Correction circuit for improving performance in a channel decoder
View Patent ↗A receiver for a mobile communication system includes a channel equalizer for receiving a burst and generating a soft decision output associated with the burst, a soft decision correction circuit follows the channel equalizer and a decoder receives and decodes a block of bursts. The soft decision correction circuit calculates a correction factor based on the soft decision output for the burst and applies the correction factor to the burst prior to the burst entering the decoder.
1. A receiver for a mobile communication system, said receiver comprising:
a channel equalizer for receiving a burst and generating a soft decision output associated with said burst;
a decoder for receiving and decoding a block of bursts including said burst; and
a soft decision correction circuit intermediate said channel equalizer and said decoder for calculating a correction factor based on said soft decision output and applying said correction factor to said burst;
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 receiver of claim 1 , further comprising demapping, de-interleaving and de-puncturing blocks provided between said channel equalizer and said decoder.
3. The receiver of claim 1 , wherein said decoder is a forward error correction decoder.
4. The receiver of claim 3 , wherein said mobile communication system is selected from the group consisting of: GSM, EDGE and GPRS.
5. The receiver of claim 1 , wherein said channel equalizer is a Viterbi equalizer.
6. The receiver 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.
7. A method of operating a receiver for a mobile communication system, comprising:
receiving, by using a channel equalizer, a burst and generating a soft decision output associated with said burst;
calculating a correction factor based on said soft decision output;
applying said correction factor to said burst; 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.
8. The method of claim 7 , further comprising demapping, de-interleaving and de-puncturing provided prior to decoding of said block of bursts.
9. The method of claim 8 , further comprising requesting at least one retransmission of a failed data block including said burst with a different puncturing scheme.