低复杂度的正交空间调制检测算法

正交空间调制(quadrature spatial modulation，QSM)系统通过增加空间维来提高传统空间调制(spatial modulation，SM)的频谱利用率(频谱效率)， 这在传统的多输入多输出 (multiple-input multiple-output，MIMO)技术中引起了极大的关注。虽然最大似然(maximum likelihood，ML)检测算法能够实现最优性能，但其穷尽搜索带来了极高的计算复杂度。而经典的线性检测算法最小均方误差(minimum mean square error，MMSE)和迫零(zero forcing，ZF) ，虽然在复杂度方面较最大似然ML最优检测低，但其误比特性能却比最大似然ML检测算法差很多。为了更好实现系统在计算复杂度和误比特性能之间的均衡，提出一种基于迫零的线性检测算法——增强型迫零(enhance zero forcing，EZF)。仿真结果表明，提出的检测算法不仅能够实现比传统检测算法(如迫零和最小均方误差)更好的性能，而且在复杂度方面较ML有明显的降低。

Low complexity detection of quadrature spatial modulation

Quadrature spatial modulation (QSM) enhances frequency spectrum utilization of classical spatial modulation (SM) by adding a modulation spatial dimension, which attracts great attention in multiple input multiple output(MIMO). Although the maximum likelihood (ML) detector is able to achieve the optimal performance in QSM, its exhaustive search results in intractable computational complexity. Minimum mean square error (MMSE) and zero forcing (ZF) with lower complexity than ML are investigated in this paper. However, they have a fairly higher bit error rate. Hence, a ZF-based linear detection scheme named enhance zero forcing (EZF) is proposed to achieve better trade-off between complexity and BER performance. Simulation results show that the proposed EZF detector provides better performance than ZF and MMSE, and numerical analysis results present conspicuous reduction in complexity compared with ML detection.