit to the entire cell during a time period, and one or more sync signal blocks may be transmitted per time unit in the time period. The sync signal block includes a primary sync signal, a secondary sync signal, and a physical broadcast channel transmission.

Downstream reference determination

As mentioned in the foregoing part of the invention, the downlink reference is used for the reference timing of the uplink transmission. The downlink reference may also be referred to as a downlink reference beam, a downlink timing reference, an uplink timing reference, etc. in the system using the beam. Any other equivalent concept is within the scope of the present invention. Hereinafter, for convenience of description, the downlink reference is referred to.

In the NR, the uplink time alignment, or the uplink and downlink time alignment may be the same as the LTE system, using a radio frame alignment, a slot alignment, or a subframe. Aligning or aligning (such as Orthogonal Frequency Division Multiplexing (OFDM) symbols or single-carrier frequency-division multiple access (SC-FDMA) symbols), further, the aligned The unit of time can also be a combination of several slots/subframes/symbols.

In the following embodiments, the uplink transmission, including NR-PUCCH and/or NR-PUSCH, may include a physical random access channel (random access preamble) or may not include a physical random access channel, unless otherwise specified. The active beam and the inactive beam may preferably be an active beam and an inactive beam for transmitting the NR-PDCCH. Alternatively, the active beam and the inactive beam of the NR-PDSCH may be transmitted, or may be transmitted. Active and inactive beams of the downlink physical channel.

FIG. 2 shows a flow diagram of a method 200 in a user equipment UE in accordance with an embodiment of the disclosure. Method 200 includes the following steps.

In step S210, a downlink beam with the best signal quality is selected from the plurality of downlink beams as a downlink reference.

Specifically, the downlink reference that the UE performs uplink transmission may be the best downlink beam. Preferably, the signal quality of the measurement result obtained by the UE according to the measurement is the best, and the measurement result may be Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), The reference signal strength indicator RSSI (Reference Signal Strength Indicator) or channel state information CSI (Channel State Information) / Channel Quality Indicator (CQI). For example, the UE determines the downlink beam with the highest RSRP value as the downlink reference for its uplink transmission according to the measured RSRP value.

Here, the downlink beam may include a downlink broadcast beam. Preferably, the downlink broadcast beam refers to a downlink (beam) of a transmission synchronization signal block; alternatively, the downlink broadcast beam refers to a downlink (beam) of transmission system information; alternatively, the downlink broadcast The beam refers to the downlink (beam) for transmitting the paging message; alternatively, the downlink broadcast beam refers to the downlink (beam) for transmitting the broadcast multicast service; alternatively, the downlink reference may also be non- Broadcast Beam, Unicast Beam Further, the UE transmits a random access preamble with the best downlink broadcast beam as a downlink reference.

Alternatively or additionally, the downlink beam may comprise a UE-specific beam. When the UE is configured with one or more active beams and one or more inactive beams, one of the one or more active beams is selected as a downlink reference.

In one embodiment, the UE is configured with one or more downlink beams, and the UE may select any one of them as the downlink reference for the uplink transmission, but the UE does not replace its determined downlink reference unless it is necessary. For example, the mandatory condition may be that the quality of the downlink reference signal determined by the UE is too poor or removed by the base station configuration. Optionally, in this embodiment, if the UE is configured with multiple downlink beams, the multiple downlink beams may serve the UE indiscriminately, and the downlink beam may be UE-specific in this embodiment. Beam or unicast beam.

In an embodiment, the UE is configured with one or more downlink beam groups, and for each downlink beam group, the UE may select any one of them as a downlink reference for uplink transmission, but the UE does not replace its determined downlink reference. Unless the situation is necessary. For example, the mandatory condition may be that the quality of the downlink reference signal determined by the UE is too poor or removed by the base station configuration. Optionally, in this embodiment, if the UE is configured with multiple downlink beams, the multiple downlink beams may serve the UE indiscriminately, and the downlink beam may be UE-specific in this embodiment. Beam or unicast beam. The downlink beam group may also include one or more uplink beams, or may be associated with one or more uplink beams. In this embodiment, the uplink transmission refers to one of the downlink beam groups included or associated. Or transmissions on multiple uplink beams.

In an embodiment, the UE is configured with one active beam and one or more inactive beams at the same time, and the UE may select the activated beam as a downlink reference for uplink transmission.

