快速移动环境中的MIMO-OFDM系统信道估计算法

Research on the algorithm for channel estimation on the MIMO-OFDM system in fast-moving environment

针对快速移动环境中存在的多普勒效应,研究了两种多输入多输出正交频分复用系统在快衰落信道中的误码性能,采用空频编码梳状等间隔导频插入方式,以及完全最大似然空频分组码解码算法,使用导频与接收信号进行信道参数估计,将一般多输入多输出正交频分复用系统中的基于训练序列的最小均方误差信道估计算法推广到了快衰落信道环境中.由仿真结果得知:这种改进的信道估计算法在子载波数为256个、插入导频为32个、并以等间隔方式插入导频时,系统的抗多径能力比较理想,可满足快速移动的信道环境要求.

Based on the analysis of the Doppler effect of the mobile channel, the performance of two MIMO-OFDM systems （STTC-OFDM and SFBC-OFDM） in the fast-moving, environment is studied. Then, the algorithm for channel estimation based on the training sequence is extended into the fast-moving environment by introducing the space frequency coding, the method of the equal-interval pectinate pilot-inserting, and the complete Maximum-Likelihood space-frequency decoding. According to the simulation results, the capability of anti-Doppler-effect of these two systems is perfect in the case of 256 sub-carriers, 32 equal-interval-inserting pilots, These results also show that this algorithm can adapt to the fast-moving channels.