Transmit Power Allocation for Distributed Spectrum Sensing in the Presence of Cochannel Interference

Abstract

The distributed spectrum sensing, in which multiple secondary users (SUs) cooperatively perform spectrum sensing, has been shown to be beneficial in improving the spectrum-hole detection performance significantly. This paper hence considers the model of distributed spectrum sensing. In addition, this paper focuses on the hybrid strategy, which combines the underlay and interweave approaches. This paper also considers the scenario, in which each SU is in the presence of co-channel interference when performing distributed spectrum sensing and data transmission. Based on the conducted performance analysis of the considered distributed model, this paper studies the transmit power allocation problem for the distributed spectrum sensing network. The power allocation problems have also been extensively studied in the literature. However, most of them are discussed in the scenario of underlay spectrum-sharing networks. As opposed to the existing works, this paper considers the power allocation problem in the hybrid paradigm and the scenario, in which the received signal at each SU is in the presence of co-channel interference. We formulate our power allocation problem as an optimization problem. The optimization problem is to seek the best power allocation scheme to maximize the throughput of secondary network while satisfying the total transmit power budget and the target SINR constraint of the primary network. The person by person optimization (PBPO) approach is used to solve the above optimization problem. Our results confirm that the proposed optimal power allocation scheme outperforms the uniform power allocation scheme.