增益自调整型正交频分复用可见光通信终端

Gain auto-adjusted orthogonal frequency division multiplex visible light communication terminals

为了改善离散多音（DMT）调制点对点可见光通信（VLC）系统在不同通信距离下的通信性能,设计并实现了一种基于16-PSK增益自调整型正交频分复用（OFDM）的VLC终端,研究了自适应增益调整和信道估计技术,分别测试了VLC系统在不同工作条件和不同通信距离下的误码率（BER）性能。实验结果显示,在30-120cm通信范围内,当未采用自适应增益调整以及信道估计技术时,系统的BER范围为0.1-1.0;使用这两种技术后,系统的BER可降至10^-2以下,并且在40-100cm通信距离内,BER更为恒定,其值小于10^-3。这表明,采用自适应增益调整以及信道估计技术,可在一定程度上降低BER并改善系统的稳定性。

In order to improve the communication performance of the point-to-point visible light communication（VLC）system based on discrete multi-tone（DMT）modulation under the different communication distances,a kind of gain-auto-adjusted VLC terminal is designed and implemented based on orthogonal frequency-division multiplexing（OFDM）and 16-phase shift keying（PSK）modulation.Gain-auto-adjustment and channel estimation technique are intensively researched.Under the working conditions with/without using gain-auto-adjustment and with/without using channel estimation,we test the bit-error-ratio（BER）performance of the VLC system under the different communication distances.Experimental results indicate that within the communication distance range of 30-120 cm,without using gainauto-adjustment and channel estimation technique,the BERof the system is as high as 0.1-1.0;by the use of the two techniques,the BERof the system can be dropped to lower than 10^-2;also,within the communication distance range of 40-100 cm,the BERbecomes more constant,whose value is no more than 10^-3.This shows that through the use of gain-auto-adjustment and channel estimation,the BER of the system can be decreased to some extent and the stability of the system can also be improved.