Improved Energy Detector Research Articles

Performance Analysis of Improved Energy Detector With Hardware Impairments for Accurate Spectrum Sensing

The impact of transceiver hardware impairments on the accuracy of spectrum sensing cannot be ignored in low-cost and high data rate cognitive radio systems. Nevertheless, ideal hardware for spectrum sensing is widely assumed in the technical literature. This paper presents a novel method for evaluating the improved energy detector (IED) statistics using α-μ distribution over additive white Gaussian noise (AWGN) and Nakagami-m fading channel by considering transceiver hardware imperfections. Moreover, the performance of the IED over AWGN channel is highlighted by the area under the receiver operating curve. Furthermore, the average probability of detection is evaluated for both fading and non-fading environments. An asymptotic analysis studies detection probability over fading channels at a low average signal-to-noise-ratio region. Moreover, p-order law combining and p-order law selecting diversity techniques are proposed to increase the performance of the detector. Our simulation results demonstrate that the diversity techniques significantly improve the detector performance.

Selfish Bandit-Based Cognitive Anti-Jamming Strategy for Aeronautic Swarm Network in Presence of Multiple Jammer

In order to enhance the anti-jamming capability of aeronautic swarm tactical network in the complicated electromagnetic environment, we address the problem of bandit-based cognitive anti-jamming strategy for enabling reliable information transmission. We first present an adversarial multiuser multi-armed bandit model for the aeronautic swarm network employing airborne cognitive radios with the same-frequency simultaneous transmit and receive feature. Then, we utilize the improved energy detection method to perform jamming sensing and derive the closed expression of false alarm probability, false detection probability, and the optimal decision threshold in the case of single and multi-jammer. Finally, using the jamming sensing output to calculate reward and with the objective of maximizing the throughput of each airborne radio, a decentralized selfish doubling trick kl-UCB <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">++</sup> anti-jamming strategy is developed to allocate an optimal configuration of transmitting power and spectrum channel to each radio. This anytime bandit strategy is simultaneously minimaxed optimal and asymptotically optimal. The simulation results validate that the aggregate average throughput, cumulative regret obtained with the proposed anti-jamming strategy outperform the well-known UCB, kl-UCB <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">++</sup> bandit algorithm.

An improved energy detection receiver for toa estimate in mm-Wave system

It is challenging to acquire the first arriving path for the estimate of the time of arrival (TOA) in multipath channels, particularly for low signal to noise ratio. The energy detection (ED) receiver is a better scheme for TOA estimate in millimeter-wave (mm-Wave) ranging system since its simple circuit structure. However, the traditional algorithms for TOA estimate using ED cannot provide the adequate accuracy. In this paper, a novel ED receiver for mm-Wave TOA estimate is developed by employing the higher order cumulant technique. Results acquired in IEEE 802.15.3c models confirm the effectiveness and better performance of this solution.

Censoring-Based Cooperative Spectrum Sensing with Improved Energy Detectors and Multiple Antennas in Fading Channels

In this paper, the performance of cooperative spectrum sensing (CSS) with threshold-based censoring is investigated in the presence of noisy and faded environments. In particular, scenarios with Rayleigh, Hoyt, and Rician fading, affecting both the sensing (S) and reporting (R) channels, are considered. Each secondary user (SU) is equipped with multiple antennas and relies on an improved energy detector (IED). More precisely, the signals from the primary user (PU), received by multiple antennas of an SU, are fed to the IED, the IED outputs are combined using a selection combiner, and the combined signal is used to make a local decision. At the fusion center (FC), censoring of SUs is done on the basis of the quality, evaluated by the FC, of the faded R-channels. The censored decisions received at the FC are fused, using majority logic or maximal ratio combining, to obtain a final decision on the status of the PU. The performance of CSS, in terms of average miss detection probability and error rate, is evaluated considering the impact of relevant network parameters. Optimized values of the censoring threshold, as well as of the required parameters of the IED, are determined under several network conditions. The performance of the proposed IED is compared with that of a conventional energy detector.

An Improved Energy Detector for Mobile Cognitive Users Over Generalized Fading Channels

A cooperative cognitive radio network (CRN) with improved energy detection-based spectrum sensing is analyzed in various fading scenarios. Generalized multipath (Nakagami- $m$ ) fading and enriched multipath (Nakagami- $q$ ) fading models are considered along with two other general fading distributions, i.e., $\kappa$ - $\mu$ and $\eta$ - $\mu$ distributions. For spectrum sensing, instead of conventional power 2-based detection method, the arbitrary power $p$ -based improved energy detector is used. The impact of the cognitive user mobility on the performance of the improved energy detector is investigated. Specifically, the statistics for the received signal are derived over various fading environments. The performance of the considered CRN system is evaluated in terms of probability of false alarm, probability of missed detection, and receiver operating characteristics (ROC) curves. Moreover, the area under the ROC curve is also obtained. Simulation results are provided to corroborate the theoretical results derived in this paper.

