CN112005591A

CN112005591A - Signaling of multiple access resources

Info

Publication number: CN112005591A
Application number: CN201880092452.3A
Authority: CN
Inventors: 田力; 曹伟; 焦戊臣; 易巧; 纵金榜
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2018-04-27
Filing date: 2018-04-27
Publication date: 2020-11-27
Also published as: WO2019205073A1

Abstract

In a wireless communication system, information regarding a multiple access signature to be used by a device is communicated to the device using a message, wherein a message communication scheme is used to identify one or more of an active transport processing block, a signature pool to be used, and signatures in the signature pool. In some embodiments, the message scheme modulates the subcarriers directly with a digital representation of the signature. For example, quadrature phase shift keying modulation is used to modulate the subcarriers using two bits of a signature for each subcarrier.

Description

Signaling of multiple access resources

Technical Field

This document relates generally to wireless communications.

Background

Mobile communication technology is pushing the world to an increasingly interconnected and networked society. Rapid development of mobile communications and advances in technology have resulted in greater demands for capacity and connectivity. Other aspects such as energy consumption, equipment cost, spectral efficiency, and latency are also important to meet the needs of various communication scenarios. Various techniques are being discussed, including new methods for providing higher quality of service.

Disclosure of Invention

Techniques for signaling signatures that may be used for multiple access transmissions are disclosed. Embodiments may use the disclosed messages to signal signatures in the signature pool and/or pool to be used hierarchically for subsequent Multiple Access (MA) transmissions.

In one exemplary aspect, a method of wireless communication is disclosed. The method includes transmitting a message to a user equipment, wherein the message identifies a signature for a non-orthogonal multiple access transmission, wherein the message is structured to identify M transport processing blocks, wherein X_iThe signature pool is available for the ith signal processing block, Xth_iEach signature pool of a block includes N_m,xA signature, where m is an integer, the message being organized as one of: a three-bit group arrangement, wherein a first bit group indicates an active-inactive status of each of the M transport processing blocks, and a second bit group indicates an active signature pool for each transport processing block and a signature within the active signature pool for each transport processing block; a two bit group permutation, wherein an outer bit group identifies the active signature pool and an inner bit group identifies a signature within the active signature pool for use by the user equipment; or a single bit group permutation identifying signatures from a single signature pool for the user equipment.

In addition toIn one exemplary aspect, another method of wireless communication is disclosed. The method includes receiving a message at a user equipment, wherein the message identifies a signature for a multiple access transmission, wherein the message is structured to identify M transmission processing blocks, wherein X is_iA signature pool is available for the ith signal processing block, Xth_iEach signature pool of a block includes N_mxA signature, where m is an integer, the message being organized as one of: a three-bit group arrangement, wherein a first bit group indicates an active-inactive status of each of the M transport processing blocks, and a second bit group indicates an active signature pool for each transport processing block and a signature within the active signature pool for each transport processing block; a two bit group permutation, wherein an outer bit group identifies the active signature pool and an inner bit group identifies a signature within the active signature pool for use by the user equipment; or a single bit group permutation that identifies signatures from a single pool of signatures for the user equipment and recovers the signatures from the message.

In another example aspect, a method of wireless communication is disclosed. The method comprises receiving, by a user equipment, a signal comprising subcarriers modulated by the user equipment using a signature for a multiple access transmission; and recovering the signature from the signal.

In yet another exemplary aspect, the above-described method is embodied in the form of processor-executable code and stored in a computer-readable program medium.

In another exemplary embodiment, an apparatus configured or operable to perform the above method is disclosed.

The above aspects and other aspects and implementations thereof are described in detail in the drawings, specification, and claims.

Drawings

Fig. 1 shows an example of the structure of a transmitter-side signal processing block for a non-orthogonal multiple access scheme.

Fig. 2 shows an example of a hierarchical design of a signaling message using three layers of bit signaling.

Fig. 3 shows an example of a hierarchical design of a signaling message using two layers of bit signaling.

Fig. 4 shows an example of a signaling message for a composite pool.

Fig. 5 shows an example of explicit signaling of a Multiple Access (MA) signature.

Fig. 6A and 6B show a flowchart of an example of a wireless communication method.

Fig. 7A and 7B show a flowchart of an example of another wireless communication method.

Fig. 8 shows an example of a wireless communication system.

Fig. 9 is a block diagram representation of a portion of a radio station.

Fig. 10 shows an example of a three-bit group arrangement of signature messaging.

Fig. 11 shows an example of a two-bit group arrangement of signature messaging.

Fig. 12 shows an example of a single bit group arrangement of signature messaging.

