Transmission pattern indication and selection for sidelink grant free transmission

1. A method comprising:

transmitting, by a first user equipment (UE) to a second UE, a first reservation signal to indicate at least one time-frequency resource for transmitting sidelink data; and

transmitting, by the first UE to the second UE, at least one sidelink data transmission using the at least one time-frequency resource indicated by the first reservation signal,

wherein the first reservation signal is transmitted before the at least one sidelink data transmission,

wherein a third UE selects the at least one time-frequency resource for second at least one sidelink data transmission from the third UE to another UE prior to receiving the first reservation signal,

wherein the third UE determines a collision between the at least one time-frequency resource of the first reservation signal and the at least one time-frequency resource selected for the second at least one sidelink data transmission from the third UE to the another UE,

wherein the third UE re-selects another at least one time-frequency resource for the second at least one sidelink data transmission from the third UE to the another UE,

wherein the third UE transmits the second at least one sidelink data transmission using the another at least one time-frequency resource, and

wherein the third UE transmits a second reservation signal indicating the another at least one time-frequency resource for the second at least one sidelink data transmission from the third UE to the another UE.

2. The method of claim 1 , wherein the at least one time-frequency resource is at least two time-frequency resources in different time slots, and the at least one sidelink data transmission is at least two sidelink data transmissions, each of the time-frequency resources for transmitting a respective sidelink data transmission, and the at least two sidelink data transmissions for transmitting a transport block (TB) and at least one retransmission of the TB to the second UE.

3. The method of claim 1 , wherein the at least one time-frequency resource is a pattern, and the first reservation signal further indicates a periodicity of the pattern.

4. A method comprising:

receiving, by a first user equipment (UE) from a second UE, a reservation signal to indicate at least one time-frequency resource for receiving sidelink data; and

receiving, by the first UE from the second UE, at least one sidelink data transmission using the at least one time-frequency resource indicated by the reservation signal, the reservation signal having been transmitted before the at least one sidelink data transmission,

wherein a third UE selects the at least one time-frequency resource for second at least one sidelink data transmission from the third UE to another UE prior to receiving the reservation signal,

wherein the third UE determines a collision between the at least one time-frequency resource of the reservation signal and the at least one time-frequency resource selected for the second at least one sidelink data transmission from the third UE to the another UE,

wherein the third UE re-selects another at least one time-frequency resource for the second at least one sidelink data transmission from the third UE to the another UE, and

wherein the third UE transmits the second at least one sidelink data transmission using the another at least one time-frequency resource, and

wherein the third UE transmits a second reservation signal indicating the another at least one time-frequency resource for the second at least one sidelink data transmission from the third UE to the another UE.

5. The method of claim 4 , wherein the at least one time-frequency resource is at least two time-frequency resources in different time slots, and the at least one sidelink data transmission is at least two sidelink data transmissions, each of the time-frequency resources for receiving a respective sidelink data transmission, and the at least two sidelink data transmissions for receiving a transport block (TB) and at least one retransmission of the TB from the second UE.

6. The method of claim 4 , wherein the at least one time-frequency resource is a pattern, and the reservation signal further indicates a periodicity of the pattern.

7. A method comprising:

selecting, by a first user equipment (UE), at least one time-frequency resource for at least one sidelink data transmission from the first UE to another UE;

receiving, by the first UE from a second UE, a first reservation signal to indicate at least one time-frequency resource for another at least one sidelink data transmission from the second UE to a third UE, the first reservation signal for the first UE to avoid using the at least one time-frequency resource indicated by the first reservation signal;

determining, by the first UE, a collision between the at least one time-frequency resource indicated by the first reservation signal and the at least one time-frequency resource selected for the at least one sidelink data transmission from the first UE to the another UE;

re-selecting, by the first UE, another at least one time-frequency resource for the at least one sidelink data transmission from the first UE to the another UE;

transmitting, by the first UE, the at least one sidelink data transmission using the another at least one time-frequency resource; and

transmitting, by the first UE, a second reservation signal indicating the another at least one time-frequency resource for the at least one sidelink data transmission from the first UE to the another UE.

8. The method of claim 7 , further comprising:

before the selecting the at least one time-frequency resource:

receiving, by the first UE, a prior reservation signal from a fourth UE to indicate a prior at least one time-frequency resource for transmitting sidelink data,

wherein the selecting the at least one time-frequency resource includes selecting the at least one time-frequency resource for the at least one sidelink data transmission from the first UE to the another UE to avoid using the prior at least one time-frequency resource indicated by the prior reservation signal.

9. The method of claim 7 , wherein the at least one time-frequency resource is at least two time-frequency resources in different time slots, and the at least one sidelink data transmission is at least two sidelink data transmissions, each of the time-frequency resources for transmitting a respective sidelink data transmission, and the at least two sidelink data transmissions for transmitting a transport block (TB) and at least one retransmission of the TB to the second UE.

10. The method of claim 7 , wherein the first reservation signal is transmitted in a different time slot than the at least one sidelink data transmission.

11. The method of claim 7 , wherein the first reservation signal is an SCI (sidelink control information).

12. The method of claim 7 , wherein the at least one time-frequency resource is a pattern, and the first reservation signal further indicates a periodicity of the pattern.