In an embodiment, the UE is configured with multiple active beams and one or more inactive beams at the same time, the UE may select any one of the active beams as the downlink reference for the uplink transmission, but the UE does not replace its determined downlink reference. Unless the situation is necessary. For example, the mandatory condition may be that the quality of the downlink reference signal determined by the UE is too poor or removed by the base station configuration.

In an embodiment, the UE is configured with one or more active beams and one inactive beam at the same time, and the UE may select the inactive beam as a downlink reference for uplink transmission.

In an embodiment, the UE is configured with one or more active beams and multiple inactive beams at the same time, and the UE may select any one of the inactive beams as the downlink reference for the uplink transmission, but the UE does not replace the determined downlink. Reference, unless necessary. For example, the mandatory condition may be that the quality of the downlink reference signal determined by the UE is too poor or removed by the base station configuration.

In one embodiment, the downlink reference for the uplink transmission of the UE is configured by the base station by signaling.

In an embodiment, the downlink reference of the uplink transmission of the UE is the first downlink unicast beam determined by the UE, and the first downlink beam configured by the base station except the broadcast beam.

In step S220, uplink transmission is performed based on the downlink reference.

As mentioned above, the downlink reference is the reference time point that the UE uses for uplink transmission. In step S220, the UE uses its downlink reception time as a reference, and adds its timing advance to obtain the time point of its uplink transmission.

Upstream time advance group

According to an embodiment of the present disclosure, a plurality of uplink beams may be grouped according to whether a plurality of uplink beams can use the same timing advance. For example, the base station groups the uplink beams according to whether the uplink beams belong to the same transmission and reception point TRP (Transmission Reception Point).

FIG. 3 shows a flow diagram of a method 300 in a user equipment UE in accordance with an embodiment of the disclosure. Method 300 includes the following steps.

In step S310, a set of uplink beams are configured, and the uplink beams in the group have the same time advance TA value.

At step S320, a TA command for the group is received from the base station.

At step S330, based on the TA command, the same TA value of the uplink beam in the group is determined.

In one embodiment, method 300 further includes applying the same time alignment timer to the uplink beams in the group.

In one example, in step S310, the UE configures a plurality of uplink beams associated with the same sounding reference signal SRS resource or SRS resource indication as a set of uplink beams. The TA command received in step S320 includes an SRS resource indication.

Specifically, the UE may configure the uplink time beam associated with the same sounding reference signal resource or the reference signal resource to use the same timing advance, that is, may be configured to belong to the same beam time advance group or the uplink beam group. Receiving, by the UE, a time advance command, if the time advance command includes the sounding reference signal resource indication, applying the time advance command and/or starting associated time alignment to the uplink beam associated with the sounding reference signal resource indication Timer. In this embodiment, the uplink beam is "associated" to a sounding reference signal resource, which may be learned by the UE from Downlink Control Information (DCI), thereby associating an uplink beam to a sounding reference signal resource. For example, if the uplink scheduling DCI includes the sounding reference signal resource indication, the UE considers that the uplink beam corresponding to the uplink resource scheduled by the DCI is associated with the sounding reference signal resource indicated by the sounding reference signal resource indication in the DCI. Alternatively, the uplink beam is "associated" to a sounding reference signal resource, which may also be learned by the UE through RRC configuration or MAC signaling sent by the base station. For example, the configuration of an uplink beam in the RRC configuration includes its associated reference. Signal resource indication; or a reference signal resource indication configuration includes one or more uplink beam indications associated with it.

In another example, in step S310, uplink beam group configuration information is received from a base station, the configuration information indicating that a plurality of uplink beams are configured as a set of uplink beams. For example, the configuration information indicates that a plurality of uplink beams associated with the same sounding reference signal SRS resource or SRS resource indication are configured as a set of uplink beams. The TA command received in step S320 includes an uplink beam group identification, which may be, for example, an SRS resource indication.

Specifically, the uplink beam group configuration information includes one or more of the following information: a group identifier corresponding to the uplink beam, an uplink beam group release list, and an uplink beam group addition modification list. The uplink beam group addition modification list includes one or more uplink beam group information for adding or modifying an uplink beam group; and one uplink beam group information includes a time alignment timer configuration and/or a group identifier corresponding to the uplink beam group. The uplink beam set release list includes one or more uplink beam group identifiers for releasing one or more uplink beam groups.

