基于星座映射降低OFDM系统峰均功率比的新方法  

New Method of Reducing PAPR Based on Constellation Mapping in OFDM System

作　　者：苏雁泳[1] 张玉巍[1] 吴华明[1] 

机构地区：[1]哈尔滨工业大学通信工程系,黑龙江哈尔滨150001

出　　处：《电视技术》2010年第S1期134-137,共4页Video Engineering

摘　　要：降低峰均功率比(PAPR)是正交频分复用(OFDM)技术所要解决的关键问题之一,为此,提出了一种新的降低PAPR的方法——星座映射法。在发送端,对经IFFT变换后的超过最大允许范围的数据样值进行软限幅,提高了发射系统的输出功率。在接收端,根据不同调制方式所具有的不同星座分布特性,恢复出被限幅的数据样值,从而减小了由于限幅而造成的信号畸变。理论分析和仿真结果表明,新方法能够有效降低OFDM系统的峰均功率比,同时使系统获得较好的误码性能。One of key problems that should be resolved urgently in the Orthogonal Frequency Division Multiplexing(OFDM) system is how to reduce Peak to Average Power Ratio(PAPR) of signal.And thus,a new method of reducing PAPR is proposed in this paper which is called constellation mapping.In the transmitter,samples that exceed the maximum allowable range with IFFT are clipped by software,thus,the output power of transmitter is enhanced.In the receiver,according to the characteristic of different constellation distribution which different modulation systems possess,clipped samples are restored,and the distortion of signal which is caused by signal chipping is diminished.Both theoretical analysis and simulation results show that the novel method can effectively reduce PAPR in the OFDM system,and the system has good performance of code error simultaneously.

关 键 词：正交频分复用 峰均功率比 星座映射 软限幅 

分 类 号：TN919.3[电子电信—通信与信息系统]