CN113676872A

CN113676872A - Method performed by user equipment and user equipment

Info

Publication number: CN113676872A
Application number: CN202010410515.4A
Authority: CN
Inventors: 赵毅男; 罗超; 刘仁茂
Original assignee: Sharp Corp
Current assignee: Sharp Corp
Priority date: 2020-05-14
Filing date: 2020-05-14
Publication date: 2021-11-19
Also published as: WO2021228138A1

Abstract

The invention provides a method executed by user equipment and the user equipment, wherein the method comprises the following steps: receiving PSCCH and corresponding PSSCH transmitted by other side communication user equipment; and under the condition that the transport block TB transmitted by the PSSCH is retransmitted and the modulation and coding scheme MCS table indicated by the PSCCH is different from the modulation and coding scheme MCS table corresponding to the initial transmission of the transport block TB, determining the time domain density of the sidelink communication phase tracking reference signal PT-RS.

Description

Method performed by user equipment and user equipment

Technical Field

The present invention relates to the field of wireless communication technologies, and in particular, to a method performed by a user equipment and a corresponding user equipment.

Background

In a conventional cellular network, all communications must pass through the base station. In contrast, D2D communication (Device-to-Device communication, direct Device-to-Device communication) refers to a communication method in which two user devices communicate directly without forwarding through a base station or a core network. The research topic on the realization of the D2D-adjacent communication service by LTE devices was approved at RAN #63 of 3rd Generation Partnership Project (3 GPP) in 2014 (see non-patent document 1). Functions introduced by LTE Release 12D 2D include:

1) discovery function (Discovery) between adjacent devices in an LTE network coverage scenario;

2) a direct Broadcast communication (Broadcast) function between neighboring devices;

3) the higher layer supports Unicast (Unicast) and multicast (Groupcast) communication functions.

On the 3GPP RAN #66 congress of 12 months in 2014, the research project of enhanced LTE eD2D (enhanced D2D) was approved (see non-patent document 2). The main functions introduced by LTE Release 13 eD2D include:

1) D2D discovery of no-network coverage scenarios and partial-network coverage scenarios;

2) priority handling mechanism for D2D communications.

Based on the design of the D2D communication mechanism, the V2X feasibility study topic based on D2D communication was approved at the RAN #68 time congress of 3GPP at 6 months 2015. V2X shows that Vehicle to evolution is expected to realize the interaction between Vehicle and all entity information that may affect the Vehicle, in order to reduce accident, slow down traffic jam, reduce environmental pollution and provide other information services. The application scenario of V2X mainly includes 4 aspects:

1) V2V, Vehicle to Vehicle, i.e. Vehicle-to-Vehicle communication;

2) V2P, Vehicle to peer, i.e. the Vehicle sends a warning to pedestrians or non-motor vehicles;

3) V2N, Vehicle to Network, i.e. Vehicle connected mobile Network;

4) V2I, Vehicle to Infrastructure, i.e. the Vehicle communicates with road Infrastructure etc.

The 3GPP has divided the research and standardization work of V2X into 3 stages. The first phase was completed in 2016 and 9 months, mainly focusing on V2V, and was formulated based on LTE Release 12 and Release 13D 2D (also called sidelink communication), i.e., proximity communication technology (see non-patent document 3). V2X stage 1 introduced a new D2D communication interface, called PC5 interface. The PC5 interface is mainly used to solve cellular internet of vehicles communication problems in high speed (up to 250 km/h) and high node density environments. The vehicles can interact with information such as position, speed and direction through the PC5 interface, i.e., the vehicles can communicate directly with each other through the PC5 interface. Compared with the proximity communication between D2D devices, the functions introduced by LTE Release 14V 2X mainly include:

1) higher density DMRS to support high speed scenarios;

2) introducing a sub-channel (sub-channel) to enhance a resource allocation mode;

3) a user equipment aware (sensing) mechanism with semi-persistent scheduling (semi-persistent) is introduced.

The second stage of the research topic of V2X belongs to the research category of LTE Release 15 (see non-patent document 4), and the introduced main characteristics include high-order 64QAM modulation, V2X carrier aggregation, short TTI transmission, and feasibility research of transmit diversity.

At the 3GPP RAN #80 congress of 6 months in 2018, the corresponding third stage was approved based on the V2X feasibility study topic of 5G NR network technology (see non-patent document 5).

In 2019, at 3GPP RAN1#98bis meetings at month 10 (see non-patent document 6), the following meeting conclusions are reached regarding the modulation scheme in NR sidelink:

● support 256QAM modulation in NR sidelink.