The uplink beam group may also be referred to as a beam time advance group, and the group identifier may also be referred to as a beam time advance group group identifier.

Preferably, the uplink beam group configuration may be obtained in the form of an RRC message, such as an RRC reconfiguration message. Alternatively, it may be obtained in the form of a MAC control element or obtained by physical layer signaling. Downlink control information on the NR-PDCCH.

For example, the UE may apply an uplink beam group configuration according to the received uplink beam group configuration information. For example, if the received configuration information includes an uplink beam group release release list, the UE or the UE RRC releases the uplink beam for each uplink beam group identifier that is part of the current UE configuration and is included in the uplink beam group release list. The group identifier identifies the corresponding uplink beam group. For example, if the received configuration information includes an uplink beam group addition modification list, the UE or the UE RRC notifies the uplink beam group identifier that is not in the current UE configuration and is included in the uplink beam group addition modification list, according to the received The uplink beam group time alignment timer adds the uplink beam group corresponding to the uplink beam group identifier. The UE or the UE RRC reconfigures the uplink beam corresponding to the uplink beam group identifier according to the received uplink beam group time alignment timer for each uplink beam group identifier that belongs to the current UE configuration and is included in the uplink beam group addition modification list. group.

For example, the UE may perform uplink transmission according to the uplink beam group configuration, including one or more of the following:

Receiving a time advance command, if the time advance command includes the uplink beam group identifier, applying the event advance command to the uplink beam group and/or starting a time alignment timer associated with the uplink beam group.

- For the uplink transmission associated with the uplink beam included in the uplink beam group, the same uplink advance amount is used, that is, the uplink advance amount is determined based on the value in the above-mentioned time advance command.

In an embodiment, when the uplink beam group is configured, when all time alignment timers associated with one cell time out, the UE considers that the cell uplink is not time synchronized. The uplink beam group is also called a beam time advance group, and all beams in the group adopt the same timing advance.

In one embodiment, when an uplink beam set is configured, the UE MAC entity has a configurable timer called a time alignment timer for each of the uplink beam groups. The time alignment timer is used to control how long the uplink beams included in the beam time advance group are up-time aligned by the MAC entity. The uplink beam group is also called a beam time advance group, and all beams in the group adopt the same timing advance.

In one embodiment, when the time alignment timer associated with the uplink beam group to which an uplink beam belongs is not operating, the MAC entity does not perform any uplink transmission on the uplink beam. Optionally, the MAC entity does not perform any uplink transmission other than random access preamble transmission on the uplink beam.

In an embodiment, when the uplink beam group is configured, when a time alignment timer expires, if the timer is associated with the primary cell and all time alignment timers associated with the primary cell are timed out, the UE performs the next One or more of the operations described:

- Clear all Hybrid Automatic Repeat Request (HARQ) caches of all serving cells;

- informing the RRC layer to release the PUCCH of all serving cells;

- informing the RRC layer to release the sounding reference signal SRS (Sounding Reference Signal) of all serving cells;

- clear all configured downlink assignments (DL assignments) and uplink grants (UL grants);

- Think all time alignment timers time out.

In an embodiment, when the uplink beam group is configured, when a time alignment timer expires, if the timer is associated with one serving cell and all time alignment timers associated with the serving cell time out, the UE Do one or more of the following:

- clearing all HARQ buffers associated with the serving cell;

- informing the RRC layer to release the PUCCH of the serving cell, if configured;

- informing the RRC layer to release the SRS of the serving cell;

- Clearing all configured downlink assignments (DL assignments) and uplink grants (UL grants) associated with the serving cell.

In the foregoing embodiment, the “uplink beam group configured” may also be described as “using an uplink beam group”, “using an (uplink) beam” or “using an “uplink” beam”.

In one embodiment, the UE is configured with a time alignment timer received by the base station, and the configuration of the alignment timer is a value of the timer, including 1 to 499 time units. Such as 2, 4, 8, 16, 32, 64, 128, 256, 50, 75, 100, 150, 175, 192, 200, 250, 275, 300, 350, 400, 450 time units. Preferably, the time unit is a subframe, and alternatively, the time unit is one millisecond, a slot, a symbol (such as an OFDM symbol, an SC-FDMA symbol), or a number of milliseconds, a slot. , a combination of symbols (such as OFDM symbols, SC-FDMA symbols), and the like.

