Sequential maximum likelihood decoding incorporating reliability determination for image sensor communication

Tang, Zhengqiang; Arai, Shintaro; Yendo, Tomohiro; He, Di; Yamazato, Takaya

doi:10.1587/comex.2020xbl0058

Cited by 6 publications

(3 citation statements)

References 5 publications

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“…The main appeal of ISC is the ability to project the received lights onto the two-dimensional image sensor plane. Based on this feature, multiple LED lights could be received in a single image [23], and the signal and noise light sources can be spatially distinguished by image processing [24]- [26]. In addition, because ISC uses a camera as the receiver, the relative position between the transmitter and the receiver can be estimated using single-view geometry [27].…”

Section: Introductionmentioning

confidence: 99%

Image Sensor Communication via Light Trail Using Propeller LED Transmitter

Tang,

Zheng,

Yamazato

et al. 2023

IEEE Photonics J.

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This paper proposes an image sensor communication (ISC) system based on light trails using rotary LEDs. The light trail refers to an optical phenomenon where light appears elongated and forms a trajectory due to the movement of luminous objects. In this study, we developed a propeller LED transmitter (P-Tx) that rotates LEDs with a propeller to generate and transmit light trail signals. According to the LED's rotation radius, the proposed system segments light trails to achieve high-capacity data transmission at short distances and high-trust transmission at long distances. In addition, we perform the rotation coordinates system conversion for the captured light trails to accurately and simply detect the signal LEDs' coordinates. We experimentally evaluate the proposed system's communication performance and data rate. The experimental results demonstrate that our system is capable of meeting communication requirements at various distances and exhibits significant potential in enhancing the data transmission rate of ISC.

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Section: Introductionmentioning

confidence: 99%

Image Sensor Communication via Light Trail Using Propeller LED Transmitter

Tang,

Zheng,

Yamazato

et al. 2023

IEEE Photonics J.

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“…Because the data are demodulated from a two-dimensional (2D) image, an image processing technique can spatially separate the signal and non-signal light sources. This means that ISC is largely immune to noise [7]- [9]. However, the speed of ISC is basically determined by the shooting speed of the camera.…”

Section: Introductionmentioning

confidence: 99%

Simplified Alamouti-Type Space-Time Coding for Image Sensor Communication Using Rotary LED Transmitter

2022

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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.

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“…Then, the data are demodulated using the extracted pixel. Because the data are demodulated from a two-dimensional captured image, ISC can spatially separate signals and noises in the image, thereby providing superior anti-interference ability [22]- [24].…”

Section: Introductionmentioning

confidence: 99%

Rotary LED Transmitter for Improving Data Transmission Rate of Image Sensor Communication

et al. 2021

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This study focuses on image sensor communication (ISC), which is a form of visible light communication, using a light-emitting diode (LED) and a camera as the transmitting and receiving device, respectively. In an ISC system, the receiver captures optical signals transmitted by blinking LEDs as an image and demodulates the data using the captured image. The ISC system can spatially separate signals and noises in the image, thus providing superior anti-interference ability. However, because the speed of ISC depends on the shooting speed of the camera, the receiver suffers from a low data transmission rate when a low-speed camera is used. To improve the data rate of ISC, we have developed a rotary LED transmitter. This transmitter cylindrically rotates the blinking LEDs during the exposure time of the camera. The camera captures multiple blinking states of LEDs as afterimages in a single image, thereby increasing the amount of data received per image. In this paper, we propose an ISC system using a rotary LED transmitter and present an experiment for the evaluation of the data rate. The result indicates that the data rate of the rotary LED transmitter is 60 times that of the conventional method.

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Sequential maximum likelihood decoding incorporating reliability determination for image sensor communication

Cited by 6 publications

References 5 publications

Image Sensor Communication via Light Trail Using Propeller LED Transmitter

Image Sensor Communication via Light Trail Using Propeller LED Transmitter

Simplified Alamouti-Type Space-Time Coding for Image Sensor Communication Using Rotary LED Transmitter

Rotary LED Transmitter for Improving Data Transmission Rate of Image Sensor Communication

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