Joint receiving mechanism based on blind equalization with variable step size for M-QAM modulation  

作　　者：卢继华 Abdallah Elhirtsia AHMED 王晓华 Kheddar BOUDJEMAA 

机构地区：[1]School of Information and Electronics,Beijing Institute of Technology [2]School of Mechatronic Engineering,Beijing Institute of Technology

出　　处：《Journal of Beijing Institute of Technology》2015年第3期381-386,共6页北京理工大学学报（英文版）

基　　金：Supported by the National Natural Science Foundation of China(61002014;61101129;61227001;61072050)

摘　　要：The problem of inter symbol interference（ ISI） in wireless communication systems caused by multipath propagation when using high order modulation like M-Q AMis solved. Since the wireless receiver doesn＇t require a training sequence,a blind equalization channel is implemented in the receiver to increase the throughput of the system. To improve the performances of both the blind equalizer and the system,a joint receiving mechanismincluding variable step size（ VSS） modified constant modulus algorithms（ MC-MA） and modified decision directed modulus algorithms（ MD DMA） is proposed to ameliorate the convergence speed and mean square error（ MSE） performance and combat the phase error when using high order QAM modulation. The VSS scheme is based on the selection of step size according to the distance between the output of the equalizer and the desired output in the constellation plane. Analysis and simulations showthat the performance of the proposed VSS-MCMA-MD DMA mechanismis better than that of algorithms with a fixed step size. In addition,the MCMA-MDDMA with VSS can performthe phase recovery by itself.The problem of inter symbol interference（ ISI） in wireless communication systems caused by multipath propagation when using high order modulation like M-Q AMis solved. Since the wireless receiver doesn＇t require a training sequence,a blind equalization channel is implemented in the receiver to increase the throughput of the system. To improve the performances of both the blind equalizer and the system,a joint receiving mechanismincluding variable step size（ VSS） modified constant modulus algorithms（ MC-MA） and modified decision directed modulus algorithms（ MD DMA） is proposed to ameliorate the convergence speed and mean square error（ MSE） performance and combat the phase error when using high order QAM modulation. The VSS scheme is based on the selection of step size according to the distance between the output of the equalizer and the desired output in the constellation plane. Analysis and simulations showthat the performance of the proposed VSS-MCMA-MD DMA mechanismis better than that of algorithms with a fixed step size. In addition,the MCMA-MDDMA with VSS can performthe phase recovery by itself.

关 键 词：inter symbol interference（ISI） modified constant modulus algorithm（MCMA） modified decision directed modulus algorithm（MDDMA） variable step size blind equalization phase rotation 

分 类 号：TN761[电子电信—电路与系统]