Research On Channel Estimation Of MIMO-OFDM System

At the moment, the 3rd mobile communication technology has been grown up for many years, and peole gradually could not feel satisfy with its performance any more. So the technology of next generation mobile communication becomes hot spots of domain in communication. MIMIO-OFDM is acknowledged that the hardcore of 4th communication technology. As the key of MIMO-OFDM, channel estimation can improve transmission rate and get higher reliability of systems.This article focused on MIMO-OFDM channel estimation,and has improved LS channel estimation.The background, course and actuality all have been told here. Texrually, it also shows us the difficulty and direction of improvement. It is methodical to introduce MIMO and OFDM, and tells us both's advantages. The integration of these two kinds of technology will depress SER and improve channel capacity. The text has introduced OFDM' theory, processing of signal in OFDM and method of channel estimation. It has paid more attention on PSAM channel estimation. Simulation of LS and MMSE channel estimation based on block polit has been finished, and comparison of SER and MMSE has also been shown. A comparative analysis on comb polit using three interpolation algorithms, i.e. linear interpolation, Gaussion interpolation and cubic-spline interpolation, has been shown. Then, Space-Time Codes of MIMO-OFDM system is introduced and compared. At last, there is a lot of work in LS algorithm of MIMO-OFDM channel estimation, and a new method that can decrease complexity of LS algorithm is brought forward. This method sets up a limen of path selecting to neglect the paths that have low power. So that LS algorithm is predigested with fewer performance lost.LMS adaptive filter is also used toget more ideal result. Finally the simulation of this method is finished in order to provide its validity.