基于门限控制的新型矢量扰动预编码方法

A new approach for Vector Perturbation based on threshold controlling

摘要:

以下行多用户多输入单输出系统为例，分析了在发送端采用矢量扰动预编码时，信道矩阵的条件数大小对算法复杂度及其系统性能的影响。通过蒙特卡洛仿真发现，当信道矩阵的条件数较小时，硬性采用矢量扰动预编码所寻找出来的扰动矢量大多是零矢量，此时不恰当的扰动甚至可能增大信号发送功率，导致不必要的浪费。当信道矩阵的条件数较大时，采用格基约缩的方法可以降低搜索扰动矢量的复杂度。在此基础上，提出了一种基于门限控制的新型矢量扰动预编码方法，该方法相对于传统的完全不考虑信道特性的矢量扰动预编码，可以极小的性能损失换取计算复杂度的显著降低。

Abstract:

Taking the Multiple User Multiple Input and Single Output(MU-MISO) downlink system as an example, the influences of the condition numbers of channel matrix on the algorithm complexity and system performance are analyzed, while the Vector Perturbation(VP) is employed at the transmitter. It is found by Monte Carlo simulation that when the condition number is small, inappropriate perturbation may even increase the signal transmission power, leading to unnecessary waste; on the other side, when the condition number is large, Lattice Reduction(LR) method can be used to reduce the complexity of searching perturbation vectors. On this basis, a novel VP method based on threshold controlling is proposed. It is proved that computational complexity of the proposed method can be significantly reduced at the expense of minimal performance loss.