Spectrum sensing in cognitive vehicular network

摘要: Vehicular Ad Hoc Network (VANET) is envisaged to play an important role in the safety of drivers and passengers when moving on roads. However, VANET still faces many challenges before it could be deployed. One such challenge shortage radio frequency spectrum channels. has been allocated 7 channels for dedicated short range communication at 5.9GHz band. The are likely get congested high vehicle densities vehicles contending same medium. Consequently, affecting transmission emergency messages. To alleviate problem scarcity channels, dynamic access (DSA) through cognitive (CR) technology proposed. core functions a CR identify holes licensed bands that can accessed by unlicensed users sensing. In VANET, sensing challenging because mobility nature vehicles, topological changes as well other unique characteristics not found networks. these have fully studied how they affect vehicular network (CVN). this paper, we discuss associated with CVN. We describe primary system activity model used schemes proposed literature. Furthermore, present depth analysis state-of-art cooperative techniques CVN from 2010 May 2016. addition, some open issues