Low-complexity turbo equalization for MIMO-OFDM system without cyclic prefix

It is well-known that, the cyclic prefix (CP) protects orthogonal frequency-division multiplexing (OFDM) system from inter-block interference (IBI), but it also reduces the spectral efficiency. In this paper, a low-complexity turbo equalization algorithm is proposed for multiple input multiple output (MIMO) OFDM system without CP. In our algorithm, tail cancellation is performed firstly by using the previously detected signal. Then soft cyclic restoration, soft co-antenna interference (CAI) cancellation and subcarrier-wise combining based on signal to interference plus noise ratio (SINR) maximization are performed iteratively to minimize the performance degradation. Simulation results show that our algorithm achieves better tradeoff between bit error rate (BER) performance and computational complexity compared to other existing algorithms.