13. A user equipment (UE) comprising:

at least one processor; and

a non-transitory memory storing programming, the programming including instructions that, when executed by the at least one processor, cause the UE to:

transmit, by the UE to a second UE, a first reservation signal to indicate at least one time-frequency resource for transmitting sidelink data; and

transmit, by the UE to the second UE, at least one sidelink data transmission using the at least one time-frequency resource indicated by the first reservation signal,

wherein the UE transmits the first reservation signal before the at least one sidelink data transmission,

wherein a third UE selects the at least one time-frequency resource for second at least one sidelink data transmission from the third UE to another UE prior to receiving the first reservation signal,

wherein the third UE determines a collision between the at least one time-frequency resource of the first reservation signal and the at least one time-frequency resource selected for the second at least one sidelink data transmission from the third UE to the another UE,

wherein the third UE re-selects another at least one time-frequency resource for the second at least one sidelink data transmission from the third UE to the another UE,

wherein the third UE transmits the second at least one sidelink data transmission using the another at least one time-frequency resource, and

wherein the third UE transmits a second reservation signal indicating the another at least one time-frequency resource for the second at least one sidelink data transmission from the third UE to the another UE.

14. The UE of claim 13 , wherein the at least one time-frequency resource is at least two time-frequency resources in different time slots, and the at least one sidelink data transmission is at least two sidelink data transmissions, each of the time-frequency resources for transmitting a respective sidelink data transmission, and the at least two sidelink data transmissions for transmitting a transport block (TB) and at least one retransmission of the TB to the second UE.

15. The UE of claim 13 , wherein the at least one time-frequency resource is a pattern, and the first reservation signal further indicates a periodicity of the pattern.

16. A user equipment (UE) comprising:

at least one processor; and

a non-transitory memory storing programming, the programming including instructions that, when executed by the at least one processor, cause the UE to:

receive, by the UE from a second UE, a reservation signal to indicate at least one time-frequency resource for receiving sidelink data; and

receive, by the UE from the second UE, at least one sidelink data transmission using the at least one time-frequency resource indicated by the reservation signal, the reservation signal having been transmitted before the at least one sidelink data transmission,

wherein a third UE selects the at least one time-frequency resource for second at least one sidelink data transmission from the third UE to another UE prior to receiving the reservation signal,

wherein the third UE determines a collision between the at least one time-frequency resource of the reservation signal and the at least one time-frequency resource selected for the second at least one sidelink data transmission from the third UE to the another UE,

wherein the third UE re-selects another at least one time-frequency resource for the second at least one sidelink data transmission from the third UE to the another UE, and

wherein the third UE transmits the second at least one sidelink data transmission using the another at least one time-frequency resource, and

wherein the third UE transmits a second reservation signal indicating the another at least one time-frequency resource for the second at least one sidelink data transmission from the third UE to the another UE.

17. The UE of claim 16 , wherein the at least one time-frequency resource is at least two time-frequency resources in different time slots, and the at least one sidelink data transmission is at least two sidelink data transmissions, each of the time-frequency resources for receiving a respective sidelink data transmission, and the at least two sidelink data transmissions for receiving a transport block (TB) and at least one retransmission of the TB from the second UE.

18. The UE of claim 16 , wherein the at least one time-frequency resource is a pattern, and the reservation signal further indicates a periodicity of the pattern.

19. A user equipment (UE) comprising:

at least one processor; and

a non-transitory memory storing programming, the programming including instructions that, when executed by the at least one processor, cause the UE to:

select at least one time-frequency resource for at least one sidelink data transmission from the UE to another UE;

receive, from a second UE, a first reservation signal to indicate the at least one time-frequency resource for the at least one sidelink data transmission from the second UE to a third UE, the first reservation signal for the UE to avoid using the at least one time-frequency resource;

determine a collision between the at least one time-frequency resource of the first reservation signal and the at least one time-frequency resource selected for the at least one sidelink data transmission from the UE to the another UE;

re-select another at least one time-frequency resource for the at least one sidelink data transmission from the UE to the another UE; and

transmit the at least one sidelink data transmission using the another at least one time-frequency resource; and

transmit a second reservation signal indicating the another at least one time-frequency resource for the at least one sidelink data transmission from the UE to the another UE.

20. The UE of claim 19 , the programming including instructions to:

before the UE selects the at least one time-frequency resource:

receive a prior reservation signal from a fourth UE to indicate a prior at least one time-frequency resource for transmitting sidelink data,

wherein selecting the at least one time-frequency resource includes selecting the at least one time-frequency resource for the at least one sidelink data transmission from the UE to the another UE to avoid using the prior at least one time-frequency resource indicated by the prior reservation signal.

21. The UE of claim 19 , wherein the at least one time-frequency resource is at least two time-frequency resources in different time slots, and the at least one sidelink data transmission is at least two sidelink data transmissions, each of the time-frequency resources for transmitting a respective sidelink data transmission, and the at least two sidelink data transmissions for transmitting a transport block (TB) and at least one retransmission of the TB to the second UE.

22. The UE of claim 19 , wherein the first reservation signal is transmitted in a different time slot than the at least one sidelink data transmission.

23. The UE of claim 19 , wherein the first reservation signal is an SCI (sidelink control information).

24. The UE of claim 19 , wherein the at least one time-frequency resource is a pattern, and the first reservation signal further indicates a periodicity of the pattern.