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This article proposes several new and improved energy detectors for detecting unknown deterministic signals perturbed by zero-mean Gaussian noise and/or fading. In contrast to the conventional total energy detector (that computes the signal energy by summing the square of all time-domain signals), we first partition the time-domain samples in pairs and then combine the signal energy estimates from...
This article shows that the non-coherent detector for random signals which maximizes the generalized likelihood function is the same as the detector that maximizes the probability of correct detection at any specified false alarm probability by deriving the exact statistics for |Y|p (where Y is a Gaussian random variable and p is a positive real number) for the following two cases: (i) sample size...
In this article, we present two distinct moment generating function (MGF) based methods for evaluating the receiver operating characteristics (ROC) of diversity-enabled energy detectors in κ-μ and η-μ generalized fading environments and their corresponding area under the ROC curve (AUC) performance measure. In contrast to the existing approaches that are based on either the circular contour integral...
Wireless physical layer security approaches can prevent eavesdropping without upper layer data encryption. But such techniques are hampered by time-varying wireless channel conditions and they are typically feasible only when the legitimate partners in the Wyner's wire-tap channel model have an advantage over the source-eavesdropper channels. Source rate adaptation and/or node cooperation strategies...
The activity of a nano sized particle is said to be greater when compared to that of its parent materials combined. Thus, an attempt was made to produce gold nanostructures having unusual physicochemical properties. In this study, eco-friendly, non-toxic gold nanoparticles (Au NPs) were biologically synthesized using the leaf extract of Euphorbia hirta L. The synthesis of Au NPs was confirmed by a...
In this article, we apply two distinct methods to obtain simple closed-form approximations for the average symbol error rate (ASER) performance metric of a broad class of coherent digital modulations in a myriad of fading environments (with/without diversity), which are known to be analytically involved as they require evaluation of the expectation of the Gaussian Q-function and/or its integer powers...
In this article we recast the problem of throughput optimization in cross-layer architecture for delay sensitive applications. Unified mathematical framework was developed for maximizing user throughput in generalised wireless environment. The optimization variables adapted include symbol rate (at the application layer), packet length (at the MAC layer), constellation size (at the physical layer)...
In this article, we first develop very tight second and third-order exponential-type approximations for the Gaussian probability integral Q(.) and/or the complementary error function erfc(.) which are subsequently used to devise the conditional symbol error probability (CEP) formulas for several classes of digital modulation schemes that are both invertible and in a “desirable” exponential form. These...
In this article, we present three moment generating function (MGF) based methods for performance evaluation of multi-hop, multi-relay cooperative amplify-and-forward (CAF) networks over a myriad of stochastic fading channel models. Method I is based on a recursive expansion of the MGF of effective SNR for a 2-hop CAF relay network developed in [10]. The second method is also similar to Method I except...
This article proposes a solution that can extend the capability of traditional energy detector to wideband sensing with improved performance. The solution involves the use of parallel detection circuitry with each tuned to different frequencies. The decision of each detection circuit can then be used to create a spectral map of the entire spectrum. This introduces some resolution component and improved...
In this article, we investigate the performance of spectrum sensing in the frequency domain. Classical and modified periodogram are analyzed based on the Neyman-Pearson (NP) criterion in terms of false alarm and detection probabilities. We introduce two novel modified periodogram algorithms and compare their performances with the existing periodogram methods. It is shown that the new modified periodogram...
In this article, we present six recently derived distinct series representations of the generalized Nuttall Q-function with their corresponding Marcum Q-function. We investigate different application areas where these series expressions might be of interest. Using these representations, we address some of the outstanding problems that have until now resisted simple solutions. First, we show that the...
Reliable spectrum sensing is the very task upon which the entire operation of the cognitive radio rests. Energy detection is one of the solutions that have been proposed for enabling opportunistic spectrum access but its capability has limited sensitivity, no resolution and requires high sampling rate when employed in the detection of wideband heterogeneous spectrum. This article proposes a solution...
In this article, we investigate the performance of classical and modified periodogram based on the Neyman-Pearson (NP) criterion in terms of the false alarm and detection probabilities. We derive analytical expressions that allow us to compare the performance of the classical periodogram with the Bartlett's and the Welch's modified periodogram over generalized fading channels. Our analytical framework...
This article develops a unified analytical framework for maximizing the user throughput of a cooperative multi-relay network over generalized wireless channels using the symbol rate, packet length and constellation size of M-ary PSK/QAM digital modulation schemes as optimization variables. Optimization equations for each of the above degrees of freedom are derived in closed-form. A low-complexity...
In this article, we develop a closed form evaluation of the area under receiver operating characteristics (ROC) curve (AUC) when employed in the analysis of cooperative amplify-and-forward (CAF) relay-based energy detection. The developed analytical expression for AUC results into finite kth order derivative of the moment generating function of the end-to-end signal-to-noise ratio. The resulting closed-form...
The joint optimization of power allocation and relay position is known to be a frightening problem in the analysis of cooperative relay communication. In this article, we present an efficient framework that tackles this problem for 2-hop cooperative amplify-and-forward (CAF) multi-relay system over generalized fading channel. First, we consider single CAF relay where we investigate (i) the optimum...
In this paper, energy detector's performance over the wireless channels with composite multipath fading and shadowing effects is analyzed using the area under the receiver operating characteristic (ROC) curve (AUC) in contrast to the conventional ROC measurement. AUC is a single statistical parameter which can be used to describe energy detector's performance more meaningfully. An energy detector...
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