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当MIMO-OFDM(Multiple Input Multiple Output-Orthogonal Frequency Division Multiplexing)系统工作于频率选择性快衰落信道时,子载波正交性会受到破坏从而引入子载波间干扰(Inter-Carrier Interference:ICI).ICI的存在将严重降低那些传统的用于检测准静止频率选择性衰落信道下MIMO-OFDM的检测算法的性能.本文将Schniter针对SISO (Single Input Single Output)OFDM系统提出的最优线性预处理扩展到MIMO-OFDM系统,基于这个信号模型推广了基于最小均方误差滤波的迭代软判决干扰抵消(Minimum Mean Square Error filtering based Iterative Soft’Decision Interference Can- cellation:MMSE-ISDIC)逐符号检测算法,同时提出一种基于准最大后验概率准则的迭代软判决干扰抵消(quasi-maximum A posteriori probability based ISDIC:quasi-MAP-ISDIC)联合检测算法.仿真结果表明在本文考虑的系统参数设定下这两种检测算法的性能均优于文献[8]中算法的性能,其中quasi-MAP-ISDIC检测算法能够获得接近基于理想ICI抵消的MAP检测算法的性能.
When a MIMO-OFDM (Multiple Input Multiple Output-Orthogonal Frequency Division Multiplexing) system operates on a frequency-selective fast fading channel, the orthogonality of subcarriers may be impaired to introduce Inter-Carrier Interference (ICI) Will severely reduce the performance of those traditional detection algorithms for MIMO-OFDM detection in quasi-stationary frequency-selective fading channels.In this paper, the optimal linear preprocessing proposed by Schniter for Single Input Single Output (OFDM) system is extended to MIMO-OFDM system. Based on this signal model, the algorithm of iterative soft decision interference cancellation based on MMSE-ISDIC is generalized. At the same time, A quasi-maximum A posteriori probability based ISDIC (quasi-MAP-ISDIC) joint detection algorithm is proposed in this paper. The simulation results show that under the system parameters set in this paper, The performance of the detection algorithm is better than the performance of the algorithm [8], where q The uasi-MAP-ISDIC detection algorithm can achieve performance close to the MAP detection algorithm based on ideal ICI cancellation.