■ whether 256QAM modulation is supported or not is based on UE capability (UE capability) from the transmitting user equipment perspective;

■ 64QAM modulation is mandatory for user equipment (mandatory).

Likewise, on 3GPP RAN1#98bis meetings at 10 months in 2019 (see non-patent document 6), the following meeting conclusions are reached with respect to the MCS table in NR sidelink:

● NR sidelink supports all three modulation and coding scheme MCS tables defined in Rel15 NR for CP-OFDM.

● at least one MCS table is configured or pre-configured in the resource pool of NR sidelink.

On 3GPP RAN1#100bis meetings at month 4 of 2020 (see non-patent document 7), the following meeting conclusions are reached regarding the indication of the MCS table in NR sidelink:

● the MCS table is indicated in the SCI and one or more MCS tables are configured or preconfigured in the configuration information of the resource pool.

■ the configuration information of the resource pool contains a default MCS table;

■, excluding the default MCS table described above, supporting additional configurations or pre-configuring 0, or 1, or 2 MCS tables;

■ the number of bits used to indicate the indication field of the MCS table in the SCI is 0 bit (corresponding to the case of additionally configuring or pre-configuring 0 MCS tables), or 1 bit (corresponding to the case of additionally configuring or pre-configuring 1 MCS table), or 2 bit (corresponding to the case of additionally configuring or pre-configuring 2 MCS tables).

● if the receiving user equipment does not support the MCS table indicated by the transmitting user equipment in the SCI, then the receiving user equipment does not need to decode the corresponding PSSCH.

In the NR sidelink, the time domain density (time diversity) of the phase tracking reference signal PT-RS is related to the MCS index (MCS index) in the MCS table, and the scheme of the invention mainly comprises a method for determining the time domain density of the NR sidelink phase tracking reference signal PT-RS under the condition that the TB indicating transmission in the SCI received by the receiving user equipment is retransmission.

Documents of the prior art

Non-patent document

Non-patent document 1: RP-140518, Work item deployment on LTE Device to Device Proximity Services

Non-patent document 2: RP-142311, Work Item Proposal for Enhanced LTE Device to Device Proximity Services

Non-patent document 3: RP-152293, New WI propofol: support for V2V services based on LTE sidelink

Non-patent document 4: RP-170798, New WID on 3GPP V2X Phase 2

Non-patent document 5: RP-181480, New SID Proposal: study on NR V2X

Non-patent document 6: RAN1#98bis, Chairman nodes, section 7.2.4.1

Non-patent document 7: RAN1#100bis, Chairman nodes, section 7.2.4.1

Disclosure of Invention

To address at least some of the above issues, the present invention provides a method performed by a user equipment and a user equipment.

The method of the first aspect of the present invention, performed by a user equipment, comprises: receiving PSCCH and corresponding PSSCH transmitted by other side communication user equipment; and determining the time domain density of a sidelink communication phase tracking reference signal PT-RS under the condition that a transport block TB transmitted by the PSSCH is a retransmission and a Modulation and Coding Scheme (MCS) table indicated by the PSCCH is different from a Modulation and Coding Scheme (MCS) table corresponding to the initial transmission of the transport block TB.

According to the method performed by the user equipment of the first aspect of the present invention, the PSCCH carries the first-level sidelink communication control information SCI.

The method performed by the user equipment according to the first aspect of the present invention, wherein the first-level SCI includes an indication field of a modulation and coding scheme, MCS, table; and the first-level SCI comprises an indication field of MCS.

According to the method performed by the user equipment of the first aspect of the present invention, the psch carries second level sidelink communication control information SCI.

According to the method performed by the user equipment of the first aspect of the present invention, the indication field of the MCS is larger than a retransmission threshold value, and the sidelink user equipment determines the psch transmission as a retransmission.

According to the method performed by the user equipment of the first aspect of the present invention, the MCS table indicated by the indication field of the MCS table and the MCS table corresponding to the initial transmission of the transport block TB transmitted by the psch are different MCS tables.

The method performed by the user equipment according to the first aspect of the invention, the MCS for determining the time domain density L of the PT-RS is obtained from the initial transmission MCS of a transport block TB transmitted by the PSSCH.

According to the method performed by the user equipment of the first aspect of the present invention, the initial MCS of the transport block TB transmitted by the psch is smaller than or equal to a retransmission threshold corresponding to the MCS table corresponding to the initial transmission.

The user equipment of the second aspect of the present invention includes: a processor; and a memory storing instructions; wherein the instructions, when executed by the processor, perform the method of the first aspect.

Drawings

The above and other features of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which:

fig. 1 is a schematic diagram illustrating LTE V2X UE sidelink communications.

Fig. 2 is a diagram illustrating a resource allocation scheme of LTE V2X.

