METHOD AND SYSTEM FOR IMPLEMENTING HYBRID AUTOMATIC REPEAT REQUEST

• US 20070245201A1
• Filed: 03/20/2007
• Published: 10/18/2007
• Est. Priority Date: 03/21/2006
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Sammour, Mohammed, Chandra, Arty, Chen, John, Zhang, Guodong, Terry, Stephen
• Granted Patent: US 7,979,768 B2
• Time in Patent Office: Days
• US Class Current: 714/748
• CPC Class Codes: H04L 1/1628 List acknowledgements, i.e. the acknowledgement message consisting of a list of identifiers, e.g. of sequence numbers H04L1/1614 takes precedence
• CPC Class Codes: H04L 1/1671 the supervisory signal being transmitted together with control information
• CPC Class Codes: H04L 1/1816 with retransmission of the same, encoded, message
• CPC Class Codes: H04L 1/1845 Combining techniques, e.g. code combining
• CPC Class Codes: H04L 1/1848 Time-out mechanisms
• CPC Class Codes: H04L 1/1854 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 1/1867 Arrangements specially adapted for the transmitter end
• CPC Class Codes: H04L 2001/0092 Error control systems characterised by the topology of the transmission link
• CPC Class Codes: H04L 2001/125 Arrangements for preventing errors in the return channel

Abstract

A receiver sends hybrid automatic repeat request (H-ARQ) feedback for a current packet and at least one previous packet, whereby an error is detected based on the H-ARQ feedback. The receiver sends H-ARQ feedback with an identification of the packet or a sequence number of a packet that the receiver expects to receive next. The receiver stores a packet in a memory before combining the packet with a previously received packet, and decodes the stored packet after failing to decode a combined packet to avoid a corruption error. The receiver may set a timer when sending a NACK. If the receiver fails to receive a packet until expiration of the timer, the receiver initiates a process for recovering the packet. Each H-ARQ feedback may be associated with other attributes. Some H-ARQ processes may operate in an asynchronous mode while others in a synchronous mode in the same direction.

Claims

1. A method for implementing hybrid automatic repeat request (H-ARQ) in a wireless communication system including a transmitter and a receiver, the transmitter including an H-ARQ transmitter and the receiver including an H-ARQ receiver, the method comprising:

the H-ARQ receiver receiving a packet from the H-ARQ transmitter; and

the H-ARQ receiver sending an H-ARQ feedback message to the H-ARQ transmitter, the H-ARQ feedback message including an H-ARQ feedback for a current packet and an H-ARQ feedback for at least one previous packet.

2. The method of claim 1 wherein retransmission of the current packet is not considered as the previous packet.

3. The method of claim 1 wherein the previous packet is a packet transmitted earlier than the current packet in time regardless of transmission sequence number assigned to the packets.

4. The method of claim 1 wherein the previous packet and the current packet are ordered in terms of transmission sequence numbers.

5. The method of claim 1 wherein the current packet and the previous packet are packets within the same traffic flow.

6. The method of claim 5 wherein the traffic flow is one of an H-ARQ flow, a medium access control (MAC) flow, an ARQ level flow, a flow to and from a particular receiver and a transmitter, a flow on a particular quality of service (QoS) class.

7. The method of claim 1 further comprising:

the H-ARQ transmitter detecting a failed packet due to an H-ARQ error based on the H-ARQ feedback message; and

the H-ARQ transmitter initiating a process for recovering the failed packet.

8. The method of claim 7 wherein the H-ARQ error is a negative acknowledgement (NACK)-to-positive acknowledgement (ACK) error.

9. The method of claim 7 further comprising:

the H-ARQ transmitter sending a local negative acknowledgement (NACK) to an ARQ transmitter to recover the failed packet at an ARQ level.

10. The method of claim 7 further comprising:

the H-ARQ transmitter sending a local positive acknowledgement (ACK) to an ARQ transmitter when the H-ARQ transmitter receives multiple ACKs for the same packet.

