Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is one of the standards of LTE-based vehicular communication, of which, the composition and titles are as follows:
a) YD/T 3400-2018 General technical requirements of LTE-based vehicular communication;
b) YD/T 3340-2018 Technical requirements of air interface of LTE-based vehicular communication.
Technical requirements and test methods of corresponding equipment will be formulated subsequently.
This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard was proposed by and is under the jurisdiction of China Communications Standards Association.
Introduction
The issuing authority of this document draws attention to the fact that the declaration of conformity with this document may involve the use of patents related to the technical requirements of PC5 interface in Clause 5 and Uu interface in Clause 6.
The issuing body of this document takes no position concerning the evidence, validity and scope of this patent right.
The holder of this patent right has assured the issuing body of this document that he/she is willing to negotiate licenses under reasonable and non-discriminatory terms and conditions with any applicant. The statement of the holder of this patent right is registered with the issuing body of this document. Information may be obtained according to the following contact information.
Name of patent holder: China Academy of Telecom Technology
Address: No. 40, Xueyuan Road, Haidian District, Beijing
Name of patent holder: Huawei Technologies Co., Ltd.
Address: Huawei Base B1, Bantian, Longgang District, Shenzhen, Guangdong
Name of patent holder: ZTE Corporation
Address: ZTE Plaza, No.55 Keji South Road, Nanshan District, Shenzhen, Guangdong
Name of patent holder: China Mobile Communications Corporation
Address: No.28 Financial Street, Xicheng District, Beijing
Name of patent holder: QUALCOMM INCORPORATED
Address: Qualcomm Wireless Communication Technology (China) Co., Ltd., 6F, Tower C, World Trade Center, No.36 North Third Ring East Road, Beijing
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights other than those identified above. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
Technical requirements of air interface of LTE-based vehicular communication
1 Scope
This standard specifies the technical requirements of air interface of LTE-based vehicular communication, including the technical requirements of PC5 interface of sidelink communication between terminals and Uu interface of uplink/downlink communication between terminal and base station; it also specifies the physical layer, MAC layer, RLC layer, PDCP layer and RRC layer in these two working modes and the UE procedure in idle mode.
This standard is applicable to the LTE-based vehicular communication, including V2V, V2I, V2P and V2N communication scenarios.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced documents (including any amendments) applies.
YD/T 3340-2018 General technical requirements of LTE-based vehicular communication
3GPP TS 23.285 (Release 14) Technical specification group services and system aspects; architecture enhancements for V2X services
3GPP TS 24.334 (Release 14) Proximity-services (ProSe) user equipment (UE) to ProSe function protocol aspects; Stage 3
3GPP TS 24.386 (Release 14) User equipment (UE) to V2X control function; Protocol aspects: Stage 3)
3GPP TS 36.101 (Release 14) Evolved universal terrestrial radio access (E-UTRA); User equipment (UE) radio transmission and reception
3GPP TS 36.133 (Release 14) Evolved universal terrestrial radio access (E-UTRA): Requirements for support of radio resource management
3GPP TS 36.211 (Release 14) Evolved universal terrestrial radio access (E-UTRA): Physical channels and modulation
3GPP TS 36.212 (Release 14) Evolved universal terrestrial radio access (E-UTRA); Multiplexing and channel coding
3GPP TS 36.213 (Release 14) Evolved universal terrestrial radio access (E-UTRA); Physical layer procedures
3GPP TS 36.214 (Release 14) Evolved universal terrestrial radio access (E-UTRA); Physical layer-measurements
3GPP TS 36.304 (Release 14) Evolved universal terrestrial radio access (E-UTRA); User equipment (UE) procedures in idle mode
3GPP TS 36.321 (Release 14) Evolved universal terrestrial radio access (E-UTRA): Medium access control (MAC) protocol specification
3GPP TS 36.322 (Release 14) Evolved universal terrestrial radio access (E-UTRA): Radio link control (RLC) protocol specification
3GPP TS 36.323 (Release 14) Evolved universal terrestrial radio access (E-UTRA); Packet data convergence protocol (PDCP) specification
3GPP TS 36.331 (Release 14) Evolved universal terrestrial radio access (E-UTRA): Radio resource control (RRC) protocol specification
3 Abbreviations
For the purposes of this document, the following abbreviations apply.