Detailed Description

In wireless communication systems, two different types of channel access policies are often used: contention-free transmission, in which a wireless device is given exclusive access to a transmission resource and can transmit, and contention-based transmission, in which a wireless device competes with other wireless devices for a transmission resource. In some embodiments, contention-based access may be performed in a cellular system, such as an upcoming 5G communication system.

In Uplink (UL) scheduling-free transmission, as the name implies, a UE can autonomously transmit data packets without the need to send a scheduling request and wait for dynamic scheduling. The advantages of this request-free scheduling are reduced signaling overhead, reduced UE power consumption, reduced latency, etc. The exempt scheduling may be based on orthogonal resources or may be based on non-orthogonal multiple access (NOMA). In the former, even if the resources themselves are orthogonal, different users may select the same resource, so that occasionally a collision occurs. Whenever such collisions occur, the link performance is significantly degraded. Therefore, resource utilization is not high for the orthogonal schedule-free transmission. Due to transmitter side processing and advanced receivers, a schedule-free transmission using NOMA can handle a larger number of overlapping or colliding users without causing a significant performance loss.

The transmitter side processing of the non-scheduled NOMA is mainly to keep the spectral efficiency per UE low, while introducing good properties of the transmitted signal to facilitate multi-user interference cancellation at the receiver side. There are different approaches to keep the bit rate low and to distinguish between different UEs, e.g. MA signatures. The UE specific MA signature may be the spreading sequence/code, interleaver/scrambler pattern, or even the preamble, demodulation reference signal. They may operate at either the modulation symbol level or the coding bit level or both.

The non-scheduled NOMA transmission may be implemented at different levels. Some possible embodiments include:

1) the resources of the UE are pre-configured (e.g., periodically allocating time-frequency resources and pre-configuring MA signatures), and each time a packet arrives, the UE automatically selects the latest transmission occasion for uplink transmission, which is referred to as semi-persistent scheduling (SPS) -based scheduling-free;

2) the UE may randomly select resources (including time-frequency resources and MA signatures) from a predefined or preconfigured resource pool for uplink transmission at any time, resulting in contention-based transmission.

On both levels, the Base Station (BS) should perform blind detection for UE identification or activation.

In this document, a signaling method for configuring MA signatures is proposed, which is applicable to transmitter or receiver embodiments using SPS-based or contention-based UL transmissions. The disclosed techniques include a variety of signaling messages that may be adapted to different types of information predefined in the specification.

Fig. 1 shows the general structure of the transmitter side processing for UL NOMA transmission. The block diagram may contain UE-specific signaling processing, as well as corresponding MA signature design (such as symbol-level spreading sequences/codes, bit-level interleaver/scrambler patterns, or resource mapping patterns).

Some examples of UE-specific processing and design of MA signatures are as follows:

UE-specific symbol level extension (104)

For the processing of symbol-level spreading, a non-orthogonal spreading sequence with low cross-correlation or low density characteristics is employed as the MA signature.

UE-specific bit-level scrambling or interleaving (106)

For bit-level processing, non-orthogonal scrambling sequences or interleaving patterns may be used as the MA signature to randomize inter-user interference.

UE-specific symbol-level resource mapping (108)

For the processing of resource mapping, the interference can be further randomized by repeated or extended symbol level permutation or transformation and concatenation.

preamble/RS mapping (110)

The preamble or reference signal can be seen as an MA signature, which is used for UE identification and channel estimation.

Channel coding (114)

The user data for the ith user equipment may be channel coded. For example, pre-equalization may be performed to compensate for channel imperfections.

Modulator (112)

The error correction coded or scrambled output may be modulated onto a plurality of subcarriers based on the respective channel qualities.

For certain embodiments, it is not necessary to include all of the processing blocks described above for each of the UL NOMA transmissions. The advantages and disadvantages of different signal processing methods can be seen in different NOMA usage scenarios. There may be different choices of MA signature design even for the same processing block, e.g., multiple sequence pools of blocks written in the standard specification for symbol level extension. Thus, the signaling message should be predefined and the content of the message configured by the BS indicating to the UE which MA signature(s) are to be used for UL data transmission. Thus, the signature may encode a particular setting for each transmitter processing block, which may include whether a given block is to be used.

Design examples

Assuming a processing block for NOMA Tx design, there are M options, and for the mth processing block, there is X of the MA signature pool_mAn option, and then for the xth MA signature pool, the pool has N_m，xThe MA signature.

