Resource allocation for secondary users is an important issue in cognitive radio networks. In our article, we introduce a resource allocation scheme for secondary users to share spectrum in a cognitive radio network. Secondary users can exploit the spectrum owned by primary links when the interference level does not exceed certain requirements. Uncertainties of channel gains pose a great impact...

Nodes and/or clusters of a wireless network operating on the same frequency can operate using three different paradigms: 1) Competition: Traditionally, this is information theoretically casted in the framework of interference channels. 2) Cooperation: Silent transmitters/receivers can help active transmitters/receivers in the transmission/reception of their messages, but have to extract this me...

The paper investigates the problem of maximizing expected sum throughput in a fading multiple access cognitive radio network when secondary user (SU) transmitters have energy harvesting capability, and perform cooperative spectrum sensing. We formulate the problem as maximization of sumcapacity of the cognitive multiple access network over a finite time horizon subject to a time averaged interf...

In this paper, we consider a cognitive relay network (CRN) in which the primary receiver (PR) is protected by peak transmit power P̄ST and/or peak interference power Q constraints. In addition, the interference effect from the primary transmitter (PT) is considered to show its impact on the performance of the CRN. We investigate the outage probability (OP) and outage capacity (OC) of the CRN by ...

Artificial neural network (ANN) has application in communication engineering in diverse areas such as channel equalization, channel modeling, error control code because of its capability of nonlinear processing, adaptability, and parallel processing. On the other hand, wavelet transform (WT) with both the time and the frequency resolution provides the exact representation of signal in both doma...

Recent advances in communication technologies and the proliferation of wireless computing and communication devices make the radio spectrum overcrowded. However, experiments from the Federal Communication Commission (FCC) reveals that the spectrum utilization varies from 15%− 85%. Consequently, Cognitive Radio Networks (CRNs) are proposed to utilize the radio spectrum opportunistically. In type...

In underlay Cognitive Radio (CR) systems, secondary users may transmit while primary transmissions take place. However, the interference aggregates on the primary system, and performance degradation will occur. Thus, quantifying and modeling of the aggregate interference is important in characterizing the network’s performance. An interference analysis for a Poisson process of CR nodes in a fin...

Cognitive radios are a natural evolution of Software Defined Radios (SDRs) that are supposed to be equipped with the ability to learn their RF environment and reconfigurability. A cognitive radio can communicate over a primary user’s channel as long as the introduced interference does not degrade the primary Signal-to-Interference-plusNoise-Ratio (SINR) below its minimum Quality of Service (QoS...

Traditional distributed resources allocation algorithms are based on the hypothesis of perfect channel in cognitive radio networks. In fact, the parameters of the channel are variable, uncertain in some degree or even turbulent. Considering an ellipsoidal uncertainty set to describe the fluctuation of the interference gain, a robust power allocation algorithm is proposed to maximize the data ra...