TRANSMISSION AND RECEIPT PROCESSING METHOD AND DEVICE FOR TIME-FREQUENCY SYNCHRONIZATION BETWEEN V2X TERMINALS

1 . A transmission processing method for time-frequency synchronization between Vehicle to Vehicle/Pedestrian/Infrastructure/Network (V2X) terminals, characterized in that, comprising the following steps of:

when a synchronization signal to be transmitted by a V2X terminal is identical to a synchronization signal of an existing Device to Device (D2D) terminal, reusing time-frequency resources configured for transmission of the synchronization signal by the D2D terminal in a cell to transmit the synchronization signal;

when a synchronization signal to be transmitted by the V2X terminal is different from a synchronization signal of an existing D2D terminal, using reconfigured time-frequency resources to transmit the synchronization signal; and

in the synchronization signal transmitted by the V2X terminal, indicating a corresponding synchronization source type by using a Sidelink Synchronization Signal (SLSS) sequence index and/or a value of a Physical Sidelink Broadcast Channel (PSBCH) specified field.

2 . The method according to claim 1 , characterized in that the V2X terminal is a controlled V2X terminal;

in the step of, when a synchronization signal to be transmitted by a V2X terminal is identical to a synchronization signal of an existing Device to Device (D2D) terminal, reusing time-frequency resources configured for transmission of the synchronization signal by the D2D terminal in a cell to transmit the synchronization signal, the time to transmit the synchronization signal is:

when a value of a Reference Signal Received Power (RSRP) received by the V2X terminal relative to an eNB is lower than syncTxThreshIC, or when an SLSS transmission indication from an eNB is received by the V2X terminal, wherein the syncTxThreshIC is a value determined by a commSyncConfig message containing txParameters in a commSyncConfigList message sequence in a System Information Block (SIB) 18 system message from the eNB.

3 . The method according to claim 1 , characterized in that the V2X terminal is a controlled V2X terminal;

when the synchronization signal to be transmitted by the V2X terminal is identical to the synchronization signal of the existing D2D terminal:

a root sequence index of a Primary Sidelink Synchronization Signal (PSSS) in the SLSS sequence index in the synchronization signal is 26;

and, an index value of a Secondary Sidelink Synchronization Signal (SSSS) in the SLSS sequence index in the synchronization signal and a value of a reserved bit in the PSBCH are determined by the commSyncConfig message containing txParameters in the commSyncConfigList message sequence in the SIB 18 system message from the eNB.

4 . The method according to claim 1 , characterized in that the V2X terminal is an autonomous V2X terminal;

in the step of, when a synchronization signal to be transmitted by a V2X terminal is identical to a synchronization signal of an existing Device to Device (D2D) terminal, reusing time-frequency resources configured for transmission of the synchronization signal by the D2D terminal in a cell to transmit the synchronization signal, the time to transmit the synchronization signal is:

if a reference synchronization source of the V2X terminal is a User Equipment (UE) transmitting the SLSS, the time is when a value of a Reference Signal Received Power (RSRP) received from the current reference synchronization source by the V2X terminal is lower than a value corresponding to syncTxThreshOoC in pre-configuration information, wherein the RSRP is measured according to a Demodulation Reference Signal (DMRS) of a PSBCH of the reference synchronization source; and

if a reference synchronization source of the V2X terminal is a Global Navigation Satellite System (GNSS), the time is when a geographical location of the V2X terminal is within a trigger region, wherein the trigger region is determined by the V2X terminal from the pre-configuration information.

