A Piecewise Linear Companding Transform for PAPR Reduction of OFDM Signals With Companding Distortion Mitigation
A Piecewise Linear Companding Transform for PAPR Reduction of OFDM Signals With Companding Distortion Mitigation
复制标题
分段线性压扩变换可减少 OFDM 信号的 PAPR 并减轻压扩失真
DOI：
10.1109/tbc.2014.2339531
复制
发表时间：
2014-09-01
影响因子：
4.5
通讯作者：
Zhang, Hailin
中科院分区：
文献类型：
--
作者：
Hu, Meixia;Li, Yongzhao;Zhang, Hailin
压扩是用于降低正交频分复用(Ofdm)信号的峰均功率比(PAPR)的众所周知的技术。然而，由于压扩变换是在对ofdm信号进行调制之后的额外运算，压扩方案以增加误码率(BER)为代价来降低PAPR。针对压扩失真问题，提出了一种新的分段线性压扩方案。在压扩变换的设计中，我们研究了压扩失真的理论特征。结果表明，对幅度增量较小的较大信号进行压扩更有利于减小压扩失真。在分析结果的基础上，提出了一种新的分段线性压扩变换，将幅度在给定压扩峰值上的信号削波以降低峰值功率，并对幅度接近给定压扩峰值的信号进行线性变换以进行功率补偿。通过对压扩峰值幅度和线性变换尺度的精心设计，所提出的变换可以在有效降低峰均比的同时获得更高的误码率和功率谱密度性能。
Companding is a well-known technique for the peak-to-average power ratio (PAPR) reduction of orthogonal frequency division multiplexing (OFDM) signals. However, as companding transform is an extra operation after the modulation of OFDM signals, companding schemes reduce PAPR at the expense of increasing the bit error rate (BER). In this paper, a new piecewise linear companding scheme is proposed aiming at mitigating companding distortion. In the design of the companding transform, we study the theoretical characterization of companding distortion. It demonstrates that companding larger signals with smaller amplitude increments are more favorable in reducing companding distortion. Based on the analysis results, a new piecewise linear companding transform is proposed by clipping the signals with amplitudes over a given companded peak amplitude for peak power reduction, and linearly transforming the signals with amplitudes close to the given companded peak amplitude for power compensation. With the careful design of the companded peak amplitude and the linear transform scale, the proposed transform can achieve enhanced BER and power spectral density performance, while reducing PAPR effectively.