基于几何整形16QAM DMT编码的可见光视觉成像通信系统  

Image-based Geometric Shaping 16QAM DMT Coded Visible Light Communication

作　　者：韩思齐[1] 王哲[1] 陈慧[1] 迟楠[1] HAN Siqi;WANG Zhe;CHEN Hui;CHI Nan(The Ministry of Education Key Laboratory of Electromagnetic Wave Information Science,Department of Communication Science and Engineering,Fudan University,Shanghai 200433,China)

机构地区：[1]复旦大学通信科学与工程系,电磁波信息科学教育部重点实验室,上海200433

出　　处：《中国照明电器》2020年第6期16-21,共6页China Light & Lighting

基　　金：科技部重点研发计划(2017YFB0403603);国家自然科学基金杰青项目(61925104)。

摘　　要：随着发光二极管(LED)的广泛应用,基于LED的可见光通信(VLC)技术得到了长足的发展。但可见光系统中接受光功率、光电二极管带宽和传输距离之间存在着普遍的矛盾,为了缓解这种矛盾并且提高可见光系统的性能,本文提出了一种基于图像的几何整形(GS)16QAM(正交幅度调制) DMT(离散多音调制)编码的可见光通信方式,将GS 16QAM DMT编码调制与二进制灰度图像结合起来,以图像的形式来传输信号,并且在接收端将最大比率合并(MRC)技术与中值滤波和均值滤波相结合的解码方法。通过MATLAB仿真,我们发现相比较单一的均值滤波和中值滤波方式,与MRC结合可以使得系统误码率(BER)显著下降,并且在MRC比值为1.5的情况下,可以获得较好的传输效果,此外,我们对比了1555、4444、169和88四种GS环形星座分布情况,发现在本系统中几何整形的最佳形状是环形1555。With the wide spread application of light-emitting diodes(LEDs), visible light communication(VLC) technology based on LED has made considerable progress. However, there are common contradictions between the received optical power, photodiode bandwidth, and transmission distance in visible light systems. In order to alleviate this contradiction and improve the performance of visible light systems, we propose a geometric shaping(GS) 16 QAM DMT-coded visible light communication based on image in this paper. We combined the GS 16 QAM DMT coded modulation with a binary grayscale image to transmit the signal, and we used a decoding method that combines the maximum ratio combining(MRC) technology with median filtering and mean filtering at the receiving end. Through MATLAB simulation, we found that compared with a single mean filtering and median filtering method, combining with MRC can significantly reduce the system bit error rate(BER), and the best MRC ratio was 1.5. In addition, we compared the four GS circle constellation distributions of 1555, 4444, 169, and 88, and found that the best shape for geometric shaping in this system was the circle 1555.

关 键 词：可见光通信 光学成像通信 几何整形 离散多音调制(DMT) 最大比率合并(MRC) 

分 类 号：TN929.1[电子电信—通信与信息系统]