In an embodiment, the UE receives an uplink beam configuration sent by the base station, where the time alignment timer configuration corresponding to the uplink beam is included; and the time alignment timer configuration refers to a value of the time alignment timer. That is, the time alignment timer is specific to each uplink beam. When the time alignment timer expires, the UE considers that an uplink beam associated with the time alignment timer is uplink misaligned, that is, uplink out-of-synchronization. When receiving the time advance command including the uplink beam identifier, the UE starts or restarts the time alignment timer associated with the uplink beam indicated by the uplink beam identifier.

FIG. 4 shows a flow diagram of a method 400 in a base station in accordance with an embodiment of the disclosure. Method 400 includes the following steps:

In step S410, uplink beam group configuration information is sent to the user equipment UE. The configuration information indicates that a plurality of uplink beams are configured as a set of uplink beams. For example, the configuration information indicates that a plurality of uplink beams associated with the same sounding reference signal SRS resource or SRS resource indication are configured as a set of uplink beams, and the uplink beams in the group have the same time advance TA value.

Specifically, the uplink beam group configuration information includes one or more of the following information: a group identifier corresponding to the uplink beam, an uplink beam group release list, and an uplink beam group addition modification list. The uplink beam group addition modification list includes one or more uplink beam group information for adding or modifying an uplink beam group; and one uplink beam group information includes a time alignment timer configuration and/or a group identifier corresponding to the uplink beam group. The uplink beam group release list includes one or more uplink beam group identifiers for releasing one or more uplink beam groups.

The uplink beam group may also be referred to as a beam time advance group, and the group identifier is also identified as a beam time advance group.

Preferably, the uplink beam group configuration may be sent in the form of an RRC message, such as an RRC reconfiguration message. Alternatively, the uplink beam group configuration may be sent in the form of a MAC control element or sent in physical layer signaling. Downlink control information on the NR-PDCCH.

In step S420, a TA command for the group is sent to the user equipment UE, and the TA command includes the uplink beam group identifier or the SRS resource indication.

Specifically, the base station performs uplink receiving according to the uplink beam group configuration information, including one or more of the following:

- Timing advance command, the time advance command includes the uplink beam group identifier.

- The same upstream advance is used for uplink reception associated with the uplink beam included in the uplink beam group.

In an embodiment, the base station considers that the uplink beams associated with the same sounding reference signal resource or the reference signal resource use the same timing advance, that is, may belong to the same time advance group. The base station sends a timing advance command, where the sounding reference signal resource indication is included, and an time advance determined by the uplink beam corresponding to the sounding reference signal resource indication is determined based on a value in the event advance command. The amount is received. The sounding reference signal resource may be associated with one TRP, and further, one TRP may be associated with one or more reference signal resources.

Time advancement acquisition during beam switching

As described above, when multiple beams are configured, like the existing mechanism, the UE acquires a timing advance of an uplink transmission by performing random access. Generally, the UE sends a random access preamble to the base station on an uplink beam with a downlink reference as a time starting point for transmitting the random access preamble, and the base station calculates the uplink based on the received time of the random access preamble of the UE. The timing advance of the beam is sent to the UE in the random access response (Random Access Response), and the UE uses the timing advance to adjust the uplink transmission time on subsequent uplink transmissions of the uplink beam. During subsequent transmissions, the base station may cause the UE to update the timing advance by a time advance command.

The scenario of the present embodiment is that when the uplink beam of the UE is switched (for example, the uplink beam signal of the original configuration is degraded due to the geographical location of the UE, a new uplink beam needs to be replaced), because the UE cannot determine the source uplink. Whether the beam and the target uplink beam can use the same timing advance, so the UE cannot determine whether to acquire a new timing advance through random access.

In the present invention, it may be determined by the network side whether the UE needs to perform random access to acquire a new timing advance. The network side may be determined based on the moving speed of the UE, and the topology of the network (such as whether the source uplink beam and the target downlink beam are in the same transmission and reception point TRP (Transmission Reception Point), the location of the UE, and the like.

FIG. 5 shows a flow diagram of a method 500 in a user equipment in accordance with an embodiment of the present disclosure. The UE switches from the source uplink beam to the target uplink beam. Method 500 can include the following steps.

In step S510, random access indication information is received from the base station, the indication information instructing the UE to perform random access for the target uplink beam to obtain a time advance TA value.