3GPP the 3rd Generation Partnership Project
AM Acknowledged Mode
BSR Buffer Status Report
CBR Channel Busy Ratio
CR Channel Occupancy Ratio
CRC Cyclic Redundancy Check
CSI Channel Status Indicator
DCI Downlink Control Information
DL Downlink
DFN Direct Frame Number
DMRS Demodulation Reference Signal
eNB E-UTRAN Node B
E-PDCCH Enhanced Physical Downlink Control Channel
E-UTRA Evolved Universal Terrestrial Radio Access
E-UTRAN Evolved Universal Terrestrial Radio Access Network
FDD Frequency Division Duplex
FDM Frequency Division Multiplex
GNSS Global Navigation Satellite System
IE Information Element
LCID Logical Channel ID
LTE Long Term Evolution
MAC Medium Access Control
MBMS Multimedia Broadcast Multicast Service
MCCH Multicast Control Channel
MCS Modulation and Coding Scheme
MIB Master Information Block
MIB-SL Master Information Block-Sidelink
NAS Non Access Stratum
P2X Pedestrian-to-Everything
PCell Primary Cell
PDCCH Physical Downlink Control Channel
PDCP Packet Data Convergence Protocol
PDU Protocol Data Unit
PLMN Public Land Mobile Network
PPPP ProSe Per-Packet Priority
PRACH Physical Random Access Channel
PRB Physical Resource Block
PSBCH Physical Sidelink Broadcast Channel
PSCCH Physical Sidelink Control Channel
PSSCH Physical Sidelink Shared Channel
PSSS Primary Sidelink Synchronization Signal
PUCCH Physical Uplink Control Channel
PUSCH Physical Uplink Shared Channel
QAM Quadrature Amplitude Modulation
QPSK Quadrature Phase Shift Keying
RB Resource Block
RIV Resource Indication Value
RLC Radio Link Control
RNTI Radio Network Temporary Identifier
RRC Radio Resource Control
RSRP Reference Signal Received Power
SBCCH Sidelink Broadcast Control Channel
SCell Secondary Cell
SCI Sidelink Control Information
SC-FDMA Single Carrier Frequency Division Multiplex Access
SDU Service Data Unit
SFN System Frame Number
SIB System Information Block
SL Sidelink
SL-BCH Sidelink Broadcast Channel
SL-SCH Sidelink Share Channel
SLSS Sidelink Synchronization Signal
SL-RNTI Sidelink RNTI
SL-V-RNTI V2X Sidelink V2X RNTI
SPS Semi-Persistent Scheduling
S-RSRP Sidelink Reference Signal Received Power
S-RSSI Sidelink Received Signal Strength Indicator
SSSS Secondary Sidelink Synchronization Signal
STCH Sidelink Traffic Channel
SyncRef UE the UE as synchronization reference
TDD Time Division Duplex
TDM Time Division Multiplex
TM Transparent Mode
TTI Transmission Time Interval
UE User Equipment
UL Uplink
UL-SCH Uplink Shared Channel
UM Unacknowledged Mode
V2I Vehicle to Infrastructure
V2N Vehicle to Network
V2P Vehicle to Pedestrian
V2V Vehicle to Vehicle
V-RNTIV2X V2X RNTI
4 General
LTE-based vehicular communication technology works in two working mode, one is sidelink communication mode between terminals, in which the air interface between terminals is called PC5 interface; the other is uplink/downlink communication mode between terminal and base station, in which the air interface between terminal and base station is called Uu interface.
Clause 5 specifies the technical requirements of PC5 interface of LTE-based vehicular communication. The sidelink communication mode includes two transmission modes, in which the sidelink transmission mode 3 is resource scheduling and allocation, and the sidelink transmission mode 4 is UE autonomous resources selection, as defined in 7.2.2 of YD/T 3400-2018 General technical requirements of LTE-based vehicular communication.
The correspondence between document structure and content of Clause 5 and 3GPP technical specification is as follows.
——5.1 specifies the technical requirements of physical layer.
——5.1.1 specifies the physical channel and modulation, corresponding to 3GPP TS 36.211 (Release 14).
——5.1.2 specifies the multiplexing and channel coding, corresponding to 3GPP TS 36.212 (Release 14).
——5.1.3 specifies the physical layer procedure, corresponding to 3GPP TS 36.213 (Release 14).
——5.1.4 specifies the physical layer measurement, corresponding to 3GPP TS 36.214 (Release 14).
