Sidelink communication method, terminal apparatus, and system
A communication method, a terminal apparatus, and a system. A first terminal apparatus and a second terminal apparatus determine, based on first configuration information, a plurality of candidate resources in a slot, and perform sidelink communication based on the candidate resources. A first symbol in any candidate resource in one slot is used to send first information. In response to a channel access moment of the first terminal apparatus being after a start moment of a first symbol in one candidate resource in a first slot, the first terminal apparatus further sends the first information based on the first symbol in another candidate resource after the channel access moment, without waiting for a next slot after the first slot. In this way, a sidelink communication delay is reduced.
1 . A communication method, comprising:
obtaining first configuration information; and
determining, based on the first configuration information, at least two candidate resources in a first slot, wherein each of the at least two candidate resources includes a plurality of consecutive symbols including at least one first symbol and at least one second symbol, the at least one first symbol in each of the at least two candidate resources is usable to transmit first information, the at least one second symbol in each of the at least two candidate resources is usable to transmit sidelink control information, and the first symbol precedes the second symbol.
2 . The method according to claim 1 , wherein the first configuration information includes information about a quantity of consecutive second symbols in each of the at least two candidate resources.
3 . The method according to claim 1 , applied to a first terminal apparatus and further comprising:
sending the first information on the at least one first symbol in a first candidate resource, and sending the sidelink control information on the at least one second symbol in the first candidate resource, wherein the first candidate resource is a 1 st candidate resource among the at least two candidate resources after a first moment, the first moment is a channel access moment of the first terminal apparatus.
4 . The method according to claim 3 , wherein the first moment is before a start moment of the first candidate resource, the method further comprises:
sending second information between the first moment and the start moment of the first candidate resource.
5 . The method according to claim 4 , wherein the sending the second information includes sending second information that includes replication information of the first information, replication information of the sidelink control information, an extended cyclic prefix of the first information, or an extended cyclic prefix of the sidelink control information.
6 . The method according to claim 3 , further comprising:
sending third information on a first resource, wherein the first resource includes the first symbol or the second symbol after the first candidate resource, and the third information is carried on a sidelink data channel.
7 . The method according to claim 1 , applied to a second terminal apparatus and further comprising:
blindly decoding the sidelink control information on the second symbol.
8 . The method according to claim 7 , further comprising:
after a second moment, stopping blindly decoding the sidelink control information, wherein the second moment is a moment at which the second terminal apparatus obtains the sidelink control information carried on the second symbol in the first candidate resource, and the first candidate resource is one of the at least two candidate resources.
9 . The method according to claim 7 , wherein the blindly decoding the sidelink control information on the second symbol includes:
performing automatic gain control adjustment based on information carried on the first symbol in an ith candidate resource before a second moment, wherein i=1, 2, . . . , n n is a quantity of candidate resources that are in the first slot and that are before the second moment, the second moment is a moment at which the second terminal apparatus obtains the sidelink control information carried on the second symbol in the first candidate resource, and the first candidate resource is one of the at least two candidate resources; and
decoding, based on a result of the automatic gain control adjustment, information carried on the second symbol in the ith candidate resource.
10 . The method according to claim 7 , further comprising:
storing at least one piece of fourth information, wherein the fourth information is information carried on the first symbol and the second symbol in a jth candidate resource before a second moment, wherein j=2, 3, . . . , n, n is a quantity of candidate resources that are in the first slot and that are before the second moment, the second moment is a moment at which the second terminal apparatus obtains the sidelink control information carried on the second symbol in the first candidate resource, and the first candidate resource is one of the at least two candidate resources.
11 . The method according to claim 10 , further comprising:
decoding, based on the sidelink control information, the fourth information after the first candidate resource and information after a last piece of the fourth information.
12 . The method according to claim 1 , wherein the first information is replication information of the sidelink control information, replication information of a subset of the sidelink control information, replication information of information on any symbol in the first slot, or a sequence used for AGC adjustment.
13 . A communication method, comprising:
determining first configuration information, wherein the first configuration information indicates at least two candidate resources in a first slot, each of the at least two candidate resources includes a plurality of consecutive symbols including at least one first symbol and at least one second symbol, the at least one first symbol in each of the at least two candidate resources is usable to transmit first information, the at least one second symbol in each of the at least two candidate resources is usable to transmit sidelink control information, and the first symbol precedes the second symbol; and
sending the first configuration information.
14 . The method according to claim 13 , wherein the first configuration information includes information about a quantity of consecutive second symbols in each of the at least two candidate resources.
15 . A communication apparatus, comprising:
at least one processor configured to:
determine a first moment;
obtain first configuration information; and
determine, based on the first configuration information, at least two candidate resources in a first slot, wherein each of the at least two candidate resources includes a plurality of consecutive symbols including at least one first symbol and at least one second symbol, the at least one first symbol in each of the at least two candidate resources is usable to transmit first information, the at least one second symbol in each of the at least two candidate resources is usable to transmit sidelink control information, and the first symbol precedes the second symbol.
16 . The communication apparatus according to claim 15 , wherein the first configuration information includes information about a quantity of consecutive second symbols in each of the at least two candidate resources.
17 . The communication apparatus according to claim 15 , wherein the at least one processor is further configured to:
send the first information on the at least one first symbol in a first candidate resource, and send the sidelink control information on the at least one second symbol in the first candidate resource, wherein the first candidate resource is a 1st candidate resource among the at least two candidate resources after a first moment, the first moment is a channel access moment of a first terminal apparatus.
18 . The communication apparatus according to claim 17 , wherein the first moment is before a start moment of the first candidate resource, and the at least one processor is further configured to:
send second information between the first moment and the start moment of the first candidate resource.
19 . The communication apparatus according to claim 18 , wherein the second information includes replication information of the first information, replication information of the sidelink control information, an extended cyclic prefix of the first information, or an extended cyclic prefix of the sidelink control information.
20 . The communication apparatus according to claim 17 , wherein the at least one processor is further configured to:
send third information on a first resource, wherein the first resource includes the first symbol or the second symbol after the first candidate resource, and the third information is carried on a sidelink data channel.
21 . The communication apparatus according to claim 15 , wherein the at least one processor is further configured to:
blindly decode the sidelink control information on the second symbol.
22 . The communication apparatus according to claim 15 , wherein the first information is replication information of the sidelink control information, replication information of a subset of the sidelink control information, replication information of information on any symbol in the first slot, or a sequence used for AGC adjustment.
23 . A communication apparatus, comprising:
at least one processor configured to:
determine first configuration information, wherein the first configuration information indicates at least two candidate resources in a first slot, each of the at least two candidate resources includes a plurality of consecutive symbols including at least one first symbol and at least one second symbol, the at least one first symbol in each of the at least two candidate resources is usable to transmit first information, the at least one second symbol in each of the at least two candidate resources is usable to transmit sidelink control information, and the first symbol precedes the second symbol; and
send the first configuration information.
24 . The communication apparatus according to claim 23 , wherein the first configuration information includes information about a quantity of consecutive second symbols in each of the at least two candidate resources.