| 摘要: |
| 针对室内高速可见光链路设计，提出了一种频谱高效的基于无载波幅度相位调制（CAP）的可见光正交频分复用（OFDM）传输方案，即CAP-OFDM。该方案首先采用一对相互正交的滤波器产生基带实信号，再利用哈特莱（Hartley）变换将其加载到频域正交的载波上，并通过添加直流偏置的方式实现信号单极化。基于朗伯(Lambert)辐射模型，推导了CAP-OFDM以及已有文献提出的基于脉冲振幅调制（PAM）的可见光正交频分复用（PAM-OFDM）、基于正交振幅调制（QAM）的可见光正交频分复用（QAM-OFDM）调制方案的误符号率理论解析式、频带利用率，并通过仿真实验验证了理论推导的正确性。仿真结果表明，调制阶数相同时，CAP-OFDM、QAM-OFDM误码性能相同，且优于PAM-OFDM；频带利用率相同时，CAP-OFDM误码性能最优，而QAM-OFDM最差。 |
| 关键词: 可见光链路 无载波幅度相位调制 正交频分复用 频带利用率 |
| DOI： |
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| 基金项目:国家自然科学基金资助项目（61371091） |
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| A visible light communication OFDM transmission scheme based on CAP modulation |
| LIU Ying,WANG Xudong,WU Nan,CUI Yu |
| (Information Science Technology College，Dalian Maritime University，Dalian 116026，China) |
| Abstract: |
| In view of the design of indoor high-speed visible light link,an Orthogonal Frequency Division Multiplexing(OFDM) transmission scheme based on Carrierless Amplitude Phase(CAP) modulation(CAP-OFDM) with high spectrum efficiency is proposed.In this scheme,a pair of orthogonal filters are used to generate the baseband real signal,the signal is then loaded into a orthogonal carrier in the frequency domain by Hartley transform and polarized by adding a DC bias.Based on the Lambert radiation model,the analytical formulas of the symbol error rate(SER) and bandwidth utilization for the CAP-OFDM and the PAM-OFDM,QAM-OFDM transmission schemes proposed in the existing literatures are deduced.The correctness of the theoretical derivation is verified through simulation experiments.The simulation results show that when the modulation order is fixed,the SER performance of CAP-OFDM and QAM-OFDM is the same and better than that of PAM-OFDM.When the bandwidth utilization is fixed,CAP-OFDM has the best SER performance and QAM-OFDM has the worst SER performance. |
| Key words: visible light link carrierless amplitude phase modulation orthogonal frequency division multiplexing bandwidth utilization |
《电讯技术》编辑部 