SYSTEM AND METHOD FOR TRANSMISSION IN A GRANT-FREE UPLINK TRANSMISSION SCHEME

• US 20160219627A1
• Filed: 01/27/2015
• Published: 07/28/2016
• Est. Priority Date: 01/27/2015
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Jianglei Ma, Kelvin Kar Kin Au, Liqing Zhang
• Inventors: AU, Kelvin Kar Kin, ZHANG, Liqing, MA, Jianglei
• Granted Patent: US 9,750,056 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 1/1861 Physical mapping arrangements for ACK signaling see also H04L5/0053
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 74/0841 with collision treatment

Abstract

A system and method includes implementing, by a base station (BS), a reliable ultra-low latency transmission mechanism in a grant-free uplink transmission scheme having defined therein contention transmission unit (CTU) access regions and a plurality of CTUs. Implementing the reliable ultra-low latency transmission mechanism includes defining a reliable ultra-low latency CTU (RULL-CTU) access region from a portion of the CTU access regions of the grant-free transmission scheme, defining an RULL-CTU mapping scheme by mapping at least a portion of plurality of CTUs to the RULL-CTU access region to define a plurality of RULL-CTUs, defining a reliable ultra-low latency user equipment (RULL-UE) mapping scheme by defining rules for mapping a plurality of RULL-UEs to the plurality of RULL-CTUs in an initial pattern for initial transmissions in a first transmission time interval (TTI), and a regrouped pattern for redundant transmissions in a second TTI subsequent to the first TTI.

Claims

1. A method comprising:

implementing, by a base station (BS), a reliable ultra-low latency (RULL) transmission mechanism in a grant-free uplink transmission scheme, the grant-free uplink transmission scheme having defined therein contention transmission unit (CTU) access regions and a plurality of CTUs;

wherein implementing the reliable ultra-low latency transmission mechanism comprises;

defining a reliable ultra-low latency user equipment (RULL-UE) mapping scheme by mapping a plurality of RULL-UEs to the plurality of CTUs in an initial pattern for initial transmissions in a first transmission time interval (TTI), and mapping the plurality of RULL-UEs to the plurality of CTUs in a regrouped pattern for redundant transmissions in a second TTI subsequent to the first TTI, wherein the initial pattern is different from the regrouped pattern.

2. The method according to claim 1, wherein implementing the RULL transmission mechanism comprises:

defining a reliable ultra-low latency CTU (RULL-CTU) access region from a portion of the CTU access regions of the grant-free transmission scheme; and

defining an RULL-CTU mapping scheme by mapping at least a portion of the plurality of CTUs to the RULL-CTU access region to define a plurality of RULL-CTUs.

3. The method according to claim 2, wherein defining the RULL-UE mapping scheme includes mapping the plurality of the RULL-UEs to the plurality of RULL-CTUs in the initial pattern and the regrouped pattern.

4. The method according to claim 2, wherein defining the RULL-UE mapping scheme includes mapping the plurality of the RULL-UEs to the plurality of RULL-CTUs in the initial pattern and mapping the plurality of RULL-UEs to the plurality of CTUs in the regrouped pattern.

5. The method according to claim 1, wherein implementing the RULL transmission mechanism further comprises:

receiving, by the BS, the initial transmissions in the first TTI and the redundant transmissions in the second TTI, wherein the BS does not transmit acknowledge or negative acknowledgement (ACK/NACK) feedback between receiving the initial and redundant transmissions;

resolving collisions utilizing the initial transmissions, the redundant transmissions, and the mapping scheme.

6. The method according to claim 5, wherein implementing the RULL transmission mechanism further comprises:

defining a remapping scheme by mapping a plurality of RULL-UEs to the plurality of CTUs in a second initial pattern for initial transmissions in the first TTI, and a second regrouped pattern for redundant transmissions in the second TTI subsequent to the first TTI when the BS determines the number of collisions in at least one of the initial transmissions and redundant transmissions meets a threshold, wherein the second initial pattern is different than the first initial pattern, and the second regrouped pattern is different than the first regrouped pattern and the second initial pattern; and

sending information related to the remapping scheme to the RULL-UEs using high-level signaling.

7. The method according to claim 5, wherein the initial transmissions and the redundant transmissions are based on a sparse code multiple access (SCMA) scheme.

8. The method according to claim 7, further comprising joint detecting and decoding of the initial transmission and the redundant transmission utilizing a message parsing algorithm (MPA).

