Mixed Sign Iteration based Blind Equalization Algorithm for Carrier Phase Recovery of QAM Signals
Zhou Qiao-xi · Jisuanji fangzhen · 2008
For overcoming the high computational complexity and large Mean Square Error (MSE) of LBE (Linear Blind Equalizer based on statistic equalization criterion), on the basis of the research on SGLBE (Sign Gradient iteration based Linear Blind Equalizer) and SEDD (Sign Error Iteration based Decision-Directed algorithm), a mixed sign iteration based blind equalizer for carrier phase recovery of QAM signals was proposed. In this proposed equalizer, Phase-Locked Loop (PLL) was introduced, the computational loads of LBE and PLL could be reduced using the sign algorithm, signed-error was employed for reducing the computational complexity of DD algorithm, and the carrier phase rotation of QAM signals introduced by multi-path fading channels could be combated via PLL. The simulation results show that the proposed equalizer has low MSE and computational complexity, fast convergence rate, and can effectively correct the channel-introduced carrier phase rotation.