Art of constructing low-complexity encoders/decoders forconstrained block codes

摘要

A rate p : q block encoder is a dataword-to-codeword assignmentnfrom 2p p-bit datawords to 2p q-bit codewords, andnthe corresponding block decoder is the inverse of the encoder. Whenndesigning block encoders/decoders for constrained systems, often, morenthan 2p codewords are available. In this paper, as our mainncontribution, we propose efficient heuristic computer algorithms toneliminate the excess codewords and to construct low hardware complexitynblock encoders/decoders. For (0,4/4) and (0,3/6) PRML constraints, blocknencoders/decoders generated using the proposed algorithms are comparablenin complexity to human-generated encoders/decoders, but arensignificantly simpler than lexicographical encoders/decoders