9. The method according to claim 1, wherein implementing the RULL transmission mechanism further comprises defining a first portion of the plurality of RULL-UEs that transmit redundant transmissions in the second TTI, and a remaining portion of the plurality of RULL-UEs do not transmit redundant transmissions in the second TTI.

10. The method according to claim 9, wherein the first portion of the plurality of RULL-UEs is defined based on RULL-UE identifications of the plurality of RULL-UEs.

11. The method according to claim 9, wherein the first portion of the plurality of RULL-UEs is defined based on the CTUs that the first portion is mapped to in the regrouped pattern.

12. The method according to claim 9, wherein the first portion of the plurality of RULL-UEs is defined based on the TTI that the redundant transmission is transmitted in.

13. The method according to claim 1, wherein defining the RULL-UE mapping scheme includes mapping the plurality of RULL-UEs to the CTUs in a plurality of unique regrouped patterns, each unique regrouped pattern for a respective one of a plurality of redundant transmissions, each redundant transmission in a respective one of a plurality of TTIs subsequent to the first TTI.

14. The method according to claim 13, wherein the number of the plurality of redundant transmissions is determined based on one or both of a latency requirement and a reliability requirement of the plurality of RULL-UEs.

15. The method according to claim 1, wherein the plurality of CTUs are frequency resources.

16. The method according to claim 1, wherein the plurality of CTUs are time resources.

17. The method according to claim 1, wherein defining a RULL-UE mapping scheme comprises mapping a second plurality of RULL-UEs to the plurality of CTUs in a second initial pattern for initial transmissions in second TTI, and mapping the second plurality of RULL-UEs to the plurality of CTUs a second regrouped pattern for redundant transmissions in a third TTI subsequent to the second TTI, the CTUs mapped to the second plurality of RULL-UEs in the second initial pattern at least partially overlaps the CTUs mapped to the first plurality of RULL-UEs in the regrouped pattern.

18. A base station (BS) comprising:

a hardware processor; and

a computer readable storage medium having stored thereon computer readable code for execution by the processor to;

implement a reliable ultra-low latency (RULL) transmission mechanism in a grant-free uplink transmission scheme, the grant-free uplink transmission scheme having defined therein contention transmission unit (CTU) access regions and a plurality of CTUs, wherein implementing the RULL transmission mechanism comprises;

defining a reliable ultra-low latency user equipment (RULL-UE) mapping scheme by mapping a plurality of RULL-UEs to the plurality of CTUs in an initial pattern for initial transmissions in a first transmission time interval (TTI), and mapping the plurality of RULL-UEs to the plurality of CTUs in a regrouped pattern for redundant transmissions in a second TTI subsequent to the first TTI, wherein the initial pattern is different from the regrouped pattern.

19. The BS according to claim 18, wherein implementing the RULL transmission mechanism further comprises:

defining a reliable ultra-low latency CTU (RULL-CTU) access region from a portion of the CTU access regions of the grant-free transmission scheme; and

defining an RULL-CTU mapping scheme by mapping at least a portion of the plurality of CTUs to the RULL-CTU access region to define a plurality of RULL-CTUs.

20. The BS according to claim 19, wherein defining the RULL-UE mapping scheme includes mapping the plurality of the RULL-UEs to the plurality of RULL-CTUs in the initial pattern and the regrouped pattern.

21. The BS according to claim 19, wherein defining the RULL-UE mapping scheme includes mapping the plurality of the RULL-UEs to the plurality of RULL-CTUS in the initial pattern and mapping the plurality of RULL-UEs to the plurality of CTUs in the regrouped pattern.

22. The BS according to claim 18, wherein implementing the RULL transmission mechanism further comprises:

receiving, by the BS, the initial transmissions in the first TTI and the redundant transmissions in the second TTI;

resolving collisions utilizing the initial transmissions, the redundant transmissions, and the mapping scheme.

23. The BS according to claim 18, wherein implementing the RULL transmission mechanism further comprises defining a first portion of the plurality of RULL-UEs that transmit redundant transmissions in the second TTI, and a remaining portion of the plurality of RULL-UEs do not transmit redundant transmissions in the second TTI.

24. The BS according to claim 18, wherein defining the RULL-UE mapping scheme includes mapping the plurality of RULL-UEs to the CTUs in a plurality of unique regrouped patterns, each unique regrouped pattern for a respective one of a plurality of redundant transmissions, each redundant transmission in a respective one of a plurality of TTIs subsequent to the first TTI.

