Low Complexity Blind Equalization Based on Parzen Window Method

The stochastic blind equalization based on the Parzen window method (SQD), which forces the probability density function (PDF) at the equalizer output to match the known constellation PDF, has a good performance. However, when the signals with high frequency band efficiency are used, the computational complexity is very huge. In this paper, a low complexity SQD algorithm (LCSQD) is presented. The judged region of the proposed algorithm is only the part of the whole constellation region, whose center is the equalization output and radius can be adjusted experimentally or adaptively. It has a low computational requires which do not increase when the modulation signal order increases. Simulations for 16QAM and 64QAM show that the proposed algorithm has a fast convergence speed and more lower residual ISI than SQD algorithm.