New Cooperation-Based Channel State Acquisition Scheme for Ad Hoc Cognitive Radio Systems

We consider a channel state acquisition scheme in the cognitive radio (CR) ad hoc system. Unlike cellular CR systems, the channel state acquisition scheme, which uses a geolocation database, is hard to implement in an ad hoc CR system. Hence, we consider hybrid channel state acquisition schemes that use cooperative multiband sensing to build a virtual spectrum database for ad hoc CR systems, which we refer to as the spectrum pool. Then, we compare three schemes, i.e., a sensing scheme and two hybrid schemes, in which the spectrum information or the band can be cooperatively shared among CR users without using a dedicated common control channel. By using the spectrum pool, the CR users can have more information on the spectrum compared with the case when there is no channel state sharing. Therefore, the number of spectrum sensing attempts to find a vacant band that can be reduced, and the performance of CR systems can be improved. Through simulation, we show that our analysis results are well matched to simulation results. We also find that the throughput can be improved by utilizing the spectrum pool.