Research On Channel Estimation And Equalization Methods In MIMO-OFDM System

MIMO-OFDM system uses multiple antennas in receiver and transmitter and uses OFDM modulation technique in every antenna. MIMO can linearly increase the volume of the system, breaks through the traditional Shannon Limit of SISO channel. OFDM can simplify the base-band processing unit of the receiver greatly and can increase the data rate. In wireless communication, MIMO-OFDM can get high data rate and large system volume without the extra power or bandwidth which make itself the key technique of the fourth generation communication. To avoid ICI (inter Carrier interference) during the transmission period, we usually first estimate the channel when processing the base-band signal and then use the channel information estimated to equalize the received data. Also, because the efficient correlated detection technique needs the support of channel estimation, channel estimation and equalization become the focus of the next generation wireless channel research. The main contents of the paper are some channel estimation and equalization methods in MIMO-OFDM system.The first chapter introduced the characteristics of the wireless channel, the small-scale fading model, multi-path fading model and WSSUS channel model.The second chapter introduced OFDM system, including series-parallel conversion, DFT/IDFT conversion, cyclic prefix. We introduced the rationale of MIMO-OFDM system, emphasizing some key techniques like space multiplexing, interference cancellation, soft decoding, synchronization and adaptive modulation.