In this study, the authors investigate the outage probability of underlay cognitive radio
systems with relay selection. In particular, they consider a secondary multi‐relay network …

In cognitive radio networks, it is often impossible to have regular information exchange
between PUs and SUs. This implies that SUs are unable to obtain up-to-date channel …

In this paper, we study energy-efficient transmissions for multiple-input multiple-output
(MIMO) cognitive radio (CR) networks in which the secondary unlicensed users coexist with …

This paper focuses on a downlink beamforming problem in the cognitive radio (CR)
communication system where primary users (PUs) coexist with secondary users (SUs). It is …

This paper considers the cooperation between a cognitive system and a primary system
where multiple cognitive base stations (CBSs) relay the primary user's (PU) signals in …

In this paper, we propose two subspace-projection-based precoding schemes, namely, full-
projection (FP)-and partial-projection (PP)-based precoding, for a cognitive radio multiple …

In this paper, we propose robust power allocation and admission control schemes for
providing probabilistically constrained quality of service (QoS) in selective relaying based …

Relaying primary signals by cognitive base-stations (CBSs) can help the primary system and
thus win CBSs a higher chance to transmit their own signals. For this purpose, conventional …

In spectrum-sharing-based cognitive radio networks, multiple secondary systems can
access a licensed spectrum to better utilize scarce radio resources. When the multiple …

In this paper, we consider a secondary broadcast network where a multi-antenna transmitter
broadcasts the same data toward a large number of secondary receivers (SRs) in the …