Fig. 3 is a diagram illustrating a basic procedure of a method performed by a user equipment in the first embodiment of the invention.

Fig. 4 is a diagram illustrating a basic procedure of a method performed by a user equipment in embodiment two of the invention.

Fig. 5 is a block diagram illustrating a user equipment according to an embodiment of the present invention.

Detailed Description

The invention is described in detail below with reference to the figures and the detailed description. It should be noted that the present invention should not be limited to the specific embodiments described below. In addition, for the sake of brevity, detailed descriptions of well-known technologies not directly related to the present invention are omitted to prevent confusion of understanding of the present invention.

Embodiments according to the present invention are described in detail below with a 5G mobile communication system and its subsequent evolution as an example application environment. However, it is to be noted that the present invention is not limited to the following embodiments, but is applicable to more other wireless communication systems, such as a communication system after 5G and a 4G mobile communication system before 5G, and the like.

Some terms to which the present invention relates will be described below, and the terms to which the present invention relates are defined herein, unless otherwise specified. The terms given in the invention may adopt different naming manners in LTE, LTE-Advanced Pro, NR and the following communication systems, but the unified terms adopted in the invention can be replaced by the terms adopted in the corresponding systems when being applied to the specific systems.

3 GPP: 3rd Generation partnershift Project, third Generation Partnership Project

LTE: long Term Evolution, Long Term Evolution technology

NR: new Radio, New Wireless, New air interface

PDCCH: physical Downlink Control Channel, Physical Downlink Control Channel

DCI: downlink Control Information, Downlink Control Information

PDSCH: physical Downlink Shared Channel (pdcch)

UE: user Equipment, User Equipment

eNB: evolved NodeB, evolved node B

And g NB: NR base station

TTI: transmission Time Interval, Transmission Time Interval

OFDM: orthogonal Frequency Division Multiplexing, Orthogonal Frequency Division Multiplexing

CP-OFDM: cyclic Prefix Orthogonal Frequency Division Multiplexing with Cyclic Prefix

C-RNTI: cell Radio Network Temporary Identifier

CSI: channel State Information, Channel State Information

HARQ: hybrid Automatic Repeat Request (HARQ)

CSI-RS: channel State Information Reference Signal (CSI-RS)

CRS: cell Reference Signal, Cell specific Reference Signal

PUCCH: physical Uplink Control Channel, Physical Uplink Control Channel

PUSCH: physical Uplink Shared Channel, Physical Uplink Shared Channel

UL-SCH: uplink Shared Channel, Uplink Shared Channel

CG: configured Grant, configuring scheduling Grant

Sidelink: sidelink communications

SCI: sidelink Control Information, Sidelink communication Control Information

PSCCH: physical Sidelink Control Channel, Physical Sidelink communication Control Channel

MCS: modulation and Coding Scheme, Modulation and Coding Scheme

RB: resource Block, Resource Block

RE: resource Element, Resource Element

CRB: common Resource Block, Common Resource Block

And (3) CP: cyclic Prefix, Cyclic Prefix

PRB: physical Resource Block, Physical Resource Block

PSSCH: physical Sidelink Shared Channel, a Physical Sidelink communication Shared Channel

FDM: frequency Division Multiplexing, Frequency Division Multiplexing

RRC: radio Resource Control, Radio Resource Control

RSRP: reference Signal Receiving Power, Reference Signal Receiving Power

SRS: sounding Reference Signal

DMRS: demodulation Reference Signal

CRC: cyclic Redundancy Check (crc)

PSDCH: physical Sidelink Discovery Channel

PSBCH: physical Sidelink Broadcast Channel, Physical Sidelink communication Broadcast Channel

SFI: slot Format Indication

TDD: time Division Duplexing

FDD: frequency Division Duplexing

SIB 1: system Information Block Type 1, System Information Block Type 1

SLSS: sidelink synchronization Signal, a side-line communication synchronization Signal

PSSS: primary Sidelink Synchronization Signal, sideline communication Primary Synchronization Signal

SSSS: secondary Sidelink Synchronization Signal, sideline communication auxiliary Synchronization Signal

PCI: physical Cell ID, Physical Cell identity

PSS: primary Synchronization Signal, Primary Synchronization Signal

SSS: secondary Synchronization Signal, Secondary Synchronization Signal

BWP: bandwidth Part, BandWidth fragment/portion

GNSS: global Navigation Satellite positioning System (GNSS)

