Scalable image transmission using rate-compatible irregular repeat accumulate (IRA) codes

This paper considers designing and applying rate-compatible irregular repeat accumulate (IRA) codes for scalable image transmission over binary symmetric channels. IRA codes of different rates are obtained by puncturing the parity bits of a mother IRA code which uses a systematic encoder. One of the main ideas presented here is the design of the mother code such that the entire set of higher rate codes obtained by puncturing are good. Using the Viterbi algorithm for finding the optimal unequal error protection of JPEG2000 bit streams, we present better results with IRA codes than those reported with turbo codes. The proposed IRA codes also have lower decoding complexity than the turbo codes.