——5.2 specifies the technical requirements of media access control (MAC) layer, corresponding to 3GPP TS 36.321 (Release 14).
——5.3 specifies the technical requirements of radio link control (RLC) layer, corresponding to 3GPP TS 36.322 (Release 14).
——5.4 specifies the technical requirements of packet data convergence protocol (PDCP) layer, corresponding to 3GPP TS 36.323 (Release 14).
——5.5 specifies the technical requirements of radio resource control (RRC) layer, corresponding to 3GPP TS 36.331 (Release 14).
——5.6 specifies the technical requirements of UE procedure in idle mode, corresponding to 3GPP TS 36.304 (Release 14).
Clause 6 specifies the technical requirements of Uu interface of LTE-based vehicular communication.
The correspondence between document structure and content of Clause 6 and 3GPP technical specification is as follows.
——6.1 specifies the technical requirements of physical layer.
——6.1.1 specifies the physical channel and modulation, corresponding to 3GPP TS 36.211 (Release 14).
——6.1.2 specifies the multiplexing and channel coding, corresponding to 3GPP TS 36.212 (Release 14).
——6.1.3 specifies the physical layer procedure, corresponding to 3GPP TS 36.213 (Release 14).
——6.1.4 specifies the physical layer measurement, corresponding to 3GPP TS 36.214 (Release 14).
——6.2 specifies the technical requirements of media access control (MAC) layer, corresponding to 3GPP TS 36.321 (Release 14).
——6.3 specifies the technical requirements of radio link control (RLC) layer, corresponding to 3GPP TS 36.322 (Release 14).
——6.4 specifies the technical requirements of packet data convergence protocol (PDCP) layer, corresponding to 3GPP TS 36.323 (Release 14).
——6.5 specifies the technical requirements of radio resource control (RRC) layer, corresponding to 3GPP TS 36.331 (Release 14).
——6.6 specifies the technical requirements of UE procedure in idle mode, corresponding to 3GPP TS 36.304 (Release 14).
5 Technical requirements of PC5 interface
5.1 Physical layer
5.1.1 Physical channel and modulation
5.1.1.1 General
5.1.1.1.1 Physical channel
The physical sidelink channel corresponds to a set of resource elements carrying information from higher layers. The sidelink contains the following physical channels.
——Physical Sidelink Shared Channel, PSSCH.
——Physical Sidelink Control Channel, PSCCH.
——Physical Sidelink Broadcast Channel, PSBCH.
Figure 1 specifies the processing procedure of baseband signal of physical sidelink channel.
Figure 1 Overview of processing procedure of baseband signal in physical sidelink channel
5.1.1.1.2 Physical signal
The physical sidelink signal is used by the physical layer but does not carry information from the higher layer. The sidelink contains the following physical signals:
——DMRS;
——Synchronization signal.
5.1.1.2 Time slot structure and physical resources
5.1.1.2.1 Radio frame structure
The transmission of sidelink is composed of radio frames with a length of Tf, and each radio frame contains 20 time slots with a length of Tslot. A sidelink subframe contains two contiguous time slots, starting from an even-numbered slot. Wherein, Tf=307200×Ts=10ms, Tslot=15360·Ts=0.5ms, Ts=1/(15000×2048). The sidelink radio frame structure is shown in Figure 2.
Figure 2 Sidelink radio frame structure
5.1.1.2.2 Resource grid
A physical sidelink channel or signal contains subcarriers and SC-FDMA symbols in a time slot. When the serving cell and the sidelink have the same uplink frequency and meet the S criterion according to 5.2.3.2 of 3GPP TS 36.304 (Release 14), the bandwidth of the sidelink is , and the bandwidth in other cases is a configurable value (defined in 5.5).
The PSSCH, PSCCH, PSBCH and synchronization signals of the sidelinks configured for transmission mode 3 and transmission mode 4 only support the normal cyclic prefix.
The resource grids are shown in Figure 3.
Figure 3 Sidelink resource grids
An antenna port is defined as the channel to which one symbol transmitted at the antenna port belongs, which may be inferred from the channel to which another symbol transmitted at the same antenna port belongs. Each antenna port corresponds to a resource grid, and the antenna ports used for physical channel or signal transmission are shown in Table 1.