In step S520, a random access preamble is transmitted on the uplink beam indicated in the indication information.

In step S530, a random access response is received on the downlink beam indicated in the indication information or on the downlink beam with the best signal quality.

In an example, in step S510, the UE receives random access indication information sent by the base station, where the indication information indicates that the UE performs random access to acquire a new timing advance to achieve uplink synchronization. The random access indication may be a PDCCH command, or may be included in a beam switching command, where the beam switching command is used to notify the UE to perform beam switching, where the new uplink beam is included. Preferably, the beam switching command is MAC signaling or physical layer signaling. Here, beam switching can also be described as beam change.

Optionally, the random access indication information may further include a first beam indication, where the first beam indication is used to inform the UE on which uplink beam to perform random access.

Optionally, the random access indication information may further include a second beam indication, where the second beam indication is used to inform the UE to send a downlink reference used by the random access preamble time.

Optionally, the random access indication information further includes a third beam indication, configured to inform the UE on which downlink beam to receive the random access response.

Optionally, the UE receives a random access response on the best downlink beam. Preferably, the signal quality of the measurement result obtained by the UE according to the measurement is the best, and the measurement result may be RSRP, RSRQ, RSSI or CSI/CQI. The downlink beam, preferably, refers to a UE-specific beam or a unicast beam; alternatively, it may refer to a broadcast beam. The downlink broadcast beam refers to a downlink (beam) of a transmission synchronization signal block; alternatively, the downlink broadcast beam refers to a downlink (beam) of transmission system information.

Optionally, the UE receives the random access response on the downlink beam that receives the random access indication information.

Optionally, the downlink beam that the UE receives the random access response may be determined according to the association relationship between the random access resource and the downlink beam. The random access resource may refer to a random access preamble, a random access preamble sequence, a physical random access channel time-frequency resource, and the like. In this case, the UE acquires the association between the downlink beam and the random access resource in advance, for example, through system information acquisition. The downlink beam may be a broadcast beam or a unicast beam.

FIG. 6 shows a flow diagram of a method 600 in a base station in accordance with an embodiment of the disclosure. Method 600 includes the following steps:

At step S610, it is determined that the user equipment UE is to be handed over from the source uplink beam to the target uplink beam.

In step S620, the UE sends random access indication information, where the indication information indicates that the UE performs random access for the target uplink beam to obtain a time advance TA value, and the indication information further indicates that the UE is configured to send and send a random access preamble. The uplink beam and/or the downlink beam used by the UE to receive the random access response.

In one example, the base station sends random access indication information to the UE, the indication information indicating that the UE performs random access to acquire a new timing advance to achieve uplink synchronization. The random access indication may be a PDCCH command, or may be included in a beam switching command, where the beam switching command is used to notify the UE to perform beam switching, where the new uplink beam is included. Preferably, the beam switching command is MAC signaling or physical layer signaling.

Optionally, the base station transmits a random access response on the best downlink beam. Preferably, the base station has the best signal quality according to the measurement reported by the UE, and the measurement result may be RSRP, RSRQ, RSSI or CSI/CQI. Or preferably, the base station can obtain the best downlink quality according to the best signal quality in the uplink measurement result, for example, when the channel has reciprocity. The downlink beam, preferably, refers to a UE-specific beam or a unicast beam; alternatively, it may refer to a broadcast beam. The downlink broadcast beam refers to a downlink (beam) of a transmission synchronization signal block; alternatively, the downlink broadcast beam refers to a downlink (beam) of transmission system information.

Optionally, the base station sends a random access response on the downlink beam that sends the random access indication information.

Optionally, the downlink beam that the base station sends the random access response may be determined according to the association relationship between the random access resource and the downlink beam. The random access resource may refer to a random access preamble, a random access preamble sequence, a physical random access channel time-frequency resource, and the like. In this case, the base station informs the UE of the association relationship between the downlink beam and the random access resource in advance, for example, by system information transmission. The downlink beam may be a broadcast beam or a unicast beam.

Corresponding to the

above method

200, 300 or 500, the present disclosure provides a user equipment UE. FIG. 7 shows a block diagram of a UE 700 in accordance with an embodiment of the disclosure. As shown, the UE 700 includes a transceiver 710, a processor 720, and a memory 730 that stores instructions executable by the processor 720 such that the user equipment 700 performs the method described above in connection with FIG. 200, method 300 described in connection with FIG. 3, or method 500 described in connection with FIG.

