Soft-output detector for partial response channels using vector quantization

An implementation of the Bahl-Cocke-Jelinek-Raviv algorithm for partial response detection which performs the usual forward and backward state metric recursions and the log-likelihood computation using only lookup tables is proposed. The state metrics are vector quantized, which requires fewer quantization points than the conventional approach of quantizing each state metric individually. This soft-output implementation is suitable for use in partial response systems using turbo equalization.