Information transmission method and apparatus
An information transmission method and a communication apparatus that is applied to a communication system, for example, V2X, LTE-V, MTC, IoT, LTE-M, and M2M, to perform information transmission between terminal devices in a contention-based scheduling mode. The method includes: a first terminal device sends first sidelink control information SCI to a second terminal device, where the first SCI includes information about a first subchannel set, the first subchannel set is an available subchannel set sensed by the first terminal device on a sidelink SL, and the first SCI does not include modulation and coding scheme MCS information. The first SCI does not include the MCS information. This can both reduce signaling overheads of the first terminal device, and improve efficiency of demodulating the first SCI by the second terminal device.
1. An information transmission method comprising:
sending first sidelink control information (SCI) to a second terminal device, wherein:
the first SCI comprises information about a first subchannel set;
the first subchannel set is a first available subchannel set sensed by a first terminal device on a sidelink (SL); and
the first SCI is free from modulation and coding scheme (MCS) information; and
receiving second SCI sent by the second terminal device, wherein:
the second SCI comprises:
information about a second subchannel set; and
the second subchannel set is a second available subchannel set sensed by the second terminal device on the SL.
2. The method according to claim 1 , wherein the first SCI further comprises:
a first field; and
a second field;
wherein the first field is used to indicate transmit end information of data transmitted on the SL, or the first field is a format identifier of the first SCI; and
the second field is used to indicate priority information of the data transmitted on the SL.
3. The method according to claim 1 ,
wherein the second SCI is free from MCS information.
4. The method according to claim 1 , wherein:
the second SCI comprises:
a third field wherein:
the third field is used to indicate receive end information of the data transmitted on the SL; or
the third field is a format identifier of the second SCI; and
a fourth field is used to indicate at least one of channel state information CSI, feedback information, or a reserved bit.
5. The method according to claim 1 , further comprising:
determining a target subchannel set based on the first subchannel set and the second subchannel set; and
sending the data transmitted on the SL to the second terminal device by using the target subchannel set.
6. An information transmission method comprising:
receiving first sidelink control information (SCI) sent by a first terminal device wherein the first SCI comprises:
information about a first subchannel set;
the first subchannel set is a first available subchannel set sensed by the first terminal device on a sidelink (SL); and
the first SCI is free from modulation and coding scheme (MCS) information; and
sending second SCI to the first terminal device, wherein the second SCI comprises:
information about a second subchannel set;
the second subchannel set is a second available subchannel set sensed by the second terminal device on the SL; and
the second SCI is free from MCS information.
7. The method according to claim 6 , wherein the first SCI further comprises:
a first field; and
a second field;
wherein the first field is used to indicate transmit end information of data transmitted on the SL, or the first field is a format identifier of the first SCI; and
the second field is used to indicate priority information of the data transmitted on the SL.
8. The method according to claim 7 , wherein the second SCI further comprises:
a third field; and
a fourth field;
wherein the third field is used to indicate receive end information of the data transmitted on the SL, or the third field is a format identifier of the second SCI; and
the fourth field is used to indicate at least one of channel state information CSI, feedback information, or a reserved bit.
9. The method according to claim 7 , further comprising:
receiving the data transmitted on the SL sent by the first terminal device by using a target subchannel set, wherein the target subchannel set is an intersection between the first subchannel set and the second subchannel set.
10. The method according to claim 7 , further comprising:
receiving third SCI sent by the first terminal device, wherein the third SCI comprises scheduling information of the data transmitted on the SL.
11. A communication apparatus comprises:
a processor;
a memory, wherein the memory stores a computer program for execution by the processor to perform operations comprising:
sending first sidelink control information (SCI) to a second terminal device, wherein the first SCI comprises:
information about a first subchannel set;
the first subchannel set is a first available subchannel set sensed by the processor on a sidelink SL; and
the first SCI is free from modulation and coding scheme (MCS) information; and
receiving second SCI sent by the second terminal device, wherein the second SCI comprises:
information about a second subchannel set; and
the second subchannel set is a second available subchannel set sensed by the second terminal device on the SL.
12. The communication apparatus according to claim 11 , wherein the first SCI further comprises:
a first field; and
a second field;
wherein the first field is used to indicate transmit end information of data transmitted on the SL, or the first field is a format identifier of the first SCI; and
the second field is used to indicate priority information of the data transmitted on the SL.
13. The communication apparatus according to claim 11 , wherein
the second SCI is free from MCS information.
14. The communication apparatus according to claim 11 , wherein the second SCI comprises:
a third field; and
a fourth field;
wherein the third field is used to indicate receive end information of the data transmitted on the SL; or
the third field is a format identifier of the second SCI; and
the fourth field is used to indicate at least one of channel state information CSI, feedback information, or a reserved bit.
15. The communication apparatus according to claim 11 , wherein the processor further performs operations further comprising:
determining a target subchannel set based on the first subchannel set and the second subchannel set, and
sending the data transmitted on the SL to the second terminal device by using the target subchannel set.
16. A communication apparatus comprises:
a processor;
a memory, wherein the memory stores a computer program for execution by the processor to perform operations comprising:
receiving first SCI from a first terminal device, wherein the first SCI comprises:
information about a first subchannel set;
the first subchannel set is a first available subchannel set sensed by the first terminal device on a sidelink (SL); and
the first SCI is free from modulation and coding scheme (MCS) information; and
sending second SCI to the first terminal device, wherein the second SCI comprises:
information about a second subchannel set;
the second subchannel set is a second available subchannel set sensed by the processor on the SL; and
the second SCI is free from MCS information.
17. The communication apparatus according to claim 16 , wherein the first SCI further comprises:
a first field; and
a second field;
wherein the first field is used to indicate transmit end information of data transmitted on the SL, or the first field is a format identifier of the first SCI; and the second field is used to indicate priority information of the data transmitted on the SL.
18. The communication apparatus according to claim 17 , wherein the second SCI further comprises:
a third field; and
a fourth field;
wherein the third field is used to indicate receive end information of the data transmitted on the SL, or the third field is a format identifier of the second SCI; and the fourth field is used to indicate at least one of channel state information CSI, feedback information, or a reserved bit.
19. The communication apparatus according to claim 17 , wherein the processor further performs operations further comprising:
receiving the data transmitted on the SL from the first terminal device by using a target subchannel set, wherein the target subchannel set is an intersection between the first subchannel set and the second subchannel set.
20. The communication apparatus according to claim 17 , wherein the processor further performs operations further comprising:
receiving third SCI from the first terminal device, wherein the third SCI comprises scheduling information of the data transmitted on the SL.