This paper addresses two fundamental and interrelated issues in device-to-device (D2D)
enhanced cellular networks. The first issue is how D2D users should access spectrum, and …

In the recent years, wireless applications and services have grown tremendously, resulting
to a shortage of radio spectrum. On one hand, most of the available radio spectrum has …

Cognitive radio networks (CRNs) have been proposed to exploit licensed bands
opportunistically, with secondary users'(SU) activity being subordinated to primary users …

In this paper, we investigate users' performance under the hybrid spectrum access model in
the massive cognitive radio network (CRN), where multiple primary users (PUs) and …

Radio spectrum is the backbone for wireless communication. Many recent studies show that
most of the available spectrum has already been allocated. Cognitive radio (CR) provides a …

Cognitive radio (CR) techniques have been proposed for improving the spectral efficiency
by exploiting the temporarily unoccupied segments of the licensed spectrum, provided that …

In this paper two novel spectrum access schemes, a hybrid spectrum access scheme
(HSAS) and a modified hybrid spectrum access scheme (MHSAS) combining underlay and …

Cognitive relay networks are designed to increase access to under-utilized spectrum. The
direct link communication can be exploited to decrease the outage probability with a buffer …

In this paper, we evaluate the secrecy outage performance and throughput of a hybrid
cognitive radio network, where a secondary user (SU) accesses the primary spectrum either …

Cognitive radio networks (CRNs) can improve spectrum utilization by allowing secondary
users (SUs) to dynamically access channels unoccupied by primary users (PUs). The …