一种基于正交投影的OFDM系统峰均比抑制技术  

An Orthogonal Projection Technique for PAPR Reduction in OFDM Systems

作　　者：韩诚亮 肖勇 HAN Chengliang;XIAO Yong(Unit 78111,PLA,Chengdu 610031,China;Xi’an Satellite Control Center,Xi’an 710043,China)

机构地区：[1]中国人民解放军78111部队,四川成都610031 [2]西安卫星测控中心,陕西西安710043

出　　处：《无线电通信技术》2020年第6期689-694,共6页Radio Communications Technology

基　　金：国家自然科学基金项目(91638202)。

摘　　要：主动式星座扩展(ACE)是一种改善OFDM系统峰均比(PAPR)的有效手段。但由于现有ACE算法只能沿着判决距离持续增加的方向迭代搜索最佳预失真量,迭代过程往往因为各类近似运算,收敛于局部次优解。针对该问题,将优化变量从相对上次迭代结果的失真改进量,转换为相对原始OFDM信号的最佳预失真,提出了一种基于正交投影的预失真量搜索技术,在最小二乘(LSA)准则约束下,可以在更大的解空间进行最佳预失真量搜索。Matlab仿真结果表明,与现有已知ACE算法相比,该算法可以进一步抑制正交频分复用信号峰均比;同时,预失真导致的原始信号畸变更小。The active constellation extension(ACE)technique is an effective way to reduce peak-to-average power ratio(PAPR)for OFDM systems.However,existing ACE algorithms can only iterate in decision distance increasing directions to find optimal pre-distortion.Iterations may stop on suboptimal solutions caused by approximations during search.Focusing on this problem,we present an iteration way to search optimum pre-distortion based on orthogonal projection.By transforming optimization variables from improvements on last pre-distortion to whole pre-distortion on primitive OFDM signal,this iteration way can search in a bigger feasible space under the least square approximation(LSA)criterion.Compared with existing algorithms,simulation results from Matlab show outstanding performance on PAPR reduction and signal distortion by adopting this proposed way.

关 键 词：正交频分复用 峰均比 星座扩展 正交投影 

分 类 号：TN911[电子电信—通信与信息系统]