针对可见光通信系统调制带宽有限的问题, 提出了将两种具有高频带利用率的调制方式应用于可见光通信系统的方案。分别论述了正交频分复用和奈奎斯特单载波调制的基本原理和产生途径, 仿真验证了正交频分复用和奈奎斯特单载波两种调制解调技术应用于可见光通信系统时的性能, 比较分析了两种技术在不同信噪比条件下的误码率和频带利用率, 仿真结果表明, 奈奎斯特单载波相对于正交频分复用有更高的频带利用率和较低的误码率, 更适用于可见光通信系统。

This paper first reviews the fundamental principle of Visible Light Communication (VLC) system, considering the limited modulation bandwidth of VLC system. Two methods with high Spectrum Efficiency (SE) is proposed to make full use of the limited bandwidth in VLC system .The paper then introduce two modulation techniques for its realization: Orthogonal Frequency Division Multiplexing (OFDM) and Nyquist-shaped Single-Carrier (N-shaped SC) and their principles. We simulate and compare the performances of OFDM and N-shaped SC in VLC system. The Bit Error Rate (BER) performance and SE of the two systems are analyzed and compared. It is shown that both of the OFDM-based VLC and N-shaped SC-based VLC have high SE, but N-shaped SC is more robust and suitable to the implementation of the VLC system.