可见光Polar-OFDM通信系统中PAPR抑制方法研究  

Research on PAPR Reduction Method in Visible Light Polar-OFDM Communication System

作　　者：曹阳 罗超 Cao Yang;Luo Chao(School of Electrical and Electronic Engineering,Chongqing University of Technology,Chongqing 401320,China)

机构地区：[1]重庆理工大学电气与电子工程学院,重庆401320

出　　处：《激光与光电子学进展》2022年第7期105-111,共7页Laser & Optoelectronics Progress

基　　金：重庆市教委科学技术项目(KJQN201901125);重庆市科委社会事业与民生保障科技创新专项(cstc2017shmsA40019);重庆市基础与前沿研究计划项目(cstc2019jcy-msxmX0233)。

摘　　要：针对可见光通信正交频分复用系统中存在峰均功率比过高的问题,提出一种降低峰均功率比的改进Polar码方案,将峰均比增长指数和修正比特引入到Polar码编码过程中。该方案首先以离线的形式计算大量Polar码元的峰均比增长指数,以获取最佳的修正集参数,该过程通过蒙特卡罗仿真实现,其次在系统传输过程中,通过信噪比反馈信息进行信道匹配,以查表方式获取仿真过程得到的最佳修正集,最后将所属修正位进行比特翻转,以实现峰均比的降低。该方案可以使用Polar码的传统解码方案对信息和修正比特进行联合解码,因此不需要传输辅助信息,编解码过程复杂度并未增加。仿真结果表明,在码长为1024,子载波数目为256,选取修正位数为32时,本文所提方案在不影响解码复杂度情况下,峰均比减少了4.9 dB,对比同类型方案具有较小的误块率性能优势。Aiming at the problem that the peak-to-average power ratio in the orthogonal frequency division multiplexing system of visible light communication is too high,this paper proposes an improved Polar codes scheme to reduce the peak-to-average power ratio.The peak-to-average ratio growth index and amendment bits are introduced into the Polar codes encoding process.First,the scheme calculates the peak-to-average ratio growth index of a large number of Polar symbols in offline form to obtain the best index of amendment.This process is realized by Monte Carlo simulation.Second,in the system transmission process,the channel matching is performed through the signal-to-noise ratio feedback information,and the optimal correction set is obtained by looking up the table.Finally,the corresponding correction bit is bit-flipped to reduce the peak-to-average ratio.This solution is able to use the traditional decoding solution of the Polar codes to jointly decode the information and amendment bits,so there is no need to transmit auxiliary information,and the complexity of the encoding and decoding process does not increase.The simulation results show that when the code length is 1024,the number of subcarriers is 256,and the number of amendment bits is selected as 32,the proposed correction scheme can reduce the peak-to-average ratio by 4.9 dB without affecting the decoding complexity,and has a smaller block error rate performance advantage compared to the same type of scheme.

关 键 词：光通信 可见光通信 正交频分复用 峰均功率比 Polar码 修正比特 误块率 

分 类 号：TN929.1[电子电信—通信与信息系统]