11. The method of claim 1 wherein the H-ARQ feedback of the current packet is repeated for a predetermined number of times and the H-ARQ feedback of the previous packet is repeated for a predetermined number of times.

12. The method of claim 1 wherein a Reed-Solomon (R-S) coding is used to code multiple H-ARQ feedback bits.

13. A method for implementing hybrid automatic repeat request (H-ARQ) in a wireless communication system including a transmitter and a receiver, the transmitter including an H-ARQ transmitter and the receiver including an H-ARQ receiver, the method comprising:

the H-ARQ transmitter sending a packet to the H-ARQ receiver; and

the H-ARQ receiver sending an H-ARQ feedback message to the H-ARQ transmitter, the H-ARQ feedback message including an identification of the packet.

14. The method of claim 13 wherein the identification is one of a transmission sequence number (TSN), a part of the TSN, a new data indicator (NDI) and a sequence number that is defined on an H-ARQ process level.

15. The method of claim 13 further comprising:

the H-ARQ transmitter receiving the H-ARQ feedback message and recognizing an error based on the identification.

16. The method of claim 13 wherein the H-ARQ feedback message includes an H-ARQ feedback for a current packet and an H-ARQ feedback for at least one previous packet.

17. The method of claim 13 wherein the H-ARQ feedback message includes an indication whether the H-ARQ receiver has flushed its memory.

18. The method of claim 17 wherein the H-ARQ receiver includes the indication when the H-ARQ receiver sends a negative acknowledgement (NACK).

19. A method for implementing hybrid automatic repeat request (H-ARQ) in a wireless communication system including a transmitter and a receiver, the transmitter including an H-ARQ transmitter and the receiver including an H-ARQ receiver, the method comprising:

the H-ARQ transmitter sending a packet to the H-ARQ receiver; and

the H-ARQ receiver sending an H-ARQ feedback message to the H-ARQ transmitter including a sequence number of a packet that the H-ARQ receiver expects to receive next.

20. The method of claim 19 further comprising:

the H-ARQ transmitter determining a transmission status of the packet based on the sequence number received from the H-ARQ receiver.

21. The method of claim 19 further comprising:

the H-ARQ transmitter sending a signal to the H-ARQ receiver to synchronize the sequence number.

22. The method of claim 21 wherein the signal is sent via in-band signaling.

23. The method of claim 19 further comprising:

the H-ARQ receiver incrementing the sequence number on its own based on implicit information without receiving an explicit signal from the H-ARQ transmitter.

24. The method of claim 19 wherein the H-ARQ feedback message includes an H-ARQ feedback for a current packet and an H-ARQ feedback for at least one previous packet.

25. The method of claim 19 wherein the H-ARQ feedback message includes an indication whether the H-ARQ receiver has flushed its memory.

26. The method of claim 25 wherein the H-ARQ receiver includes the indication when the H-ARQ receiver sends a negative acknowledgement (NACK).

27. A method for implementing hybrid automatic repeat request (H-ARQ) in a wireless communication system including a transmitter and a receiver, the transmitter including an H-ARQ transmitter and the receiver including an H-ARQ receiver, the method comprising:

the H-ARQ receiver receiving a packet from the H-ARQ transmitter;

the H-ARQ receiver storing the packet in a memory before combining the packet with a previous received packet;

the H-ARQ receiver decoding a combined packet; and

if decoding fails, the H-ARQ receiver decoding the packet stored in the memory.

28. The method of claim 27 wherein available resources are pooled and dynamically allocated for multiple H-ARQ processes and a certain H-ARQ process is given a higher priority for the resources.

29. A method for implementing hybrid automatic repeat request (H-ARQ) in a wireless communication system including a transmitter and a receiver, the transmitter including an H-ARQ transmitter and the receiver including an H-ARQ receiver, the method comprising:

the H-ARQ receiver setting a timer when the H-ARQ receiver sends a NACK to the H-ARQ transmitter;

if the H-ARQ receiver receives a packet corresponding to the NACK, the H-ARQ receiver clearing the timer;

if the H-ARQ receiver does not receive a packet corresponding to the NACK until expiration of the timer, the H-ARQ receiver initiating a process for recovering the packet.

