A Comprehensive Survey on Spectrum Sensing Techniques for the Implementation of Cognitive Vehicular Networks

Vehicular Ad Hoc network-VANET plays a crucial role in daily vehicular users and ensures safety for drivers and passengers. But there are some issues before VANET can be utilized. One of those issues is spectrum scarcity i.e., some vehicular users have insufficient spectrum which is used for their communication. In the United States of America, the Federal Communications Commission (FCC) allocated the 75 MHz in the 5.850–5.925 GHz band covering 7 channels with 10 MHz each and 5 MHz reserved as a guard band. So, to overcome the above issue we have Dynamic spectrum access (DSA) via Cognitive radio technology. CR main function is to find the spectrum holes in licensed frequency channels so that unlicensed spectrum users can utilize the unused spectrum. But due to their high speed and topology there are some challenges for spectrum sensing which are as follows. At first to develop effective spectrum sensing solution for vehicular networks we present Existing data for complete classification of CVN spectrum sensing techniques and next we talk about Results of the automotive environment like speed, traffic density fading on spectrum sensing, at last we proceed to a set of prerequisite for CVN spectrum techniques that gives specific cognitive vehicular networks environment characteristics.