WO2021203411A1

WO2021203411A1 - Enhancement for sl communication

Info

Publication number: WO2021203411A1
Application number: PCT/CN2020/084193
Authority: WO
Inventors: Tao Chen
Original assignee: Mediatek Singapore Pte. Ltd.
Priority date: 2020-04-10
Filing date: 2020-04-10
Publication date: 2021-10-14
Also published as: CN113573410B; CN113573410A

Abstract

For SL CSI-RS transmission for SL CSI measurement, it can be rated matched according to the presence derived from SCI field (e. g., 2 ^nd SCI) for CSI request and the configuration of CSI-RS resources. Additionally, CSI-RS resources can be mapped on the PSSCH resources transmitting TBs. Alternatively, SL CSI-RS resources can be punctured. It will be transparent to UE receiver with minor or ignorable performance degradation. For SL CSI reporting, the assumed SL CSI table (e. g., 64QAM, 256QAM or URLLC table) can be configured per resource pool/BWP and/or exchanged between UEs by PC5-RRC. Alternatively, the assumed SL CSI table can be indicated in SCI field (e. g., 2 ^nd SCI) from a set of (pre-) configured CSI tables. For the SL BWP with the number of RBs not the multiple of sub-channel size which is configured as N RBs per sub-channel, one or multiple resource pools can be configured for fully utilizing all resources with the minimized fragmented resources (i. e., not multiple of the sub-channel size). The multiple resource pools can be configured for a SL BWP with at most (or at least) one resource pools configured with RBs not the multiple of the sub-channel size. PSSCH transmission/reception will be restricted to the resources which are the multiple of sub-channel size.

Description

ENHANCEMENT FOR SL COMMUNICATION

TECHNICAL FIELD

This disclosure relates generally to wireless communications, and, more particularly, to methods and apparatus about enhancement for SL communications.

BACKGROUND

In 5G new radio, V2X sidelink (SL) communication may be supported by the unicast, groupcast and broadcast communications. However, there are several issues to be addressed for CSI operation, resource pool allocation, and TDD UL/DL information carried in S-SSB for V2X communications.

SUMMARY

This disclosure relates generally to wireless communications, and, more particularly, to methods and apparatus about the CSI operation, resource pools allocation, and TDD UL/DL information carried in S-SSB for V2X communications.

For CSI-RS transmission for CSI measurement, it can be rated matched according to the presence derived from SCI field (e.g., 2 ^nd SCI) for CSI request and the configuration of CSI-RS resources. Additionally, CSI-RS resources can be mapped on the PSSCH resources transmitting TBs. In other words, it can’ t be mapped to PSSCH transmitting 2 ^nd SCI and/or PSSCH carrying 1 ^st SCI. Alternatively, it can be punctured to reduce the complexity. The assumed CSI table should be indicated in SCI (i.e., 2 ^nd SCI) and/or the higher layer signaling for UE to derive the proper CSI index based on the CSI measurement.

For resource pool allocation, a special sub-channel can be introduced for accommodating resources (or RBs) not multiple or less than the sub-channel size. For such special sub-channels, it can be restricted for PSSCH transmission, or transmission of FDMed multiplexed PSSCH and PSCCH. In this case, PSCCH may across the symbols over all symbols in a SL slot (except GP symbols and PSFCH symbols if available. multiple resource pools can be configured with the different sub-channel size. The UE may select the resource pool randomly or based on a rule if the priority levels are same for these resource pools.

For UL slots indication in S-SSB, a reference pattern can be defined and some of the patterns can refer to the reference pattern to derive the UL slots by taking into account the different granularity.

BRIEF DESCRIPTION OF DRAWINGS

The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:

FIG. 1 shows an exemplary block diagram of a UE (a.k.a device) according to an embodiment of the disclosure.

DETAILED DESCRIPTION

Certain terms are used throughout the description and following claims to refer to particular components. As one skilled in the art will appreciate, manufacturers may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to ... " . Also, the term "couple" is intended to mean either an indirect or direct electrical connection. Accordingly, if one device is coupled to another device, that connection may be through a direct electrical connection, or through an indirect electrical connection via other devices and connections. The making and using of the embodiments of the disclosure are discussed in detail below. It should be appreciated, however, that the embodiments can be embodied in a wide variety of specific contexts. The specific embodiments discussed are merely illustrative, and do not limit the scope of the disclosure. Some variations of the embodiments are described. Throughout the various views and illustrative embodiments, like reference numbers are used to designate like elements.

The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. Note that the 3GPP specifications described herein are used to teach the spirit of the invention, and the invention is not limited thereto.

