This paper presents an evolution framework of resource allocation by infection among secondary users (SUs) in an OFDMA-based cognitive radio cellular networks. Each primary user (PU) sells his extra sub-channels to SUs in his sensing range to achieve the highest payoff and each SU may come across another in his sensing range to make infection. We first analyze the sensing range to guarantee the...

In cognitive radio (CR) networks, the secondary users (SUs) sense the spectrum licensed to the primary users (PUs) to identify and possibly transmit over temporarily unoccupied channels. Cooperative sensing was proposed to improve the sensing accuracy, but in heterogeneous scenarios SUs do not contribute equally to the cooperative sensing result because they experience different received PU sig...

In this paper, we develop a spectrum allocation algorithm for hierarchical cognitive ad hoc networks based on the secondary user (SU) priority. The algorithm assures that the SUs with higher priority can get more spectrum bandwidths, and thus the revenue of the whole spectrum band can be maximized. The proposed algorithm is a twostage spectrum allocation scheme, in which the licensed spectrum a...

In this paper, novel enhanced Cognitive Radio Network (CRN) is considered by using power control where secondary users (SUs) are allowed to use wireless resources of the primary users (PUs) when PUs are deactivated, but also allow SUs to coexist with PUs while PUs are activated by managing interference caused from SUs to PUs. Therefore, a novel finite horizon adaptive optimal distributed power ...

BACKGROUND AND PURPOSE Multiple methods to detect paroxysmal atrial fibrillation (pAF) in patients with acute stroke are available. However, it is unknown which approaches are currently used in clinical routine and guidelines remain vague to the extent of cardiac monitoring. We characterize diagnostic efforts for pAF detection on German stroke units (SU). METHODS A standardized anonymous ques...

This paper addresses power allocation problem for spectrum sharing multi-band cognitive radio networks, where the primary user (PU) allows secondary users (SUs) to transmit simultaneously with it by coding SU's signal together with its own signal. The PU acts as the relay for the SUs and sells its transmit power to the SUs to increase its benefit, and the SUs bid for the PU's transmit power for...

In Cognitive Radio Networks (CRN), Cooperative Spectrum Sensing (CSS) is used to improve performance of spectrum sensing techniques used for detection of licensed (Primary) user’s signal. In CSS, the spectrum sensing information from multiple unlicensed (Secondary) users are combined to take final decision about presence of primary signal. The mixing techniques used to generate final decision a...

In this work, the issue of joint relay selection and power allocation in Underlay MIMO Cooperative Cognitive Radio Networks (U-MIMO-CCRN) is addressed. The system consists of a number of secondary users (SUs) in the secondary network and a primary user (PU) in the primary network. We consider the communications in the link between two selected SUs, referred to as the desired link which is enhan...

In this paper, a novel spectrum association approach for cognitive radio networks (CRNs) is proposed. Based on a measure of both inference and confidence as well as on a measure of qualityof-service, the association between secondary users (SUs) in the network and frequency bands licensed to primary users (PUs) is investigated. The problem is formulated as a matching game between SUs and PUs. I...

Cognitive radio has attracted considerable attention as an enabling technology for addressing the problem of radio frequency shortages. In cognitive radio networks (CRNs), secondary users (SUs) are allowed to opportunistically utilize the licensed spectrum bands of primary users (PUs) when these bands are temporarily unused. Thus, SUs should monitor the licensed spectrum bands to detect any PU ...