Research Of MIMO-OFDM System And Its Channel Estimation Performance Bound

As the time goes on, the demands for data transfer rate and application environment of wireless communication are increasing rapidly. In recent decades, especially in recently years, the mobile communication technology has been developed rapidly, and it's time to step into the mobile information era for all over the world. At the beginning of 2009, Ministry of Industry and Information Technology (MIIT) of our country issued three 3G licenses to China Mobile Communication Corporation, China Telecom and China Unicom, which marked the beginning of our country's 3G era. Meanwhile, in order to improve the frequency spectrum utilization and suppress the inter-symbol interference (ISI), MIMO and OFDM technology has been paid much attention. The combination of the two technologies, MIMO-OFDM system, has the advantages of the two technologies.The main content of this paper is the specific analysis and simulation about the channel estimation of MIMO-OFDM system so that the system could reach optimum performance in certain complex rate. In order to achieve the goal, the paper introduces the fading features and transmission technology of wireless communication channel and analyses the models of wireless mobile channel. In the following, there are introductions of OFDM and MIMO technologies and their key features, especially the channel estimation methods of OFDM based on pilot. Then, the model of MIMO-OFDM system and its key technologies and channel estimation ways are discussed. A vector formulation of the Cramer-Rao bound (CRB) for biased estimators and for functions of parameters is used to derive a lower bound on the channel estimation and prediction error of such a system. Numerical calculations using the bound demonstrate the benefits fo multiple antennas for channel estimation and prediction and illustrate the impact of modeling errors on estimation performances when using channel models based on calibrated arrays.