1. Example embodiments for hierarchical design of signaling messages

Fig. 2 shows a simple design of a signaling message that may include all the combination possibilities of Tx-side processing. The total number of bits of the message is:

where each of the first M bits indicates whether each processing block in fig. 1 is activated or not, and for each possible block there are two other parts indicating which signature pool to select and which MA signature in the selected pool to select, respectively. This is illustrated in fig. 2 and 10.

If only one MA signature pool is configured at a time. The three-layer indication can be reduced to a two-layer indication, as shown in the example in fig. 3.

The total number of bits of the message is:

from the UE side, which block is activated is implicitly indicated by the pool indicator. This is shown in the examples of fig. 3 and 11.

Signaling messages for composite pool of MA signatures

This message is applicable to the case where both BS and UE know only one pool of composite MA signatures and only one MA signature will be used and indicated by the message. As shown in the examples in fig. 4 and 12, the signaling message is used to directly indicate which MA signature is to be used. The total number of bits of the message is:

from the UE side, it is implicitly derived which blocks are activated and which pool is selected, based on the received message and predefined rules known to both the BS and the UE, e.g. a look-up table written in a standard specification.

Example embodiments for explicit signaling of MA signatures

In case the elements of the MA signature have a limited choice of values. The signaling message may be used to directly carry information bits of the MA signature.

For example, as shown in fig. 5, 2 bits may be used to carry an MA signature S ═ S with QPSK constellation₁，S₂，...，S_LEach element of (1), and the total number of bits is 2 x L. For any other constellation with Q value selection, there will be

A number of bits to carry each element of the MA signature, and a total number of bits of the signaling message is

Fig. 6A shows a flow diagram of an example of a wireless communication method 600. The method 600 includes transmitting (610) a message to a user equipment, wherein the message identifies a signature for a non-orthogonal multiple access transmission. The message is structured to identify M transport processing blocks, where X_iA signature pool is available for the ith signal processing block, Xth_iEach signature pool of a chunk includes N_m,xA signature, wherein m is an integer. The message is organized using one of three possibilities (only one possibility can be implemented in the wireless network): (A) a three-bit group arrangement, wherein a first bit group indicates an active-inactive status of each of the M transport processing blocks, and a second bit group indicates an active signature pool for each transport processing block and signatures in the active signature pool for each transport processing block; (B) a two bit group arrangement, wherein an outer bit group identifies the active signature pool and an inner bit group identifies for the user deviceSignatures in the activation signature pool to be used; or (C) a single bit group permutation that identifies signatures from a single signature pool for the user device. As described with respect to fig. 2, in some embodiments, the first bit group in the three bit group arrangement may use a single bit identification indicating whether a subsequent message block is activated or deactivated (e.g., to be used by the receiver, or temporarily ignored). The signature pool may correspond to one or more of the M blocks described with respect to fig. 1.

Fig. 6B shows a flow chart of an example of a wireless communication method 650. The method 650 comprises transmitting (620), by a user equipment, a signal comprising subcarriers modulated by the user equipment with a signature for a multiple access transmission. The method 650 may also include receiving a multiple access transmission using the signature. For example, the base station may implement the transmitting operation 620 and then subsequently receive a multiple access transmission from one or more user devices. Additional example embodiments are described with respect to fig. 5. The signature pool may correspond to one or more of the M blocks described with respect to fig. 1.

Method 600 and method 650 may be implemented by a base station. With respect to method 600, fig. 2 and 10 depict some example embodiments of the three-bit group arrangement, fig. 3 and 11 depict some example embodiments of the two-bit group arrangement, and fig. 4 and 12 depict some example embodiments of the single-bit group arrangement.

Fig. 7A shows a flow diagram of an example of a wireless communication method 700. Method 700 includes receiving (710) a message at a user equipment, wherein the message identifies a signature for a multiple access transmission, wherein the message is structured to identify M transmission processing blocks, wherein X is_iA signature pool is available for the ith signal processing block, Xth_iEach signature pool of a chunk includes N_m,xA signature, wherein m is an integer, the message being organized as one of: (A) a three-bit group arrangement, wherein a first bit group indicates an active-inactive status of each of the M transport processing blocks, and a second bit group indicates an active signature pool for each transport processing block and the active signature for each transport processing blockSignatures in the name pool; (B) a two bit group permutation, wherein an outer bit group identifies the active signature pool and an inner bit group identifies signatures in the active signature pool for use by the user equipment; or (C) a single bit group permutation that identifies signatures from a single signature pool for the user device. The method 700 further includes recovering (712) a signature from the message. The signature pool may correspond to one or more of the M blocks described with respect to fig. 1.

