Multi-users network model and the corresponding networking scheme for indoor VLC systems.

Recently, the visible light communication (VLC) based on LEDs has attracted much attention. In order to realize multi-users indoor VLC system based on the hybrid full-duplex, we design a kind of illumination/communication terminal and present the corresponding network model in this paper. We propose a multi-access scheme, which can avoid the access collision and network congestion. Meanwhile, we present a method to establish the link between users and expound the routing strategy of information forwarding. Besides, we evaluate the network performance by numerical simulations in aspects of access collision probability, throughput, access time and link establishment time. The results show that the proposed multi-access scheme and routing strategy are feasible for indoor VLC system.

Improved neural network based scene-adaptive nonuniformity correction method for infrared focal plane arrays.

An improved scene-adaptive nonuniformity correction (NUC) algorithm for infrared focal plane arrays (IRFPAs) is proposed. This method simultaneously estimates the infrared detectors' parameters and eliminates the nonuniformity causing fixed pattern noise (FPN) by using a neural network (NN) approach. In the learning process of neuron parameter estimation, the traditional LMS algorithm is substituted with the newly presented variable step size (VSS) normalized least-mean square (NLMS) based adaptive filtering algorithm, which yields faster convergence, smaller misadjustment, and lower computational cost. In addition, a new NN structure is designed to estimate the desired target value, which promotes the calibration precision considerably. The proposed NUC method reaches high correction performance, which is validated by the experimental results quantitatively tested with a simulative testing sequence and a real infrared image sequence.