Study On Precoding And Blind Channel Estimation Of MIMO-OFDM System

Multiple Input Multiple Output-Orthogonal Frequency Division Multiplexing system is the new generation of communication technology. MIMO-OFDM system can increase the channel capacity without increasing band-width, which can use the special diversity obtained by spatially separated antennas. Meanwhile, it can combat the multi-path fading and noise. Therefore, MIMO-OFDM system is increasingly concerned and has great research value.Precoding technique in MIMO-OFDM system became a study hotspot because of adopting channel better and better system performance.Blind channel estimation of MIMO-OFDM system can get the channel estimate without training. Compared with pilot-based channel estimation, it has high spectrum efficiency for practical application and so on. It has a great potential to study.The main ideas of author are as follows:Firstly, we describe the principles and models of the MIMO-OFDM system. We analyze the classic blind channel estimation of the MIMO-OFDM, and introduce a blind channel estimation method-subspace method. Finally, we propose an improved blind channel estimation method.We further describe the precoding theory and propose an optimal precoding based on the partial channel information.Finally, we propose an improved model of MIMO-OFDM. We apply the improved blind channel estimation method and the optimal precoding technology to MIMO-OFDM system. The experiments show that, it has good performance.