Channel Estimation Algorithm for MIMO OFDM Systems in Fast Time-Varying Environments

In order to realize the channel estimation for multiple input multiple output(MIMO) orthogonal frequency division multiplexing(OFDM) systems in fast time-varying environments,an algorithm of channel estimation based on the polynomial basis expansion model(BEM) and the parallel interference cancellation algorithm with iterative decision feedback is proposed.With help of the parallel interference cancellation algorithm,the accurate channel estimation and the removed inter-carrier interference are achieved based on the feature of which the BEM can transfer the channel estimation to a small amount of parameter estimation.Simulations shows that the signal to noise ratio gain reaches approximately 5 dB when the bit error rate is about 10-3,compared to the traditional estimation algorithms of least square and linear minimum mean square error.Furthermore,the algorithm doesn't need to know the channel characteristic of time domain.The phase shift orthogonal pilot sequence is adopted,and the computational complexity of channel estimation is reduced thereafter.