Simplified Alamouti-Type Space-Time Coding for Image Sensor Communication Using Rotary LED Transmitter
Simplified Alamouti-Type Space-Time Coding for Image Sensor Communication Using Rotary LED Transmitter
复制标题
使用旋转 LED 发射器进行图像传感器通信的简化 Alamouti 型空时编码
DOI：
10.1109/jphot.2021.3137601
复制
发表时间：
2022
影响因子：
2.4
通讯作者：
Yamazato Takaya
中科院分区：
文献类型：
--
作者：
Tang Zhengqiang;Arai Shintaro;Yamazato Takaya
本研究提出了一种简化的alamouti型空时编码（STC），提高了使用旋转LED发射器的图像传感器通信（ISC）的性能。为了利用LED灯的后像提高ISC的数据速率，研制了旋转LED发射机。发射器同时使led闪烁并围绕垂直轴旋转。由于在相机曝光时间内发生的闪烁led的运动，多个闪烁状态被捕获为后像，从而增加了每个图像可以接收的信息量。然而，随着通信距离的增加，图像传感器上捕获的LED光的尺寸减小。在这种情况下，很难区分每个LED闪烁状态，导致解调性能下降。为了克服这一问题，本文提出的STC将相邻的角后像编码为符号对，并使用两个符号次数传输这些符号对。此外，我们通过使用标准化的LED亮度值简化了数据解码过程。通过实验对该方法的解调性能进行了评价。与传统的编码方法相比，本文提出的STC不需要信道估计，显著提高了解调性能。
This study proposes a simplified Alamouti-type space-time coding (STC), improving the performance of image sensor communication (ISC) using a rotary LED transmitter. The rotary LED transmitter was developed to increase the data rate of ISC using afterimages of LED lights. The transmitter simultaneously causes the LEDs to blink and rotates them around a vertical axis. Owing to the movement of the blinking LEDs that occurs within the exposure time of the camera, multiple blinking states are captured as afterimages, thus increasing the amount of information that can be received per image. However, with increasing communication distance, the size of the LED light captured on the image sensor decreases. In this case, it is difficult to distinguish each LED blinking state, leading to a degradation of the demodulation performance. To overcome this problem, the proposed STC encodes adjacent angular afterimages as symbol pairs and transmits these symbol pairs using two symbol times. In addition, we simplified the data decoding process by using normalized LED luminance values. We evaluate the demodulation performance of the proposed method through experiments. Compared with conventional coding methods, the proposed STC requires no channel estimation and significantly improves the demodulation performance.