Joint interframe separation and gamma correction for asynchronous optical camera communication systems based on high-order statistics

Optical camera communication (OCC), which is enabled by large-scale light-emitting diodes (LEDs) arrays and image-sensor (IS) based cameras, has garnered significant attention from both researchers and industries. Existing OCC synchronization techniques typically rely on either super-Nyquist sampling or on computationally expensive asynchronous recovery algorithms to relax the required camera frame rate. In this paper, we propose a kurtosis-based asynchronous interference cancellation (K-AIC) algorithm, enabling the estimation for both the asynchronous interframe overlapping ratios and nonlinear Gamma distortion levels for each grayscale frame captured by camera. Through comprehensive numerical simulations, we demonstrate that the K-AIC algorithm exhibits low computational complexity, unique global optimum, high reliability and robust performance in mitigating asynchronous-induced bit errors across diverse scenarios. Short-range OCC experiment shows that the K-AIC scheme can effectively compensate for both interframe overlapping and Gamma distortions in a plesiochronous reception scenario, resulting in a Q-factor enhancement of approximately 12 dB with fluctuations of less than 1 dB. Consequently, the system achieves a net data rate of around 200 kbps.