25. A method comprising:

implementing, by a reliable ultra-low latency user equipment (RULL-UE), a reliable ultra-low latency (RULL) mechanism in a default reliable ultra-low latency contention transmission unit (RULL-CTU) mapping scheme by;

determining a first contention transmission unit (CTU) for an initial transmission in a first transmission time interval (TTI) in accordance with an initial RULL-UE mapping rule and the default RULL-CTU mapping scheme;

transmitting, to a base station (BS), the initial transmission on the first CTU during the first TTI;

determining a second CTU for a redundant transmission in a second TTI subsequent to the first TTI in accordance with a redundant RULL-UE mapping rule and the default RULL-CTU mapping scheme;

transmitting, to the BS, the redundant transmission on the second CTU during the second TTI without receiving, at the RULL-UE, acknowledgement/negative acknowledgement (ACK/NACK) feedback from the BS.

26. The method according to claim 25, wherein determining a second CTU includes determining a plurality of redundant CTUs, each of the redundant CTUs for one of a plurality of redundant transmissions, each redundant transmission in one of a plurality of TTIs subsequent to the first TTI;

and

wherein transmitting the redundant transmission on the second CTU includes transmitting each of the redundant transmissions on a respective one of the plurality of CTUs during a respective one of the plurality of TTIs.

27. The method according to claim 26, wherein transmitting the redundant transmission on the second CTU comprises automatically transmitting a first portion of the plurality of redundant transmissions, and not transmitting a remaining portion of the redundant transmissions.

28. The method according to claim 27, wherein the first portion is determined based on the respective CTU that each of the plurality of redundant transmissions transmits on.

29. The method according to claim 27, wherein the first portion is determined based on the respective TTI that each of the plurality of redundant transmissions transmit during.

30. The method according to claim 25, wherein:

the first CTU determined by the RULL-UE for the initial transmission in the first TTI is mapped to a first CTU access region; and

the second CTU determined by the RULL-UE for the redundant transmission in the second TTI is mapped to a second CTU access region different from the first CTU access region.

31. A reliable ultra-low latency user equipment (RULL-UE) comprising:

a hardware processor; and

a computer readable storage medium having stored thereon computer readable code for execution by the processor to;

implement a reliable ultra-low latency (RULL) transmission mechanism in a default reliable ultra-low latency contention transmission unit (RULL-CTU) mapping scheme, wherein implementing the RULL transmission mechanism comprises;

determining a first contention transmission unit (CTU) for an initial transmission in a first transmission time interval (TTI) in accordance with an initial RULL-UE mapping rule and the default RULL-CTU mapping scheme;

transmitting, to a base station (BS), the initial transmission on the first CTU during the first TTI;

determining a second CTU for a redundant transmission in a second TTI subsequent to the first TTI in accordance with a redundant RULL-UE mapping rule and the default RULL-CTU mapping scheme;

transmitting, to the BS, the redundant transmission on the second CTU during the second TTI without receiving, at the RULL-UE, acknowledgement/negative acknowledgement (ACK/NACK) feedback from the BS.

32. The RULL-UE according to claim 31, wherein determining a second CTU includes determining a plurality of redundant CTUs, each of the redundant CTUs for one of a plurality of redundant transmissions, each redundant transmission in one of a plurality of TTIs subsequent to the first TTI;

and

wherein transmitting the redundant transmission on the second CTU includes automatically transmitting each of the redundant transmissions on a respective one of the plurality of CTUs during a respective one of the plurality of TTIs.

33. The RULL-UE according to claim 32, wherein transmitting the redundant transmission on the second CTU comprises automatically transmitting a first portion of the plurality of redundant transmissions, and not transmitting a remaining portion of the redundant transmissions.

34. The RULL-UE according to claim 33, wherein the first portion is determined based on the respective CTU that each of the plurality of redundant transmissions transmits on.

35. The RULL-UE according to claim 33, wherein the first portion is determined based on the respective TTI that each of the plurality of redundant transmissions transmit during.

36. The RULL-UE according to claim 31, wherein:

the first CTU determined by the RULL-UE for the initial transmission in the first TTI is mapped to a first CTU access region; and

the second CTU determined by the RULL-UE for the redundant transmission in the second TTI is mapped to a second CTU access region different from the first CTU access region.