Dynamic retransmission mode selector

• US 20060179387A1
• Filed: 11/09/2005
• Published: 08/10/2006
• Est. Priority Date: 11/10/2004
• Status: Abandoned Application

• Current Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Taffin, Arnauld, Jard, Alexandre
• Application Number:
  US11/270,888
• Publication Number:
  US 20060179387A1
• Time in Patent Office: Days
• US Class Current: 714/746
• CPC Class Codes: H03M 13/2957 Turbo codes and decoding
• CPC Class Codes: H03M 13/296 Particular turbo code structure
• CPC Class Codes: H03M 13/353 Adaptation to the channel
• CPC Class Codes: H03M 13/6306 Error control coding in combination with Automatic Repeat reQuest [ARQ] and diversity transmission, e.g. coding schemes for the multiple transmission of the same information or the transmission of incremental redundancy H03M13/3761, H03M13/3769 and H03M13/635 take precedence
• CPC Class Codes: H03M 13/6356 by repetition or insertion of dummy data, i.e. rate reduction
• CPC Class Codes: H03M 13/6362 by puncturing
• CPC Class Codes: H03M 13/653 3GPP HSDPA, e.g. HS-SCCH or DS-DSCH related
• 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 1/1874 Buffer management
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements

Abstract

A method of selecting a retransmission mode, for the transmission of data which have been first transmitted in acknowledged mode between a transmitter unit and a receiver unit over an interface, and for which no positive acknowledgement of said first transmission has been received at the transmitter unit, the data being processed according to an error correcting encoding scheme prior to transmission over the interface, is provided. The number of bits to be encoded and the number of bits to be sent over the interface are compared, and a type of retransmission mode for the retransmission of the first transmitted data is determined.

Claims

1. A method of selecting a retransmission mode, for the transmission of data which have been first transmitted in acknowledged mode between a transmitter unit and a receiver unit over an interface, and for which no positive acknowledgement of said first transmission has been received at the transmitter unit, the data being processed according to an error correcting encoding scheme prior to transmission over the interface, the method comprising:

first comparing the number of bits to be encoded (N_SYS) and the number of bits to be sent over the interface (N_DATA); and

determining, responsive to said first comparison, a type of retransmission mode for the retransmission of the first transmitted data.

2. A method according to claim 1, which further comprises:

second comparing a number of bits representative of an available memory size at the receiver unit (N_IR) and the number of bits to be sent over the air interface (N_DATA); and

determining, responsive to said first and second comparisons, a type of retransmission mode for the retransmission of the first transmitted data.

3. A method according to claim 1, wherein the determining a type of retransmission mode comprises determining whether the retransmission of data may be done according to an incremental redundancy scheme.

4. A method according to claim 2, herein the second comparing comprises a comparison of a number of bits representing a maximum memory size at the receiver unit available for a retransmission process (N_IR), with the number of bits to be sent over the interface (N_DATA).

5. A method according to claim 1, herein the first comparing of the number of bits to be encoded (N_SYS) and the number of bits to be sent over the interface (N_DATA) comprises comparing the overall coding rate (N_SYS/N_DATA) to the error correcting encoding rate (1/n).

6. A method according to claim 5, wherein the determining of a type of retransmission mode comprises:

excluding an incremental redundancy retransmission scheme if the overall coding rate (N_SYS/N_DATA) is smaller than the error correcting encoding rate (1/n).

7. A method according to claim 4, wherein the determining of a type of retransmission mode comprises:

excluding an incremental redundancy retransmission scheme if the overall coding rate (N_SYS/N_DATA) is greater than the error correcting encoding rate (1/n) and the number of bits representing a maximum memory size at the receiver unit available for a retransmission process (N_IR) is smaller than the number of bits to be sent over the interface (N_DATA).

8. A method according to claim 4, herein the determining of a type of retransmission mode comprises:

selecting an incremental redundancy retransmission scheme if the overall coding rate (N_SYS/N_DATA) is greater than the error correcting encoding rate (1/n) and the number of bits representing a maximum memory size at the receiver unit available for a retransmission process (N_IR) is greater than the number of bits to be sent over the interface (N_DATA).

9. A method according to claim 5, in which the error correcting scheme is turbo coding, and the error correcting encoding rate (1/n) equals ⅓

.

10. A method according to claim 1, the data being processed according to the error correcting encoding scheme and a rate matching scheme prior to transmission over the interface, the method further comprising:

calculating a number (N_PUNCT2) of bits to be punctured in order to match the number of bits to be sent over the interface (N_DATA);

third comparing the number of bits, exclusive of the number of bits to be encoded, to be sent over the interface (N_DATA−

N_SYS) and said number (N_PUNCT2) of bits to be punctured in order to match the number of bits to be sent over the interface (N_DATA);

selecting, responsive to said third comparison, an incremental redundancy scheme for the retransmission of the first transmitted data.

11. A method according to claim 10, in which the selecting of an incremental redundancy scheme for the retransmission of data comprises selecting the Full Incremental Redundancy mode or the Partial Incremental Redundancy Mode.

12. A method of selecting an incremental redundancy retransmission scheme, for the transmission of data which have been first transmitted in acknowledged mode between a transmitter unit and a receiver unit over an interface, and for which no positive acknowledgement of said first transmission has been received at the transmitter unit, the data being processed according to an error correcting encoding scheme and a rate matching scheme prior to transmission over the interface, the method comprising:

determining whether the retransmission of data may be done according to an incremental redundancy retransmission scheme;

calculating a number (N_PUNCT2) of bits to be punctured in order to match the number of bits to be sent over the interface (N_DATA);

comparing the number of bits, exclusive of the number of bits to be encoded, to be sent over the interface (N_DATA−

N_SYS) and said number (N_PUNCT2) of bits to be punctured in order to match the number of bits to be sent over the interface (N_DATA); and

selecting, responsive to said comparison, an incremental redundancy scheme for the retransmission of the first transmitted data.

