基于信号分解降低OFDM信号峰均比的优化建模

PAR Reduction in OFDM Based on Signal Decomposition Through Optimization Programming

针对正交频分复用(OFDM)系统时域信号具有较高峰均比(PAR)的特点,提出一种新的减小PAR方法.首先经过削峰处理削去幅度大于阈值的信号,然后利用信号分解理论对OFDM削峰信号进行分解,从有用信号中分离出噪声,最后通过限定信号幅度阈值和频谱发射模板来建立误差向量幅度(EVM)优化模型.计算机仿真实验结果表明:新方法在性能上优于传统的非优化建模方法;且与已有的PAR减小优化模型相比,新方法在减小计算复杂度的同时还保持了与已有文献中提出的优化模型的性能.

In this paper, we propose a new method for reducing the high time-domain peak to average power ratio （PAR） of orthogonal frequency division multiplexing （OFDM） signals. First, simple hard limited clipping is used to reduce PAR of a signal by limiting the magnitude of the signal to a threshold value. Then, in order to separate noises form useful signals, we use signal decomposition theory to decompose clipped OFDM signals. Finally, we formulate the problem into an Error Vector Magnitude （EVM） optimization model subject to a deterministic amplitude threshold constraint and spectral mask constraint. Simulation results show that the new method is superior in performance to the traditional non-optimized modeling method. Compared with the existing optimization model, the computational complexity of the proposed method is lower at the expense of insignificant performance degradation.