一种分布式MIMO-OFDM系统的多参数估计方法

Method of Multiple Parameters Estimation for the Distributed MIMO-OFDM System

对分布式多输入多输出正交频分复用(MIMO-OFDM)系统中的多频偏多信道估计问题进行研究,提出一种基于多项式求根和迭代干扰消除的多参数联合估计算法。该算法利用导频将多维搜索函数简化成多个一维搜索函数,通过泰勒级数将一维搜索函数转换成闭合的多项式形式,求多项式的根来获得频偏,利用迭代干扰消除进一步得到频偏和信道的迭代估计。仿真结果表明,提出算法适用于通信环境较为复杂的多径衰落信道和广泛应用的OFDM信号分析,与现有算法相比,估计精度高,性能较好,可以达到近似最大似然的最优解。

An efficient method of multiple frequency offsets and multiple channels responses estimation was proposed for distributed multiple input multiple output orthogonal frequency division multiplexing systems,which utilize the polynomial root finding method and the iterative interference cancellation procedure. The scheme transforms the multi-dimensional frequency searching function into multi one-dimensional searching functions by using the optimum training sequences,which is specially designed,and turns these one-dimensional functions into closed-form estimators by Taylor series expanding. The multiple frequency offsets estimation can be obtained by finding the one-dimensional polynomial roots and iterative interference cancellation procedure is used to get the improved estimation results of multiple frequency offsets and multiple channel responses. Simulation results indicate that the proposed algorithm is suitable for the multipath fading channel which is more complicated in real wireless communication and the widely used orthogonal frequency division multiplexing signals,and has a better estimation performance than the existing multiple parameter estimation algorithms. Also,the performance is approaching the maximum likelihood results.