Fig. 7B shows a flowchart of an example of a wireless communication method 750. The method 750 comprises receiving (720), by a user equipment, a signal comprising subcarriers modulated by the user equipment with a signature for a multiple access transmission, and recovering (722) the signature from the signal. Additional example embodiments are described with respect to fig. 5. The signature pool may correspond to one or more of the M blocks described with respect to fig. 1.

Methods

700 and 750 may be implemented by a base station. With respect to method 700, fig. 2 and 10 depict some example embodiments of the three-bit group arrangement, fig. 3 and 11 depict some example embodiments of the two-bit group arrangement, and fig. 4 and 12 depict some example embodiments of the single-bit group arrangement.

In some embodiments of method 600, method 650, method 700, and method 750, the message includes a plurality of bits that signal operational parameters of a transmitter-side function, such as a channel coding scheme, a scrambler setting, an interleaver setting, a modulation scheme, a spreading scheme, a resource mapping scheme, a preamble mapping scheme, a reference signal mapping scheme, and so forth, as described with respect to fig. 1. The channel coding scheme may specify a function by which the signal is modified after passing through the transmission channel to improve detection. The scrambler setting may specify whether to use a scrambler and a scrambling code (or an index thereof). The interleaver settings may specify various interleaver parameters such as interleaving depth. In general, each of the transmitter settings may be signaled as an index to entries from a set of predetermined and known options in the wireless communication network. In some embodiments, the MA signature sequence may be selected from a predefined set of MA signature sequences.

Fig. 8 shows an example of a wireless communication system including a Base Station (BS)120 and one or more User Equipments (UEs) 111, 112 and 113. The UEs may share some transmission resources when transmitting from the UE to the base station (e.g., uplink transmissions). Base station 120 may generate statistics that indicate which of at least

UEs

111, 112, and 113 are attempting to initiate uplink transmissions to base station 120. The base station may then select a Multiple Access (MA) signature sequence for each UE based on the current traffic load. The base station may then send a message (131, 132, 133) to the UE (111, 112, 113, respectively) indicating which MA signature sequences the UE may use for subsequent transmissions (e.g., 141, 142, 143) to the base station.

Figure 9 is a block diagram representation of a portion of a radio station 907 in accordance with some embodiments of the disclosed technology. A radio station 907, such as a base station or wireless device (or UE), may include processor electronics 901, such as a microprocessor implementing one or more of the techniques presented in this document. The radio station 907 may include transceiver electronics 903 to transmit and/or receive wireless signals over one or more communication interfaces, such as one or more antennas 909. The radio station 907 may include other communication interfaces for transmitting and receiving data. The radio station 907 may include one or more memories (not explicitly shown) configured to store information, such as data and/or instructions. In some embodiments, processor electronics 901 may include at least a portion of transceiver electronics 903. In some embodiments, at least some of the disclosed techniques, modules, or functions are implemented using a radio station 907. Processor electronics 901 may be programmed to implement the methods described with respect to one or more of fig. 6A, 6B, 7A, and 7B. The transceiver electronics 903 may be configured to receive or transmit the various messages described in this document.

Fig. 10, 11, and 12 show examples of three-bit group, two-bit group, and single-bit group implementations of message delivery of multiple access signatures, respectively.

As depicted in fig. 10, each of the M processing blocks of the transmitter may have multiple signature pools associated therewith, describing the functionality of the block, and each pool may have multiple signatures associated therewith. Three sets of systems may indicate a specified block, a specified pool, and signatures in the pool.

In the arrangement depicted in fig. 11, the signature pools for all M processing blocks may be indexed via a single index, and the two levels of signaling include which of the combined signature pools is to be used, and the particular signature from the pool to be used.

Fig. 12 depicts a case where a single signature list is used to specify all M processing blocks of the transmitter, and a single bit field is used to indicate the signature to be used for transmitter-side processing.

It should be understood that this document discloses techniques that can be used in the following embodiments: (1) signaling messages to distinguish between different MA signatures; (2) the signaling message is composed of different parts, wherein the activation of the transport processing block, the selection of the signature pool may be indicated explicitly or implicitly; (3) the signaling message is used to directly carry the information bits of the MA signature.

This description, together with the drawings, is intended to be exemplary only, in that the illustrations are meant to be exemplary, and not meant to imply ideal or preferred embodiments unless otherwise specified. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. Moreover, use of "or" is intended to include "and/or" unless the context clearly indicates otherwise.

