An efficient channel estimation technique for OFDM systems with transmitter diversity

In this paper, we propose an efficient channel estimation technique for ort hogonal frequency-division multiplexing (OFDM) systems with transmitter div ersity. The proposed technique estimates uniquely all channel frequency res ponses needed in space-time coded OFDM systems using " comb-type " training symbols. The computational complexity of the proposed technique is reduced dramatically, compared with the previous minimum mean-squared error (MMSE) technique, due to the processing made all in tile frequecy-domain. Also, s everal other techniques fur mitigating random noise effect and tracking cha nnel variation are discussed to further improve the performance of the prop osed approach. Tile performances of tile proposed approach are demonstrated by computer simulation for mobile wireless channels.