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Cognitive Radio has been proposed as a solution to the spectrum underutilization problem in Wireless Sensor Networks. This paper describes most used cooperative and non-cooperative sensing techniques in Cognitive Radio Sensor Networks. Energy detection is an optimal method when no prior information about primary signal is available. However, most of the contribution focus on the cooperative sensing...
In cognitive radio systems, fast and efficient spectrum selection is a vital task to minimize the overhead of spectrum scanning, and hence to improve the response time of the system. So, the choice of channel sensing sequence plays an important role for better performance of the system. This paper proposes a co-operative Q-learning based spectrum sensing technique for the secondary users of an ad...
VANET and cognitive radio network (CRN) are both new emerging technologies in wireless networking. The application of CR concept in wireless communication systems for intelligent vehicles has been envisioned as a promising idea towards solving the problem of scarce spectrum. This paper discusses CR technologies for VANETs aimed at opportunistic spectrum access (OSA) for improved vehicular communication...
The paper presents an exhaustive visualization of different problems encountered in efficient utilization of spectrum for advanced wireless communication. It is a well known fact that there is a crisis for available radio spectrum due to incredible expansion and advancement of the communication systems and technologies. But in reality, there is no shortage of available spectrum but only lack of advance...
With the increasing development of industrial wireless technologies and standards, the scarce spectrum in the industrial, scientific, and medical (ISM) band has been extremely overcrowded, which can be mitigated by harvesting more spectrum in licensed bands with the emerging cognitive radio technology. In industrial cognitive radio networks (ICRNs), security is one of the most important problems....
The cognitive radio positioning system requires a distributed localization algorithm, since the secondary uses (SUs) can not communication with primary users (PUs) directly. The localization algorithm should also be robust to the topology changes of SUs due to the opportunistic access nature. In this paper, we propose a distributed particle filtering method to locate the PU's position. The ranging...
In cognitive radio networks (CRNs), spectrum sensing data falsification (SSDF) is one of the most typical attack which hugely degrades the detection performance of cooperative spectrum sensing (CSS). SSDF and defense strategies have been an active field of research, but countermeasures of existing researches are sensitive to the number of malicious users (MUs). In this paper, we propose a two-stage...
Nowadays, wideband spectrum sensing, as one of the vital technologies of cognitive radio (CR), has the potential to find more temporarily available frequency bands to meet the growing demands of wireless services. As the vast number of samples are required to be collected and processed, traditional wideband spectrum sensing methods become inefficient and cause large energy consumption. Therefore,...
In the non-time-slotted cognitive radio networks (CRNs), the synchronization between PUs and secondary users (SUs) cannot be guaranteed, resulting in two challenging problems: the reactivation-failure of PUs and the frequently unexpected hand-offs among SUs. The reactivation-failure of PUs is the incident that the SUs cannot detect the PUs' reactivation when the SUs are occupying the channels to transmit...
This paper proposes a channel allocation scheme for Wide-Area Low-Rate Wireless Personal Area Networks (LR-WPAN) based on a cooperative centralized spectrum sensing approach. We refer here to a three-tiers LR-WPAN architecture, where we can distinguish the sensor devices level, the Child-coordinators level and, finally, the super LR-WPAN coordinator level. In the proposed scheme, channels allocation...
With the growing number of connected devices (e.g. smartphones, sensors, actuators and cameras) in 5G, the massive Internet of Thing (IoT) is expected to address a wide range of characteristics and demands, with more radio-frequency (RF) bands to support multiple frequency transmission by 2020. Separate antennas and RF chips may be required for widely separated frequency bands. The development of...
Recently, wireless cognitive networks have taken great attention due to the increasing spectrum scarcity. For example, the usage of a cognitive radio network infrastructure is inevitable for emergency communication needs in cases of natural disaster and extraordinary situations. Apart from this, cognitive networks may also be utilized in daily life by providing necessary permissions. Channel bonding...
Frequency spectrum scarcity has been a strong research motivation. Those researches have focused on developing methodologies to utilize frequency spectrum as much as it could be. Meanwhile, this spectrum utilization and its great revenue should not affect the quality of services being provided by network providers. In most cases, statistics have shown that only quarter of the spectrum is well utilized...
One of the important trends which is supposed to have more attention in the system of cognitive radio is wireless security models. Security requirements for CRNs are the same as the general wireless networks, taking into consideration that the frequency band changes dynamically adding a specific feature when we deal with security of CRNs. A new category of security issues and challenges have been...
Spectrum sensing is the method used in Cognitive Radio (CR) to find the unused spectrum. Based on spectrum sensing only other functions of CR can be implemented. So for Cognitive Radio, efficient spectrum sensing is compulsory. In this paper, spectrum sensing techniques, challenges are presented. An overview of cognitive radio architecture, on the basis of research is discussed. This paper explains...
This paper proposes a spectrum edge decision method for an energy detection with fast Fourier transfer (FFT) in cognitive radio system. Whereas the energy detection method is simple algorithm and that using FFT can detect spectrum over a wide band, there is a problem that the spectrum edges in frequency domain are unclearly detected under environment without previous knowledges of primary systems...
Cognitive radio networks (CRNs) are vulnerable to various attacks. Primary user emulation attack (PUEA) is one kind of serious attacks. In order to combat PUEA, we propose an algorithm to detect PUEA in CRNs based on probability density function (PDF) assisted by belief propagation (BP), called PDF-BP. In the proposed algorithm, every secondary user (SU) calculates its belief value based on the PDF...
As a critical technique to support the multimedia services - the major traffic in cooperative cognitive radio networks (CRNs), the statistical quality-of-service (QoS) technique has been proved to be effective in statistically guaranteeing delay-bounded video transmissions over the time- varying wireless channels. On the other hand, in modern cooperative CRNs, the full-duplex spectrum sensing (FD-SS)...
Border surveillance has many applications in national security, infrastructure security, habitat monitoring, detecting illegal trespasses, military applications, and so on. This topic has received an increased attention recently. Sensing coverage and reliable data transmission are critical aspects in border surveillance using wireless sensor networks. In this paper we propose RMA-BS, a cognitive radio...
Cognitive radio (CR) is an intelligent technique which is used to improve the spectrum utilization through four main functions: spectrum sensing, spectrum decision, spectrum sharing and spectrum mobility. In this paper, we focus on spectrum mobility (or called spectrum handoff) that occurs when the primary users (PUs) appear to occupy its licensed band that used by secondary users (SUs). We discuss...
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