Kumar Arulandu

Performance comparison for illumination and visible light communication system using buck converters

This paper presents a new analysis of the illumination and communication performance for visible light communication (VLC) with variable pulse position modulation (VPPM). In particular, it addresses the extra power losses due to the data modulation if a traditional buck converter LED driver is adapted for VLC. We compare VLC systems using two previously proposed driver schemes in the aspects of efficiency, illumination power, data rate and BER.

Effect of buck driver ripple on BER performance in visible light communication using LED

This paper analyses the communication performance for visible light communication (VLC) with Manchester encoded amplitude modulation. In particular, it considers the ripple generated by the LED driver as an important noise contribution for VLC. The ripple depends on the oscillation frequency of the converter which typically is chosen to satisfy other performance criteria such as power conversion efficiency. This paper models the ripple as an additional noise if a buck converter LED driver is adapted for VLC. We argue that ripple can as a worst case be modeled as a random binary offset in the bit detection that randomly affects the distance between the data signal and the decision threshold. We derive expressions for the BER, propose approximations and we compare these with a simulation.

Performance Analysis for Joint Illumination and Visible Light Communication Using Buck Driver

The visible light communication (VLC) can provide data transmission via the illumination light emitting diodes (LED). This paper introduces a new model to analyze the bit error rate (BER) of binary phase modulation in VLC for an arbitrary modulation depth and data duty cycle while taking into account both the Gaussian and signal-dependent shot noise. The impact of the driver design on the BER and its impact on ripple have not been considered in detail before. We compare two different LED driver schemes, namely directly adapting the driver control loop and binary shunting. We address data rate, BER, and power efficiency, for which we propose to use the extra energy per symbol above unmodulated light. We further introduce an analysis of the effect that (truncated) ripple interference has in the (matched or other) filter of the receiver. Ripple causes a harmful interference in VLC, and thus a BER expression is derived to include its effect. Two approximations are proposed to model the ripple interference, and their accuracies are compared by simulations. A low-pass filtering is proposed to alleviate the impact of ripple interference in VLC system.