Patent ID: 7783963
Filing Date: 2010-08-24
Classification: H03M

Abstract:
1. A method of decoding a concatenated convolutional-encoded and block encoded signal, the method comprising the steps of: a) applying the encoded signal to a first soft metric generator means to generate soft metrics and to a first delay means to output a delayed encoded signal; b) applying the first soft metrics to a first Viterbi decoder means to decode the soft metrics representing convolutional-encoded symbols of the encoded signal and to output a first block encoded Viterbi-decoded signal; c) decoding the block encoded signal with a first block decoder means and marking decoded bits identified as belonging to correctly decoded blocks to form a marked decoded signal; d) applying the delayed encoded signal and the marked decoded signal to a modified soft metric generator means arranged to generate modified soft metrics for remaining uncertain bits constrained by the decoded bits identified as belonging to correctly decoded blocks to generate modified soft metrics for remaining uncertain bits consistent with the decoded bits identified as belonging to correctly coded blocks; e) applying the modified soft metrics to a second Viterbi decoder means to decode the modified soft metrics representative of convolutional encoded symbols of the delayed encoded signal and to output a block encoded second Viterbi-decoded signal; and f) decoding the block encoded second Viterbi-decoded signal with a second block decoder means and outputting a second decoded signal.