虚拟多天线OFDM系统中多频偏和信道联合最大似然估计算法研究

虚拟多天线OFDM系统中多频偏和信道联合最大似然估计算法研究

内容简介：针对各个收发天线间都具有不同的频偏和信道参数的虚拟多天线、OFDM系统目的节点中数据辅助的多频偏和信道参数估计问题进行了研究.通过利用级数展开的方法进行矩阵求逆,提出了一种基于最大似然准则的高计算效率参数估计算法,从而能够同时对虚拟多天线OFDM系统中的频偏和信道等参数进行估计.给出了本算法估计结果的均方误差与CR下界的对比,同时还对训练序列的设计进行分析和仿真验证,仿真结果表明所设计的低复杂度算法性能上逼近CR下界,同时克服了现有算法的缺陷.

Abstract：A pilot-aided joint estimation of the carrier frequency offsets(CFO) and channels of a virtual multi- anten-nas(VMA) orthogonal frequency-division multiple(OFDM) system was considered. For a VMA-OFDM system, each pair of transmit and receive antennas possibly having a different CFO and CIR(channel impulse response) parameters made the parameters joint estimation a challenge task. By utilizing the series expansion of the matrix inversion and maximum likelihood(ML) criterion, a computationally efficient estimator allowing for simultaneously estimating the unknown pa-rameters was developed. The mean square-error(MSE) performance of the interested parameters for the proposed estima-tor was compared with the Cramer-Rao bound (CRB). In addition, the pilot sequence design was investigated by analysis and simulations. Simulation results show that the proposed low-complexity estimator asymptotically achieves the CRB and overcomes the drawbacks of existing estimators.

作者：姜建, 姜华, 严凯, 刘海涛,

关键词：虚拟多天线, 正交频分复用, 多频偏, 信道冲激响应, 最大似然准则, Cramer-Rao下界,