For SL CSI-RS transmission for SL CSI measurement, it can be rated matched according to the presence derived from SCI field (e.g., 2 ^nd SCI) for CSI request and the configuration of CSI-RS resources. Additionally, CSI-RS resources can be mapped on the PSSCH resources transmitting TBs. In other words, it can’ t be mapped to PSSCH transmitting 2 ^nd SCI and/or PSSCH carrying 1 ^st SCI. Because UE can know how to do de-ratemaching after decoding 1 ^st SCI and 2 ^nd SCI carrying CSI request field. Due to the resource size for 2 ^nd SCI may vary, the exact CSI-RS resource location may vary as well to avoid collision with the 2 ^nd SCI and 1 ^st SCI resources. More specifically, CSI-RS resources can be only mapped on the symbols with PSSCH for TB transmission (i.e., without any 1 ^st SCI and 2 ^nd SCI transmission) . In this case, the exact CSI-RS resource location can be derived implicitly according to the time/frequency resources of 1 ^st SCI and/or 2 ^nd SCI or up to configuration.

Alternatively, SL CSI-RS resources can be punctured. It will be transparent to UE receiver with minor or ignorable performance degradation.

For SL CSI reporting, the assumed SL CSI table (e.g., 64QAM, 256QAM or URLLC table) can be configured per resource pool/BWP and/or exchanged between UEs by PC5-RRC. Alternatively, the assumed SL CSI table can be indicated in SCI field (e.g., 2 ^nd SCI) from a set of (pre-) configured CSI tables. It enables the dynamic switching between SL MCS tables based on SL CSI reporting derived from the different assumed SL CSI tables corresponding to the different SL MCS tables. One way is that only one assumed CSI table is indicated by SCI and/or higher layer signaling. In this case, the reported CSI is implicitly associated with such assumption. Another way is to indicate multiple assumed CSI tables. In this case, the UE may report CSI associated with the assumed CSI table index, i.e., different CSI reports associated with the different CSI table. In case of multiple CSI resources are configured, the UE may report the CSI result associated with the corresponding CSI-RS resource index.

For the SL BWP with the number of RBs not the multiple of sub-channel size which is configured as N RBs per sub-channel, one or multiple resource pools can be configured for fully utilizing all resources with the minimized fragmented resources (i.e., not multiple of or less than the sub-channel size) . For example, the multiple resource pools can be configured with the different sub-channel size so that the fragmented resources will be quite limited. The UE may select the resource pool randomly or based on a rule if the priority levels are same for these resource pools. In another example, the fragmented resources can be configured as a separated resource pool which can be used for PSSCH and/or PSCCH and/or PSFCH transmission. So any number of PRBs can be configured for a resource pool. Alternatively, at most (or at least) one resource pool in SL BWP can be configured with the RBs not multiple of sub-channel size. For example, the multiple resource pools can be configured for a SL BWP with at most (or at least) one resource pools configured with RBs not the multiple of the sub-channel size. PSSCH transmission/reception will be restricted to the resources which are the multiple of sub-channel size. The lowest RB index of the lowest sub-channel index of the resource pool is the lowest RB index of the resource pool. The remaining RBs in the resource pool (i.e., less than the sub-channel size) can be specified as a special sub-channel, which can be used for PSSCH transmission but not PSCCH transmission, i.e., a kind of supplementary sub-channel for PSSCH transmission. Alternatively or additionally, such special sub-channel can be used to carry PSCCH and PSSCH by FDMed multiplexing. In this case, PSCCH may be transmitted across all SL symbols in the SL slot except for GP symbols and PSFCH symbols if available.

For TDD UL/DL information carried in S-SSB to determine the available SL slots, the indication for single period and dual-period patterns associated with the UL slots per period can be indicated in S-SSB derived from the TDD UL/DL configuration in uu interface (e.g., SIB messages) . Due to the limited bits in S-SSB, not all combinations can be carried. To save the bits, the patterns with the same period for each period in the dual-period, i.e., {P1=n, P2=n} , the same indication can be used with different granularity applied for different n value. For example, for dual-period patterns {P1, P2} = {5, 5} , the UL (or SL) slots for the pattern {5, 5} can be indicated by some bits indicating the consecutive UL (or SL) slots. For the other patterns with the same period in P1 and P2, i.e., {2, 2} , {2.5, 2.5} and {10, 10} , they can refer to indication of UL (or SL) slots for {5, 5} pattern to derive the corresponding information taking into account the difference of the granularity. That is, for a target pattern {Pt, Pt} , the UL slots can be derived by using the indicated UL slots in a reference pattern {Pr, Pr} as such: UL_slots_ {Pt, Pt} = floor (UL_slots_ {Pr, Pr} /Pr *Pa) , i.e., wherein Pt is the period of the target pattern (e.g., {2, 2} , {2.5, 2.5} , {10, 10} ) and Pr is the period of the reference pattern (e.g., {5, 5} ) . For example, if the indicated UL_slots_ {5, 5} = 5 slots, then UL_slots_ {2, 2} = floor (5/5*2) = 2 slots per period.

