Research on Adaptive Cancellation of Inter-Carrier Interference in MIMO-OFDM

MIMO传输技术在OFDM系统中是非常有效的。然而，在移动的接收下，信道多普勒扩展的影响在MIMO-OFDM中更为严重。本文研究了降低信道多普勒扩展引起的载波间干扰的方法。在该方案中，使用基于多普勒扩展信道模型的导频符号来估计信道特性，并且使用所估计的信道特性来减小载波间干扰的影响。此外，通过将预编码方案与MIMO传输相结合，可以进一步改善信道特性的影响。在预编码方案的改进方面，本文还提出了迭代译码方案，使其在提高性能和降低复杂度方面成为可能。通过仿真验证了该方案的性能。结果，证实了良好的性能。在进一步的研究中，将在更多的实际接收情况下，进一步提高性能.并对硬件的简化进行了研究。

MIMO Transmission technique is very effective in OFDM systems. However, influence of channel Doppler spread under mobile reception is more severe in MIMO-OFDM. In this research, the scheme to reduce inter carrier interference generated by channel Doppler spread is. In this scheme, the channel characteristics is estimated using pilot symbols based on the Doppler spread channel model and influence of inter-carrier interference is reduced using the estimated channel characteristics. Moreover, by combining the pre-coding scheme with MIMO transmission, the influence of channel characteristics can be improved further. As for the improvement of pre-coding scheme, iterative decoding scheme is also prcposed and it made possible to improve performance and reduce complexily. The performance of the proposed scheme was examined by simulations. As the result, good performance was confirmed. In the further researches, the scheme to improve the performance further under more actual reception situations. And simplification of the hardware is also studied.