基于特殊导频序列的多用户OFDM系统中的频偏和信道联合估计  

Optimal training signals for joint estimation of channel response and frequency offset in multiuser OFDM

作　　者：康瑞[1] 徐超雄[1] 王俊[1] 徐洪波[1] 

机构地区：[1]华中师范大学电子与信息工程系,武汉430079

出　　处：《电子测量技术》2007年第10期107-110,共4页Electronic Measurement Technology

摘　　要：本文提出了一种新的导频设计方法应用在多用户OFDM系统中来进行联合估计频偏和信道。根据最小化MSE准则,设计最优的导频序列以满足均方误差最小,从而得到该导频序列是等功率的且具有循环移位正交性。仿真结果表明,本文所提出的最优导频序列优于任意导频序列在对频偏和信道联合估计的运算中。同时,通过采用改进的ML(最大似然估计)算法能够大大减小运算的复杂度。这种方法在系统具有较小频率偏移的情况下非常适用。A new method for pilot-tone design is presented to perform Joint estimation of channel response and frequency offset for multiuser orthogonal frequency division multiplexing （OFDM） systems. According to mean square error （MSE） principle, We calculate the optimized pilot-tone sequences to ensure the minimum of MSE, so as to obtain the equal-powered pilot sequences and phase shift orthogonal. Simulation results show that the optimal pilot sequences derived in this paper outperform the random pilot sequences for joint estimation of channel response and frequency offset in multiuser OFDM systems. Simultaneously, by using the modified maximum likelihood（ML） algorithm can reduce the complex of computation. Simulations also indicate that this scheme is especially useful for the system has small frequency offset.

关 键 词：信道估计 频偏 多用户OFDM 改进的ML算法 

分 类 号：TN929.5[电子电信—通信与信息系统]