Adaptive Incremental Redundancy Coding and Decoding Schemes using Feedback Information

Abstract

If we can use a high capacity feedback channel, the receiver may transmit the indices of unreliable bits in a received sequence instead of ACK/NAK signals. We consider the error correction schemes using the indices of unreliable bits. The suitable parity symbols are incrementally transmitted using the feedback information. The bitwise reliability can be calculated by message passing algorithms on the variable graph constructed by adding the new nodes and arcs corresponding to the received parity bits to a former graph at each stage