A Public Information Precoding for MIMO Visible Light Communication System Based on Manifold Optimization

Visible light communication (VLC) is an attractive subset of optical communication that provides a high data rate in the access layer of the network. The combination of multiple inputmultiple output (MIMO) with a VLC system leads to a higher speed of data transmission named as MIMO-VLC system. In multi-user (MU) MIMO-VLC, a LED array transmits signals for users. These signals are categorized as signals of private information for each user and signals of public information for all users. The main idea of this paper is to design an omnidirectional precoding to transmit the signals of public information in the MUMIMO-VLC network. To this end, we propose to maximize the achievable rate which leads to maximizing the received mean power at the possible location of the users. Besides maximizing the achievable rate, we consider equal mean transmission power constraint in all LEDs to achieve higher power efficiency of the power amplifiers used in the LED array. Based on this we formulate an optimization problem in which the constraint is in the form of a manifold and utilize a gradient method projected on the manifold to solve the problem. Simulation results indicate that the proposed omnidirectional precoding can achieve superior received mean power and bit error rate with respect to the classical form without precoding utilization.Comment: This paper has been submitted to an IEEE Journa

Application of NOMA in Vehicular Visible Light Communication Systems

In the context of an increasing interest toward reducing the number of traffic accidents and of associated victims, communication-based vehicle safety applications have emerged as one of the best solutions to enhance road safety. In this area, visible light communications (VLC) have a great potential for applications due to their relatively simple design for basic functioning, efficiency, and large geographical distribution. Vehicular Visible Light Communication (VVLC) is preferred as a vehicle to everything (V2X) communications scheme. Due to its highly secure, low complexity, and radio frequency (RF) interference-free characteristics, exploiting the line of sight (LoS) propagation of visible light and usage of already existing vehicle light-emitting diodes (LEDs). This research is addressing the application of the Non-Orthogonal Multiple Access (NOMA) technique in VLC based Vehicle-to- Vehicle (V2V) communication. The proposed system is simulated in almost realistic conditions and the performance of the system is analyzed under different scenarios

On the performance analysis of NOMA-based vehicular visible light communication systems

Communication-based vehicle safety applications have emerged as one of the best solutions to enhance road safety. In this area, visible light communication (VLC) has great potential for such applications, named Vehicular VLC (V-VLC). V-VLC is preferred due to its highly secure, low complexity, and radio frequency (RF) interference-free characteristics, exploiting the line of sight (LoS) propagation of visible light and usage of already existing vehicle light-emitting diodes. This research addresses the application of the non-orthogonal multiple access (NOMA) technique in V-VLC based vehicle-to-vehicle communication. In this study, we proposed a system integrating NOMA in V-VLC networks and comprehensively provided an analysis of the system. Subsequently, we derived theoretical achievable capacity and an exact bit error rate expression for the proposed scenario. This paper also covers discussions about system performance under the non-ideal NOAM at the receiver, the effect of transmitter-receiver distance, and the impact of different weather conditions. The derived analytical BER and channel capacity expressions are verified with the simulation results