Adaptive Equalization of Nonlinear Digital Satellite Channels Using a Frequency-domain Volterra Filter

The objective of this paper is t o present a new structure f o r an adaptive nonlinear equalizer f o r digital transmission over a nonlinear satellite channel with PSK modulation. The adaptive nonlinear equalizer is based o n a discrete frequencydomain third-order Volterra filter with the multidimensional overlap-save filtering technique, and o n the block least mean square (BLMS) algorithm f o r updating the filter coeficients. Since the proposed equalizer performs fast convolution by blocks, in decision-directed mode, it provides potentially larger savings in computational complexity compared to the conventional t ime-domain Volterra equalizers. The feasibili ty and practicality of the proposed equalizer structure is demonstrated by utilizing it to equalize a nonlinear satellite channel.