论文部分内容阅读
目前,基于单白光LED的光正交频分复用(OFDM)系统结构的频谱效率(SE)成倍低于传统OFDM系统,为了提高SE,对多基色LED的宽带通信潜能进行了研究,在综合分析经典光OFDM调制技术的基础上,提出一种基于多基色LED和OFDM的可见光通信(VLC)系统。系统发射机采用M基色LED作为发射天线,并采用OFDM对二进制数据进行调制,调制后的多个复信号再通过二维复信号转M维实向量信号的方法和极性编码方法,驱动M基色LED发出复合光信号,接收机采用M个前端设置有不同颜色滤波器的光电二极管(PD)接收叠加复合光信号。仿真结果表明,在相同误符号率情况下,本文系统在加性高斯白噪声环境和实测信道条件下比经典的非对称限幅光OFDM(ACO-OFDM)的VLC系统大约有2dB的信噪比(SNR)增益。
At present, the spectral efficiency (SE) of a single Orthogonal Frequency Division Multiplexing (OFDM) system based on a single white LED is twice as low as that of a conventional OFDM system. In order to improve the SE, the broadband communication potential of a multi-primary LED is studied. Based on the analysis of classical optical OFDM modulation technology, a visible light communication (VLC) system based on multi-primary LED and OFDM is proposed. The system transmitter adopts the M primary color LED as the transmitting antenna and uses OFDM to modulate the binary data. The modulated multiple complex signals are converted into two-dimensional complex signals by the M-dimensional real vector signals and the polarity coding method to drive the M primary colors LED emits a composite optical signal, and the receiver uses M photodiodes (PDs) with different color filters arranged at the front end to receive and superimpose a composite optical signal. The simulation results show that the system has SNR of about 2dB better than the classical asymmetric limiting optical OFDM (ACO-OFDM) VLC system under additive white Gaussian noise environment and measured channel condition under the same error symbol rate (SNR) gain.