METHODS AND APPARATUS FOR CONTROL CHANNEL SCHEDULING IN WIRELESS COMMUNICATIONS

• US 20190053267A1
• Filed: 08/09/2018
• Published: 02/14/2019
• Est. Priority Date: 08/14/2017
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: KIM, Tae Min, LIN, Jing, SANTHANAM, Arvind, PALS, Timothy, RAO, Subramanya
• Granted Patent: US 10,904,913 B2
• Time in Patent Office: Days
• CPC Class Codes: H04L 1/1896 ARQ related signaling
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/005 of common pilots, i.e. pilots destined for multiple users or terminals
• CPC Class Codes: H04L 5/0051 of dedicated pilots, i.e. pilots destined for a single user or terminal
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861
• CPC Class Codes: H04L 5/0057 Physical resource allocation for CQI
• CPC Class Codes: H04W 4/40 for vehicles, e.g. vehicle-to-pedestrians [V2P]
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/121 for groups of terminals or users
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 72/569 of the traffic information
• CPC Class Codes: H04W 76/14 Direct-mode setup
• CPC Class Codes: H04W 92/18 between terminal devices

Abstract

Various aspects related to control channel (e.g., PSCCH) scheduling/prioritizing techniques in wireless communications are described. When a UE may not be able to decode various PSCCH transmissions detected in a subframe, a subset of the PSCCHs may be selected for decoding based on the described methods. In accordance with one aspect, a UE may determine that a total number of PSCCH transmissions in a subframe is greater than a number of PSCCH transmissions that can be decoded within the subframe. Upon such a determination, the UE may select at least one PSCCH transmission in the subframe for decoding based on at least one of: retransmission information, information regarding a transmitting UE associated with the at least one PSCCH transmission, or scheduling priority history associated with a sub-channel carrying the at least one PSCCH transmission. The UE may then decode the at least one PSCCH transmission selected for decoding.

Claims

1. A method of wireless communication of a first user equipment (UE), comprising:

determining that a total number of physical sidelink control channel (PSCCH) transmissions in a subframe is greater than a number of PSCCH transmissions that can be decoded within the subframe;

selecting at least one PSCCH transmission in the subframe for decoding based on at least one of;

retransmission information, information regarding a second UE associated with the at least one PSCCH transmission, or a scheduling priority history associated with a sub-channel carrying the at least one PSCCH transmission; and

decoding the at least one PSCCH transmission selected for decoding.

2. The method of claim 1, wherein the retransmission information is based on one or more previous PSCCH transmissions received by the first UE.

3. The method of claim 1, wherein the retransmission information indicates whether the at least one PSCCH transmission is a retransmission of a previous PSCCH transmission.

4. The method of claim 1, wherein the retransmission information indicates resources that carry the at least one PSCCH transmission and an associated physical sidelink shared channel (PSSCH) transmission.

5. The method of claim 4, wherein the first UE determines that the at least one PSCCH transmission is a retransmission of a previous PSCCH transmission based on the retransmission information.

6. The method of claim 4, wherein the retransmission information further includes information indicating decoding statistics of a previous transmission of the associated PSSCH transmission.

7. The method of claim 1, wherein the at least one PSCCH transmission is selected for decoding based on the retransmission information, the at least one PSCCH transmission being selected for decoding when the retransmission information indicates at least one of:

the at least one PSCCH transmission is a retransmission of a first PSCCH transmission, a first physical sidelink shared channel (PSSCH) transmission associated with the first PSCCH transmission failed decoding, and unsuccessfully decoded data for the first PSSCH transmission is stored at least as log-likelihood ratios (LLRs) of a payload corresponding to the first PSSCH transmission.

8. The method of claim 7, wherein the at least one PSCCH transmission is selected for decoding further based on a priority of a PSSCH transmission associated with the at least one PSCCH transmission.

