基于N重最小频移键控映射的FHT-OFDM可见光通信系统性能研究  

Performance of FHT-OFDM Visible Light Communication System Based on N Minimum Shift Keying Mapping

作　　者：张颖[1] 李宁[1] Zhang Ying;Li Ning(School of Automation and Information Engineering,Xi’an University of Technology,Xi’an,Shaanxi 710048,China)

机构地区：[1]西安理工大学自动化与信息工程学院,陕西西安710048

出　　处：《激光与光电子学进展》2022年第5期115-121,共7页Laser & Optoelectronics Progress

摘　　要：为解决正交频分复用(OFDM)可见光通信中存在的发光二极管(LED)非线性及由其引起的载波频率偏移问题,建立了N重最小频移键控(N-MSK)映射下的OFDM可见光通信系统模型,并利用蒙特卡罗方法,对比分析了N-MSK映射与二进制相移键控(BPSK)映射在信号功率谱密度、星座图、载波干扰比、误码率等性能方面的差异。实验结果表明:N-MSK(N>1)映射系统具有良好的带外衰减特性;在相同频率偏移的情况下,采用N-MSK(N=1)映射方式,系统载波干扰比提升约15 dB,抑制载波频偏引起的载波间干扰的能力增强;相同误码率情况下(10^(-6)),MSK映射系统所需的信噪比(SNR)较BPSK映射低2 dB;相同SNR条件下,MSK映射方式能够克服LED非线性对系统性能的影响。因此,所提模型在信号星座图及误码率方面性能较好。An orthogonal frequency division multiplexing(OFDM)visible light communication system model based on N minimum shift keying(N-MSK)mapping is established to solve challenges related to light-emitting diode(LED)nonlinearity and carrier frequency offset caused by OFDM visible light communication.The Monte Carlo method is used to compare and analyze the differences between N-MSK and binary phase-shift keying(BPSK)mapping in the performance of signal power spectral density,constellation,carrier interference ratio,and bit error rate.The experimental results reveal that the N-MSK(N>1)mapping system has superior out-of-band attenuation characteristics.In the case of the same frequency offset,the carrier interference ratio of the system is increased by approximately 15 dB using the N-MSK(N=1)mapping mode,and the ability to suppress the intercarrier interference caused by carrier frequency offset is enhanced.For the same bit error rate(10^(-6)),the signal-noise ratio(SNR)required by the MSK mapping system is 2 dB lower than that of BPSK mapping.The MSK mapping method can overcome the influence of LED nonlinearity on the system performance under the same SNR condition.Therefore,the proposed model has excellent signal constellation and bit error rate performance.

关 键 词：光通信 发光二极管非线性 N重最小频移键控 正交频分复用 载波频率偏移 哈特莱变换 

分 类 号：TN929.1[电子电信—通信与信息系统]