Correction circuit for improving performance in a channel decoder

1. A soft decision correction circuit for a receiver having a channel equalizer for receiving a burst and generating a soft decision output associated with said burst and a decoder for receiving and decoding a block of bursts including said burst, the soft decision correction circuit being intermediate said channel equalizer and said decoder for calculating a correction factor based on said soft decision output and multiplying said soft decision output in said burst by said correction factor; wherein said correction factor is

c

=

m



sd



2

σ



sd



2

,

where m |sd| 2 is the square of the mean of the absolute value of the soft decision and σ |sd| 2 is the variance of the absolute value of the soft decision.

2. The circuit of claim 1 , further comprising demapping, de-interleaving and de-puncturing blocks provided between said channel equalizer and said decoder.

3. The circuit of claim 2 , wherein said receiver is used in a mobile communication system comprising any of: Global Systems for Mobile Communications “GSM”, Enhanced Data rates for GSM Evolution “EDGE” and General Packet Radio Service “GPRS”.

4. The circuit of claim 2 , wherein said channel equalizer is a Viterbi equalizer.

5. The circuit of claim 2 , wherein said receiver supports incremental redundancy reception for requesting at least one retransmission of a failed data block including said burst with a different puncturing scheme.

6. The circuit of claim 1 , wherein said decoder is a forward error correction decoder.

7. The circuit of claim 6 , wherein said receiver is used in a mobile communication system comprising any of: Global Systems for Mobile Communications “GSM”, Enhanced Data rates for GSM Evolution “EDGE” and General Packet Radio Service “GPRS”.

8. The circuit of claim 6 , wherein said channel equalizer is a Viterbi equalizer.

9. The circuit of claim 6 , wherein said receiver supports incremental redundancy reception for requesting at least one retransmission of a failed data block including said burst with a different puncturing scheme.

10. The circuit of claim 1 , wherein said receiver is used in a mobile communication system comprising any of: Global Systems for Mobile Communications “GSM”, Enhanced Data rates for GSM Evolution “EDGE” and General Packet Radio Service “GPRS”.

11. The circuit of claim 10 , wherein said channel equalizer is a Viterbi equalizer.

12. The circuit of claim 10 , wherein said receiver supports incremental redundancy reception for requesting at least one retransmission of a failed data block including said burst with a different puncturing scheme.

13. The circuit of claim 1 , wherein said channel equalizer is a Viterbi equalizer.

14. The circuit of claim 13 , wherein said receiver supports incremental redundancy reception for requesting at least one retransmission of a failed data block including said burst with a different puncturing scheme.

15. The circuit of any one of claim 1 , wherein said receiver supports incremental redundancy reception for requesting at least one retransmission of a failed data block including said burst with a different puncturing scheme.

16. A soft decision correction method comprising:

receiving a burst and equalising it to thereby generate a soft decision output associated with said burst;

calculating a correction factor based on said soft decision output;

multiplying said soft decision output in said burst by said correction factor; and

decoding a block of bursts including said burst having said correction factor applied; wherein said correction factor is

c

=

m

❘

sd

❘

2

σ

❘

sd

❘

2

,

where m |sd| 2 is the square of the mean of the absolute value of the soft decision and σ |sd| 2 is the variance of the absolute value of the soft decision.

17. The method of claim 16 , further comprising demapping, de-interleaving and de-puncturing provided prior to decoding said block of bursts.

18. The method of claim 17 , further comprising requesting at least one retransmission of a failed data block including said burst with a different puncturing scheme.