Enhanced channel estimation for OFDM systems with multiple transmit antennas

For OFDM systems with multiple transmit antennas, it is necessary to obtain a reliable CFR of each transmitted signal from the received signal which is the superposition of transmitted signals. Generally, pilot symbol aided frame structure is used for bandwidth efficient frame structure; hence interpolation method can be used to separate CIR of each transmitted signal for channel estimation. However, the performance of this method is seriously degraded by aliasing and interpolation error. Therefore, we propose an enhanced DFT-based estimation method based on the iterative algorithm which can estimate the CIR without aliasing and interpolation error. By using computer simulation, we show that the proposed method approaches the low bound in terms of MSE performance by reducing the estimation error of the CFR of each transmitted signal, and verify that the proposed method is attractive and suitable for implementation with stable operation.