Decision feedback equalization in channels with signal-dependent media noise

Since maximum likelihood sequence detection in channels with media noise requires too many trellis states, it is advantageous to seek simpler detectors. This paper formulates the signal-dependent decision feedback equalizer (SD-DFE) for these channels. For the purpose of designing the feedforward equalizer, the channel is treated as linear and the noise as stationary. These assumptions guide the design of the minimum-mean-square-error feedforward equalizer. The feedback structure is derived using the autoregressive signal/noise model. In 90% jitter noise dominated channels, the SD-DFE performs as well as a 16-state signal-dependent Viterbi detector, at a fraction of the complexity. A drawback of this method is error propagation due to the feedback.