Optimal Resource Allocation to Improve Energy Efficiency of Cognitive Radio-Based Vehicular Ad Hoc Network Under Imperfect Sensing

Abstract

The evolution of wireless communication from fourth generation (4G) to fifth generation (5G) is envisioning massive growth in application of vehicular ad hoc network (VANET) based on cognitive radio (CR) technology. In this VANET, fast and efficient spectrum sensing techniques are required to co-exist with heterogenous network. Most of the current applications are done with assuming perfect carrier sensing, but in actual practice, channel sensing is imperfect. We have investigated the performance under imperfect sensing, so as to exactly analyse the key concern of co-existence, i.e. the average/peak transmission power constraints of secondary user (SU) and average interference power constraints of primary user (PU). However, to alleviate these concerns, we need to have optimum resource allocation, to improve the capacity and energy efficiency of this VANET. To solve the resource allocation and power distribution problem, we have investigated two popular cooperative relay transmission schemes such as Decode-and-Forward (DF) and Amplify-and-Forward (AF). Moreover, we have analytically derived the required transmission rates for both AF and DF schemes. In addition to this, we have also develop the new optimal resource allocation strategies for the CR based co-operative relay protocol to improve the capacity and energy efficiency (EE) of the VANET. The MATLAB simulation results are incorporated to validate the correctness of the analysis.