Throughput of cognitive radio networks with improved energy detector under security threats

SummarySpectrum sensing in cognitive radio networks (CRNs) is subjected to some security threats such as primary user emulation (PUE) attack and spectrum sensing data falsification (SSDF) attack. In PUE attack, a malicious user (MUPUE) transmits an emulated primary signal throughout the spectrum sensing interval to secondary users (SUs) to forestall them from accessing the primary user (PU) spectrum bands. In SSDF attack, malicious users (MUSSDF) intentionally report false sensing decisions to the fusion center (FC) to influence the overall decision. While most of the existing literatures have studied the effects of these 2 types of attacks separately, the present paper evaluates the secondary network performance in terms of throughput under both the PUE and SSDF attacks with improved energy detectors (IEDs) where SU's spectrum access is hybrid, ie, either in overlay or in underlay mode. An analytical expression on throughput of SU under the simultaneous influence of both of these attacks is developed. Impact of several parameters such as IED parameter, attacker probabilities, and attacker strength on the throughput of SU is investigated. Performance of the present scheme is also compared with only PUE and only SSDF attacks. A simulation test bed is developed in MATLAB to validate our analytical results.

A novel time of arrival estimation algorithm using an energy detector receiver in MMW systems

This paper presents a new time of arrival (TOA) estimation technique using an improved energy detection (ED) receiver based on the empirical mode decomposition (EMD) in an impulse radio (IR) 60 GHz millimeter wave (MMW) system. A threshold is employed via analyzing the characteristics of the received energy values with an extreme learning machine (ELM). The effect of the channel and integration period on the TOA estimation is evaluated. Several well-known ED-based TOA algorithms are used to compare with the proposed technique. It is shown that this ELM-based technique has lower TOA estimation error compared to other approaches and provides robust performance with the IEEE 802.15.3c channel models.

The effect of Weibull fading channel on cooperative spectrum sensing network using an improved energy detector

This paper analyses the performance of proposed cooperative spectrum sensing (CSS) network in Weibull fading environment. First, we have derived the novel analytic expressions for probabilities of missed detection and false alarm in Weibull fading channel, assuming an improved energy detector (IED), selection combining diversity scheme and multiple antennas at each cognitive radio (CRs). Next, performance is analyzed using complementary receiver operating characteristics curves, total error rate, average channel throughput, and network utility function curves for the proposed CSS network. The optimal performance of CSS network is achieved by optimizing the CSS network parameters. The closed form of expressions for the optimum value of number of CRs, arbitrary power of received signal, and detection threshold at each CR are derived using OR-Rule and AND-Rule at fusion center (FC). The average channel throughput and network utility function analysis are evaluated using $$k=1+n$$ and $$k=N-n$$ fusion rules at FC. Finally, the impact of several network parameters such as, multiple antennas at each CR (M), number of CRs (N) in CSS network, Weibull fading parameter (V), arbitrary power of received signal (p), and sensing channel SNR ( $${\bar{\gamma }})$$ on the performance of proposed CSS network are investigated using the simulation results. The performance comparison between conventional energy detector and an IED has been highlighted with the simulations.

Improved energy detection receiver for ranging in IEEE 802.15.4a standard

In this paper, we propose a novel energy detection (ED) receiver architecture combined with time-of-arrival (TOA) estimation algorithm, compliant to the IEEE 802.15.4a standard. The architecture is based on double overlapping integrators and a sliding correlator. It exploits a series of ternary preamble sequences with perfect autocorrelation property. This property ensures coding gain, which allows an accurate estimation of power delay profile (PDP). To improve TOA estimation, the interpolation of PDP samples is proposed and the architecture is validated by using an ultra-wideband signals measurements platform. These measurements are carried out in line-of-sight and non-line-of-sight multipath environments. The experimental results show that the ranging performances obtained by the proposed architecture are higher than those obtained by the conventional architecture based on a single-integrator in both LOS and NLOS environments.

