快变信道环境下的MIMO OFDM系统信道估计算法

为了实现对快变信道环境下的多输入多输出正交频分复用(MIMO OFDM)系统信道估计,提出了一种基于多项式的基扩展模型(BEM),并联合迭代判决反馈并行干扰抵消(PIC)检测的信道估计算法.利用BEM将信道估计转化为对少量模型参数估计的特性,并结合PIC检测算法,以达到精确信道估计和消除载波间干扰的目的.仿真结果表明,该算法与传统最小二乘、线性最小均方误差信道估计算法相比,在误码率约为10-3时,信噪比增益为5dB左右.此外,新算法不需要知道信道的时域统计特性,且采用了移相正交导频设计,在一定程度上降低了信道估计的复杂度.

Channel Estimation Algorithm for MIMO OFDM Systems in Fast Time-Varying Environments

In order to realize the channel estimation for multiple input multiple output(MIMO) orthogonal frequency division multiplexing(OFDM) systems in fast time-varying environments,an algorithm of channel estimation based on the polynomial basis expansion model(BEM) and the parallel interference cancellation algorithm with iterative decision feedback is proposed.With help of the parallel interference cancellation algorithm,the accurate channel estimation and the removed inter-carrier interference are achieved based on the feature of which the BEM can transfer the channel estimation to a small amount of parameter estimation.Simulations shows that the signal to noise ratio gain reaches approximately 5 dB when the bit error rate is about 10-3,compared to the traditional estimation algorithms of least square and linear minimum mean square error.Furthermore,the algorithm doesn’t need to know the channel characteristic of time domain.The phase shift orthogonal pilot sequence is adopted,and the computational complexity of channel estimation is reduced thereafter.