HARQ systems and methods for grant-free uplink transmissions

• US 10,651,980 B2
• Filed: 10/04/2018
• Issued: 05/12/2020
• Est. Priority Date: 04/01/2016
• 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: Cao, Yu, Zhang, Liqing
• Primary Examiner(s): Vallecillo, Kyle
• Application Number:
  US16/151,920
• Publication Number:
  US 20190036655A1
• Time in Patent Office: 586 Days
• CPC Class Codes: H04L 1/0079 Formats for control data H04L1/16 takes precedence; training sequences H04L25/00 and H04L27/00
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04L 1/1819 with retransmission of additional or different redundancy
• CPC Class Codes: H04L 1/1845 Combining techniques, e.g. code combining
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements

Abstract

Systems and methods are disclosed for performing hybrid automatic repeat request (HARQ) for grant-free uplink transmissions. Some of the systems and methods disclosed herein may address problems such as how to perform acknowledgement (ACK) and/or negative acknowledgement (NACK), how to determine and signal retransmission timing, how to determine the transmission/retransmission attempt and the redundancy version (RV), and/or how to perform the HARQ combining.

Claims

1. A method for transmitting uplink data, comprising:

receiving, by a user equipment (UE), a resource configuration for K grant-free uplink transmissions of a data packet, wherein the resource configuration configures K uplink time-frequency resources for the K grant-free uplink transmissions;

performing, by the UE, an initial grant-free uplink transmission of a data packet on one of the K uplink time-frequency resources; and

performing, by the UE, a grant-free retransmission of the data packet on an uplink time-frequency resource among the K uplink time-frequency resources, until a scheduling grant for a retransmission of the data packet is received before a time domain location of a last uplink time-frequency resource of the K uplink time-frequency resources for the K grant-free uplink transmissions;

wherein the grant-free retransmission is performed without waiting for acknowledgement/negative acknowledgement (ACK/NACK) feedback for a transmission of the data packet.

2. The method of claim 1, wherein the method further comprises performing, by the UE, a retransmission of the data packet according to the scheduling grant.

3. The method of claim 2, wherein the scheduling grant indicates resources for the retransmission of the data packet.

4. The method of claim 2, wherein the scheduling grant indicates a modulation and coding scheme (MCS) for the retransmission of the data packet.

5. The method of claim 2, wherein the scheduling grant indicates a power parameter for the retransmission of the data packet.

6. A user equipment (UE) comprising:

at least one antenna; and

a grant-free transmission module configured to;

receive, via the at least one antenna, a resource configuration for K grant-free uplink transmissions of a data packet, wherein the resource configuration configures K uplink time-frequency resources for the K grant-free uplink transmissions;

perform an initial grant-free uplink transmission of a data packet on one of the K uplink time-frequency resources; and

perform a grant-free retransmission of the data packet on an uplink time-frequency resource among the K uplink time-frequency resources, until a scheduling grant for a retransmission of the data packet is received before a time domain location of a last uplink time-frequency resource of the K uplink time-frequency resources for the K grant-free uplink transmissions;

wherein the grant-free transmission module is configured to perform the grant-free retransmission without waiting for acknowledgement/negative acknowledgement (ACK/NACK) feedback for a transmission of the data packet.

7. The UE of claim 6, wherein the grant-free transmission module is configured to perform a retransmission of the data packet according to the scheduling grant.

8. The UE of claim 7, wherein the scheduling grant indicates resources for the retransmission of the data packet.

9. The UE of claim 7, wherein the scheduling grant indicates a modulation and coding scheme (MCS) for the retransmission of the data packet.

10. The UE of claim 7, wherein the scheduling grant indicates a power parameter for the retransmission of the data packet.

11. A method, comprising:

transmitting, by a base station to a user equipment (UE), a resource configuration for K grant-free uplink transmissions of a data packet, wherein the resource configuration configures K uplink time-frequency resources for the K grant-free uplink transmissions;

receiving, by the base station, an initial grant-free uplink transmission of a data packet on one of the K uplink time-frequency resources; and

receiving, by the base station, a grant-free retransmission of the data packet on uplink time-frequency resources among the K uplink time-frequency resources, until a scheduling grant for a retransmission of the data packet is sent by the base station before a time domain location of a last uplink time-frequency resource of the K uplink time-frequency resources for the K grant-free uplink transmissions;

wherein the grant-free retransmission is received without the base station transmitting acknowledgement/negative acknowledgement (ACK/NACK) feedback for the data packet.

12. The method of claim 11, wherein the method further comprises receiving, by the base station, a retransmission of the data packet according to the scheduling grant.

13. The method of claim 12, wherein the scheduling grant indicates resources for the retransmission of the data packet.

14. The method of claim 12, wherein the scheduling grant indicates a modulation and coding scheme (MCS) for the retransmission of the data packet.

15. The method of claim 12, wherein the scheduling grant indicates a power parameter for the retransmission of the data packet.

16. A base station, comprising:

at least one antenna; and

a grant-free transmission module configured to;

transmit, to a user equipment (UE) via the at least one antenna, a resource configuration for K grant-free uplink transmissions of a data packet, wherein the resource configuration configures K uplink time-frequency resources for the K grant-free uplink transmissions;

receive an initial grant-free uplink transmission of a data packet on one of the K uplink time-frequency resources; and

receive a grant-free retransmission of the data packet on uplink time-frequency resources among the K uplink time-frequency resources, until a scheduling grant for a retransmission of the data packet is sent by the base station before a time domain location of a last uplink time-frequency resource of the K uplink time-frequency resources for the K grant-free uplink transmissions;

wherein the grant-free transmission module is configured to receive the grant-free retransmission without transmitting acknowledgement/negative acknowledgement (ACK/NACK) feedback for the data packet.

17. The base station of claim 16, wherein the grant-free transmission module is configured to receive a retransmission of the data packet according to the scheduling grant.

18. The base station of claim 17, wherein the scheduling grant indicates resources for the retransmission of the data packet.

19. The base station of claim 17, wherein the scheduling grant indicates a modulation and coding scheme (MCS) for the retransmission of the data packet.

20. The base station of claim 17, wherein the scheduling grant indicates a power parameter for the retransmission of the data packet.