30. The method of claim 29 wherein the H-ARQ receiver sends a report to the H-ARQ transmitter indicating an H-ARQ error to recover a failed packet at an H-ARQ level.

31. The method of claim 29 further comprising:

the H-ARQ receiver sending a local negative acknowledgement (NACK) to an ARQ receiver indicating an H-ARQ error; and

the ARQ receiver sending a report to an ARQ transmitter, whereby the packet is recovered at an ARQ level.

32. A method for implementing hybrid automatic repeat request (H-ARQ) in a wireless communication system including a transmitter and a receiver, the transmitter including an H-ARQ transmitter and the receiver including an H-ARQ receiver, the method comprising:

the H-ARQ receiver receiving a packet from the H-ARQ transmitter; and

the H-ARQ receiver sending one of a positive acknowledgement (ACK) and a negative acknowledgement (NACK) to the H-ARQ transmitter, at least one of the ACK and the NACK being associated with other attribute.

33. The method of claim 32 wherein at least one of the ACK and NACK is associated with a channel quality indicator (CQI).

34. The method of claim 32 wherein at least one of the ACK and NACK is associated with at least one of time, frequency and space attributes.

35. The method of claim 34 wherein a NACK is associated with certain orthogonal frequency division multiplexing (OFDM) symbols and an ACK is associated with other OFDM symbols.

36. The method of claim 34 wherein a transmission time interval (TTI) is partitioned into an early slot and a late slot and one of the NACK and the ACK is sent in the early slot and the other is sent in the late slot.

37. The method of claim 34 wherein one of the ACK and NACK is sent on an odd timeslot and the other is sent on an even timeslot.

38. The method of claim 34 wherein the NACK and the ACK are associated with different physical layer and medium access control (MAC) attributes.

39. A method for implementing hybrid automatic repeat request (H-ARQ) in a wireless communication system including a transmitter and a receiver, the transmitter including an H-ARQ transmitter and the receiver including an H-ARQ receiver, both the H-ARQ transmitter and the H-ARQ receiver including a plurality of H-ARQ processes, the method comprising:

configuring some H-ARQ processes to operate in an asynchronous mode and other H-ARQ processes to operate in a synchronous mode; and

sending a control signal to indicate which H-ARQ processes are running in which mode.

40. The method of claim 39 wherein the control signal is transmitted via one of a radio resource control (RRC) signal and an H-ARQ-level signal.

41. A method for implementing hybrid automatic repeat request (H-ARQ) in a wireless communication system including a transmitter and a receiver, the transmitter including an H-ARQ transmitter and the receiver including an H-ARQ receiver, both the H-ARQ transmitter and the H-ARQ receiver including a plurality of H-ARQ processes, the method comprising:

determining an H-ARQ mode for a packet between a synchronous mode and an asynchronous mode; and

sending a control signal indicating whether potential retransmissions of the packet will be sent in one of the synchronous mode and the asynchronous mode, whereby the H-ARQ mode is dynamically switched for the H-ARQ processes.

42. The method of claim 41 wherein the H-ARQ transmitter indicates a time instance when a potential retransmission of the packet may occur.

43. A wireless communication system for implementing hybrid automatic repeat request (H-ARQ), the system comprising:

a transmitter including an H-ARQ transmitter configured to send a packet; and

a receiver including an H-ARQ receiver configured to receive the packet and send an H-ARQ feedback message including an H-ARQ feedback for a current packet and an H-ARQ feedback for at least one previous packet.

44. The system of claim 43 wherein retransmission of the current packet is not considered as the previous packet.

45. The system of claim 43 wherein the previous packet is a packet transmitted earlier than the current packet in time regardless of transmission sequence number assigned to the packets.

46. The system of claim 43 wherein the previous packet and the current packet are ordered in terms of transmission sequence numbers.

