Superposition-based cooperative spectrum sensing in cognitive radio networks

In cognitive radio networks, cooperation is presented to improve the performance of spectrum sensing. Conventional cooperative scheme assumes that all cooperative secondary users spend the same duration on sensing, sensing results are then reported to the fusion center sequentially. With the number of cooperative users growing, the more data needs to be reported to a fusion center, thus the more reporting time overhead would be consumed. However, reporting of sensing results just consumes reporting time overhead and has no contribution to the performance of cooperative spectrum sensing. In this paper, we propose a superposition-based cooperative spectrum sensing framework. It combines spectrum sensing duration and results reporting duration to sense. Each cooperative user adopts a different sensing duration because they are superposed on different reporting durations. The proposed framework makes cooperative spectrum sensing in a more accurate way without adding extra expected time overhead. Compared with the conventional cooperative scheme, simulation results indicate that significant detection performance enhancements may be achieved through our proposed scheme.