Some embodiments described herein are described in the general context of methods or processes, which may be implemented in one embodiment by a computer program product, embodied in a computer-readable medium, including computer-executable instructions, such as program code, executed by computers in networked environments. Computer-readable media may include removable and non-removable storage devices including, but not limited to, read-only memory (ROM), random-access memory (RAM), Compact Disks (CDs), Digital Versatile Disks (DVDs), and the like. Accordingly, the computer readable medium may include a non-transitory storage medium. Generally, program modules may include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. The computer or processor may execute instructions, associated data structures, and program modules representing examples of program code for executing steps of the methods disclosed herein. The particular sequence of such executable instructions or associated data structures represents examples of corresponding acts for implementing the functions described in such steps or processes.

Some embodiments disclosed may be implemented as a device or module using hardware circuitry, software, or a combination thereof. For example, a hardware circuit implementation may include discrete analog and/or digital components that are integrated as part of a printed circuit board, for example. Alternatively, or in addition, the disclosed components or modules may be implemented as Application Specific Integrated Circuits (ASICs) and/or as Field Programmable Gate Array (FPGA) devices. Some embodiments may additionally or alternatively include a Digital Signal Processor (DSP), which is a special purpose microprocessor having an architecture optimized for the operational needs of the digital signal processing associated with the disclosed functionality of the present application. Similarly, various components or sub-components within each module may be implemented in software, hardware, or firmware. Connections between modules and/or components within modules may be provided using any of a variety of connection methods and media known in the art, including, but not limited to, communications over the internet, wired or wireless networks using an appropriate protocol.

While this document contains many specifics, these should not be construed as limitations on the scope of the claimed invention or of what may be claimed, but rather as descriptions of features specific to particular embodiments. Certain features that are described in this document in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Furthermore, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination. Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results.

Only a few implementations and examples are described and other embodiments, enhancements and variations can be made based on what is described and illustrated in this disclosure.

Claims

1. A method of wireless communication implemented at a network node, the method comprising:

transmitting a message to a user equipment, wherein the message identifies a signature for a non-orthogonal multiple access transmission, wherein the message is structured to identify M transmission processing modules, wherein X_iA signature pool is available for the ith signal processing block, Xth_iEach signature pool of a chunk includes N_m,xA signature, wherein m is an integer, the message being organized as one of:

a three-bit group arrangement, wherein a first bit group is used for indicating the activation-deactivation state of each of the M transmission processing modules, and a second bit group is used for indicating the activation signature pool of each transmission processing module and the signature in the activation signature pool of each transmission processing block;

a two bit group permutation, wherein an outer bit group determines the active signature pool and an inner bit group determines signatures in the active signature pool for use by the user equipment; or

And arranging single bit groups, and determining one signature in a single signature pool for the user equipment.

2. The method of claim 1, wherein the first group of bits comprises a single bit corresponding to each of the M transport processing blocks.

3. A method of wireless communication, the method comprising:

transmitting a signal comprising subcarriers modulated by a user equipment with a signature for a multiple access transmission.

4. The method of claim 3, further comprising:

receiving the multiple access transmission; and is

Separating the multiple access transmission from multiple access transmissions of other user equipments using the signature.

5. A method of wireless communication, the method comprising:

receiving a message at a user equipment, wherein the message identifies a signature for a multiple access transmission, wherein the message is structured to identify M transport processing blocks, where X is_iA signature pool is available for the ith signal processing block, Xth_iEach signature pool of a chunk includes N_m,xA signature, wherein m is an integer, the message being organized as one of:

a three-bit group arrangement, wherein a first bit group indicates an active-inactive state for each of the M transport processing blocks, and a second bit group indicates an active signature pool for each transport processing block and a signature in the active signature pool for each transport processing block;

a two bit group permutation, wherein an outer bit group identifies the active signature pool and an inner bit group identifies signatures in the active signature pool for use by the user equipment; or

A single bit group permutation identifying signatures from a single signature pool for the user equipment; and is

Recovering the signature from the message.

6. The method of claim 1, wherein the message comprises the three-bit group permutation, and wherein the method further comprises:

signatures of active transport processing blocks are used to generate multiple access transmissions.

7. A method of wireless communication, the method comprising:

receiving, by a user equipment, a signal comprising subcarriers modulated by the user equipment using a signature for a multiple access transmission; and is

Recovering the signature from the signal.

8. The method of claim 7, further comprising:

transmitting, by the user equipment, a multiple access transmission generated using the signature.

9. A wireless communication apparatus comprising a processor and a memory, wherein the processor is configured to read code from the memory and implement the method of any of claims 1-8.

10. A computer program product comprising a computer readable program medium code stored thereon, which when executed by a processor, causes the processor to carry out the method according to any one of claims 1 to 8.