基于牛顿迭代法预留子载波功率分配的峰均比抑制方法

A Subcarrier Power Allocation Algorithm of Tone Reservation with Newton Iterative Solver for PAPR Reduction

针对现有正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)系统峰均比(Peak to Averaye Power Ratio,PAPR)抑制方法中子载波预留技术只是预留未承载数据的空子载波,没有考虑预留子载波功率分配的问题,提出了一种通过牛顿迭代法对预留子载波进行功率分配来降低PAPR的方法.该方法通过把预留子载波降低PAPR的过程归纳为一阶线性展开时域模型和离散功率谱频域模型的软限幅过程,通过时域限幅,频域滤波操作生成初始预留子载波信号,以信号失真功率比(Signal to Distortion and Noise Rutio,SDNR)最大化为目标函数,运用牛顿迭代法对预留子载波进行功率分配.仿真结果表明,该方法能有效降低峰均比,在载波数为256,预留载波数分别为16和32的条件下,峰均比抑制效果分别改善了4.0d B和4.3d B.

For existing Tone Reservation algorithms for PAPR reduction of the OFDM system,null subcarriers are reserved without considering the subcarrier power allocation. It proposed a subcarriers power allocation algorithm of an improved tone reservation with Newton iterative solver for PAPR Reduction. The process was summarized as a soft limiter process of a first-order linear expansion time-domain model and discrete power spectrum frequency-domain model. The method was to generate reserved tone by clipping in the time domain and filtering in the frequency domain and to view distortion power ratio（ SDNR） maximization as the goal for the reserved sub-carrier power allocation. Simulation results show that this method can effectively reduce the PAPR when the total number of carriers is 256,the numbers of reserved carriers are 16 and 32,and that PAPR suppression has been improved by 4. 0dB and 4. 3dB.