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In this paper we characterize the radio frequency (RF) spectrum opportunities available in a common GSM (Global System for Mobile Communications) channel to support the operation of a cognitive radio network (CRN). In a first step, we describe the technical details involved to sample the channel using a Software Defined Radio (SDR) device. Adopting a simple Energy-based detector, we identify the two...
Cooperative spectrum sensing along with censored energy detection are used in this paper with the aim of improving the efficiency of the available spectrum bands detection schemes in cognitive radio networks. Two witnesses, AND and OR fusion rules are as well considered to decide about the spectrum status based on cognitive users local observations. The analytical expressions of the probabilities...
Trade-off between performance and overhead of cooperative spectrum sensing (CSS) in cognitive radio Networks (CRNs) still attracts researchers' attention. In this paper, novel energy efficient strategies are proposed for the centralized CSS systems using hard decision fusion rules. The strategies considerably minimize the number of collaborating cognitive radios (CRs) required for the CSS system,...
In cognitive radio networks, spectrum sensing aims to detect the unused spectrum channels in order to use the radio spectrum more efficiently. Various methods have been proposed in the past, such as energy, feature detection, and matched filter. These methods are characterized by a sensing threshold, which plays an important role in the sensing performance. Most of the existing techniques used a static...
This paper presents double stage energy detectors for spectrum sensing (SS). The first stage carries fixed threshold (FT) based energy detector (ED), and the second stage carries adaptive double threshold (ADT) based ED. Numerical analysis has been carried out on the basis of results obtained and shows that proposed scheme outperforms the cyclostationary based sensing method and adaptive SS by 12...
In this paper, we present a performance study between two-stage detectors and propose estimated signal to noise ratio (SNR) based detector. The propose sensing technique consists two detectors, energy detector (ED) & ED with ADT detector, out of these two detectors only one will perform sensing operation at a time. Selection of detector depends on condition between estimated SNR value (Se)...
Cognitive Radio Networks (CRN) is a future based wireless communication technology which resolves spectrum scarcity problems in an efficient ways. In this paper, we present the comparative analysis between proposed multiple energy detectors (MED) and cyclostationary feature detector based spectrum sensing techniques. Proposed MED is using adaptive double-threshold (ADT) scheme for spectrum sensing...
In dynamic spectrum access paradigm, reliable spectrum sensing is essential for the efficient utilization of the underutilized spectrum as well as the protection of legacy spectrum users. To achieve reliability, it is important for sensing techniques to meet detection requirements, such as the maximum allowed detection time, the probability of misdetection and the probability of false alarm. In this...
A truncated censored sequential spectrum sensing technique is considered as an energy saving approach for a cooperative spectrum sensing system. In order to design the underlying sensing parameters, the maximum energy consumption per sensor is minimized subject to a lower bounded global probability of detection and an upper bounded false alarm rate. We compare the performance of the proposed scheme...
A serious threat to cognitive radio networks which sense the spectrum in a cooperative manner is the transmission of false spectrum sensing data by malicious secondary nodes. This enforces the system to acquire authentication. Actually, the decision maker needs to determine the reliability or trustworthiness of the shared data. In this paper, the evaluation process is considered as an estimation dilemma...
Spectrum sensing is a fundamental technology to detect the presence of primary user in cognitive radio networks. Usually, the requirements for spectrum sensing are very stringent. It requires that the spectrum sensing scheme has a good performance even in extremely low signal-to-noise ratio (SNR) environments. In this paper, we propose a novel spectrum sensing method based on stochastic resonance...
Cognitive radio networks require fast and reliable spectrum sensing to achieve high network utilization by secondary users. Current optimization approaches to spectrum sensing to-date have focussed on maximizing aggregate throughput while considering only a single parameter variable pertinent to sensing, notably the threshold or duration, but not both. In this work, we consider joint minimization...
Cognitive radio (CR) networks require reliable spectrum sensing techniques in order to avoid interference to the primary users of the spectrum. Most existing spectrum sensing techniques are based on simple energy detection. However, in practice, the signals transmitted by primary users usually also contain known symbol such as pilots and preambles for synchronization and channel estimation purposes...
The ability of adapting to the environment in the most efficient way is a crucial issue in Cognitive Radio (CR) networks. For this purpose, an accurate estimation of the characteristics and activity of the Primary Users (PUs) is required. A system that takes into account heterogeneous PUs with several features is developed. A new scheme is integrated in the system to exploit these motleys and to improve...
Cooperative spectrum sensing improves reliability and the detection performance of sensing. However, the fully cooperative scenario may not be realistic to assume in many cases. We consider a cognitive radio network with heavy traffic users and light traffic users and analyze their behavior towards sensing using the concept of mixed strategy Nash equilibrium. Further, we design a distributed game...
Conventional spectrum sensing techniques using multiple antennas has two weak points to develop further in practice. The first point is the requirement of channel state information (CSI) to combine signal from each antenna. The second point is the assumption of exact values of the signal and noise variance to perform spectrum sensing. In practice, it is not easy and requires time to obtain CSI due...
The well-known energy detector, due to its simplicity, has been proposed as an efficient spectrum sensing method for cognitive radio networks. However, shadowing and fading degrade performance of energy detector. In this paper, to combat these effects, we exploit multiple antennas for each user and cooperation among users. Moreover, we consider spatial correlation among users as well as among antennas...
Eigenvalue based detection is an ideal solution to spectrum sensing problem in cognitive radio networks. However, results on its sensing performance are very limited. In this paper, we analytically investigate the sensing performance of the eigenvalue ratio based detection. Firstly, a simple and accurate Gaussian approximation to the extreme eigenvalue distribution is proposed. Secondly, a closed-form...
Cooperation can improve the performance of spectrum sensing in the cognitive radio networks by taking advantage of diversity gains. It has been shown that sequential probability ratio test (SPRT) is a promising data fusion technique for cooperative spectrum sensing. However, most exiting works assume that the primary spectrum status stays unchanged during the cooperative sensing process. We argue...
In this paper, we propose a cognitive MAC scheme which combines cooperative spectrum sensing and RTS-CTS scheme. The remainder of this paper is organized as follows. Section II describes the proposed scheme. Section III gives the mathematical derivation. Section IV gives numerical results.
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