9. The method of claim 8, wherein the priority of the PSSCH transmission associated with the at least one PSCCH transmission is indicated in the first PSCCH transmission.

10. The method of claim 1, wherein the at least one PSCCH transmission is selected for decoding based on the information regarding the second UE, the at least one PSCCH transmission being selected for decoding when the information regarding the second UE indicates a high threat level associated with the second UE based on at least one of:

information about a distance from the second UE, or information about a direction and speed of movement of the second UE.

11. The method of claim 1, wherein the at least one PSCCH transmission is selected for decoding based on the scheduling priority history associated with a sub-channel carrying the at least one PSCCH transmission, the at least one PSCCH transmission being selected for decoding when the scheduling priority history indicates that the sub-channel has frequently carried high priority PSCCH transmissions and has an overall high scheduling priority.

12. The method of claim 11, wherein an overall scheduling priority of the sub-channel is determined based on P_m(n)=C_m(n)/s_m(n), where P_m(n) denotes the overall scheduling priority of sub-channel m in subframe n, C_m(n) denotes a priority of sub-channel m in subframe n indicated by higher layers, and S_m(n) is a moving average of A_m(t) observed in subframe n, where A_m(t) indicates whether a new PSCCH transmission is scheduled on the sub-channel m in subframe t.

13. The method of claim 1, wherein selecting at least one PSCCH transmission in the subframe comprises refraining from selecting a PSCCH transmission in the subframe when the retransmission information indicates at least one of:

the PSCCH transmission is associated with a physical sidelink shared channel (PSSCH) retransmission whose previous transmission was successfully decoded, or a resource allocation for an associated PSSCH overlaps with a resource allocation for another PSSCH whose associated PSCCH has a higher scheduling priority than the PSCCH.

14. The method of claim 1, wherein the first UE comprises a first vehicle and the second UE comprises a second vehicle in a vehicle-to-everything (V2X) communication system.

15. A first user equipment (UE) for wireless communication, comprising:

a memory; and

at least one processor coupled to the memory and configured to;

determine that a total number of physical sidelink control channel (PSCCH) transmissions in a subframe is greater than a number of PSCCH transmissions that can be decoded within the subframe;

select at least one PSCCH transmission in the subframe for decoding based on at least one of;

retransmission information, information regarding a second UE associated with the at least one PSCCH transmission, or a scheduling priority history associated with a sub-channel carrying the at least one PSCCH transmission; and

decode the at least one PSCCH transmission selected for decoding.

16. The first UE of claim 15, wherein the retransmission information is based on one or more previous PSCCH transmissions received by the first UE.

17. The first UE of claim 15, wherein the retransmission information indicates resources that carry the at least one PSCCH transmission and an associated physical sidelink shared channel (PSSCH) transmission.

18. The first UE of claim 17, wherein the at least one processor is further configured to determine that the at least one PSCCH transmission is a retransmission of a previous PSCCH transmission based on the retransmission information.

19. The first UE of claim 15, wherein the at least one processor is configured to select the at least one PSCCH transmission for decoding based on the retransmission information, the at least one PSCCH transmission being selected for decoding when the retransmission information indicates at least one of:

the at least one PSCCH transmission is a retransmission of a first PSCCH transmission, a first physical sidelink shared channel (PSSCH) transmission associated with the first PSCCH transmission failed decoding, and unsuccessfully decoded data for the first PSSCH transmission is stored at least as log-likelihood ratios (LLRs) of a payload corresponding to the first PSSCH transmission.

20. The first UE of claim 15, wherein the at least one processor is configured to select the at least one PSCCH transmission for decoding based on the information regarding the second UE, the at least one PSCCH transmission being selected for decoding when the information regarding the second UE indicates a high threat level associated with the second UE based on at least one of:

information about a distance from the second UE, or information about a direction and speed of movement of the second UE.