5 . The method according to claim 1 , characterized in that the V2X terminal is an autonomous V2X terminal;

when the synchronization signal to be transmitted by the V2X terminal is identical to the synchronization signal of the existing D2D terminal:

if the reference synchronization source of the V2X terminal is the GNSS, a root sequence index of a PSSS in the synchronization signal to be transmitted is 26, and an index value of an SSSS is randomly selected from 0 to 167; if the reference synchronization source of the V2X terminal is a UE transmitting the SLSS and this UE uses an eNB as a reference synchronization source, the root sequence index of the Primary Sidelink Synchronization Signal (PSSS) in the synchronization signal to be transmitted is 26, and the index value of the Secondary Sidelink Synchronization Signal (SSSS) is identical to an index value of an SSSS transmitted by the reference synchronization source; if the reference synchronization source of the V2X terminal is a UE transmitting the SLSS and this UE uses a GNSS as a reference synchronization source, a root sequence index value of the PSSS in the synchronization signal to be transmitted is 37, and the index value of the SSSS is ID_r+168, where the ID_r is the index value of the SSSS transmitted by the reference synchronization source; and, if the reference synchronization source of the V2X terminal is a synchronization source other than the above-mentioned synchronization sources, the synchronization signal is not transmitted, or the root sequence index value of the PSSS in the synchronization signal to be transmitted is 37 and the index value of the SSSS is ID_r+168, where the ID_r is the index value of the SSSS transmitted by the reference synchronization source.

6 . The method according to claim 1 , characterized in that the V2X terminal is a controlled V2X terminal;

in the step of, when a synchronization signal to be transmitted by the V2X terminal is different from a synchronization signal of an existing D2D terminal, using reconfigured time-frequency resources to transmit the synchronization signal, the time to transmit the synchronization signal is:

if the V2X terminal uses a GNSS as a reference synchronization source, the time is when a location of the V2X terminal is within a trigger region, wherein the trigger region is determined by the V2X terminal by receiving an eNB configuration signaling or by pre-configuration;

if the V2X terminal uses an eNB as a reference synchronization source, the time is when a value of an RSRP received by the V2X terminal relative to the eNB is lower than syncTxThreshIC, or when an SLSS transmission indication from the eNB is received by the V2X terminal, wherein the value of the syncTxThreshIC is determined according to a commSyncConfig message containing txParameters in a commSyncConfigList message sequence in an SIB 18 system message from the eNB, or determined according to a system message redefined by the V2X terminal;

and/or,

when the synchronization signal to be transmitted by the V2X terminal is different from the synchronization signal of the existing D2D terminal: the root sequence index of a PSSS in the synchronization signal is not equal to the root sequence index that has been used for the PSSS, and also not equal to the root sequence index that has been used for the PSSS transmitted by the D2D terminal; the index value of an SSSS in the synchronization signal is determined by the V2X terminal according to the system message of the eNB, and the index value of the SSSS is not equal to the index value that has been used for a sequence of the SSSS transmitted by the D2D terminal; and, the value of a reserved bit in a PSBCH in the synchronization signal is determined by the V2X terminal according to the received eNB signaling.

7 . The method according to claim 1 , characterized in that the V2X terminal is a controlled V2X terminal;

the step of, in the synchronization signal transmitted by the V2X terminal, indicating a corresponding synchronization source type by using an SLSS sequence index and/or a value of a PSBCH specified field specifically comprises:

if the V2X terminal uses an eNB as a reference synchronization source, an even or odd number bits among first N bits of reserved bits in the PSBCH are set as a first specified value;

if the V2X terminal uses a GNSS as a reference synchronization source, an even or odd number bits among first N bits of reserved bits in the PSBCH are set as a second specified value; and

the value of an inCoverage field in the PSBCH is set as TRUE to indicate that the V2X terminal is in coverage.

