The Research On Channel Estimation Algorithm In The MIMO-OFDM Wireless Communication Systems

The development of the scientific research and production in wireless mobile communications are quickly. The 3G and 4G are aimed to achieve seamless coverage of high-quality, high-speed mobile multimedia and data transmission business. MIMO-OFDM technology becomes a necessary selection. Channel estimation is a hot technology in communication research and it is one of the important tasks for designing the receiver in MIMO-OFDM system.In this thesis the frequency domain pilot-based channel estimation technology and LS-based channel estimation method are studyed. The main contributions of the thesis are expounded as follows.The existing research fruits are summarized, including MIMO technology, OFDM technology,the combination of MIMO and OFDM, channel estimation technology and etc..The wireless fading channel and MIMO channel's physical properties are analyzed. According to the common simulation model the signal's decline in the wireless channel is simulated. The MIMO channel capacity is different with the changes of the receiving and sending antennas.A modified variable coefficients Korteweg-de Vries (MKdV) equation is derived by using the reductive perturbation method with the inhomogeneity, the dust charge fluctuation, the dust temperature and the external magnetic field. So the wireless wave's transmitting characterisitics are well known.Focusing on the use of different interpolation estimated channel frequency response of the algorithm based on the comb-type pilots, the simulation is finished. Then the most widely used channel estimation techniques in MIMO-OFDM system are discussed. For example, the LS-based channel estimation technology. Because of the inadequacies of the LS algorithms a LS-based frequency-time parameters of the channel estimation is proposed. At last IDFT-based algorithm and noise reductiong algorithm for channel estimation are derived.