13. A method according to claim 12, in which the selecting of an incremental redundancy scheme for the retransmission of data comprises selecting the Full Incremental Redundancy mode or the Partial Incremental Redundancy Mode.

14. A method, according to claim 12, herein the selecting of an incremental redundancy scheme for the retransmission of data, comprises selecting a predetermined incremental redundancy scheme for the retransmission of data if the number of bits, exclusive of the number of bits to be encoded (N_SYS), to be sent over the interface (N_DATA−

N_SYS) is smaller than said number (N_PUNCT2) of bits to be punctured in order to match the number of bits to be sent over the interface (N_DATA).

15. A method, according to claim 14, in which said selected predetermined incremental redundancy scheme is Full Incremental Redundancy.

16. A method, according to claim 12, in which the selecting of an incremental redundancy scheme for the retransmission of data, comprises selecting a predetermined incremental redundancy scheme for the retransmission of data if the number of bits, exclusive of the number of bits to be encoded (N_SYS), to be sent over the interface (N_DATA−

N_SYS) is greater than said number (N_PUNCT2) of bits to be punctured in order to match the number of bits to be sent over the interface (N_DATA).

17. A method, according to claim 16, in which said selected predetermined incremental redundancy scheme is Partial Incremental Redundancy.

18. A retransmission mode selector having means to select a retransmission mode, for the transmission of data which have been first transmitted in acknowledged mode between a transmitter unit and a receiver unit over an interface, and for which no positive acknowledgement of said first transmission has been received at the transmitter unit, the data being processed according to an error correcting encoding scheme prior to transmission over the interface, the selector comprising:

means for first comparing the number of bits to be encoded (N_SYS) and the number of bits to be sent over the interface (N_DATA); and

means for determining, responsive to said first comparison, a type of retransmission mode for the retransmission of the first transmitted data.

19. An incremental redundancy retransmission scheme selector having means for selecting an incremental redundancy retransmission scheme, for the transmission of data which have been first transmitted in acknowledged mode between a transmitter unit and a receiver unit over an interface, and for which no positive acknowledgement of said first transmission has been received at the transmitter unit, the data being processed according to an error correcting encoding scheme and a rate matching scheme prior to transmission over the interface, the selector comprising:

means for determining whether the retransmission of data may be done according to an incremental redundancy retransmission scheme;

means for calculating a number (N_PUNCT2) of bits to be punctured in order to match the number of bits to be sent over the interface (N_DATA);

means for comparing the number of bits, exclusive of the number of bits to be encoded, to be sent over the interface (N_DATA−

N_SYS) and said number (N_PUNCT2) of bits to be punctured in order to match the number of bits to be sent over the interface (N_DATA); and

means for selecting, responsive to said comparison, an incremental redundancy scheme for the retransmission of the first transmitted data.

20. A computer readable medium having processor executable instructions thereon for implementation by a processor, the instructions providing means to select a retransmission mode, for the transmission of data which have been first transmitted in acknowledged mode between a transmitter unit and a receiver unit over an interface, and for which no positive acknowledgement of said first transmission has been received at the transmitter unit, the data being processed according to an error correcting encoding scheme prior to transmission over the interface, the instructions further comprising:

means for first comparing the number of bits to be encoded (N_SYS) and the number of bits to be sent over the interface (N_DATA); and

means for determining, responsive to said first comparison, a type of retransmission mode for the retransmission of the first transmitted data.

21. A signal processing apparatus, in a transmitter unit adapted to transmit data to a receiver unit in acknowledged mode over an interface, comprising, for the transmission of data which have been first transmitted between said transmitter unit and a receiver unit over an interface, and for which no positive acknowledgement of said first transmission has been received at the transmitter unit, the data being processed according to an error correcting encoding scheme prior to transmission over the interface:

first comparator means, for first comparing the number of bits to be encoded (N_SYS) and the number of bits to be sent over the interface;

first control means, for determining, responsive to said first comparison, a type of retransmission mode for the retransmission of the first transmitted data.

22. A signal processing apparatus according to claim 21, further comprising:

second comparator means, for second comparing a number of bits representative of an available memory size at the receiver unit (N_IR) and the number of bits to be sent over the air interface (N_DATA);

second control means, for determining, responsive to said first and second comparisons, a type of retransmission mode for the retransmission of the first transmitted data.

23. A signal processing apparatus according to claim 21, in which said first comparator means are adapted to compare the overall coding rate (N_SYS/N_DATA) with the error correcting encoding rate.

25. A base station comprising a signal processing apparatus according to claim 21.

26. A mobile terminal comprising a signal processing apparatus according to claim 21.

24. A signal processing apparatus, in a transmitter unit adapted to transmit data to a receiver unit in acknowledged mode over an interface, comprising, for the transmission of data which have been first transmitted between said transmitter unit and a receiver unit over an interface, and for which no positive acknowledgement of said first transmission has been received at the transmitter unit, the data being processed according to an error correcting encoding scheme and a rate matching scheme prior to transmission over the interface:

means for determining whether the retransmission of data may be done according to an incremental redundancy retransmission scheme;

means for calculating a number (N_PUNCT2) of bits to be punctured in order to match the number of bits to be sent over the interface (N_DATA);

means for comparing the number of bits, exclusive of the number of bits to be encoded, to be sent over the interface (N_DATA−

N_SYS) and said number (N_PUNCT2) of bits to be punctured in order to match the number of bits to be sent over the interface (N_DATA);

means for selecting, responsive to said comparison, an incremental redundancy scheme for the retransmission of the first transmitted data.