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Cognitive radio network (CRN) is a 5-G future technology which is helpful to mitigate band width crises. There are several factors that are responsible to improve CRN quality such as modulation, routing protocols, and transmission power, etc. In this paper, we have analyzed various modulation techniques like QPSK, QAM-16, & QAM-64, and shown that QAM-64 modulation scheme performs well in terms...
Cognitive radio is the one of the technique which used to solve the problems of spectrum inefficiency and limited spectrum availability in wireless networks. However, while designing the availability and efficiency of spectrum in wireless network the security in cognitive radio is one of the key challenge. The selfish attack is one of major security issue found in cognitiveradio. The selfish attack...
In Cognitive Radio Networks (CRNs), Cognitive radios (CRs) learn from their environment and adapt to the environment based on their learned beliefs accordingly. Malicious nodes may exploit the cognitive engine of CRs, and conduct belief manipulation attacks to degrade the network performance. In this paper, we address the problem of belief manipulation attacks and develop a distributed trust management...
A cooperative cognitive radio (CR) network that accomplishes both spectrum sensing (SS) and sharing is considered in this work. System model is assumed to be a cognitive ad hoc network that consists of multiple secondary transmitter (ST) and receiver (SR) pairs sharing transmission over a spectrum with a primary network of single transmitter-receiver pair. Based on SS outcome, secondary users (SUs)...
In this paper, we propose a modified cooperative sensing scheme as documented by IEEE 802.22 standard to develop a spectrum agile simpler implementable cognitive radio network (CRN) by minimizing the probability of false alarm and maximizing the probability of detection to optimize the maximum achievable system throughput through the optimal decision fusion rule. In addition, we develop a dynamic...
IEEE 802.11 is one of the most common technologies these days. Due to its simplicity and easy integration in various applications its usage in recent years has grown exponentially [1]. The increasing amount of wireless devices and various applications such as WBAN (Wireless Body Area Networks), WISPs (Wireless internet service provides) have increased the interference in unlicensed band, which reduced...
Cognitive radio may discover more idle (unoccupied) spectrum by spending more power for spectrum sensing, while the transmission power can be reduced by using more spectrum (bandwidth). We analyze the tradeoff between the sensing power and transmission power in achieving a given throughput in cognitive radio networks and examine the optimum sensing bandwidth that maximizes the energy efficiency, defined...
Cognitive radio now-a-days has opened a new horizon for researchers to mitigate the up-growing demand for RF spectrum within our limited resources. The threshold plays very important role for sensing process in energy based detectors as it is widely used in CR network due to its fast performance and ability to perform without any prior knowledge or information. Conventional energy detectors has fixed...
In this paper, to maximize the total throughput of secondary users (SUs), we investigate the problem that how to allocate SUs cooperatively parallel sensing multiple primary users (PUs) channels, how to select the best SUs making full use of the available channels, and how to determine the sensing time and detection threshold for each PU channel. To efficient protect PUs from harmful interference,...
In this paper, we consider energy harvesting cognitive radio networks (CRNs) where each secondary user (SU) has no fixed power supplies and extract energy only via harvesting energy by Radio Frequency (RF) provided by the control center (CC). Cooperative spectrum sensing is employed to improve the sensing performance. The spectrum sensing policy should maximize the probability of discovering and utilizing...
Cognitive Radio has a potential to improve spectrum efficiency for future wireless communication systems. However, the performance of such systems can be degraded by various factors e.g. imperfect sensing, non-accurate result reporting of the sensed spectrum either due to error-prone reporting channel (RC) or malicious user attack. Moreover the phenomena of reporting only from those cognitive users...
In this paper, we propose a hybrid cognitive radio (CR) system where underlay and overlay CR approaches are combined under SIRN constraints. This new access type allows to optimize the spectrum sensing time with throughput improvement. Our proposed access type is based on a merger of these two modes depending on the number of secondary users (SU) in the Underlay Mode and on the access probabilities...
Prior to access license channel, secondary user (SU) is supposed to sense available channel to confirm that channel spectrum is unoccupied by primary user (PU) in cognitive radio (CR). Secondary user necessarily performs spectrum sensing at a certain time. Longer time allocation for spectrum sensing is expected can increase the fidelity of sensing outcome that leads to improve detection performance...
In this paper, a novel spectrum handoff scheme for cognitive ultra-wide band industrial networks (CUWBINs) is proposed, where secondary users (SUs) can access the licensed channels despite the present of primary users' signals. To maintain continuous connectivity between the cognitive users, licensed channels can be opportunistically used by an SU as long as its transmission does not interfere with...
Reducing interference to primary users while achieving high throughput for secondary user transmissions is a critical issue in an underlay cognitive radio network. In this paper, we explore the use of beamforming at secondary user transmitters. Two power allocation schemes, fixed transmit power allocation (FTPA) and adaptive transmit power allocation (ATPA) are investigated considering scenarios with/without...
Spectrum scarcity is increasing with the growing demand of number of wireless technologies and services. Cognitive Radio (CR) techniques have become reliable solution for solving spectral congestion problem. For utilization of unused electromagnetic spectrum in a cognitive radio network, it is necessary for secondary users to monitor the available spectrum (allocated to primary users) and identify...
Cognitive Radio (CR) dynamically finds the spectrum opportunity i.e. spectrum hole in space-time-frequency and code to do its adaptive transmission without harming the incumbent or the Primary User (PU). TV white spaces (TVWS) are the unused or underutiliised bands in the UHF and VHF part of the band which according to Federal Communication Commission (FCC) can be exploited if the secondary user (SU)...
The exponential growth of wireless data traffic has pushed wireless network vendors and researchers to seek for new paradigms to revolutionize the traditional communication technologies to support 100 times the network capacity of the current communication systems. Therefore, cognitive radio (CR) has been one of the most promising technologies for the next generation communication system, such as...
We propose adding a vigilante player and using non-traditional game strategy for decision making to improve the performance of a cognitive radio network. To date, the application to cognitive radio networks of a hybrid player such as a vigilante, which is both cooperative and non- cooperative, has not been significantly studied. We use a novel play strategy (i.e., altruism) to police a wireless network...
Several techniques such as carrier aggregation (CA) and cognitive radio (CR) have been proposed to achieve high data rates to meet the demand of future wireless communication systems. Those techniques pose a strict adjacent channel interference (ACI) requirement. However, currently employed orthogonal frequency division multiplexing (OFDM) systems suffer from significant spectrum leakage and require...
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