基于小波变换的可见光OFDM通信系统性能优化  

Performance optimization of visible light OFDM communication system based on wavelet transform

作　　者：张雨桐 赵黎[1] 张峰[1] ZHANG Yutong;ZHAO Li;ZHANG Feng(School of Electronic Information Engineering,Xi’an Technological University,Xi’an 710021,China)

机构地区：[1]西安工业大学电子信息工程学院,西安710021

出　　处：《激光技术》2020年第2期261-265,共5页Laser Technology

基　　金：国家自然科学基金资助项目(61671362);陕西省重点研发计划资助项目(2018GY-188);西安市科技计划资助项目(2017075CG/RC038(XAGY001));陕西省教育厅专项科研计划资助项目(17JK0373)。

摘　　要：在可见光通信中,由于信道的多径效应和信道衰减在传统正交频分复用(OFDM)系统会产生符号间干扰,从而降低系统的可靠性。为了保障通信质量,采用带有循环前缀的OFDM系统来抵抗多径效应引起的符号干扰;为了降低系统的误比特率和峰均比,采用Haar小波来实现系统有效性、可靠性、峰均比等参量的性能优化,并采用蒙特卡洛法进行了仿真验证。结果表明,当系统的误比特率为10-4时,离散小波变换OFDM系统较快速傅里叶变换OFDM(FFT-OFDM)系统的误码性能大约提高了5dB,通信效率提高了大约11%;当系统的峰均比为5dB时,FFT-OFDM系统的互补累计分布函数(CCDF)值接近10-2,DWT-OFDM系统的CCDF值为0。该研究为可见光小波变换OFDM通信提供了参考。In visible light communications,multipath effects and channel attenuation in traditional orthogonal frequency division multiplexing(OFDM)systems can generate intersymbol interference and reduce system reliability.In order to guarantee the quality of communication,OFDM system with cyclic prefix was used to resist the symbolic interference caused by multipath effect.In order to reduce bit error rate(BER)and peak-to-average power ratio(PAPR)of the system,Haar wavelet was used to optimize the performance of system parameters such as validity,reliability and PAPR.Monte Carlo method was used to verify the simulation results.The results show that,when bit error rate of the system is 10-4,BER performance of discrete wavelet transform OFDM system is about 5dB higher than that of fast Fourier transform OFDM(FFT-OFDM)system.Communication efficiency has been improved by about 11%.When PAPR of the system is 5dB,complementary cumulative distribution function(CCDF)of FFT-OFDM system is close to 10-2.CCDF value of DWT-OFDM system is 0.This study provides a reference for OFDM communication based on visible light wavelet transform.

关 键 词：光通信 正交频分复用 HAAR小波 峰均比 系统误比特率 

分 类 号：TN92[电子电信—通信与信息系统]