8 . The method according to claim 1 , characterized in that the V2X terminal is an autonomous V2X terminal;

in the step of, when a synchronization signal to be transmitted by the V2X terminal is different from a synchronization signal of an existing D2D terminal, using reconfigured time-frequency resources to transmit the synchronization signal, the time to transmit the synchronization signal is: when a geographical location of the V2X terminal is within a trigger region, wherein the trigger region is determined by the V2X terminal by pre-configuration information;

and/or,

when the synchronization signal to be transmitted by the V2X terminal is different from the synchronization signal of the existing D2D terminal: if the reference synchronization source of the V2X terminal is a V2X terminal transmitting an SLSS within an in-coverage range, and this V2X terminal transmitting the SLSS uses an eNB as a reference synchronization source, the index value of an SSSS in the synchronization signal to be transmitted is identical to the index value of the SSSS transmitted by the reference synchronization source; if the reference synchronization source of the V2X terminal is a V2X terminal transmitting an SLSS, and this reference synchronization source V2X terminal uses a GNSS as a reference synchronization source, the index value of the SSSS in the synchronization signal to be transmitted is a specified value, or the index value of the SSSS is identical to the index value of the SSSS transmitted by the reference synchronization source V2X terminal; if the reference synchronization source of the V2X terminal is a GNSS, the index value of the SSSS in the synchronization signal to be transmitted is a value randomly selected from a range from 336 to 503 or a subset of the range, or is a specified value; if the V2X terminal does not detect any synchronization source, the index value of the SSSS in the synchronization signal to be transmitted is a specified value; and, if the reference synchronization source of the V2X terminal is a synchronization source other than the above-mentioned synchronization sources, the synchronization signal is not transmitted.

9 . The method according to claim 1 , characterized in that the V2X terminal is an autonomous V2X terminal;

the step of, in the synchronization signal transmitted by the V2X terminal, indicating a corresponding synchronization source type by using an SLSS sequence index and/or a value of a PSBCH specified field specifically comprises:

if the V2X terminal uses a GNSS as a reference synchronization source, an even or odd number bits among first N bits of reserved bits in the PSBCH are set as a first specified value, and a specified bit other than the first N bits of the reserved bits in the PSBCH is set as TRUE;

if the V2X terminal uses a V2X terminal referring to a GNSS, as a reference synchronization source, an even or odd number bits among first N bits of reserved bits in the PSBCH are set as the first specified value, and a specified bit other than the first N bits of the reserved bits in the PSBCH is set as FALSE;

if the V2X terminal uses a UE referring to an eNB, as the reference synchronization source, an even or odd number bits among first N bits of reserved bits in the PSBCH are set as a second specified value; and

the value of an inCoverage field in the PSBCH is set as FALSE to indicate that the V2X terminal is out of coverage.

10 . The method according to claim 1 , characterized in that, when the synchronization signal to be transmitted by the V2X terminal is different from the synchronization signal of the existing D2D terminal, an SLSS sequence in the synchronization signal to be transmitted is different from that of the synchronization signal of the existing D2D terminal.

11 . A receipt processing method for time-frequency synchronization between V2X terminals, characterized in that, comprising the following steps of:

detecting a synchronization signal, and determining corresponding synchronization source types according to an SLSS sequence index and/or a value of a PSBCH specified field in the detected synchronization signal; and

selecting, from the synchronization source types determined in the above step, a synchronization source type having a highest priority as a reference synchronization source according to a specified synchronization source priority.

12 . The method according to claim 11 , characterized in that the step of determining corresponding synchronization source types according to an SLSS sequence index and/or a value of a PSBCH specified field in the detected synchronization signal specifically comprises at least one of the following steps of:

if the value of an inCoverage field in a PSBCH in the synchronization signal is TRUE, and a corresponding bit in reserved bits of the PSBCH indicates that a transmitting V2X terminal transmitting the synchronization signal uses an eNB as a reference synchronization source, deciding that a synchronization source corresponding to the synchronization signal is a UE that directly uses an eNB as a reference synchronization source and is in coverage;

if the value of the inCoverage field in the PSBCH in the synchronization signal is TRUE, and a corresponding bit in the reserved bits of the PSBCH indicates that a transmitting V2X terminal transmitting the synchronization signal uses a GNSS as a reference synchronization source, deciding that a synchronization source corresponding to the synchronization signal is a UE that directly uses a GNSS as a reference synchronization source and is in coverage;