21. The first UE of claim 15, wherein the at least one processor is configured to select the at least one PSCCH transmission for decoding based on the scheduling priority history associated with a sub-channel carrying the at least one PSCCH transmission, the at least one PSCCH transmission being selected for decoding when the scheduling priority history indicates that the sub-channel has frequently carried high priority PSCCH transmissions and has an overall high scheduling priority.

22. The first UE of claim 21, wherein the at least one processor is further configured to determine an overall scheduling priority of the sub-channel based on p_m(n)=C_m(n)/s_m(n), where p_m(n) denotes the overall scheduling priority of sub-channel m in subframe n, C_m(n) denotes a priority of sub-channel m in subframe n indicated by higher layers, and S_m(n) is a moving average of A_m(t) observed in subframe n, where A_m(t) indicates whether a new PSCCH transmission is scheduled on the sub-channel m in subframe t.

23. The first UE of claim 15, wherein the at least one processor is configured to refrain from selecting a PSCCH transmission in the subframe for decoding when the retransmission information indicates at least one of:

the PSCCH transmission is associated with a physical sidelink shared channel (PSSCH) retransmission whose previous transmission was successfully decoded, or a resource allocation for an associated PSSCH overlaps with a resource allocation for another PSSCH whose associated PSCCH has a higher scheduling priority than the PSCCH.

24. A first user equipment (UE) for wireless communication, comprising:

means for determining that a total number of physical sidelink control channel (PSCCH) transmissions in a subframe is greater than a number of PSCCH transmissions that can be decoded within the subframe;

means for selecting at least one PSCCH transmission in the subframe for decoding based on at least one of;

retransmission information, information regarding a second UE associated with the at least one PSCCH transmission, or a scheduling priority history associated with a sub-channel carrying the at least one PSCCH transmission; and

means for decoding the at least one PSCCH transmission selected for decoding.

25. The first UE of claim 24, wherein the retransmission information indicates resources that carry the at least one PSCCH transmission and an associated physical sidelink shared channel (PSSCH) transmission.

26. The first UE of claim 24, wherein the means for determining is further configured to determine that the at least one PSCCH transmission is a retransmission of a previous PSCCH transmission based on the retransmission information.

27. The first UE of claim 24, wherein the means for selecting is configured to select the at least one PSCCH transmission for decoding based on the retransmission information, the at least one PSCCH transmission being selected for decoding when the retransmission information indicates at least one of:

the at least one PSCCH transmission is a retransmission of a first PSCCH transmission, a first physical sidelink shared channel (PSSCH) transmission associated with the first PSCCH transmission failed decoding, and unsuccessfully decoded data for the first PSSCH transmission is stored at least as log-likelihood ratios (LLRs) of a payload corresponding to the first PSSCH transmission.

28. The first UE of claim 24, wherein the means for selecting is configured to select the at least one PSCCH transmission for decoding based on the information regarding the second UE, the at least one PSCCH transmission being selected for decoding when the information regarding the second UE indicates a high threat level associated with the second UE based on at least one of:

information about a distance from the second UE, or information about a direction and speed of movement of the second UE.

29. The first UE of claim 24, wherein the means for selecting is configured to select the at least one PSCCH transmission for decoding based on the scheduling priority history associated with a sub-channel carrying the at least one PSCCH transmission, the at least one PSCCH transmission being selected for decoding when the scheduling priority history indicates that the sub-channel has frequently carried high priority PSCCH transmissions and has an overall high scheduling priority.

30. A computer-readable medium of a first UE, the computer-readable medium storing computer executable code, comprising code to:

determine that a total number of physical sidelink control channel (PSCCH) transmissions in a subframe is greater than a number of PSCCH transmissions that can be decoded within the subframe;

select at least one PSCCH transmission in the subframe for decoding based on at least one of;

retransmission information, information regarding a second UE associated with the at least one PSCCH transmission, or a scheduling priority history associated with a sub-channel carrying the at least one PSCCH transmission; and

decode the at least one PSCCH transmission selected for decoding.