SFN: system Frame Number, System (radio) Frame Number

DFN: direct Frame Number, Direct Frame Number

IE: information Element, Information Element

And (3) SSB: synchronization Signal Block, synchronous System information Block

EN-DC: EUTRA-NR Dual Connection, LTE-NR Dual connectivity

MCG (calcium carbonate): master Cell Group, Master Cell Group

SCG: secondary Cell Group, Secondary Cell Group

PCell: primary Cell, Primary Cell

SCell: secondary Cell, Secondary Cell

PSFCH: physical Sidelink Feedback Channel, Physical Sidelink communication Feedback Channel

SPS: semi-persistent Scheduling, Semi-persistent Scheduling

TA: timing Advance, uplink Timing Advance

PT-RS: Phase-Tracking Reference Signals

TB: transport Block

CB: code Block, Code Block/Code Block

QPSK: quadrature Phase Shift Keying (QPSK)

16/64/256 QAM: 16/64/256 Quadrature Amplitude Modulation

AGC: auto Gain Control, automatic Gain Control

The following is a description of the prior art associated with the inventive arrangements. Unless otherwise specified, the meanings of the same terms in the specific examples are the same as those in the prior art.

It is to be noted that V2X referred to in the description of the present invention has the same meaning as sidelink. V2X herein may also represent sidelink; similarly, sidelink herein may also refer to V2X, and is not specifically distinguished or limited hereinafter.

In the description of the present invention, the resource allocation method of V2X (sidelink) communication and the transmission mode of V2X (sidelink) communication may be replaced by equivalent methods. The resource allocation pattern referred to in the specification may indicate a transmission mode, and the transmission mode referred to may indicate a resource allocation pattern.

The PSCCH in the description of the present invention is used to carry SCI. The PSCCH referred to in the description of the present invention is referred to as corresponding PSCCH, or related PSCCH, or scheduled PSCCH, which all have the same meaning and all represent either an associated PSCCH or a associated PSCCH. Similarly, PSSCH references in the specification refer to corresponding, or related SCIs (including first-level SCI and second-level SCI) as having the same meaning, and all refer to associated SCI or associated SCI. It is noted that the first stage SCI, referred to as the 1st stage SCI, is transmitted in the PSCCH; the second level SCI is called 2nd stage SCI and is transmitted in the resource of the corresponding PSSCH.

Scenarios for Sidelink communications

1) Out-of-Coverage (Out-of-Coverage) sidelink communication: neither UE performing sidelink communication has network coverage (e.g., the UE does not detect any cell satisfying the "cell selection criterion" on the frequency on which the sidelink communication is required, indicating that the UE has no network coverage).

2) Network Coverage (In-Coverage) side communication: both UEs performing sidelink communications have network coverage (e.g., the UE detects at least one cell satisfying the "cell selection criteria" on the frequency on which the sidelink communications are desired, indicating that the UE has network coverage).

3) Partial-Coverage (Partial-Coverage) sidelink communications: one of the UEs performing sidelink communication has no network coverage, and the other UE has network coverage.

From the UE side, the UE has only two scenarios, namely, network coverage and non-network coverage. Partial network coverage is described from the perspective of sidelink communications.

Basic procedure for LTE V2X (sidelink) communication

Fig. 1 is a schematic diagram illustrating LTE V2X UE sidelink communications. First, the UE1 transmits sidelink communications control information (SCI format 1), carried by the physical layer channel PSCCH, to the UE 2. SCI format 1 includes scheduling information of the pscch, such as frequency domain resources of the pscch. Second, UE1 transmits sidelink communications data to UE2, carried by the physical layer channel PSSCH. The PSCCH and the corresponding PSCCH are frequency division multiplexed, that is, the PSCCH and the corresponding PSCCH are located on the same subframe in the time domain and are located on different RBs in the frequency domain. The specific design modes of the PSCCH and the PSSCH are as follows:

1) the PSCCH occupies one subframe in the time domain and two consecutive RBs in the frequency domain. The initialization of the scrambling sequence takes a predefined value 510. The PSCCH may carry SCI format 1, where SCI format 1 at least includes frequency domain resource information of the PSCCH. For example, for the frequency domain resource indication field, SCI format 1 indicates the starting sub-channel number and the number of consecutive sub-channels of the pschs corresponding to the PSCCH.

2) The PSCCH occupies one subframe in the time domain, and the corresponding PSCCH employs Frequency Division Multiplexing (FDM). The PSSCH occupies one or more continuous sub-channels in the frequency domain, and the sub-channels represent n in the frequency domain_subCHsizeA plurality of RB, n in succession_subCHsizeConfigured by RRC parameters, the number of starting sub-channels and consecutive sub-channels is indicated by the frequency domain resource indication field of SCI format 1.

