Optimal Primary Exclusive Region Design for Cognitive Radio VANETs on Multiple Roads

摘要

This paper presents the stochastic geometry analysis and design of a primary exclusive region (PER) for cognitive radio vehicular ad hoc networks (CR-VANETs). Recently, to satisfy the increasing demands for vehicular communications, cognitive radio (CR) technology has been applied to broaden the vehicular communication spectrum. However, while utilizing the licensed spectrum opportunistically as secondary transmitters (STs), vehicles must avoid harmful interference with primary receivers (PRs), e.g., TV broadcasters. In contrast to cooperative spectrum sensing and stand-alone spectrum sensing in most existing works, in this paper, we proposed a geo-location-database-driven opportunistic spectrum access (OSA) approach to maximize the spectrum opportunity of SUs. For the proposed OSA approach, this paper presents a line segment model for CR-VANETs and introduces the allowable transmission probability of STs in each line segment. We theoretically analyze the outage probability of the primary user using stochastic geometry. From these analyses, we introduce the optimization problem to maximize the spectrum opportunity of STs while ensuring a minimal outage threshold for the PR. Subsequently, we numerically evaluate the solution of the optimization problem. Our results show that a PER for CR-VANETs has been successfully designed. With the decrease in the length of the line segment and further detailed information, a smaller and more complex-shaped PER can be achieved.