47. The system of claim 43 wherein the current packet and the previous packet are packets within the same traffic flow.

48. The system of claim 47 wherein the traffic flow is one of an H-ARQ flow, a medium access control (MAC) flow, an ARQ level flow, a flow to and from a particular receiver and a transmitter, a flow on a particular quality of service (QoS) class.

49. The system of claim 43 wherein the H-ARQ transmitter is configured to detect a failed packet due to an H-ARQ error based on the H-ARQ feedback message and initiate a process for recovering the failed packet.

50. The system of claim 49 wherein the H-ARQ error is a negative acknowledgement (NACK)-to-positive acknowledgement (ACK) error.

51. The system of claim 49 wherein the transmitter includes an ARQ transmitter and the H-ARQ transmitter is configured to send a local negative acknowledgement (NACK) to the ARQ transmitter to recover the failed packet at an ARQ level.

52. The system of claim 49 wherein the transmitter includes an ARQ transmitter and the H-ARQ transmitter is configured to send a local positive acknowledgement (ACK) to the ARQ transmitter when the H-ARQ transmitter receives multiple ACKs for the same packet.

53. The system of claim 43 wherein the H-ARQ feedback of the current packet is repeated for a predetermined number of times and the H-ARQ feedback of the previous packet is repeated for a predetermined number of times.

54. The system of claim 43 wherein a Reed-Solomon (R-S) coding is used to code multiple H-ARQ feedback bits.

55. A wireless communication system for implementing hybrid automatic repeat request (H-ARQ), the system comprising:

a transmitter including an H-ARQ transmitter configured to send a packet; and

a receiver including an H-ARQ receiver configured to send an H-ARQ feedback message to the H-ARQ transmitter, the H-ARQ feedback message including an identification of the packet.

56. The system of claim 55 wherein the identification is one of a transmission sequence number (TSN), a part of the TSN, a new data indicator (NDI) and a sequence number that is defined on an H-ARQ process level.

57. The system of claim 55 wherein the H-ARQ transmitter is configured to receive the H-ARQ feedback message and recognize an error based on the identification.

58. The system of claim 55 wherein the H-ARQ receiver is configured to send an H-ARQ feedback for a current packet and an H-ARQ feedback for at least one previous packet.

59. The system of claim 55 wherein the H-ARQ receiver is configured to include an indication in the H-ARQ feedback message whether the H-ARQ receiver has flushed its memory.

60. The system of claim 59 wherein the H-ARQ receiver is configured to include the indication when the H-ARQ receiver sends a negative acknowledgement (NACK).

61. A wireless communication system for implementing hybrid automatic repeat request (H-ARQ), the system comprising:

a transmitter including an H-ARQ transmitter configured to send a packet; and

a receiver including an H-ARQ receiver configured to send an H-ARQ feedback message to the H-ARQ transmitter including a sequence number of a packet that the H-ARQ receiver expects to receive next.

62. The system of claim 61 wherein the H-ARQ transmitter is configured to determine a transmission status of the packet based on the sequence number received from the H-ARQ receiver.

63. The system of claim 61 wherein the H-ARQ transmitter is configured to send a signal to the H-ARQ receiver to synchronize the sequence number.

64. The system of claim 63 wherein the signal is sent via in-band signaling.

65. The system of claim 61 wherein the H-ARQ receiver is configured to increment the sequence number on its own based on implicit information without receiving an explicit signal from the H-ARQ transmitter.

66. The system of claim 61 wherein the H-ARQ receiver is configured to send an H-ARQ feedback for a current packet and an H-ARQ feedback for at least one previous packet.

67. The system of claim 61 wherein the H-ARQ receiver is configured to include an indication in the H-ARQ feedback message whether the H-ARQ receiver has flushed its memory.

68. The system of claim 67 wherein the H-ARQ receiver is configured to include the indication when the H-ARQ receiver sends a negative acknowledgement (NACK).