Table 1 Antenna ports used for different physical channels and signals
Physical channel or signal Antenna port number
PSSCH 1000
PSCCH 1000
PSBCH 1010
Synchronization signal 1020
5.1.1.2.3 Resource elements
Every element in the resource grid is called a resource element, and (k, l) is uniquely indicated by an index in a time slot. Wherein, k=0, …, , l=0, …, represent the number in frequency domain and time domain respectively.
The resource element (k, l) on the antenna port p corresponds to a complex number , and the index pp may be omitted where no confusion will be caused or no specific antenna port is designated.
If a resource element is not used to transmit physical channel or physical signal, the value of shall be set to 0.
5.1.1.2.4 Resource block
A resource block is defined as contiguous SC-FDMA symbols and contiguous frequency-domain subcarriers in the time domain, see Table 2 for and . A physical resource block is composed of resource elements, which respectively correspond to a time slot in a time domain and 180kHz in a frequency domain.
Table 2 Physical resource block parameters
Configuration
Normal cyclic prefix 12 7
Extended cyclic prefix 12 6
The relationship between physical resource block number nPRB and the resource element (k, l) in a time slot is shown in Equation (1).
(1)
5.1.1.2.5 Resource pool
5.1.3 defines the subframe pool and resource block pool.
For PSSCH, the current time slot number in the subframe pool is , where i∈{0,1} is the number of the current time slot in the current sidelink subframe , k is equal to the footnote of , is defined by sidelink transmission mode 3 in 5.1.3.2.1.2 and by sidelink transmission mode 4 in 5.1.3.2.1.3.
5.1.1.2.6 Guard interval
The last SC-FDMA symbol of the sidelink subframe serves as a guard interval and cannot be used for the transmission of sidelink.
5.1.1.3 PSSCH
5.1.1.3.1 Scrambling
Bit blocks b(0), ..., b(Mbit-1) transmitted on PSSCH within a subframe (where Mbit is the number of transmitted bits) shall be scrambled according to 5.3.1 of 3GPP TS 36.211 (Release 14).
Scrambling sequence shall be initialized at the beginning of each PSSCH subframe according to , where, for sidelink transmission modes 3 and 4, , p and L are given in 5.1.1 of 3GPP TS 36.212 (Release 14), is equal to the decimal representation of CRC check code of PSCCH transmitted in the same subframe as PSSCH.
5.1.1.3.2 Modulation
Conduct modulation according to 5.3.2 of 3GPP TS 36.211 (Release 14). See Table 3 for the modulation mode of PSSCH.
Table 3 Modulation mode of PSSCH
Physical channel Modulation mode
PSSCH QPSK, 16QAM
5.1.1.3.3 Layer mapping
Conduct layer mapping according to 5.3.2A of 3GPP TS 36.211 (Release 14), assuming that there is only one antenna port with v=1.
5.1.1.3.4 Transform precoding
Conduct transform precoding according to 5.3.3 of 3GPP TS 36.211 (Release 14), and replace and with and respectively.
5.1.1.3.5 Pre-coding
Conduct pre-coding according to 5.3.3A of 3GPP TS 36.211 (Release 14), and it shall be assumed that there is only one antenna port with v=1.
5.1.1.3.6 Physical resource mapping
Multiply complex symbol blocks z(0), ..., z( ) by the amplitude scaling factor βPSSCH to adjust the transmission power PPSSCH (defined in 5.1.3.2.1.5), and then map to the physical resource blocks allocated to PSSCH for transmission on the antenna port p in a sequence from z(0). The mapping to the resource elements (k, l) starts from the first time slot of the subframe, and the index k is increased first, and then the index l is increased, wherein the resource elements (k, l) are those except for reference signal transmission in the above resource block for transmission. The resource elements of the last SC-FDMA symbol in a subframe need to be counted in the mapping procedure but cannot be used for transmission.
V2X communication does not support sidelink hopping, and the physical resource block for transmission is nPRB=n′VRB, where n′VRB is provided in 5.1.3.
Foreword i
Introduction ii
1 Scope
2 Normative references
3 Abbreviations
4 General
5 Technical requirements of PC5 interface
5.1 Physical layer
5.2 MAC Layer
5.3 RLC Layer
5.4 PDCP layer
5.5 RRC layer
5.6 UE procedure in idle mode
6 Technical requirements of Uu interface
6.1 Physical layer
6.2 MAC Layer
6.3 RLC layer
6.4 PDCP layer
6.5 RRC layer
6.6 UE procedure in idle mode
Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is one of the standards of LTE-based vehicular communication, of which, the composition and titles are as follows:
a) YD/T 3400-2018 General technical requirements of LTE-based vehicular communication;
b) YD/T 3340-2018 Technical requirements of air interface of LTE-based vehicular communication.
