基于LWT的可见光OFDM-IM系统研究  

Research on visible light OFDM-IM system based on LWT

作　　者：王宁[1] 赵黎[1] 张峰[1] 孟祥艳[1] WANG Ning;ZHAO Li;ZHANG Feng;MENG Xiangyan(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：《激光杂志》2024年第1期148-153,共6页Laser Journal

基　　金：国家自然科学基金项目(No.12004292);陕西省科技厅一般项目-工业领域(No.2022GY-072);西安市科技计划项目(No.2020KJRC0040);西安工业大学优秀学位论文培育基金(No.YS202211)。

摘　　要：针对索引调制正交频分复用(OFDM-IM)技术峰均比过高,对相位噪声和载波频偏敏感,系统复杂度高等问题,提出基于小波提升变换(LWT)的可见光OFDM-IM系统。首先选择正交小波基作为子载波,通过对信号的分裂、预测和更新,将信号分为高频信号和低频信号,再结合可见光信道构成LWT-OFDM-IM系统,最后通过理论分析和蒙特卡罗方法对系统的可靠性、峰均比特性和最佳小波分解层数进行了仿真验证,结果表明:当子载波N=256,子块中子载波数量L=4,激活子载波数量k=2,系统误码率为10~(-4)时,LWT-OFDM-IM比FFT-OFDM-IM改善约8 dB,相较于DWT-OFDM-IM提高约4 dB。当系统互补累计分布函数(CCDF)为10^(-1)数量级时,LWT-OFDM-IM的峰均比较FFT-OFDM-IM改善约2.3 dB。随着小波层数的递增,系统的误码性能越好,当小波层数为3层时,大约在10 dB附近,误码率可到10^(-5)量级。Aiming at the problems of index modulation orthogonal frequency-division multiplexing technology with high peak-to-average ratio,sensitivity to phase noise and carrier frequency,and high system complexity,this paper proposes a visible OFDM-IM system based on wavelet boost transform.Firstly,the orthogonal wavelet group is selected as the subcarrier,and the signal is divided into high-frequency signal and low-frequency signal through the splitting,prediction and update of the signal,and then combined with the visible light channel to form the LWT-OFDM-IM system,and finally the reliability,peak-to-average ratio characteristics and optimal wavelet decomposition layer of the system are simulated and verified by theoretical analysis and Monte Carlo method,and the results show that when the subcarrier N=256,the number of neutron carriers in the subblock L=4,the number of activated subcarriers k=2,and the system bit error rate is 10-4.LWT-OFDM-IM is about 8 dB better than FFT-OFDM-IM and about 4 dB higher than DWT-OFDM-IM.When the system complementary cumulative distribution function is 10^(-1)orders of magnitude,the peak-average improvement of LWT-OFDM-IM is about 2.3 dB compared with FFT-OFDM-IM.As the number of wavelet layers increases,the better the bit-error performance of the system,when the wavelet layer is 3 layers,it is about 10 dB,and the bit error rate can reach the order of 10^(-5).

关 键 词：可见光通信 正交频分复用 提升小波变换 索引调制 峰均比 

分 类 号：TN929.1[电子电信—通信与信息系统]