Fixed-point realization of lattice-reduction aided MIMO receivers with complex K-best algorithm

Multiple-input multiple-output (MIMO) techniques provide high data rates but the optimal maximum likelihood (ML) detector exhibits high complexity. Recently lattice reduction (LR) aided detectors have been proposed to achieve near-ML performance with low complexity. In this paper, we develop a LR-aided complex K-best algorithm which reduces the complexity of the existing sphere decoding based K-best algorithm. Then we provide the fixed-point design of the LR-aided K-best MIMO receiver for both coded and uncoded systems. The architecture selection of each sub-module is developed and a simulation-based wordlength optimization procedure is proposed. Simulations show that the fixed-point results can keep bit error rate degradation within 0.2dB under 8 × 8 256-QAM MIMO systems.