LTE V2X resource allocation Mode Transmission 3/4

Fig. 2 shows two resource allocation manners of LTE V2X, which are respectively referred to as resource allocation based on base station scheduling (Transmission Mode 3) and resource allocation based on UE sensing (sensing) (Transmission Mode 4). In LTE V2X, when there is eNB network coverage, a base station may configure a resource allocation manner of a UE, or referred to as a transmission mode of the UE, through UE-level proprietary RRC signaling (dedicated RRC signaling) SL-V2X-ConfigDedicated, specifically:

1) resource allocation scheme based on base station scheduling (Transmission Mode 3): the resource allocation method based on base station scheduling represents that the frequency domain resources used by sidelink communication are scheduled by the base station. The transmission mode 3 includes two scheduling modes, namely dynamic scheduling and semi-persistent scheduling (SPS). For dynamic scheduling, the UL grant (DCI format 5A) includes frequency domain resources of the pscch, and the CRC of the PDCCH or EPDCCH carrying the DCI format 5A is scrambled by the SL-V-RNTI. For SPS semi-persistent scheduling, the base station passes IE: the SPS-ConfigSL-r14 configures one or more (up to 8) configured scheduling grants (configured grant), each configured scheduling grant containing a scheduling grant number (index) and a resource period of the scheduling grant. The UL grant (DCI format 5A) includes frequency domain resources of the psch, and indication information (3bits) of a scheduling grant number and indication information of SPS activation (activation) or release (release or deactivation). The CRC of the PDCCH or EPDCCH carrying the DCI format 5A is scrambled by SL-SPS-V-RNTI.

Specifically, when the RRC signaling SL-V2X-ConfigDedicated is set to scheduled-r14, it indicates that the UE is configured to a transmission mode based on base station scheduling. The base station configures SL-V-RNTI or SL-SPS-V-RNTI through RRC signaling, and sends uplink scheduling permission UL grant to the UE through PDCCH or EPDCCH (DCI format 5A, CRC adopts SL-V-RNTI scrambling or adopts SL-SPS-V-RNTI scrambling). The uplink scheduling grant UL grant at least includes scheduling information of psch frequency domain resources in sidelink communication. And when the UE successfully monitors PDCCH or EPDCCH scrambled by SL-V-RNTI or SL-SPS-V-RNTI, taking a PSSCH frequency domain resource indication domain in an uplink scheduling grant UL grant (DCI format 5A) as indication information of a PSSCH frequency domain resource in the PSCCH (SCI format 1), and sending the PSCCH (SCI format 1) and the corresponding PSSCH.

For semi-persistent scheduling SPS in transmission mode 3, the UE receives DCI format 5A scrambled by SL-SPS-V-RNTI on downlink subframe n. If the DCI format 5A contains indication information of SPS activation, the UE determines frequency domain resources of the PSSCH according to the indication information in the DCI format 5A, and determines time domain resources of the PSSCH (transmission sub-frame of the PSSCH) according to information such as sub-frame n and the like.

2) Resource allocation method based on UE sensing (sensing) (Transmission Mode 4): the UE sensing-based resource allocation mode represents a sensing (sensing) process of a UE-based candidate available resource set for sidelink communication. The RRC signaling SL-V2X-ConfigDedicated when set to UE-Selected-r14 indicates that the UE is configured to transmit mode based on UE sending. In the UE sensing-based transmission mode, the base station configures an available transmission resource pool, and the UE determines a sidelink transmission resource of the PSCCH in the transmission resource pool (resource pool) according to a certain rule (for a detailed description of the procedure, see LTE V2X UE sensing procedure part), and transmits the PSCCH (SCI format 1) and the corresponding PSCCH.

Side communication resource pool (sidelink resource pool)

In the sidestream communication, the resources transmitted and received by the UE belong to a resource pool. For example, for a transmission mode based on base station scheduling in sidestream communication, the base station schedules transmission resources for sidelink UEs in the resource pool, or for a transmission mode based on UE perception in sidestream communication, the UE determines the transmission resources in the resource pool.

Parameter set (numerology) in NR (including NR sidelink) and in NR (including NR) sidelink) of Slot slot

Parameter set numerology includes both subcarrier spacing and cyclic prefix CP length implications. Where NR supports 5 subcarrier spacings, 15k, 30k, 60k, 120k, 240kHz (corresponding to μ ═ 0, 1, 2, 3, 4), and table 4.2-1 shows the set of supported transmission parameters, as shown below.

