基于双重调制技术的可见光通信系统研究

Research on visible light communication system based on hybrid modulation technique

LED调制带宽制约着可见光通信(VLC)系统的数据传输速率。为此,提出一种基于双重调制技术COB(chip on board)封装的LED灯具,通过实现16级脉冲振幅调制(PAM),将系统数据传输速率提升4倍;结合脉冲宽度调制(PWM)技术进行调光,同时兼顾室内的照明及通信。采用Matlab软件模拟仿真视频传输试验。结果表明,在相同信噪比(SNR)的情况下,基于双重调制技术的VLC系统的误码率(BER)比传统使用开关键控(OOK)调控技术系统的BER更低。本文系统在不增加器件带宽前提下,成倍提高了无线通信的质量与数据传输速率;从照明与通信的角度优化了VLC系统的信源,具有广阔的应用前景。

The transmission rate of visible light communication（VLC）system remains low due to the low bandwidth performance of the light emitting diode（LED）.Therefore,a VLC transmitter,which consists of a chip on board（COB）packaging LED lamp integrated with hybrid modulation technique,is presented.With a 16-level pulse amplitude modulation（PAM）scheme,the transmission rate of the VLC system is enhanced by about four times.In addition,it also can be directly compatible with the pulse width modulation（PWM）dimming control schemes,which can control illumination levels to suit for indoor lighting and communication.Then,a video transmission system is simulated through MATLAB software.The results show that with the same signal-to-noise ratio（SNR）,the LED based on COB packaging with hybrid modulation technique has lower bit error rate（BER）compared with the traditional system which is controled by a single LED that is either ON or OFF modulation.Without increasing the bandwidth of the device,the quality and the data transmission rate of the VLC are improved.