GMRES Interference Canceler for doubly iterative MIMO system with a Large Number of Antennas

In this paper, we propose a reduced complexity interference canceler for a Turbo Space-Time Codes (TSTC) receiver. Actually, the TSTC receiver is based on a linear Minimum Mean Squared Error (MMSE) filter inside an Interference Canceler (IC) loop. In this scheme, considering the matrix inversion cost, the overall complexity remains important for a large number of transmit and receive antennas. In the proposed receiver, we integrate the Generalized Minimum residual method (GMRES) for symbol detection to compute the MMSE filter without matrix inversion. A good tradeoff between performances and complexity is thus achieved for a system with a large number of transmit and receive antennas. The bit error ratio (BER) and the complexity are evaluated with respect to the number of iterations of the GMRES and the number of transmit/receive antennas. A comparison with the existent IC-MMSE is presented and discussed at the end of the paper.