Specifically, the processor 730 stores instructions executable by the processor 720, so that the user equipment 700 can select a downlink beam with the best signal quality from among a plurality of downlink beams as a downlink reference; and based on the downlink reference. For uplink transmission. The downlink beam may include: a broadcast beam, and/or a UE dedicated beam. When the UE is configured with one or more active beams and one or more inactive beams, one of the one or more active beams may be selected as a downlink reference.

Alternatively, the processor 730 stores instructions executable by the processor 720 such that the user equipment 700 can configure a set of uplink beams, the uplink beams in the group having the same time advance TA value; Receiving a TA command for the group; and determining the same TA value for the uplink beam in the group based on the TA command. The configuration may include configuring a plurality of uplink beams associated with the same sounding reference signal SRS resource or SRS resource indication as a set of uplink beams, or receiving uplink beam group configuration information from the base station, where the configuration information indication is to be The plurality of uplink beams associated with the same sounding reference signal SRS resource or SRS resource indication are configured as a set of uplink beams. The TA command may include the SRS resource indication. The UE 700 can also apply the same time alignment timer to the uplink beams in the group.

Alternatively, the UE 700 can switch from the source uplink beam to the target uplink beam. The processor 730 stores instructions executable by the processor 720, such that the user equipment 700 can receive random access indication information from a base station, the indication information instructing the UE to perform random access for the target uplink beam to obtain time advancement a TA value; transmitting a random access preamble on the uplink beam indicated in the indication information; and receiving a random access response on the downlink beam indicated in the indication information or on the downlink beam with the best signal quality.

All of the embodiments and examples described above in connection with method 200, method 300, or method 500 are also applicable to UE 700.

Corresponding to the

above method

400 or 600, the present disclosure provides a base station. FIG. 8 shows a block diagram of a base station 800 in accordance with an embodiment of the present disclosure. As shown, base station 800 includes a transceiver 810, a processor 820, and a memory 830 that stores instructions executable by the processor 820 such that the base station 800 performs the method 400 described above in connection with FIG. Or the method 600 described in connection with FIG.

Specifically, the processor 830 stores instructions executable by the processor 820, so that the base station 800 can send uplink beam group configuration information to the user equipment UE, where the configuration information indicates that the same sounding reference signal SRS resource will be used. Or the SRS resource indicates that the associated plurality of uplink beams are configured as a set of uplink beams, the uplink beams in the group have the same time advance TA value; and the TA command for the group is sent to the user equipment UE, the TA The command includes the SRS resource indication.

Alternatively, the processor 830 stores instructions executable by the processor 820 such that the base station 800 can determine that the user equipment UE is to be handed off from the source uplink beam to the target uplink beam; and send the random access indication information to the UE. And the indication information indicates that the UE performs random access for the target uplink beam to obtain a time advance TA value, where the indication information further indicates that the UE is used to send an uplink beam that sends a random access preamble and/or the UE is used to receive random access. The downstream beam of the response.

All of the embodiments and examples described above in connection with method 400 or method 600 are also applicable to base station 800.

In the present application, "base station" refers to a mobile communication data and control switching center having a large transmission power and a relatively large coverage area, including resource allocation scheduling, data reception and transmission, and the like. "User equipment" refers to a user mobile terminal, for example, a terminal device including a mobile phone, a notebook, etc., which can perform wireless communication with a base station or a micro base station.

The methods and apparatus of the present disclosure have been described above in connection with the preferred embodiments. Those skilled in the art will appreciate that the methods shown above are merely exemplary. The methods of the present disclosure are not limited to the steps and sequences shown above. The base stations and user equipment shown above may include more modules, for example, may also include modules that may be developed or developed in the future for base stations, MMEs, or UEs, and the like. The various logos shown above are merely exemplary and not limiting, and the disclosure is not limited to the specific cells as examples of such identifications. Many variations and modifications can be made by those skilled in the art in light of the teachings of the illustrated embodiments.

The program running on the device according to the present invention may be a program that causes a computer to implement the functions of the embodiments of the present invention by controlling a central processing unit (CPU). The program or information processed by the program may be temporarily stored in a volatile memory (such as a random access memory RAM), a hard disk drive (HDD), a non-volatile memory (such as a flash memory), or other memory system.

