Multi-channel collaborative spectrum sensing in cognitive radio networks

Collaborative spectrum sensing (CSS) consumes a significant amount of energy during sensing and reporting the sensing results. Such an issue becomes a challenge in the multi-channel systems. In this paper we propose two different energy-efficient CSS schemes, namely, Reduced-Energy Sensing Scheme (RESS) and Reduced-Energy Reporting Scheme (RERS). In RESS, the channels that have been identified as occupied will not be sensed for a number of next sensing rounds, while in RERS, only the sensing results of a subset of the sensed channels will be reported channels. In both schemes, the energy and time resources expended in CSS will be saved. Moreover, the saved time will be exploited in data transmission, improving the throughput. Simulation results show a significant improvement in the energy efficiency of multi-channel CSS.