TABLE 4.2-1 NR supported subcarrier spacing

μ	Δf＝2^μ·15[kHz]	CP (Cyclic prefix)
			0	15	Is normal
1	30	Is normal
			2	60	Normal, extended
3	120	Is normal
			4	240	Is normal

Extended (Extended) CP is supported only when μ ═ 2, i.e., in the case of 60kHz subcarrier spacing, and only normal CP is supported in the case of other subcarrier spacing. For Normal (Normal) CP, each slot (slot) contains 14 OFDM symbols; for extended CP, each slot contains 12 OFDM symbols. For a sub-carrier spacing of 15kHz, 0, 1 slot 1 ms; mu is 1, namely 30kHz subcarrier interval, and 1 time slot is 0.5 ms; mu is 2, i.e. 60kHz subcarrier spacing, 1 slot is 0.25ms, and so on.

Parameter set in LTE (including LTE V2X) and slot and subframe in LTE (including LTE V2X)

LTE supports only 15kHz subcarrier spacing. Extended (Extended) CP is supported in LTE, as is normal CP. The subframe duration is 1ms, and comprises two slot slots, and the duration of each slot is 0.5 ms.

For Normal (Normal) CP, each subframe contains 14 OFDM symbols, and each slot in the subframe contains 7 OFDM symbols; for extended CP, each subframe contains 12 OFDM symbols, and each slot in the subframe contains 6 OFDM symbols.

Resource blocks RB and resource elements RE

The resource block RB is defined as in the frequency domain

The RB is 180kHz in the frequency domain for a contiguous number of subcarriers, e.g., 15kHz subcarrier spacing. For subcarrier spacing 15kHz 2^μThe resource element RE represents 1 subcarrier in the frequency domain and 1 OFDM symbol in the time domain.

Modulation scheme and modulation and coding scheme MCS table

Assuming that the number of bits of information bits after channel coding is N, and the modulation order (modulation order) of the modulation scheme adopted by the N bits is m (indicating that one coded modulation symbol or modulation symbol includes m bits), rate matching is performed on the N bits, and the obtained modulation symbol number is s, which indicates that the number of resource elements RE occupied by the bits after rate matching is s during resource mapping, the total number of bits is equal to s m, and s m is less than or equal to N. It is to be noted that, for the modulation order m, when the modulation scheme is QPSK, m is 2, and when the modulation scheme is 16QAM, 64QAM, or 256QAM, m is equal to 4, 6, or 8, respectively.

In NR, for a CP-OFDM waveform, a total of three modulation coding scheme MCS tables are supported, as follows:

TABLE 1 default MCS Table

TABLE 2 MCS Table with 256QAM

TABLE 3 MCS Table for Low spectral efficiency (low spectral efficiency)

In NR sidelink, the indication of the MCS table,

■ the configuration information of the resource pool contains a default MCS table (Table 1);

■, in addition to the default MCS tables described above, supports additional (Table 2 and Table 3) configurations or pre-configures 0, or, 1, or, 2 MCS tables;

■ the number of bits used to indicate the indication field of the MCS table in the SCI is 0 bit (corresponding to the case of additionally configuring or pre-configuring 0 MCS tables, i.e. containing only table 1), or 1 bit (corresponding to the case of additionally configuring or pre-configuring 1 MCS table), or 2 bit (corresponding to the case of additionally configuring or pre-configuring 2 MCS tables).

In table 1, MCS indices 29 to 31 indicate that TB of psch transmission is a retransmission; similarly, in table 2, MCS indices 28 to 31 indicate that TB of psch transmission is a retransmission; in table 3, MCS indices 29 to 31 indicate that the TBs of the psch transmission are retransmissions. In the description of this patent, a parameter V (V may be referred to as retransmission threshold) is introduced, and for tables 1 and 3, V is 28; for table 2, V-27, when the MCS index is greater than V, indicates that the TB of the psch transmission is a retransmission.

Phase tracking reference signal PT-RS

In Rel-15 NR, at the higher frequency band, the PT-RS is used to track phase fluctuations over the entire transmission period (e.g., one slot). Since the PT-RS is designed to track phase noise, the PT-RS is dense in the time domain and sparse in the frequency domain. The PT-RS will only appear with the DMRS and will be sent only if the network is configured with PT-RS. For CP-OFDM waveforms, PT-RS occupies the first symbol allocated for PDSCH or PUSCH transmission and counts OFDM symbols from the starting symbol, and every time L is counted (L represents the time domain density of PT-RS), PT-RS occupies one OFDM symbol and resets the counter, and then continues to count the subsequent symbols. The repetition count is also reset each time the DM-RS is encountered, since it is not necessary to insert a PT-RS immediately after the DM-RS to estimate the phase noise. The density L of the time domain is related to the scheduled MCS index. In NR, taking PT-RS of PDSCH as an example, the UE determines the time domain density L of PT-RS including but not limited to MCS (index) indicated by the base station.