69. A wireless communication system for implementing hybrid automatic repeat request (H-ARQ), the system comprising:

a transmitter including an H-ARQ transmitter configured to send a packet; and

a receiver including;

a memory for storing the packet received from the transmitter; and

a plurality of H-ARQ processes configured to receive the packet, store the packet in the memory before combining the packet with a previous received packet, and decode the combined packet first and if decoding of the combined packet fails, decode the packet stored in the memory.

70. The system of claim 69 wherein the memory is dynamically allocated for multiple H-ARQ processes and a certain H-ARQ process is given a higher priority for the resources.

71. A wireless communication system for implementing hybrid automatic repeat request (H-ARQ), the system comprising:

a transmitter including an H-ARQ transmitter configured to send a packet; and

a receiver including;

a timer; and

an H-ARQ receiver configured to set the timer when the H-ARQ receiver sends a negative acknowledgement (NACK) to the H-ARQ transmitter, if the H-ARQ receiver receives a packet corresponding to the NACK, clear the timer, and if the H-ARQ receiver does not receive a packet corresponding to the NACK until expiration of the timer, initiate a process for recovering the packet.

72. The system of claim 71 wherein the H-ARQ receiver is configured to send a report to the H-ARQ transmitter indicating an H-ARQ error to recover a failed packet at an H-ARQ level.

73. The system of claim 71 wherein the receiver further comprises an ARQ receiver and the transmitter further comprises an ARQ transmitter, and the H-ARQ receiver is configured to send a local NACK to the ARQ receiver indicating an H-ARQ error and the ARQ receiver is configured to send a report to the ARQ transmitter to recover the packet at an ARQ level.

74. A wireless communication system for implementing hybrid automatic repeat request (H-ARQ), the system comprising:

a transmitter including an H-ARQ transmitter configured to send a packet; and

a receiver including an H-ARQ receiver configured to send one of a positive acknowledgement (ACK) and a negative acknowledgement (NACK) to the H-ARQ transmitter in response to the packet, at least one of the ACK and the NACK being associated with other attribute.

75. The system of claim 74 wherein at least one of the ACK and NACK is associated with a channel quality indicator (CQI).

76. The system of claim 74 wherein at least one of the ACK and NACK is associated with at least one of time, frequency and space attributes.

77. The system of claim 76 wherein a NACK is associated with certain orthogonal frequency division multiplexing (OFDM) symbols and an ACK is associated with other OFDM symbols.

78. The system of claim 76 wherein a transmission time interval (TTI) is partitioned into an early slot and a late slot and one of the NACK and the ACK is sent in the early slot and the other is sent in the late slot.

79. The system of claim 76 wherein one of the ACK and NACK is sent on an odd timeslot and the other is sent on an even timeslot.

80. The system of claim 76 wherein the NACK and the ACK are associated with different physical layer and medium access control (MAC) attributes.

81. A wireless communication system for implementing hybrid automatic repeat request (H-ARQ), the system comprising:

an H-ARQ transmitter including a plurality of H-ARQ processes; and

an H-ARQ receiver including a plurality of H-ARQ processes,

wherein some H-ARQ processes are configured to operate in an asynchronous mode and other H-ARQ processes are configured to operate in a synchronous mode and the H-ARQ transmitter and the H-ARQ receiver are configured to exchange a control signal to indicate which H-ARQ processes are running in which mode.

82. The system of claim 81 wherein the control signal is transmitted via one of a radio resource control (RRC) signal and an H-ARQ-level signal.

83. A wireless communication system for implementing hybrid automatic repeat request (H-ARQ), the system comprising:

an H-ARQ receiver including a plurality of H-ARQ processes; and

an H-ARQ transmitter including a plurality of H-ARQ processes, the H-ARQ transmitter being configured to determine an H-ARQ mode for a packet between a synchronous mode and an asynchronous mode and send a control signal to the H-ARQ receiver to indicate whether potential retransmissions of the packet will be sent in one of the synchronous mode and the asynchronous mode, whereby the H-ARQ mode is dynamically switched for the H-ARQ processes.

84. The system of claim 83 wherein the H-ARQ transmitter indicates a time instance when a potential retransmission of the packet may occur.