Iterative Channel Estimation for a 2 × 2 and a 4 × 2 Non-Orthogonal MIMO Schemes

Multiple-input multiple-output OFDM systems receive a great deal of attention due to their great potential in achieving high data rates in wireless communications. Nevertheless, performance of MIMO-OFDM systems can severely degrade due to inaccurate channel estimation especially over frequency-selective fast-varying channels. In this paper, a new efficient iterative channel estimation process based on linear regression algorithm is proposed in order to iteratively improve calculation of channel coefficients during data stage by taking into account multi-antenna interference. The efficiency of the proposed solution is demonstrated for non-orthogonal MIMO schemes over frequency selective fast-time varying channels thanks to comparison with other turbo-channel estimation techniques.