基于 Givens旋转变换的PSWF脉冲调制信号PAPR抑制方法

摘要

To reduce the high Peak-to-Average Power Ratio (PAPR) of modulated signals based on Prolate Spheroidal Wave Function (PSWF) pulse, a novel PAPR reduction method for PSWF pulse based on Givens rotation is proposed. The method represents firstly orthogonal PSWF pulses with weighted eigenvectors, and then uses Givens matrix ( , , )i j qG to rotate all the two-dimensional planes of coordinate( , )i j with any angle. The rotation matrix which most greatly reduces the PAPR of pulse set is searched and the original PSWF pulse set is transformed with the matrix. To reduce the realizaition complexity, a flipping iteration scheme based on grouping is proposed. It is theoretically proved that the transform can maintenance orthogonality of pulse set and high energy concentration in the given frequency domain. Simulation results show that the method can effectively reduce the PAPR of pulse set and preserve the transmission efficiency, the Power Spectral Density (PSD) and Bit Error Ratio (BER) performance of modulated signals.%　　针对基于椭圆球面波函数(Prolate Spheroidal Wave Function, PSWF)脉冲的调制信号峰均功率比过高的问题，该文提出一种基于Givens旋转的PSWF脉冲峰均功率比抑制方法。该方法从正交PSWF脉冲组的特征向量加权表示入手，利用 Givens旋转矩阵(,,)i j qG 对所有子坐标平面(,)i j 进行q角度的旋转，搜寻使脉冲组PAPR (Peak-to-Average Power Ratio, PAPR)值最小的旋转矩阵，最后利用该矩阵对原PSWF脉冲组进行Givens变换，从而实现降低PAPR的目标。针对Givens旋转次数较多导致计算复杂度大的问题，该文提出分组flipping迭代的算法实现方案。理论证明了该变换方法能够保持脉冲组的带内能量聚集和正交性。仿真结果表明，该方法有效降低了脉冲组的PAPR，同时系统传输效率、调制信号功率谱密度与系统误码率性能均保持不变。