Spectrum sensing in cognitive radio sensor networks: towards ultra low overhead, distributed channel findings
Fei Hu, Rahul Patibandla, Yang Xiao · International Journal of Sensor Networks · 2008
Cognitive radios can utilise the idle spectrum holes that are not occupied by the Primary Users (PUs) (i.e. licensed users) for temporary wireless communication tasks. A challenging issue is to efficiently reach global/regional views among the Secondary Users (SUs) on channel availability. The SUs need to exchange control messages on their spectrum sensing results. A traditional way is to send out 'raw' channel information from each individual node. It consumes much wireless communication bandwidth. This research proposes a new cognitive radio spectrum sensing scheme based on our proposed Spatially-Decaying, Time-Incremental (SDTI) updating algorithm. Our SDTI algorithm is based on the extension of Gossiping Updates for Efficient Spectrum Sensing (GUESS) scheme that adopts Flajolet-Martin (FM) aggregation to reduce data amount. Our SDTI automatically assigns weights to channel information based on the distance between a source node and an observing node. Further, distance nodes have less important information to the observing node.