Latency-constrained low-complexity lattice reduction for MIMO-OFDM systems

Recent studies have investigated lattice-reduction (LR) preprocessing technique formultiple-input multiple-output (MIMO) detection. However, if LR is applied to the orthogonal-frequency-division-multiplexing (OFDM) system, its complexity and latency increase greatly because of the large number of sub-carriers. This paper proposes a new processing architecture for LR-aided MIMO-OFDM system. This LR processing architecture reduces the number of iteration loops by using preprocessing matrix of adjacent sub-carrier. Beside, the grouping of sub-carriers can break the long critical computational path so as to comprise the computational complexity and latency. We simulate the proposed LR-aided MIMO-OFDM processing in the 3GPP-LTE system. The proposed method not only reduces the computational complexity but also shortens the latency for the lattice reduction.