A program for realizing the functions of the embodiments of the present invention can be recorded on a computer readable recording medium. The corresponding functions can be realized by causing a computer system to read programs recorded on the recording medium and execute the programs. The so-called "computer system" herein may be a computer system embedded in the device, and may include an operating system or hardware (such as a peripheral device). The "computer readable recording medium" may be a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a recording medium of a short-term dynamic storage program, or any other recording medium readable by a computer.

The various features or functional blocks of the apparatus used in the above embodiments may be implemented or executed by circuitry (e.g., monolithic or multi-chip integrated circuits). Circuitry designed to perform the functions described in this specification can include general purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or other programmable logic devices, discrete Gate or transistor logic, discrete hardware components, or any combination of the above. A general purpose processor may be a microprocessor or any existing processor, controller, microcontroller, or state machine. The above circuit may be a digital circuit or an analog circuit. One or more embodiments of the present invention may also be implemented using these new integrated circuit technologies in the context of new integrated circuit technologies that replace existing integrated circuits due to advances in semiconductor technology.

Further, the present invention is not limited to the above embodiment. Although various examples of the embodiments have been described, the invention is not limited thereto. Fixed or non-mobile electronic devices installed indoors or outdoors can be used as terminal devices or communication devices such as AV devices, kitchen devices, cleaning devices, air conditioners, office equipment, vending machines, and other home appliances.

As above, the embodiments of the present invention have been described in detail with reference to the accompanying drawings. However, the specific structure is not limited to the above embodiments, and the present invention also includes any design modifications not departing from the gist of the present invention. In addition, various modifications may be made to the invention within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments are also included in the technical scope of the present invention. Further, the components having the same effects described in the above embodiments may be substituted for each other.

Claims

A method in a user equipment UE, comprising:

Selecting a downlink beam with the best signal quality from among the plurality of downlink beams as a downlink reference;

Uplink transmission is performed based on the downlink reference.
The method of claim 1 wherein said downlink beam comprises:

Broadcast beam, and/or

A UE-specific beam, wherein when the UE is configured with one or more active beams and one or more inactive beams, one of the one or more active beams is selected as a downlink reference.
A method in a user equipment UE, comprising:

Configuring a set of uplink beams, the uplink beams in the group having the same time advance TA value;

Receiving a TA command for the group from a base station;

Based on the TA command, the same TA value of the uplink beams in the group is determined.
The method of claim 3 wherein

The configuration includes:

Configuring a plurality of uplink beams associated with the same sounding reference signal SRS resource or SRS resource indication as a set of uplink beams, or

Receiving uplink beam group configuration information from a base station, the configuration information indicating that a plurality of uplink beams associated with the same sounding reference signal SRS resource or SRS resource indication are configured as a set of uplink beams, and

The TA command includes the SRS resource indication.
The method of claim 3 or 4, further comprising:

The same time alignment timer is applied to the uplink beams in the group.
A method in a user equipment UE, where the UE is to be switched from a source uplink beam to a target uplink beam, the method includes:

Receiving random access indication information from the base station, where the indication information indicates that the UE performs random access for the target uplink beam to obtain a time advance TA value;

Transmitting a random access preamble on an uplink beam indicated in the indication information;

A random access response is received on the downlink beam indicated in the indication information or on the downlink beam with the best signal quality.
A user equipment UE comprising a transceiver, a processor and a memory, the processor storing instructions executable by the processor, such that the user equipment performs the method of any of claims 1-6.
A method in a base station, comprising:

Transmitting uplink beam group configuration information to the user equipment UE, the configuration information indicating that a plurality of uplink beams associated with the same sounding reference signal SRS resource or SRS resource indication are configured as a set of uplink beams, and uplink beams in the group Have the same time advance TA value;

A TA command for the group is sent to the user equipment UE, the TA command including the SRS resource indication.
A method in a base station, comprising:

Determining that the user equipment UE is to be handed over from the source uplink beam to the target uplink beam;

Sending the random access indication information to the UE, the indication information instructing the UE to perform random access for the target uplink beam to obtain a time advance TA value, where the indication information further indicates that the UE is configured to send an uplink beam that transmits the random access preamble and/or Or a downlink beam used by the UE to receive a random access response.
A base station comprising a transceiver, a processor and a memory, the processor storing instructions executable by the processor such that the base station performs the method of claim 8 or 9.