WLC45-6: A Family of Low Complexity Adaptive Binary Linear Block Codes

A family of linear binary block codes is constructed from ordinary block repetition codes using cyclic shifts of the input information vector which greatly simplifies encoding. These codes have variable block length and variable minimum Hamming distance. Several sets of cyclic shifts are defined to constrain the search for good codes. Codeword enumeration strategies are discussed. The proposed codes are shown to be good candidates for adaptive coding, turbo product coding, retransmission schemes and multihop routing, and block differential encoding. A generic parallel encoder structure well suited to OFDM systems, and a non-recursive block differential encoder capable of arbitrarily increasing the code rate with the block length, for given minimum Hamming distance, are proposed. Numerical examples compare the bit-error rate assuming iterative soft- decision decoding and the union bound.