A newly high-speed equalizer for QAM signals

A new algorithm SGD-CMA for QAM signals in high-speed equalizer is presented in this paper. SGD-CMA integrates conventional CMA and DD-LMS under stop-and-go principle. The SGD-CMA equalizer performs six times faster, with 3~5 dB better in rudimental MSE, more rapidly on capturing the channel variety than conventional CMA and almost the same error rate characteristic, while decreasing 82% of operation complexity and increasing 5% of hardware consumption. MATLAB simulations support SGD-CMA on all performance and characteristics, validating its feasibility and advantages. Finally using CMOS 0.18 mum library to synthesis, the new equalizer is embedded into DVB-C demodulation chip, and chip test result shows that the performance of the new equalizer is better.