A high-speed equalizer based on a new algorithm： stop-and-go-DD-LMS CMA （SGLMS-CMA） for quadrature amplitude modulation （QAM） signals ispresented. It integrates conventional constant modulus algorithm （CMA） and decision-direct least-mean-square （DD-LMS） under stop-and-go principle. Matlab simulations indicate that, compared with conventional CMA,the new algorithm performs five times faster in convergence speed, 3-5dB improved in rudimental mean square error （MSE）, 82% decreased in operation complexity and can correct a final phase ambiguity. As to the equalizer block in the system,synthesis results show that the SGLMS-CMA ＋ DD-LMS equalizer＇s hardware consumption is only 5% greater than the CMA＋ DD-LMS equalizer＇ s. Finally by using SMIC 0.18μm library to synthesis, the new equalizer is embedded into QAM demodulation chip,and test results show that the new equalizer acts better.
