Channel Estimation For MIMO-OFDM Systems Using Superimposed Training In VLSI

Channel estimation for multiple-input multiple-output/orthogonal frequency-division multiplexing (MIMO-OFDM) systems in linearly time invariant or time varying channel using superimposed training is considered. The linear time invariant channel is modeled by truncated discrete Fourier basis. A two step approach is adopted to estimate the channel over multiple OFDM symbols. In the first step we estimate the channel using only the first order statistics of the data. Using the estimated channel from the above step, a linear minimum mean square error equalizer are used to estimate the information sequence. In second step, to enhance the channel estimation performance in MIMO-OFDM system with limited pilot power and introduce an interference cancellation procedure to iteratively mitigate the information sequence interference. We also present a performance analysis of the channel estimation and to obtain the closed form expression for the channel estimation variances. Illustrative simulation results are provided.