Lattice-reduction-aided detection in spatial correlated MIMO channels

To overcome the drawback that the diversity order of the traditional linear MMSE detection algorithm decreases with the increase of the correlation coefficient, a lattice-reduction-aided MMSE (LRA-MMSE) detection algorithm is proposed for spatial correlated MIMO channels. The LRA-MMSE detection algorithm considers the effect of spatial correlation in the algorithm design and takes advantage of the complex Lenstra-Lenstra-Lovász (LLL) algorithm so that its BER (bit error rate) is several orders of magnitude smaller than that of the traditional linear MMSE detection at a high SNR (signal to noise ratio). Theoretical analysis and simulation results show that with QPSK modulation and the MMSE channel estimator at the receiver, the uncoded BER of the LRA-MMSE detector is lower than that of the traditional linear MMSE detector if the bit SNR (Eb/N0) is greater than 18dB, while the coded BER of the LRA-MMSE detector is lower than that of the traditional linear MMSE detector if Eb/N0 is greater than 16dB when (2,1,3) convolutional channel coding and Viterbi decoding are adopted under the Kronecker correlated flat fading channel. Furthermore, the diversity order of the LRA-MMSE detector in the correlated MIMO channel is equal to the number of the receive antenna N.