Abstract
A novel variable step-size modified super-exponen-tial iteration(MSEI)decision feedback blind equalization(DFE)algorithm with second-order digital phase-locked loop is put for-ward to improve the convergence performance of super-expo-nential iteration DFE algorithm.Based on the MSEI-DFE algo-rithm,it is first proposed to develop an error function as an improvement to the error function of MSEI,which effectively achieves faster convergence speed of the algorithm.Subse-quently,a hyperbolic tangent function variable step-size algo-rithm is developed considering the high variation rate of the hyperbolic tangent function around zero,so as to further improve the convergence speed of the algorithm.In the end,a second-order digital phase-locked loop is introduced into the decision feedback equalizer to track and compensate for the phase rotation of equalizer input signals.For the multipath underwater acoustic channel with mixed phase and phase rota-tion,quadrature phase shift keying(QPSK)and 16 quadrature amplitude modulation(16QAM)modulated signals are used in the computer simulation of the algorithm in terms of conver-gence and carrier recovery performance.The results show that the proposed algorithm can considerably improve convergence speed and steady-state error,make effective compensation for phase rotation,and efficiently facilitate carrier recovery.
基金项目
National Natural Science Foundation of China(61671461)
维普
万方数据