Technical requirements and test methods of corresponding equipment will be formulated subsequently.
This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard was proposed by and is under the jurisdiction of China Communications Standards Association.
Introduction
The issuing authority of this document draws attention to the fact that the declaration of conformity with this document may involve the use of patents related to the technical requirements of PC5 interface in Clause 5 and Uu interface in Clause 6.
The issuing body of this document takes no position concerning the evidence, validity and scope of this patent right.
The holder of this patent right has assured the issuing body of this document that he/she is willing to negotiate licenses under reasonable and non-discriminatory terms and conditions with any applicant. The statement of the holder of this patent right is registered with the issuing body of this document. Information may be obtained according to the following contact information.
Name of patent holder: China Academy of Telecom Technology
Address: No. 40, Xueyuan Road, Haidian District, Beijing
Name of patent holder: Huawei Technologies Co., Ltd.
Address: Huawei Base B1, Bantian, Longgang District, Shenzhen, Guangdong
Name of patent holder: ZTE Corporation
Address: ZTE Plaza, No.55 Keji South Road, Nanshan District, Shenzhen, Guangdong
Name of patent holder: China Mobile Communications Corporation
Address: No.28 Financial Street, Xicheng District, Beijing
Name of patent holder: QUALCOMM INCORPORATED
Address: Qualcomm Wireless Communication Technology (China) Co., Ltd., 6F, Tower C, World Trade Center, No.36 North Third Ring East Road, Beijing
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights other than those identified above. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
Technical requirements of air interface of LTE-based vehicular communication
1 Scope
This standard specifies the technical requirements of air interface of LTE-based vehicular communication, including the technical requirements of PC5 interface of sidelink communication between terminals and Uu interface of uplink/downlink communication between terminal and base station; it also specifies the physical layer, MAC layer, RLC layer, PDCP layer and RRC layer in these two working modes and the UE procedure in idle mode.
This standard is applicable to the LTE-based vehicular communication, including V2V, V2I, V2P and V2N communication scenarios.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced documents (including any amendments) applies.
YD/T 3340-2018 General technical requirements of LTE-based vehicular communication
3GPP TS 23.285 (Release 14) Technical specification group services and system aspects; architecture enhancements for V2X services
3GPP TS 24.334 (Release 14) Proximity-services (ProSe) user equipment (UE) to ProSe function protocol aspects; Stage 3
3GPP TS 24.386 (Release 14) User equipment (UE) to V2X control function; Protocol aspects: Stage 3)
3GPP TS 36.101 (Release 14) Evolved universal terrestrial radio access (E-UTRA); User equipment (UE) radio transmission and reception
3GPP TS 36.133 (Release 14) Evolved universal terrestrial radio access (E-UTRA): Requirements for support of radio resource management
3GPP TS 36.211 (Release 14) Evolved universal terrestrial radio access (E-UTRA): Physical channels and modulation
3GPP TS 36.212 (Release 14) Evolved universal terrestrial radio access (E-UTRA); Multiplexing and channel coding
3GPP TS 36.213 (Release 14) Evolved universal terrestrial radio access (E-UTRA); Physical layer procedures
3GPP TS 36.214 (Release 14) Evolved universal terrestrial radio access (E-UTRA); Physical layer-measurements
3GPP TS 36.304 (Release 14) Evolved universal terrestrial radio access (E-UTRA); User equipment (UE) procedures in idle mode
3GPP TS 36.321 (Release 14) Evolved universal terrestrial radio access (E-UTRA): Medium access control (MAC) protocol specification
3GPP TS 36.322 (Release 14) Evolved universal terrestrial radio access (E-UTRA): Radio link control (RLC) protocol specification
3GPP TS 36.323 (Release 14) Evolved universal terrestrial radio access (E-UTRA); Packet data convergence protocol (PDCP) specification
3GPP TS 36.331 (Release 14) Evolved universal terrestrial radio access (E-UTRA): Radio resource control (RRC) protocol specification
3 Abbreviations
For the purposes of this document, the following abbreviations apply.
