Efficient and Robust Spectrum Allocation Algorithm for underlay Cognitive Radio Network under imperfect Channel State Information
Kyrillos Youssef, Nagy Wadie Messiha, Mohammed Abd‐Elnaby · Menoufia Journal of Electronic Engineering Research · 2018
Designing efficient radio resource allocation scheme for Underlay Cognitive radio (CR) has drawn many interests. Most of the existing works assumed perfect channel state information (CSI). In this paper, a spectrum allocation algorithm for underlay multi-user orthogonal frequency division multiplexing (MU-OFDM) based cognitive radio systems under imperfect CSI is proposed to maximize the throughput performance. During the first phase, the receiver estimates the channel and sends a feedback to the transmitter. During the second phase, the proposed scheme efficiently distributes the available subcarriers among cognitive users to maximize the cognitive network throughput while preserving the QoS of the primary users. The proposed algorithm considers the conventional Interference Power Constraint (IPC) to preserve the QoS of the primary users. The simulations results demonstrate that the proposed scheme significantly outperform the conventional IPC based scheme in terms of the achieved CR network throughput and the robustness against estimation error of CSI. Also, it is shown that the achieved CR throughput by the proposed algorithm is enhanced by 102% than that of the conventional IPC based schemes.