Similarly, a sidelink communication phase tracking reference signal sidelink PT-RS is introduced in the NR sidelink. In the high frequency band, the user equipment performs phase tracking according to the received PT-RS to improve demodulation performance. The scheme of the patent is a method for determining the time domain density L of the PT-RS in the sidelink, and the specific method is a method for determining the MCS (index) corresponding to retransmission and further determining the time domain density L of the PT-RS of the sidelink.

Specific examples, embodiments, and the like according to the present invention will be described in detail below. As described above, the examples and embodiments described in the present disclosure are illustrative for easy understanding of the present invention, and do not limit the present invention.

[ example one ]

Fig. 3 is a diagram illustrating a basic procedure of a method performed by a user equipment according to a first embodiment of the present invention.

The method executed by the ue according to the first embodiment of the present invention is described in detail below with reference to the basic process diagram shown in fig. 3.

As shown in fig. 3, in a first embodiment of the present invention, the steps performed by the user equipment include:

in step S101, the sidestream communication user equipment receives the PSCCH and the corresponding PSCCH transmitted from the other user equipment.

The PSCCH carries first-level sidelink communication control information SCI (1)^ststage SCI)。

The first-level SCI comprises an indication field of a Modulation Coding Scheme (MCS) table.

The first-level SCI includes an indication field of MCS (index).

The PSSCH carries second-level sidelink communication control information SCI (2)^nd stage SCI)。

Optionally, the side communication ue determines the psch to be a retransmission (retransmission) according to the first level SCI and/or the second level SCI,

and/or the presence of a gas in the gas,

optionally, the MCS (index) indication field is greater than V (V28 for table 1 and table 3; V27 for table 2), and the sidelink user equipment determines that the psch transmission is a retransmission.

Optionally, the MCS table indicated by the indication field of the MCS table and the MCS table corresponding to the second transmission corresponding to the transport block TB of the PSSCH transmission are different MCS tables, or the same MCS table.

Optionally, the second transmission corresponding to the TB represents an initial transmission (initial transmission) of the TB or a latest transmission (latest) of the last transmission of the PSSCH.

In step S102, the user equipment for sidestream communication determines the time domain density L of the sidestream communication phase tracking reference signal PT-RS corresponding to the psch transmission.

Optionally, the MCS (index) for determining the time domain density L of the PT-RS is obtained (obtain) from the MCS (index) of the second transmission corresponding to the transport block TB of the PSSCH transmission. Wherein, optionally, the MCS (index) of the second transmission corresponding to the transport block TB of the psch transmission is less than or equal to V corresponding to the MCS table corresponding to the second transmission.

[ example two ]

Fig. 4 is a diagram showing a basic procedure of a method performed by a user equipment according to a second embodiment of the present invention.

Next, the method executed by the user equipment according to the second embodiment of the present invention is described in detail with reference to the basic process diagram shown in fig. 4.

As shown in fig. 4, in the second embodiment of the present invention, the steps performed by the user equipment include:

in step S201, the sidestream communication user equipment transmits the first PSCCH and the corresponding first PSCCH.

The first-level SCI carried by the first PSCCH comprises a first MCS table indication field.

Optionally, the transport block TB transmitted by the first psch is an initial transmission of the TB, or a certain retransmission of the TB.

In step S202, the user equipment transmits a second PSCCH and a corresponding second PSCCH.

The first-level SCI carried by the second PSCCH comprises a second MCS table indication field.

The first-level SCI carried by the second PSCCH includes an indication field of MCS (index).

Optionally, the transport block TB transmitted by the second psch and the transport block TB transmitted by the first psch are the same TB.

Optionally, the first MCS table indicated by the first MCS table indication field and the second MCS table indicated by the second MCS table indication field are the same MCS table,

alternatively, the first and second electrodes may be,

when the field of indication of the MCS (index) is greater than V (V28 for tables 1 and 3; V27 for table 2), optionally, the first MCS table indicated by the first MCS table field of indication and the second MCS table indicated by the second MCS table field of indication are the same MCS table.

Fig. 5 is a block diagram showing a user equipment UE according to the present invention. As shown in fig. 5, the user equipment UE80 includes a processor 801 and a memory 802. The processor 801 may include, for example, a microprocessor, microcontroller, embedded processor, or the like. The memory 802 may include, for example, volatile memory (e.g., random access memory RAM), a Hard Disk Drive (HDD), non-volatile memory (e.g., flash memory), or other memory, among others. The memory 802 has stored thereon program instructions. Which when executed by the processor 801 may perform the above-described method performed by the user equipment as described in detail herein.