if the value of the inCoverage field in the PSBCH in the synchronization signal is FALSE, and a corresponding bit in the reserved bits of the PSBCH indicates that a transmitting V2X terminal transmitting the synchronization signal uses a GNSS as a reference synchronization source, further deciding, according to the index value of an SSSS of the synchronization signal, that a synchronization source corresponding to the synchronization signal is a UE that directly uses a GNSS as a reference synchronization source and is out of coverage, or a UE that indirectly uses a GNSS as a reference synchronization source and is out of coverage, or an independent UE; and

if the value of the inCoverage field in the PSBCH in the synchronization signal is FALSE, and a corresponding bit in reserved bits of the PSBCH indicates that a transmitting V2X terminal transmitting the synchronization signal uses an eNB as a reference synchronization source, deciding that a synchronization source corresponding to the synchronization signal is a UE that indirectly uses an eNB as a reference synchronization source and is out of coverage.

13 . The method according to claim 11 , characterized in that, further comprising the following steps of:

if a VUE can detect an eNB on a carrier performing V2X communication, indicating, according to the eNB, that the eNB or GNSS is preferentially used as a reference synchronization source, and/or, determining, by the VUE, an eNB as a reference synchronization source according to a physical cell ID and/or an operating carrier frequency in a configuration signaling;

or, if the VUE can detect a configuration signaling of an eNB on a carrier other than a V2X communication carrier, and the configuration signaling contains synchronization source priority configuration information on the current V2X communication carrier, preferentially selecting, by the VUE, the eNB or GNSS as a reference synchronization source according to the configuration of the eNB;

or, if the VUE does not detect any eNB on all carriers but can detect a reliable GNSS synchronization signal, using a GNSS as a reference synchronization source;

or, if the VUE does not detect any eNB on all supported carriers and also does not receive any reliable GNSS synchronization signal, but detects synchronization signals transmitted by other UEs, selecting, by the VUE, a detected synchronization source having a highest priority as a reference synchronization source according to the following priorities a1 to a5 or priorities A1 to A5:

synchronization sources are successively as follows according to priorities a1 to a5 from high to low:

a1: a UE that directly uses an eNB as a reference synchronization source and is in coverage, or a UE that directly uses a GNSS as a reference synchronization source and is in coverage;

a2: a UE that directly uses a GNSS as a reference synchronization source and is out of coverage;

a3: a UE that indirectly uses a GNSS as a reference synchronization source and is out of coverage;

a4: a UE that indirectly uses an eNB as a reference synchronization source; and

a5: an independent UE;

or, synchronization sources are successively as follows according to priorities A1 to A5 from high to low:

A1: a UE that directly uses a GNSS as a reference synchronization source;

A2: a UE that indirectly uses a GNSS as a reference synchronization source and is out of coverage;

A3: a UE that directly uses an eNB as a reference synchronization source;

A4: a UE that indirectly uses an eNB as a reference synchronization source; and

A5: an independent UE;

or, if the VUE can detect an eNB on a carrier, and this eNB configures the current V2X communication carrier to preferentially use an eNB as a reference synchronization source and also configures a physical cell ID and/or an operating carrier frequency corresponding to the eNB serving as the reference synchronization source, but the VUE does not detect the configured eNB serving as the reference synchronization source, selecting, by the VUE, a detected synchronization source having a highest priority as a reference synchronization source according to the following priorities b1 to b6, or priorities c1 to c6 or priorities d1 to d6:

synchronization sources are successively as follows according to priorities b1 to b6 from high to low:

b1: a UE that directly uses an eNB as a reference synchronization source;

b2: a UE that indirectly uses an eNB as a reference synchronization source;

b3: a GNSS;

b4: a UE that directly uses a GNSS as a reference synchronization source;

b5: a UE that indirectly uses a GNSS as a reference synchronization source and is out of coverage; and

b6: an independent UE;

or, synchronization sources are successively as follows according to priorities c1 to c6 from high to low:

c1: a GNSS;