The UL slots associated with a pattern can be derived from the TDD UL/DL configuration indicated in SIB. In case of the different numerology used for SL and uu interface, the UL_slots_ {Pr, Pr} should take into account the numerology difference between SL and uu to derive the number of UL (or potential SL) slots indicated in SL SSB. For example, if uu is using 15khz and SL is 30khz, the UL_slots_SL_u1 = floor (UL_slots_uu_u2 *2^ (u1-u2) ) , wherein u1 and u2 belong to u = {0, 1, 2, 3} corresponding to 15khz, 30khz, 60khz and 120khz numerology.

In case of the inter-carrier indication of the TDD UL/DL configuration from eNB/gNB in a frequency to another frequency for SL operation, the numerology associated with TDD UL/DL configuration for SL frequency should be indicated via BS signaling for SL operation, e.g., dedicated RRC or SIB messages for SL operation.

FIG. 1 shows an exemplary block diagram of a UE 800 according to an embodiment of the disclosure. The processor 810 can be configured to perform various functions of the UE 120 described above with reference to the invention. The processor 810 can include signal processing circuitry to process received or to be transmitted data according to communication protocols specified in, for example, LTE and NR standards. Additionally, the processor 810 may execute program instructions, for example, stored in the memory 820, to perform functions related with different communication protocols. The processor 810 can be implemented with suitable hardware, software, or a combination thereof. For example, the processor 810 can be implemented with application specific integrated circuits (ASIC) , field programmable gate arrays (FPGA) , and the like, that includes circuitry. The circuitry can be configured to perform various functions of the processor 810.

In one example, the memory 820 can store program instructions that, when executed by the processor 810, cause the processor 810 to perform various functions as described herein. The memory 820 can include a read only memory (ROM) , a random access memory (RAM) , a flash memory, a solid state memory, a hard disk drive, and the like.

The RF module 830 can be configured to receive a digital signal from the processor 810 and accordingly transmit a signal to a base station in a wireless communication network via an antenna 840. In addition, the RF module 830 can be configured to receive a wireless signal from a base station and accordingly generate a digital signal which is provided to the processor 810. The RF module 830 can include digital to analog/analog to digital converters (DAC/ADC) , frequency down/up converters, filters, and amplifiers for reception and transmission operations. For example, the RF module 830 can include converter circuits, filter circuits, amplification circuits, and the like, for processing signals on different carriers or bandwidth parts.

The UE 800 can optionally include other components, such as input and output devices, additional CPU or signal processing circuitry, and the like. Accordingly, the UE 800 may be capable of performing other additional functions, such as executing application programs, and processing alternative communication protocols.

The processes and functions described herein can be implemented as a computer program which, when executed by one or more processors, can cause the one or more processors to perform the respective processes and functions. The computer program may be stored or distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with, or as part of, other hardware. The computer program may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. For example, the computer program can be obtained and loaded into an apparatus, including obtaining the computer program through physical medium or distributed system, including, for example, from a server connected to the Internet.

The computer program may be accessible from a computer-readable medium providing program instructions for use by or in connection with a computer or any instruction execution system. A computer readable medium may include any apparatus that stores, communicates, propagates, or transports the computer program for use by or in connection with an instruction execution system, apparatus, or device. The computer-readable medium can be magnetic, optical, electronic, electromagnetic, infrared, or semiconductor system (or apparatus or device) or a propagation medium. The computer-readable medium may include a computer-readable non-transitory storage medium such as a semiconductor or solid state memory, magnetic tape, a removable computer diskette, a random access memory (RAM) , a read-only memory (ROM) , a magnetic disk and an optical disk, and the like. The computer-readable non-transitory storage medium can include all types of computer readable medium, including magnetic storage medium, optical storage medium, flash medium and solid state storage medium.

While aspects of the present disclosure have been described in conjunction with the specific embodiments thereof that are proposed as examples, alternatives, modifications, and variations to the examples may be made. Accordingly, embodiments as set forth herein are intended to be illustrative and not limiting. There are changes that may be made without departing from the scope of the claims set forth below.

Claims

A method, comprising:

receiving a (pre-) configuration SL opeartion;

obtaining CSI-RS and/or TDD UL/DL configuration; and

performing transmission/reception of CSI-RS and/or S-SSB transmission/reception.