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Soon heterogeneous TV white space (TVWS) systems will operate in underutilized TV bands. Potential interference between TVWS systems and Digital TV (DTV) broadcast is a major concern. This paper determines the conditions necessary for harmonious coexistence between TVWS and DTV system. There are three types of white space devices (WSDs), i.e. fixed WSD (FWSD), personal/portable WSD (PWSD), and sensing...
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...
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...
In this paper, an interferer-tolerant receiver for the first group of ultra-wideband systems (3.1–4.8 GHz) is presented. The entire system operates in two modes; detecting and receiving. In the detecting mode, the locations of up to three blockers in 2.35–2.75 GHz and 5.1–5.9 GHz bands are reported to three notch filters used in the receiving path for rejection. In the receiving mode, the receiver...
This paper presents a computationally efficient cyclostationarity detection based spectrum sensing in cognitive radio. Traditionally, several cyclostationarity detection based spectrum sensing techniques with a low computational complexity have been presented, e.g., peak detector (PD) or maximum cyclic autocorrelation selection (MCAS), and so on. Compared to both techniques, PD can be affected the...
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...
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...
In this paper, the filtering characteristics of Empirical Mode Decomposition (EMD) are used to create a blind and adaptive energy detector for single or multi-channel spectrum sensing. EMD is an adaptive tool that decomposes time-series signals into a set of modes called Intrinsic Mode Functions (IMF). Due to the EMD filtering behavior, the first IMF is mostly contaminated by noise from the received...
The methods of dynamic access to spectrum developed in Cognitive Radio require efficient and robust spectrum detectors. Most of these detectors suffer from four main limits: the computational cost required for the detection procedure; the need of prior knowledge of Primary User's (PU) signal features; the poor performances obtained in low SNR (Signal to Noise Ratio) environment; finding an optimal...
The α-η-μ distribution is a generalized distribution which models the fading statistics to a sufficient degree of accuracy in practice. This distribution includes the well-studied models such as Rice, Rayleigh, Nakagami-m, Weibull, η-μ and α-μ distributions as special cases. We study the problem of energy-based spectrum sensing over the α-η-μ fading channel, following a Bayesian approach. We present...
The prevailing condition of forthcoming cognitive radio networks will be the existence of primary user and other unknown secondary users in a same band of interest. Thus to accommodate such situation, a combined spectrum sensing scheme is proposed which utilizes waveform detector(WD) and energy detector(ED) based on the available signal pattern of Primary User(PU) waveform. By not activating the second...
In this paper, a novel closed form expressions for the area under the receiver operating characteristic curve (AUC) of an energy detector is measured over generalized fading channel in terms of computable Meijer G-function. We consider the reporting channel in the Multiple-Input Multiple-Output (MIMO) based centralized cooperative spectrum sensing is experiencing a κ — μ fading channel. We assume...
As we know, Cognitive Radio comes to improve the underutilization problem of available radio spectrum by using one of its functional called spectrum sensing. In this paper, we compare two methods between Fixed Sample Size Test and Sequential Detection specifically for spectrum sensing using OFDM signals with Gaussian noise. The compared parameter in this simulation is OFDM Average Block (AVB) which...
Spectrum sensing is one of component in cognitive radio (CR). The sensing algorithm that usually used is the matched filter and the energy detector. Because there is a shortage in energy detector, which is very sensitive to noise power uncertainty. Then formed a new method based on the covariance matrix of the received signal. In this paper analysis on cognitive radio spectrum sensing using signal...
In recent times, the popularity of Cognitive Radio has been increased because of its spectrum sensing characteristics. Using CR, the spectrum is utilized efficiently and maintain efficient communication when the primary user is not using the spectrum. In this paper, Bayesian detector is used for detecting the presence of primary user's signal. This approach is optimal when PU is not using the spectrum...
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