基于多基色LED和OFDM的可见光通信系统

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。

Visible light communication system based on multi-prime color LED and OFDM

In order to investigate the potential broadband communication performance of multi-prime color light-emitting diode (LED),a vi sible light communication (VLC) system based on multi-prime color LED and orthogonal frequency division multiplexing (OFDM) is proposed.In the proposed system,the transmitter adopts M-prime color LE Ds as the transmitting antenna and uses OFDM technology to modulate the binary data.By the method of two-dime nsion (2-D) to M-dimension (M-D) real vector and bipolar encoding scheme,the modulated compl ex signals are converted into an M-D vector signal and then it drives M-prime color LEDs to e mit compound light signals. The receiver adopts M photo diodes with different color filters in the front end to receive the compound optical signals.The simulation results show that under the same symbol error rate,the new system has about 2dB signal-to-noise ratio (SNR) gain than the classic asymmetrically clipped optical OFDM (ACO-OFDM) VLC syste m in additive white Gaussian noise (AWGN) and measured channel.