System and method for coexistence of grant-free and grant-based uplink traffic

• US 10,299,283 B2
• Filed: 04/29/2016
• Issued: 05/21/2019
• Est. Priority Date: 04/29/2016
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Islam, Toufiqul, Au, Kelvin Kar Kin, Ma, Jianglei
• Primary Examiner(s): Mian, Omer S
• Application Number:
  US15/142,638
• Publication Number:
  US 20170318598A1
• Time in Patent Office: 1,117 Days
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 72/1215 for collaboration of different radio technologies
• CPC Class Codes: H04W 72/1268 of uplink data flows
• CPC Class Codes: H04W 74/04 Scheduled access hybrid access H04W74/02
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02

Abstract

Systems and methods of scheduling grant-based traffic and mapping resources for grant-free traffic are provided. Grant-based traffic is scheduled in a first frequency partition, and grant-free traffic is mapped in a second frequency partition. In a first option, grant-based traffic is also scheduled in part of the first partition, but in a limited manner that ensures a given device'"'"'s transmission and retransmissions do not all experience interference with the grant-based traffic. In another option, some grant-free traffic is mapped to part of the second partition and is spread in frequency across the second partition.

Claims

1. A method in a network element, the method comprising:

scheduling uplink grant-based traffic in a first frequency partition that is not used for uplink grant-free traffic;

mapping a plurality of UEs for uplink grant-free transmission to a corresponding plurality of time-frequency regions of a second frequency partition that does not overlap with the first frequency partition by mapping each UE to a respective plurality of time-frequency regions of the second frequency partition;

scheduling uplink grant-based traffic in at least one time-frequency region of the second frequency partition, such that;

for a UE of said plurality of UEs configured for a plurality of uplink grant-free transmissions that includes an initial grant-free transmission and at least one grant-free retransmission using time-frequency regions indicated by said mapping, the time-frequency region corresponding to each of at least one of the uplink grant-free transmissions configured for the UE overlaps with the at least one time-frequency region of the second frequency partition in which uplink grant-based traffic has been scheduled, and the time-frequency region corresponding to each of at least one of the uplink grant-free transmissions configured for the UE does not overlap with the at least one time-frequency region of the second frequency partition in which uplink grant-based traffic has been scheduled;

said scheduling comprising transmitting scheduling information to at least one UE in order to schedule the uplink grant-based traffic in the first frequency partition and in the second frequency partition;

receiving grant-based traffic from said at least one UE based on said scheduling in the first frequency partition and the second frequency partition;

receiving grant-free traffic based on said mapping from at least one UE of said plurality of UEs.

2. The method of claim 1 wherein the scheduling and mapping are subject to a constraint that for any UE of said plurality of UEs that transmits an initial transmission and a fixed number of retransmissions, at most a predetermined number of time-frequency regions used for the UE'"'"'s initial transmission and retransmissions overlap with the at least one time-frequency region of the second frequency partition.

3. The method of claim 1 wherein:

the scheduling and the mapping are subject to a first constraint that for a given UE of said plurality of UEs that transmits an initial transmission and a first fixed number of retransmissions, at most a first predetermined number of time-frequency regions used for the UE'"'"'s initial transmission and retransmissions overlap with the at least one time-frequency region of the second frequency partition; and

the scheduling and the mapping are subject to a second constraint that for a given UE of said plurality of UEs that transmits an initial transmission and a second fixed number of retransmissions, at most a second predetermined number of time-frequency regions used for the UE'"'"'s initial transmission and retransmissions overlap with the at least time-frequency region of the second frequency partition, wherein the second fixed number is different from the first fixed number.

4. The method of claim 1 further comprising:

allocating the first frequency partition and the second frequency partition to first and second numerologies having differing sub-carrier spacings.

5. The method of claim 1 further comprising assigning a first transmission time unit (TTU) duration to the first frequency partition and a second TTU duration to the second frequency partition, wherein the first TTU duration is shorter than the second TTU duration.

6. The method of claim 1 wherein:

scheduling uplink grant-based traffic comprises scheduling enhanced mobile broadband (eMBB) traffic; and

mapping the plurality of UEs for uplink grant-free transmission comprises mapping UEs for ultra-reliable low latency (URLL) traffic.

7. The method of claim 1 wherein mapping a plurality of UEs for uplink grant-free transmission to time-frequency regions of a second frequency partition that does not overlap with the first frequency partition comprises:

mapping at least one UE to different frequency resources for first transmission and retransmission.

8. The method of claim 1 wherein mapping a plurality of UEs for uplink grant-free transmission to time-frequency regions of a second frequency partition that does not overlap with the first frequency partition comprises:

mapping the UEs such that no two UEs can overlap for both an initial transmission and all retransmissions.

9. The method of claim 1 further comprising:

configuring at least one UE to perform CTU hopping as between an initial transmission and a retransmission.

10. The method of claim 1 further comprising:

configuring at least one UE to perform at least one retransmission using a different MCS than for initial transmissions.

11. The method of claim 2 wherein the fixed number of retransmissions is one or two, and wherein the predetermined number is one.

