Blind Equalization Algorithms Based on Orthogonal Wavelet and Coordinate Transformation

This paper proposes a blind equalization algorithm based on orthogonal wavelet and coordinate transformation by analyzing the character of 16-QAM signals constellations and orthogonal wavelet transform theory. In the proposed algorithm, a new error function of constant modulus algorithm (CMA) is obtained after making coordinate transformation to output signal of equalizer, the error function will become exactly zero when the channel is perfectly equalized; then we make orthogonal wavelet transform to input signal of equalizer to decrease the correlation of signal, the rate of convergence is further improved. Simulation results with an underwater acoustic channel model demonstrate that the proposed algorithm has faster convergence rate and lower residual error, the significant improvements in performance is achieved, compared with CMA and CMA based on coordinate-transformation.