Study Of Blind Channel Estimation For OFDM Communication Systems

Data transmission in wireless channels with high speed and reliability is required in future wireless systems. Orthogonal Frequency Division Multiplexing(OFDM) is one of the best solutions to this problem. It can strongly combat multipath and dispersive channel interference. Using DFT, it can be easily realized in transceivers. Therefore, the application of OFDM in wireless communication systems is robust and remarkable.This paper mainly deals with the problem of channel estimation in OFDM communication systems. Above all, the basic principle and key technologies of OFDM are analyzed. Then channel estimation methods for OFDM are discussed in detail. A blind channel estimation algorithm is proposed based on subspace. Theoretic analysis shows that the algorithm still works for OFDM systems with insufficient CP. A blind OFDM channel estimation algorithm is proposed using receiver diversity, which can estimate the channel response within only several OFDM block and suit for time-vary channel.