AF cooperative VLC communication systems : cascaded channel analysis

Abstract: Visible light communications (VLC) technology is a relatively new emerging telecommunication paradigm. It offers the opportunity to design cost-effective communication systems due to the dual use of the light sources, which are exploited as illumination devices and as communication antennas. However, this technology is mostly deployed in short-range communication applications because of the light diffusion range, which is short by nature. One good response to this dilemma is the imple- mentation of relay-assisted cooperative communication systems. Cooperative VLC systems provide three advantages, which are an increase in the transmission range, an improvement of the detection, hence of the bit error rate (BER), and an improved lighting system. In this paper, we analyze the channel response of a single-relay indoor VLC system based on an amplify-and- forward (AF) strategy. The system takes into account the fact that the relay also receives a reflected message. Results show the influence of the room’s reflection index, Lambertian index, the number of scattered rays on the overall channel response and confirms the importance of relay-assisted strategies in improving systems’ reliability

A Study Of Cooperative Spectrum Sharing Schemes For Internet Of Things Systems

The Internet of Things (IoT) has gained much attention in recent years with the massive increase in the number of connected devices. Cognitive Machine-to-Machine (CM2M) communications is a hot research topic in which a cognitive dimension allows M2M networks to overcome the challenges of spectrum scarcity, interference, and green requirements. In this paper, we propose a Generalized Cooperative Spectrum Sharing (GCSS) scheme for M2M communication. Cooperation extends the coverage of wireless networks as well as increasing their throughput while reducing the energy consumption of the connected low power devices. We study the outage performance of the proposed GCSS scheme for M2M system and derive exact expressions for the outage probability. We also analyze the effect of varying transmission powers on the performance of the system