The method of the invention and the apparatus involved have been described above in connection with preferred embodiments. It will be appreciated by those skilled in the art that the above illustrated approaches are exemplary only, and that the various embodiments described above can be combined with each other without conflict. The method of the present invention is not limited to the steps or sequence shown above. The network nodes and user equipment shown above may comprise further modules, e.g. modules that may be developed or developed in the future, which may be available to a base station, MME, or UE, etc. The various identifiers shown above are exemplary only and not limiting, and the invention is not limited to the specific information elements that are examples of these identifiers. Many variations and modifications may occur to those skilled in the art in light of the teachings of the illustrated embodiments.

It should be understood that the above-described embodiments of the present invention can be implemented by software, hardware, or a combination of both software and hardware. For example, various components within the base station and the user equipment in the above embodiments may be implemented by various means, including but not limited to: analog circuit devices, Digital Signal Processing (DSP) circuits, programmable processors, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), programmable logic devices (CPLDs), and the like.

In this application, a "base station" may refer to a mobile communication data and control switching center with a large transmission power and a wide coverage area, and includes functions of resource allocation scheduling, data receiving and transmitting, and the like. "user equipment" may refer to a user mobile terminal, including, for example, a mobile phone, a notebook, etc., which may wirelessly communicate with a base station or a micro base station.

Furthermore, embodiments of the invention disclosed herein may be implemented on a computer program product. More specifically, the computer program product is one of the following: there is a computer readable medium having computer program logic encoded thereon that, when executed on a computing device, provides related operations for implementing the above-described aspects of the present invention. When executed on at least one processor of a computing system, the computer program logic causes the processor to perform the operations (methods) described in embodiments of the present invention. Such arrangements of the invention are typically provided as downloadable software images, shared databases, etc. arranged or encoded in software, code and/or other data structures on a computer readable medium such as an optical medium (e.g., CD-ROM), floppy or hard disk or other medium such as firmware or microcode on one or more ROM or RAM or PROM chips or in one or more modules. The software or firmware or such configurations may be installed on a computing device to cause one or more processors in the computing device to perform the techniques described in embodiments of the present invention.

Further, each functional block or respective feature of the base station device and the terminal device used in each of the above embodiments may be implemented or executed by a circuit, which is typically one or more integrated circuits. Circuitry designed to perform the various functions described in this specification may include a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC) or a general purpose integrated circuit, a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, or discrete hardware components, or any combination thereof. A general-purpose processor may be a microprocessor, or the processor may be an existing processor, controller, microcontroller, or state machine. The general-purpose processor or each circuit described above may be configured by a digital circuit, or may be configured by a logic circuit. Further, when advanced technology capable of replacing the current integrated circuit is developed due to the advancement of semiconductor technology, the present invention can also use the integrated circuit obtained by the advanced technology.

Although the present invention has been described in conjunction with the preferred embodiments thereof, it will be understood by those skilled in the art that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention. Accordingly, the present invention should not be limited by the above-described embodiments, but should be defined by the appended claims and their equivalents.

Claims

1. A method performed by a user equipment, comprising:

receiving PSCCH and corresponding PSSCH transmitted by other side communication user equipment; and the number of the first and second groups,

and under the condition that the transport block TB transmitted by the PSSCH is retransmitted and the modulation and coding scheme MCS table indicated by the PSCCH is different from the modulation and coding scheme MCS table corresponding to the initial transmission of the transport block TB, determining the time domain density of the sidelink communication phase tracking reference signal PT-RS.

2. The method of claim 1,

the PSCCH carries first-level sidelink communication control information SCI.

3. The method of claim 2,

the first-level SCI comprises an indication field of a Modulation Coding Scheme (MCS) table; and the number of the first and second groups,

the first-level SCI comprises an indication field of MCS.

4. The method of claim 1,

the PSSCH carries second-level sidelink communication control information SCI.

5. The method of claim 3,

and the indication field of the MCS is larger than a retransmission threshold value, and the user equipment for the sidelink communication determines that the PSSCH transmission is retransmission.

6. The method of claim 3,

the MCS table indicated by the indication field of the MCS table and the MCS table corresponding to the initial transmission of the transport block TB transmitted by the PSSCH are different MCS tables.

7. The method of claim 6,

the MCS used for determining the time domain density L of the PT-RS is obtained by the MCS of the initial transmission of the transport block TB transmitted by the PSSCH.

8. The method of claim 7,

the initially transmitted MCS of the transport block TB transmitted by the PSSCH is less than or equal to a retransmission threshold value corresponding to the MCS table corresponding to the initial transmission.

9. A user equipment, comprising:

a processor; and

a memory storing instructions;

wherein the instructions, when executed by the processor, perform the method of any of claims 1 to 9.