Sensor cooperation and decision fusion to improve detection in cognitive radio spectrum sensing

Cooperative spectrum sensing has been shown to significantly improve the spectrum utilization in cognitive radio networks. In this paper, we deal with the problem of error in reporting the local decisions to the fusion center by the secondary users. First, we formulate a protocol of cooperation among the secondary users to share their local decisions and then relay each others information to the fusion center. Second, we use low-density parity-check coded communication in the second hop to protect the relayed information against variations in the wireless channel. The reported information from each sensor is then combined at a fusion center and a final decision is made based on majority-voting fusion mechanism. We refer to this scheme as coded cooperative spectrum sensing (CCSS). Finally, it is shown that the proposed CCSS scheme improves the spectrum utilization of the cognitive radio network by reducing the error in reporting the local decisions to the fusion center