A New Practical MIMO Channel Estimation Technique for IEEE802.16a: Performance Analysis

Both orthogonal frequency division multiplexing (OFDM) and multi-input multi-output (MIMO) are key enabling technologies for future wireless communications systems. For both these technologies to work optimally, the channel between each pair of transmitter and receiver needs to be estimated accurately. In an earlier work, we had proposed a simple channel estimation method for a MIMO-OFDM system based on IEEE802.16a (wireless metropolitan area network (MAN)). The channel estimates were obtained by cyclically rotating the preamble in such a way that the time domain channel impulse response (CIR) from each transmitter can be separated in time within one symbol period. Results show that the overall system BER are nearly as good as the upper bound performance that is obtained with perfect channel state information (CSI) with only 0.5 dB worst case degradation in performance.