Space-time Diversity, Channel Estimation And Signal Detection Technique For MIMO-OFDM System

In OFDM, the entire channel is divided into many narrow parallel subchannels, thereby increasing the symbol duration and combating the frequency-selective fading caused by the multi-path. In this paper, MIMO-OFDM, as the combination of OFDM with MIMO technique, can be used to increase the capacity by a factor of the minimum number of transmit and receive antennas and enhance system performance, is a promising choice for future high-data-rate transmission over mobile wireless channels. The focus here is space-time diversity, channel estimation and signal detection. Since space-time coding is characterized by high code efficiency and good diversity gain, we investigate transmitter diversity using space-time coding for MIMO-OFDM, and analyses of the system performance is made by computer simulation with two kinds of code. Then, the channel estimation technique based on pilot is introduced and briefly discussed. At last, in order to lower receiver's complexity, several signal detection techniques and their performance analyses for MIMO-OFDM systems are presented.