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This paper presents a novel centralized cooperative scheme which combines compressed sensing (CS) method based on the analog-to-information converter (AIC) with statistical and graphical chi-square Quantile-Quantile (QQ) plot detector. The received signal at every cognitive radio (CR) user in the presence of Additive-White-Gaussian-Noise (AWGN) and intentional interference attack signal (jamming)...
The demand for radio spectrum is rapidly increasing for applications such as mobile telephony, digital video broadcasting (DVB), wireless local area networks (WiFi), and wireless sensor networks (ZigBee), and internet of things. Indeed, these resources are becoming increasingly scarce or even nonexistent. This scarcity has led to the concept of Cognitive Radio (CR) communication which has used to...
Spectrum sensing is a method which is used to find out whether the channel is idle or not in Cognitive Radio Network (CRN). Traditional methods are not much reliable due to the uncertain noise during the detection. In this paper, a weighted cooperative spectrum sensing strategy with jointing energy and spectrum-width detection under noise uncertainty is proposed to improve the detection performance...
This paper presents the design technique of the selection diversity combining based spectrum sensing in cognitive radio networks. In general, the selection diversity combining scheme requires period to choose an optimal element, and spectrum sensing also requires period to detect a target signal. Because spending a long time for the selection and sensing increases the accuracy of the selection and...
Most often in cognitive radio systems, the Neyman-Pearson energy detector is used. The test statistics compared with the threshold in this case has a chi-square distribution. At the same time, the threshold calculation in on-line mode is characterized by considerable computational complexity. In this paper, we investigate the accuracy of calculating the threshold for various approximations of the...
In this paper are presented the results obtained after of evaluating three techniques of blind detection of spectrum holes used in Cognitive Radio (CR). The techniques evaluated correspond to the general technique of detection of energy levels, the method LAD BASED and the technique based on forward methods. The operation of these techniques was tested in simulation scenarios of a telecommunications...
As wireless technologies continue to advance the radio spectrum has become more congested. Spectrum utilization can be enhanced considerably by allowing a secondary user to use a licensed band when the primary user (PU) is not present. Cognitive radio (CR) promotes the efficient use of the spectrum. Cyclostationary detection is a method for detecting primary user transmissions by taking advantage...
This paper presents multiple beacon vectors based robust detection schemes for cooperative spectrum sensing (CSS) in multiple-input multiple-output (MIMO) cognitive radio (CR) networks under channel state information (CSI) uncertainty. The inaccuracies in the estimate of the CSI are modeled as the standard ellipsoidal uncertainty set. We develop a multiple beacon vector based linear discriminant framework...
Due to the observed increasing scarcity of economically usable spectrum, it is becoming difficult to accommodate the data demand of countless mobile data terminals into existing bands. The TV White spaces, the scarcely used bands of former analog TV broadcasting, could be a viable option to alleviate this problem. The concept of Cognitive Radio must be employed though, as primary users within the...
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...
An efficient spectrum sensing scheme is proposed for detecting a primary signal corrupted by a Generalized Gaussian Noise (GGN). It is assumed that the power of the primary signal is much smaller than the noise power, and secondary users are equipped with multiple antenna receivers. The proposed scheme, referred to as sigmoid detector, uses a sigmoid soft limiter. The sigmoid limiter is characterized...
Cyclostationary feature (CSF) detection plays an important role in spectrum sensing for cognitive radio systems, since it has low requirements on a-priori knowledge about the primary user signals and high robustness to noise and interferences. Existing CSF detecting technologies depend on full-size Fast Fourier Transform (FFT), which leads to high implementation cost in case of high carrier frequency...
In this paper, we developed a software defined radio (SDR) system for implementing energy detection spectrum sensing. The SDR module can be used for a wide range of applications. The use of the SDR module is motivated by its high interoperability, availability for relatively cheaper prices and being software independent. Energy detection for cognitive radios is chosen for its simplicity and popularity...
Cognitive Radio (CR) is an innovative approach based on Software Defined Radio (SDR) that utilizes frequency spectrum efficiently to accommodate large number of users. Fast & fine spectrum sensing (to determine available free spectrum) is the primary objective in CR systems. Spectrum sensing is effected by multipath and shadowing which are the major hindrances in wireless communication; there...
This paper proposes a Bayesian detector for spectrum sensing in a multi-antenna cognitive radio (CR) network in which no channel state information (CSI) is available. The Bayesian approach for detection necessitates a prior distribution of the CSI in terms of the spatial covariance matrix, and unfortunately it is often improper and cannot be applied directly. We shall introduce the use of the Fractional...
In this work, the inter-dependency of TCM signals is studied. Using this inter-dependency, correlation-based detectors are proposed for spectrum sensing of TCM signals in white Gaussian noise. In particular, a constant false alarm rate (CFAR) detector is presented and its performance is evaluated using simulations. We also describe an application of our detector for the classification of uncoded modulation...
In order to assist dynamic spectrum access in the cognitive radio framework, a precise real-time identification of the signals sent by either the primary or secondary users should be necessary. Orthogonal frequency-division multiplexing (OFDM) signals with and without DFT precoding are commonly adopted in the recent wireless communications standards. Therefore, the accurate classification of such...
Noise estimation plays an essential role in enhancing the performance of non-coherent spectrum sensors such as energy detectors. If the noise energy is misestimated, detector performance may deteriorate. In this paper, we present an energy detector based on the behavior that Empirical Mode Decomposition (EMD) has on noise-only channels. EMD decomposes time-series signals into a finite set of components...
Cooperative spectrum sensing (CSS) is one of the efficient scheme that helps in improving the spectrum sensing performance of a cognitive radio network. In this paper we propose a Dempster-Shafer theory (DST) based CSS for cognitive radio network. The fusion rule is the D-S combination rule which is well known for its ability to handle uncertainty and has been used in quite a different number of fields...
In this paper we investigate cooperative spectrum sensing technique in which double threshold based energy detection is used at local cognitive radio (CR) sensors. Cooperative spectrum sensing improves reliability in detection of underutilized spectrum by fusing the decisions of local CR sensors. Local CR sensors use two thresholds, λ1 and λ2 (with λ2 > λ1). If the sensed energy is greater than...
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