Throughput analysis in proposed cooperative spectrum sensing network with an improved energy detector scheme over Rayleigh fading channel

In this paper, we have proposed the cooperative spectrum sensing network in which each CR is equipped with multiple antennas and an improved energy detector (IED) technique is considered as detection scheme. The CRs utilize the selection combining (SC) technique based on the decision statistics obtained by an IED with multiple antennas in-order to make binary decisions about the primary user (PU). The analysis of average channel throughput and network utility function (NUF) is performed for the proposed CSS system with multiple antennas at each CR using an IED scheme over Rayleigh fading channel. The performance is analyzed using different fusion rules (k=1+n and k=M−n) at fusion center, where k is the number of selected CRs, M is the total number of CRs, and n is a positive integer (n=2). The error rate is considered in reporting channel (R-channel) to show the effect of an error rate on the channel throughput and NUF. Performance of error free and error present R-channel is compared using MATLAB simulations. The impact of several network parameters like detection threshold (λ), multiple antennas at each CR (Z), the number of secondary users (M), and the error rate in R-channel on the performance of throughput and NUF are shown using the simulation results. The optimal number of secondary users are calculated to maximize the average channel throughput for various fusion rules.

Performance of improved energy detector with cognitive radio mobility and imperfect channel state information

A cooperative cognitive radio (CR) network with multiple secondary users (or CRs) is considered. Each CR consists of an arbitrary M number of antennas. For spectrum sensing, at each CR, an improved energy detector with selection combining mechanism is assumed. Moreover, the impact of secondary user mobility on the performance of spectrum sensing is analysed. Specifically, the expression for received signal at destination is derived considering the imperfect channel state information in Rayleigh fading environment. The authors derive the expression for probability of false alarm and miss detection using arbitrary power p-based improved energy detector and analyse the error performance of the system. The area under receiver operating characteristics curve is also obtained. Simulation results are provided to verify the analysis presented in this study.

Performance Analysis of Cooperative Spectrum Sensing Network Using Optimization Technique in Different Fading Channels

Spectrum sensing is an important task to find out the spectrum holes in a given radio spectrum. Spectrum sensing performance is improved with the aid of multiple cognitive radios (CRs) in the network and each CR having multiple antennas in different fading channels (Rayleigh, Hoyt and Weibull fading channel). In this paper, we have considered that each CR having multiple antennas and improved energy detector (IED) scheme is used for detection of primary user. Imperfect channel is considered between CRs and fusion center (i.e. in reporting channel) with an error probability rate (r). We have derived the novel expression for missed detection probability (P m ), closed form of expression to find out optimal value of number of CR users (N opt ), closed form of expression and procedure to find an optimal value of normalized threshold value (λ n,opt ), expression for optimal value of arbitrary power of received signal (P opt ) and calculation of minimum value of total error in different fading channels are provided. Performance is evaluated to find out (N opt ), (λ n,opt ), (P opt ) and to calculate minimum error value for various network parameters like SNR, r, λ n and multiple number of antennas (M). It is observed that detection performance is improved by using multiple antennas at each CR. Comparison between conventional energy detector and IED, comparison among Rayleigh, Hoyt and Weibull fading channels also provided for different cases of network parameters.

Optimal Allocation Techniques for Reducing the Sensing Error Probability with Improved Energy Detection in Cognitive Radio

Optimal Allocation Techniques for Reducing the Sensing Error Probability with Improved Energy Detection in Cognitive Radio

Optimization Analysis of Improved Energy Detection based Cooperative Spectrum Sensing Network in Nakagami-m and Weibull Fading Channels

Optimization Analysis of Improved Energy Detection based Cooperative Spectrum Sensing Network in Nakagami-m and Weibull Fading Channels

Multi slot-throughput tradeoff in an improved energy detector based faded cognitive radio network

In this paper, the impact of a multi slot based cooperative spectrum sensing (CSS) on the performance of a cognitive radio (CR) network has been investigated. Each CR user, equipped with an improved energy detector (IED), uses a number of mini slots of the sensing time to perform the spectrum sensing. Each CR uses OR logic to combine the sub local decisions generated in each mini slot to obtain a local decision at CR level. Local decisions are sent to fusion centre (FC) over reporting channel. The FC obtains a final decision about the presence of primary user (PU) by combining the local decisions using a fusion rule: Majority or Maximal Ratio Combining. The performance of the CSS is assessed in terms of detection probability and false alarm probability considering both the sensing and reporting channels are Rayleigh faded. Furthermore, the impact of a number of sensing slots and IED parameter on throughput of CR network is also evaluated under the proposed spectrum sensing scenario. Impacts of several sensing parameters such as sensing channel SNR and reporting channel SNR on the performance of CR network are also evaluated. Performances of two fusion rules under study are compared. Effect of sensing error and synchronisation error is indicated. Further the study is extended for independent but non identically distributed (i.n.i.d.) Rayleigh faded channels as well as for a multiple PU scenario also.

