DESIGN TECHNIQUE FOR NONLINEAR EQUILIZERS

A theoretical analysis, using the properties of linear vector spaces, is applied to the design of a nonlinear equalizer. The design minimizes the probability of error in the detection of a serial digital signal, subject to the accurate equalization of the time-invariant channel, when the signal is received in the presence of additive white Gaussian noise with a high snr. The equalizer contains a conventional combination of linear feed-forward and nonlinear feedback transversal filters. Certain commonly used assumptions are made concerning the transmitted signal and the channel, but it is not assumed that the channel can necessarily be equalized by a linear feedforward transversal filter of limited length. A simple example shows the advantage in tolerance to additive Gaussian noise, which is achieved by the nonlinear equalizer over the corresponding linear equalizer, in a particular case where accurate equalization of the channel is achieved by the linear equalizer.