A Minimum Mean-Square Error Equalizer for Nonlinear Satellite Channels

Abstract

The problem of designing and evaluating the performance of a minimum mean-square error equalizer (MMSEE) for binary PSK transmission over band-limited nonlinear satellite channels is considered in this correspondence. The effect of intersymbol interference followed by AM/AM and AM/PM conversions are taken into account while optimizing the performance in the presence of the downlink white Gaussian noise. In analyzing the problem, the decision is made on a typical signal in a received sequence taking into account past and future interfering signals, i.e., ISI. As an illustrative example of the receiver, a typical channel model is considered in details. Based on the analysis, an alternative receiver structure which is more suitable for implementation is introduced. The taps gain coefficients for minimum mean-square error, between the received sample and the actual transmitted bit, are obtained using numerical methods. The performance of the equalizer is evaluated using computer simulation techniques and it is shown that significant performance improvement over the single-sample sign detector can be obtained.