OFDM系统中低失真峰均比抑制模块设计实现  

Design and Implementation of Low Distortion Peak-to-Average Power Ratio Module in OFDM System

作　　者：郭强胜[1] 郑重 肖飞[1] 杨建平[1] GUO Qiang-sheng;ZHENG Zhong;XIAO Fei;YANG Jian-ping(No.30 Institute of CETC, Chengdu Sichuan 610041, China)

机构地区：[1]中国电子科技集团公司第三十研究所

出　　处：《通信技术》2019年第9期2102-2111,共10页Communications Technology

摘　　要：OFDM多载波系统一个主要的缺点就是多个子载波的相互叠加造成峰均比过高的问题,为了克服这一问题的传统办法就是采用具有大动态范围的功率放大器,但这样做的缺点会导致功率放大器的效率大大降低,在工程实现上会导致设备的功耗增加和散热困难等难题,因此对OFDM系统进行峰均比抑制是必须要首先解决的问题。针对该问题,研究并实现了峰值脉冲抵消(PCCFR)削峰算法。采用MATLAB仿真软件对该算法在OFDM多载波系统的削峰效果进行了仿真,同时仿真评估了该算法对系统性能的恶化影响。最后将该算法在FPGA平台中进行设计实现和Modelsim仿真,将系统原本15 dB的峰均比降低到7 dB,同时具有非常小的信噪比恶化损失。通过该算法模块的仿真实现,极大的降低了OFDM多载波系统对功率放大器线性度的要求,有效的减小了产品的体积和功耗,具有广泛的实用价值。The main disadvantage of OFDM multi-carrier system is that the mutual superposition of multiple sub-carriers would cause the peak-to-average ratio to be too high. The traditional way to overcome this problem is to use a power amplifier with a large dynamic range. However, the disadvantage of this doing is that the efficiency of the power amplifier is greatly reduced, and in engineering implementation would lead to problems such as increased power consumption and difficulty in heat dissipation of equipment. Therefore, peak-to-average ratio suppression for OFDM systems is a problem that must be firstly solved. Aiming at this problem, the PC-CFR peak clipping algorithm is explored and implemented. The peak clipping effect of the algorithm in OFDM multi-carrier system is simulated with MATLAB simulation software, and simultaneously, the deteriorating effect of the algorithm on system performance is evaluated by simulation. Finally, the design implementation of this algorithm on the FPGA platform and Modelsim simulation are done, and the original 15 dB peak-to-average ratio of the system is reduced to 7 dB, with very small signalto-noise ratio degradation loss. Through the simulation implementation of the algorithm module, the linearity requirement of power amplifier for OFDM multi-carrier system is greatly reduced, the volume and power consumption of the product effectively decreased, and all this has a wide range of practical value.

关 键 词：OFDM多载波系统 峰均比 峰值脉冲抵消削峰 信噪比 功放线性度 

分 类 号：TN924.2[电子电信—通信与信息系统]