HYBRID HIGHER-ORDER CEPSTRUM AND FUNCTIONAL-LINK NETWORK-BASED BLIND EQUALIZER (HOCFLN)

A new hybrid higher-order cepstrum (HOC) and functional link network ( FLN)-based blind equaliser (HOCFLN) is presented. The system initially uses the complex cepstrum of the 1-D slice of the fourth-order cumula nts of the unknown received signal to partially estimate the equaliser coefficients, then it switches to an FLN adaptive equaliser operating in the decision directed mode (DDM) to further improve the mean-squar ed error (MSE) convergence. In this system two nonlinearities are used ; one on the input data where the HOC is used and the other one in the FLN equaliser filter. It is shown that in the new HOCFLN system multi ple nonlinearities give significant performance improvement with less computational complexity, particularly in severe channel distortion co mpared to the conventional equalisation algorithms. This method can ac commodate both nonminimum phase MA and ARMA channels. Performance resu lts for channels exhibiting abrupt characteristic changes are also sho wn. (C) 1997 Elsevier Science B.V.