Abstract:

Conventional equalizers could hardly work effectively in the severe fading channel with zeros on the unit circle. A novel combing technique is presented in this paper aiming at the equalization of such nonminimum phase channels. The received signal is equalized separately by the IIR equalizer and time-reversal (TR) IIR equalizer with decision feedback (DF) architecture, and then the output signals from the two equalizers are combined together before demodulation. Since IIR and TR-IIR equalizers deal with the same symbol under independent noise background, the signal-to-noise ratio (SNR) can be increased evidently after combining, and the error propagation effect in the DF-IIR equalizer can be effectively depressed. It is evaluated through computer simulation to verify the advantages of the new scheme which can surpass the perfect performance of filter equalization methods.

Key words: Nonminimum Phase, Decision Feedback, IIR Filter, Bit Error Rate