3GPP the 3rd Generation Partnership Project
AM Acknowledged Mode
BSR Buffer Status Report
CBR Channel Busy Ratio
CR Channel Occupancy Ratio
CRC Cyclic Redundancy Check
CSI Channel Status Indicator
DCI Downlink Control Information
DL Downlink
DFN Direct Frame Number
DMRS Demodulation Reference Signal
eNB E-UTRAN Node B
E-PDCCH Enhanced Physical Downlink Control Channel
E-UTRA Evolved Universal Terrestrial Radio Access
E-UTRAN Evolved Universal Terrestrial Radio Access Network
FDD Frequency Division Duplex
FDM Frequency Division Multiplex
GNSS Global Navigation Satellite System
IE Information Element
LCID Logical Channel ID
LTE Long Term Evolution
MAC Medium Access Control
MBMS Multimedia Broadcast Multicast Service
MCCH Multicast Control Channel
MCS Modulation and Coding Scheme
MIB Master Information Block
MIB-SL Master Information Block-Sidelink
NAS Non Access Stratum
P2X Pedestrian-to-Everything
PCell Primary Cell
PDCCH Physical Downlink Control Channel
PDCP Packet Data Convergence Protocol
PDU Protocol Data Unit
PLMN Public Land Mobile Network
PPPP ProSe Per-Packet Priority
PRACH Physical Random Access Channel
PRB Physical Resource Block
PSBCH Physical Sidelink Broadcast Channel
PSCCH Physical Sidelink Control Channel
PSSCH Physical Sidelink Shared Channel
PSSS Primary Sidelink Synchronization Signal
PUCCH Physical Uplink Control Channel
PUSCH Physical Uplink Shared Channel
QAM Quadrature Amplitude Modulation
QPSK Quadrature Phase Shift Keying
RB Resource Block
RIV Resource Indication Value
RLC Radio Link Control
RNTI Radio Network Temporary Identifier
RRC Radio Resource Control
RSRP Reference Signal Received Power
SBCCH Sidelink Broadcast Control Channel
SCell Secondary Cell
SCI Sidelink Control Information
SC-FDMA Single Carrier Frequency Division Multiplex Access
SDU Service Data Unit
SFN System Frame Number
SIB System Information Block
SL Sidelink
SL-BCH Sidelink Broadcast Channel
SL-SCH Sidelink Share Channel
SLSS Sidelink Synchronization Signal
SL-RNTI Sidelink RNTI
SL-V-RNTI V2X Sidelink V2X RNTI
SPS Semi-Persistent Scheduling
S-RSRP Sidelink Reference Signal Received Power
S-RSSI Sidelink Received Signal Strength Indicator
SSSS Secondary Sidelink Synchronization Signal
STCH Sidelink Traffic Channel
SyncRef UE the UE as synchronization reference
TDD Time Division Duplex
TDM Time Division Multiplex
TM Transparent Mode
TTI Transmission Time Interval
UE User Equipment
UL Uplink
UL-SCH Uplink Shared Channel
UM Unacknowledged Mode
V2I Vehicle to Infrastructure
V2N Vehicle to Network
V2P Vehicle to Pedestrian
V2V Vehicle to Vehicle
V-RNTIV2X V2X RNTI
4 General
LTE-based vehicular communication technology works in two working mode, one is sidelink communication mode between terminals, in which the air interface between terminals is called PC5 interface; the other is uplink/downlink communication mode between terminal and base station, in which the air interface between terminal and base station is called Uu interface.
Clause 5 specifies the technical requirements of PC5 interface of LTE-based vehicular communication. The sidelink communication mode includes two transmission modes, in which the sidelink transmission mode 3 is resource scheduling and allocation, and the sidelink transmission mode 4 is UE autonomous resources selection, as defined in 7.2.2 of YD/T 3400-2018 General technical requirements of LTE-based vehicular communication.
The correspondence between document structure and content of Clause 5 and 3GPP technical specification is as follows.
——5.1 specifies the technical requirements of physical layer.
——5.1.1 specifies the physical channel and modulation, corresponding to 3GPP TS 36.211 (Release 14).
——5.1.2 specifies the multiplexing and channel coding, corresponding to 3GPP TS 36.212 (Release 14).
——5.1.3 specifies the physical layer procedure, corresponding to 3GPP TS 36.213 (Release 14).
——5.1.4 specifies the physical layer measurement, corresponding to 3GPP TS 36.214 (Release 14).
