低复杂度的MIMO系统粒子滤波检测

Low-Complexity Particle Filtering Detection for MIMO Systems

该文通过降低采样大小和信号检测搜索空间给出了两种低复杂度的多输入多输出(MIMO)系统粒子滤波(PF)检测方法:球形约束PF和多层映射PF。在球形约束PF中,首先基于迫零原则求得所需的球形约束,然后利用该球形约束减少粒子滤波过程中每一级重要性采样生成的粒子数。多层映射PF则采用多层映射将大小为4L的正交幅度调制(QAM)星座划分为L个4-QAM星座的级联以降低信号检测的搜索范围。计算机仿真结果表明,第1种方法能够在大发送天线数的情况下保持系统性能且有效地降低粒子滤波的计算复杂度;而第2种方法能够以较低的错误性能损失为代价获得计算复杂度的极大降低。

Two low-complexity Particle Filtering （PF） detections for Multi-Input Multi-Output （MIMO） systems, namely sphere-constrained PF and multi-level mapping PF, are proposed by reducing the sample size and the search space of signal detection, respectively. In the proposed sphere-constrained PF, a sphere bound is first obtained based on zero-forcing principle, then the sphere bound is utilized to decrease the number of particles resulted by the importance sampling of each stage in the PF procedure. While the proposed multi-level mapping PF partitions the high-order Quadrature Amplitude Modulation （QAM） constellation of size 4L into L 4-QAM constellations with the aid of multi-level mapping, which reduces the search space of signal detection. Simulation results show that the first method can reduce the computational complexity of PF detection effectively without performance degradation especially when the number of transmit antennas is large; and the second method can significantly reduce the computational complexity at the cost of little performance degradation.