c2: a UE that directly uses an eNB as a reference synchronization source and is in coverage, or a UE that directly uses a GNSS as a reference synchronization source and is in coverage;

c3: a UE that directly uses a GNSS as a reference synchronization source and is out of coverage;

c4: a UE that indirectly uses a GNSS as a reference synchronization source and is out of coverage;

c5: a UE that indirectly uses an eNB as a reference synchronization source; and

c6: an independent UE;

or, synchronization sources are successively as follows according to priorities d1 to d6 from high to low:

d1: a GNSS;

d2: a UE that directly uses a GNSS as a reference synchronization source;

d3: a UE that indirectly uses a GNSS as a reference synchronization source and is out of coverage;

d4: a UE that directly uses an eNB as a reference synchronization source;

d5: a UE that indirectly uses an eNB as a reference synchronization source; and

d6: an independent UE;

or, if the VUE can detect an eNB on a carrier, and this eNB configures the current V2X communication carrier to preferentially use a GNSS as a reference synchronization source, but the VUE does not detect any reliable GNSS signal, selecting, by the VUE, a detected synchronization source having a highest priority as a reference synchronization source according to the following priorities e1 to e6, or priorities f1 to f6 or priorities g1 to g5:

synchronization sources are successively as follows according to priorities e1 to e6 from high to low:

e1: a UE that directly uses a GNSS as a reference synchronization source;

e2: a UE that indirectly uses a GNSS as a reference synchronization source and is out of coverage;

e3: an eNB;

e4: a UE that directly uses an eNB as a reference synchronization source;

e5: a UE that indirectly uses an eNB as a reference synchronization source; and

e6: an independent UE;

or, synchronization sources are successively as follows according to priorities f1 to f6 from high to low:

f1: an eNB;

f2: a UE that directly uses an eNB as a reference synchronization source and is in coverage, or a UE that directly uses a GNSS as a reference synchronization source and is in coverage;

f3: a UE that indirectly uses an eNB as a reference synchronization source;

f4: a UE that directly uses a GNSS as a reference synchronization source and is out of coverage;

f5: a UE that indirectly uses a GNSS as a reference synchronization source and is out of coverage; and

f6: an independent UE;

or, synchronization sources are successively as follows according to priorities g1 to g5 from high to low:

g1: a UE that directly uses an eNB as a reference synchronization source and is in coverage, or a UE that directly uses a GNSS as a reference synchronization source and is in coverage;

g2: a UE that directly uses a GNSS as a reference synchronization source and is out of coverage;

g3: a UE that indirectly uses a GNSS as a reference synchronization source and is out of coverage;

g4: a UE that indirectly uses an eNB as a reference synchronization source; and

g5: an independent UE.

14 . A transmission processing device for time-frequency synchronization between V2X terminals, characterized in that, comprising:

a reuse synchronization transmission module, configured to, when a synchronization signal to be transmitted by a V2X terminal is identical to a synchronization signal of an existing D2D terminal, reuse time-frequency resources configured for transmission of the synchronization signal by the D2D terminal in a cell to transmit the synchronization signal; and

a reconfiguration synchronization transmission module, configured to, when a synchronization signal to be transmitted by the V2X terminal is different from a synchronization signal of an existing D2D terminal, use reconfigured time-frequency resources to transmit the synchronization signal;

wherein, in the synchronization signal transmitted by the V2X terminal, a corresponding synchronization source type is indicated by using an SLSS sequence index and/or a value of a PSBCH specified field.

15 . A receipt processing device for time-frequency synchronization between V2X terminals, characterized in that, comprising:

a detection and deciding module, configured to detect a synchronization signal, and determine corresponding synchronization source types according to an SLSS sequence index and/or a value of a PSBCH specified field in the detected synchronization signal; and

a selection module, configured to select, from the synchronization source types determined by the detection and deciding module, a synchronization source type having a highest priority as a reference synchronization source according to a specified synchronization source priority.