Car To Car Communication Using RF Cognitive Radio with VLC Common Control Channel

Abstract

This paper combines the advantages of both cognitive radio (CR) communication and visible light communication (VLC) for car-to-car applications to achieve a higher data rate, low delay, minimum outage probability, minimum cost, and minimum bit error rate (BER). CR technology hops among the existing radio frequency (RF) available channels to increase the RF spectrum usage efficiency and dodge the scarcity limitation. Moreover, using CR as a license-free application will reduce car-to-car communication costs. However, CRs require a common control channel (CCC) to communicate the spectrum availability map within the CR network and to inform the receiver end about the change in the transmitter-end channel. Therefore, the CCC is the bottleneck in the car-to-car CR network. Therefore, we explore the types of CCCs and use each of them to solve this bottleneck issue. In the proposed scheme, we assume alternative CCCs such as licensed overlay, unlicensed CR overlay in the ISM band, underlay CR, and using VLC. A MATLAB simulation for a car-to-car framework is built to demonstrate and compare these types of CCC through the chosen metrics. Our metrics include data rate, delay, outage probability, cost, and bit error rate. The comparison analyses shall include comparing VLC versus the other CCC types. We compare practical systems, not the theoretically achievable system therefore the results might prefer a CCC type according to one metric and prefer another type of CCC due to the second metric. Our results show that VLC can achieve up to 90% of the licensed data rate with a small outage probability of 21.2% while maintaining moderate BER and delay. In addition, VLC presents the minimum cost, and as the introduced combined metric it placed second after the licensed type with a score of 84.2%. In conclusion, with the VLC’s bright future of expansion and growing the car-to-car application, we have proven VLC is worthy of implementation practically in modern cars.