Joint equalization and soft decoding for vector quantization over channels with intersymbol interference

An approach to joint equalization and decoding for vector quantization over a Gaussian channel with intersymbol interference is presented. The decoder is based on a Hadamard transform representation of the vector quantizer. This gives the decoder a structure that allows the decoding to be based on estimates of the transmitted bits in an efficient manner. The decoder is soft in the sense that soft channel information is used and no decisions are involved in the decoding. Simulations demonstrate that the soft decoder can outperform a scheme based on Viterbi equalization plus table look-up decoding