Research on Blind Equalization of Cross-QAM Signals
Mingzeng Dai · Dianzi qijian · 2008
Two new blind equalization algorithms suitable for cross-QAM signals are proposed,modified CXA(MCXA)and decision-directed MCXA(DD-MCXA).By adding a constellation-matched error(CME)term to the cost function of the CXA,the MCXA is obtained.In the MCXA,the CXA term provides global convergence and the CME term helps to decrease the residual error and accelerate convergence.The DD-MCXA improves performance of the MCXA because it retains the good initial convergence characteristics of the CXA at the same time,and automatically decreases the effect of the CXA errors when the equalizer is near convergence.Two outdoor wireless microwave channel models are adopted in the simulation,and the simulation results demonstrate the good performance of the proposed algorithms.