——5.2 specifies the technical requirements of media access control (MAC) layer, corresponding to 3GPP TS 36.321 (Release 14).
——5.3 specifies the technical requirements of radio link control (RLC) layer, corresponding to 3GPP TS 36.322 (Release 14).
——5.4 specifies the technical requirements of packet data convergence protocol (PDCP) layer, corresponding to 3GPP TS 36.323 (Release 14).
——5.5 specifies the technical requirements of radio resource control (RRC) layer, corresponding to 3GPP TS 36.331 (Release 14).
——5.6 specifies the technical requirements of UE procedure in idle mode, corresponding to 3GPP TS 36.304 (Release 14).
Clause 6 specifies the technical requirements of Uu interface of LTE-based vehicular communication.
The correspondence between document structure and content of Clause 6 and 3GPP technical specification is as follows.
——6.1 specifies the technical requirements of physical layer.
——6.1.1 specifies the physical channel and modulation, corresponding to 3GPP TS 36.211 (Release 14).
——6.1.2 specifies the multiplexing and channel coding, corresponding to 3GPP TS 36.212 (Release 14).
——6.1.3 specifies the physical layer procedure, corresponding to 3GPP TS 36.213 (Release 14).
——6.1.4 specifies the physical layer measurement, corresponding to 3GPP TS 36.214 (Release 14).
——6.2 specifies the technical requirements of media access control (MAC) layer, corresponding to 3GPP TS 36.321 (Release 14).
——6.3 specifies the technical requirements of radio link control (RLC) layer, corresponding to 3GPP TS 36.322 (Release 14).
——6.4 specifies the technical requirements of packet data convergence protocol (PDCP) layer, corresponding to 3GPP TS 36.323 (Release 14).
——6.5 specifies the technical requirements of radio resource control (RRC) layer, corresponding to 3GPP TS 36.331 (Release 14).
——6.6 specifies the technical requirements of UE procedure in idle mode, corresponding to 3GPP TS 36.304 (Release 14).
5 Technical requirements of PC5 interface
5.1 Physical layer
5.1.1 Physical channel and modulation
5.1.1.1 General
5.1.1.1.1 Physical channel
The physical sidelink channel corresponds to a set of resource elements carrying information from higher layers. The sidelink contains the following physical channels.
——Physical Sidelink Shared Channel, PSSCH.
——Physical Sidelink Control Channel, PSCCH.
——Physical Sidelink Broadcast Channel, PSBCH.
Figure 1 specifies the processing procedure of baseband signal of physical sidelink channel.
Figure 1 Overview of processing procedure of baseband signal in physical sidelink channel
5.1.1.1.2 Physical signal
The physical sidelink signal is used by the physical layer but does not carry information from the higher layer. The sidelink contains the following physical signals:
——DMRS;
——Synchronization signal.
5.1.1.2 Time slot structure and physical resources
5.1.1.2.1 Radio frame structure
The transmission of sidelink is composed of radio frames with a length of Tf, and each radio frame contains 20 time slots with a length of Tslot. A sidelink subframe contains two contiguous time slots, starting from an even-numbered slot. Wherein, Tf=307200×Ts=10ms, Tslot=15360·Ts=0.5ms, Ts=1/(15000×2048). The sidelink radio frame structure is shown in Figure 2.
Figure 2 Sidelink radio frame structure
5.1.1.2.2 Resource grid
A physical sidelink channel or signal contains subcarriers and SC-FDMA symbols in a time slot. When the serving cell and the sidelink have the same uplink frequency and meet the S criterion according to 5.2.3.2 of 3GPP TS 36.304 (Release 14), the bandwidth of the sidelink is , and the bandwidth in other cases is a configurable value (defined in 5.5).
The PSSCH, PSCCH, PSBCH and synchronization signals of the sidelinks configured for transmission mode 3 and transmission mode 4 only support the normal cyclic prefix.
The resource grids are shown in Figure 3.
Figure 3 Sidelink resource grids
An antenna port is defined as the channel to which one symbol transmitted at the antenna port belongs, which may be inferred from the channel to which another symbol transmitted at the same antenna port belongs. Each antenna port corresponds to a resource grid, and the antenna ports used for physical channel or signal transmission are shown in Table 1.
