基于手机摄像头的VLC数据帧性能增强及识别

Performance Enhancement and Recognition of VLC Data Frame based on Mobile Camera

将手机的互补金属氧化物半导体摄像头作为可见光通信链路的接收端时,互补金属氧化物半导体的晕染效应会降低摄像头获得的数据帧的消光比,背景光和互补金属氧化物半导体热噪声还会使数据帧的识别率降低。针对上述问题,提出了利用高低帽变换和极大值抑制的优化数据帧的方法,该方法提高了数据帧的消光比并且抑制了局部噪声,得到易于解码的数据帧。但上述优化算法耗时长,为了将算法移植到手机中使用,采用了耗时短的局部加权回归散点平滑信号识别方法对数据帧进行处理。结果表明,局部加权回归散点平滑算法受局部噪声影响较小,与前人采用的算法相比可以获得最佳信噪比。

In view of the data frame obtained by the mobile phone CMOS camera which is regard as the receiver in VLC link, the data frame has a low extinction ration due to the blooming effect of the CMOS. In addition to the background light, the thermal noise of CMOS will reduce the data frame recognition rate. Aiming at the above problems, an optimization method using high-low-hat transformation and maximum value suppression is proposed. This method improves the extinction ratio of the data frame and suppresses the local noise. Therefore, the data frame can be decoded easily. However, the optimization algorithm is time consuming. In order to transplant the algorithm into the mobile phone, the data frame is processed by a short time-Local Weighted Scatterplot Smoothing （lowess） signal recognition method. The results show that the lowess algorithm is less affected by local noise, and the optimal signal to noise ratio can be obtained when compared with previous algorithm.