12. A method in a network element, the method comprising:

scheduling uplink grant-based traffic in a first frequency partition;

mapping a UE for an initial uplink grant-free transmission to a time-frequency region of a second frequency partition that does not overlap with the first frequency partition and that is not used for grant-based traffic;

mapping the UE for an uplink grant-free retransmission corresponding to said initial uplink grant-free transmission in at least one portion of the first frequency partition, such that;

a first TTU duration is used for grant-based traffic in the first frequency partition, and a second TTU duration is used for grant-free transmission in the second frequency partition and for grant-free transmission in the at least one portion of the first frequency partition, the second TTU duration being shorter than the first TTU duration;

the at least one portion is spread in frequency across the first frequency partition and the at least one portion is within a time period having the second TTI duration;

said scheduling comprising transmitting scheduling information to at least one UE to schedule the uplink grant-based traffic in the first frequency partition;

receiving grant-based traffic from said at least one UE based on said scheduling in the first frequency partition;

receiving grant-free traffic based on said mapping from at least one of UE of said plurality of UEs.

13. A network element comprising:

a scheduler for scheduling uplink grant-based traffic in a first frequency partition that is not used for uplink grant-free traffic;

a mapper for mapping a plurality of UEs for uplink grant-free transmission to a corresponding plurality of time-frequency regions of a second frequency partition that does not overlap with the first frequency partition by mapping each UE to a respective plurality of time-frequency regions of the second frequency partition;

wherein the scheduler is further configured to schedule uplink grant-based traffic in at least one time-frequency region of the second frequency partition, such that;

for UE of said plurality of UEs configured for a plurality of uplink grant-free transmissions that includes an initial grant-free transmission and at least one grant-free retransmission using time-frequency regions indicated by said mapping, the time-frequency region corresponding to each of at least one of the uplink grant-free transmissions configured for the UE overlaps with the at least one time-frequency region of the second frequency partition in which grant-based traffic has been scheduled, and the time-frequency region corresponding to each of at least one of the uplink grant-free transmissions configured for the UE does not overlap with the at least one time frequency region of the second frequency partition in which uplink grant-based traffic has been scheduled;

a transmitter for transmitting scheduling information to at least one UE to schedule the uplink grant-based traffic in the first frequency partition and in the second frequency partition;

a receiver for receiving grant-based traffic from said at least one UE based on said scheduling in the first frequency partition and the second frequency partition, and for receiving grant-free traffic based on said mapping from at least one UE of said plurality of UEs.

14. The network element of claim 13 wherein the scheduler and the mapper are configured to operate subject to a constraint that for any UE of said plurality of UEs that transmits an initial transmission and a fixed number of retransmissions, at most a predetermined number of time-frequency regions used for the UE'"'"'s initial transmission and retransmissions overlap with the at least one time-frequency region of the second frequency partition.

15. The network element of claim 14 wherein the fixed number of retransmissions is one or two, and wherein the predetermined number is one.

16. The network element of claim 13 wherein:

the scheduler and the mapper are configured to operate subject to a first constraint that for a given UE of said plurality of UEs that transmits an initial transmission and a first fixed number of retransmissions, at most a first predetermined number of time-frequency regions used for the UE'"'"'s initial transmission and retransmissions overlap with the at least one time-frequency region of the second frequency partition; and

the scheduler and the mapper are configured to operate subject to a second constraint that for a given UE of said plurality of UEs that transmits an initial transmission and a second fixed number of retransmissions, at most a second predetermined number of time-frequency regions used for the UE'"'"'s initial transmission and retransmissions overlap with the at least time-frequency region of the second frequency partition, wherein the second fixed number is different from the first fixed number.

17. The network element of claim 13 further configured to assign a first TTU duration to the first frequency partition and a second TTU duration to the second frequency partition, wherein the first TTU duration is shorter than the second TTU duration.

18. The network element of claim 13 wherein:

the scheduler is configured to schedule enhanced mobile broadband (eMBB) traffic; and

the mapper is configured to map UEs for ultra-reliable low latency (URLL) traffic.

19. The network element of claim 13 wherein the mapper mapping maps

the UEs such that no two UEs can overlap for both an initial transmission and all retransmissions.

20. The network element of claim 13 further configured to instruct at least one UE to perform CTU hopping as between an initial transmission and a retransmission.

21. A network element comprising:

a scheduler for scheduling uplink grant-based traffic in a first frequency partition; and

a mapper that;

maps a UE for an initial uplink grant-free transmission to a time-frequency region of a second frequency partition that does not overlap with the first frequency partition and that is not used for grant-based traffic; and

maps the UE for an uplink grant-free retransmission corresponding to said initial uplink grant-free transmission in at least one portion of the first frequency partition, such that;

a first TTU duration is used for grant-based traffic in the first frequency partition, and a second TTU duration is used for grant-free transmission in the second frequency partition, and for grant-free transmission in the at least one portion of the first frequency partition, the second TTU duration being shorter than the first TTU duration;

the at least one portion is spread in frequency across the first frequency partition, and the at least one portion is within a time period having the second TTI duration;

a transmitter for transmitting scheduling information to at least one UE to schedule the uplink grant-based traffic in the first frequency partition;

a receiver for receiving grant-based traffic from at least one UE based on said scheduling in the first frequency partition and for receiving grant-free traffic based on said mapping from said at least one UE.