Table 1 Antenna ports used for different physical channels and signals
Physical channel or signal Antenna port number
PSSCH 1000
PSCCH 1000
PSBCH 1010
Synchronization signal 1020
5.1.1.2.3 Resource elements
Every element in the resource grid is called a resource element, and (k, l) is uniquely indicated by an index in a time slot. Wherein, k=0, …, , l=0, …, represent the number in frequency domain and time domain respectively.
The resource element (k, l) on the antenna port p corresponds to a complex number , and the index pp may be omitted where no confusion will be caused or no specific antenna port is designated.
If a resource element is not used to transmit physical channel or physical signal, the value of shall be set to 0.
5.1.1.2.4 Resource block
A resource block is defined as contiguous SC-FDMA symbols and contiguous frequency-domain subcarriers in the time domain, see Table 2 for and . A physical resource block is composed of resource elements, which respectively correspond to a time slot in a time domain and 180kHz in a frequency domain.
Table 2 Physical resource block parameters
Configuration
Normal cyclic prefix 12 7
Extended cyclic prefix 12 6
The relationship between physical resource block number nPRB and the resource element (k, l) in a time slot is shown in Equation (1).
(1)
5.1.1.2.5 Resource pool
5.1.3 defines the subframe pool and resource block pool.
For PSSCH, the current time slot number in the subframe pool is , where i∈{0,1} is the number of the current time slot in the current sidelink subframe , k is equal to the footnote of , is defined by sidelink transmission mode 3 in 5.1.3.2.1.2 and by sidelink transmission mode 4 in 5.1.3.2.1.3.
5.1.1.2.6 Guard interval
The last SC-FDMA symbol of the sidelink subframe serves as a guard interval and cannot be used for the transmission of sidelink.
5.1.1.3 PSSCH
5.1.1.3.1 Scrambling
Bit blocks b(0), ..., b(Mbit-1) transmitted on PSSCH within a subframe (where Mbit is the number of transmitted bits) shall be scrambled according to 5.3.1 of 3GPP TS 36.211 (Release 14).
Scrambling sequence shall be initialized at the beginning of each PSSCH subframe according to , where, for sidelink transmission modes 3 and 4, , p and L are given in 5.1.1 of 3GPP TS 36.212 (Release 14), is equal to the decimal representation of CRC check code of PSCCH transmitted in the same subframe as PSSCH.
5.1.1.3.2 Modulation
Conduct modulation according to 5.3.2 of 3GPP TS 36.211 (Release 14). See Table 3 for the modulation mode of PSSCH.
Table 3 Modulation mode of PSSCH
Physical channel Modulation mode
PSSCH QPSK, 16QAM
5.1.1.3.3 Layer mapping
Conduct layer mapping according to 5.3.2A of 3GPP TS 36.211 (Release 14), assuming that there is only one antenna port with v=1.
5.1.1.3.4 Transform precoding
Conduct transform precoding according to 5.3.3 of 3GPP TS 36.211 (Release 14), and replace and with and respectively.
5.1.1.3.5 Pre-coding
Conduct pre-coding according to 5.3.3A of 3GPP TS 36.211 (Release 14), and it shall be assumed that there is only one antenna port with v=1.
5.1.1.3.6 Physical resource mapping
Multiply complex symbol blocks z(0), ..., z( ) by the amplitude scaling factor βPSSCH to adjust the transmission power PPSSCH (defined in 5.1.3.2.1.5), and then map to the physical resource blocks allocated to PSSCH for transmission on the antenna port p in a sequence from z(0). The mapping to the resource elements (k, l) starts from the first time slot of the subframe, and the index k is increased first, and then the index l is increased, wherein the resource elements (k, l) are those except for reference signal transmission in the above resource block for transmission. The resource elements of the last SC-FDMA symbol in a subframe need to be counted in the mapping procedure but cannot be used for transmission.
V2X communication does not support sidelink hopping, and the physical resource block for transmission is nPRB=n′VRB, where n′VRB is provided in 5.1.3.
Contents of YD/T 3340-2018
Foreword i
Introduction ii
1 Scope
2 Normative references
3 Abbreviations
4 General
5 Technical requirements of PC5 interface
5.1 Physical layer
5.2 MAC Layer
5.3 RLC Layer
5.4 PDCP layer
5.5 RRC layer
5.6 UE procedure in idle mode
6 Technical requirements of Uu interface
6.1 Physical layer
6.2 MAC Layer
6.3 RLC layer
6.4 PDCP layer
6.5 RRC layer
6.6 UE procedure in idle mode
