Bandwidth efficient combination for cooperative spectrum sensing in cognitive radio networks

In this paper, we investigate bandwidth efficient combination of spectrum sensing information in cooperative cognitive radio (CR) networks. We propose a general approach in which CR users are allowed to simultaneously send local sensing data to a combining node through a common control channel, based on which we discuss bandwidth efficient combination schemes under two different cases. In the proposed schemes, the bandwidth required for reporting is fixed regardless of the number of cooperative users. With proper preprocessing at individual users, the proposed schemes maintain reasonable performance with the superposition of sensing data at the combining node. Simulation results also demonstrate the effectiveness of the proposed approach.