Comparative study of MIMO-OFDM channel estimation in wireless systems

Determining the channel characteristics and how it affects transmitted signals is known as channel estimation. MIMO OFDM is a combination of MIMO and OFDM techniques. In this paper, comparative studies of MIMO, MISO and SISO channel estimation, using OFDM was performed. The block type and the comb type pilot arrangements were compared, and also various interpolation techniques were also compared to determine the optimum performance. The Bit Error Rate and MSE were employed as the performance metrics. This research was carried out by modeling and simulating the wireless communication system using MATLAB. It was discovered that the FFT interpolation has the best performance compared to other interpolation techniques. It was also shown that the MMSE outperformance the LS, but this is achieved at the cost of system complexity. An improvement in system performance was also observed with an increase in the number of antennas (i.e SISO, MISO and MIMO respectively), and also the OFDM helps combat interference and improves the bandwidth efficiency.