Joint impact of sensing time and SPRF parameter on the performance of a continuous energy harvesting cooperative cognitive radio network

SummaryJoint impact of sensing time and signal power raise factor is studied for an improved energy detector–based energy harvesting cooperative cognitive radio network. All the cognitive radio nodes harvest energy either from radio frequency resources or from non–radio frequency resources. The probability density function of harvested energy from both the sources is exponentially distributed. Novel theoretical expressions for harvested energy and throughput are derived. Impact of several sensing parameters and a device constraint on the outage is studied. Optimal values of sensing time and signal power raise factor parameter pair are estimated for maximum harvested energy and maximum throughput. Energy efficiency of the network is also evaluated, and impact of sensing time on it is indicated.

Multi-slot based spectrum sensing with improved energy detector for cognitive radio network in presence of Rayleigh fading

In this paper, the performance of multi-slot based spectrum sensing is investigated in a cooperative scenario where each cognitive radio (CR) user is equipped with an improved energy detector (IED). Two levels of fusion are employed: (i) sub-local decisions obtained in multiple mini slots are combined using OR logic fusion at a CR to obtain a local decision (ii) local decisions from CRs are combined using Majority logic fusion at FC to obtain final decision about the presence of PU. Both the sensing channel (S-channel) and reporting channel (R-channel) are assumed to be Rayleigh faded. Each CR sends its local decision over R-channel to FC after BPSK modulation. The performance of the cooperative spectrum sensing (CSS) using multi-slot and IED is assessed in terms of detection probability and false alarm probability. Furthermore, throughput of a CR is also evaluated under the proposed spectrum sensing scheme. Novel analytical expressions for the detection performance are developed. Performance of multi-slot based sensing is also compared with spectrum sensing without slotted sensing time. Impact of several sensing parameters such as sensing threshold, number of mini-slot, sensing channel SNR (SSNR), reporting channel SNR (RSNR) and IED parameters (p) on the detection performance of CR is indicated. The impact of multi-slot and IED parameter on throughput is also investigated.

An Improved Energy Detection Scheme based on Channel Estimation

Energy detection is most commonly employed technique for spectrum sensing in cognitive radio networks due to its low computational and implementation complexities. However, the performance of energy detector deteriorate considerably under severe fading environment especially in low SNR region. The performance metrics used for energy detector are probability of detection, probability of false alarm and number of samples requirements. The detection threshold plays a significant role in PU signal detection and thus must be chosen appropriately to meet tradeoff between probability of detection and probability of false alarm under severe fading. In this paper, we have proposed adaptive threshold detection scheme for severe fading environment to work under low SNR. The simulated results are presented to validate the proposed scheme and it has been shown that proposed scheme is more robust against noise uncertainty under severe fading environment and performs better than conventional energy detection scheme to yield same detection performance.

Joint impact of sensing time and IED parameter on the performance of an energy efficient cognitive radio system

SummaryJoint impact of sensing time and improved energy detector (IED) parameter is evaluated for an energy efficient cooperative cognitive radio (CR) system where the CR users use IED. The aim of this work is to design the CR system in such a way that it can achieve two objectives for a given level of protection on primary user: (i) optimization of sensing time to make balance between detection performance and throughput and (ii) appropriate allocation of energy between sensing time and transmission time so as to enhance the energy efficiency of the CR system. The key parameters such as sensing time and IED parameter are set appropriately to meet the objectives. The performance is assessed in terms of throughput and energy efficiency of the system. The effect of the sensing time and the IED parameter on the performance is evaluated under a collision constraint. Furthermore, the optimal sensing time and IED parameter are investigated jointly for which the higher throughput as well as maximum energy efficiency can be obtained, and at the same time, a desired detection probability can also be maintained by the CR system. Copyright © 2016 John Wiley &amp; Sons, Ltd.

Performance of an Improved Energy Detector in Multihop Cognitive Radio Networks

Cooperative spectrum sensing in a multihop cognitive radio (CR) network based on multiple antennas using an improved energy detector is studied in this paper. The improved energy detector uses the $p$ th power of the absolute value of samples of primary user's (PU's) signals. We replace the conventional energy detector by an improved energy detector to enhance the performance of CR. Analytical expressions of the probability of false alarm and missed detection in each CR are derived. Furthermore, we extend our study to a multihop cooperative diversity system containing multiple multihop secondary transmission paths between the PU and the fusion center. Performance analysis of multihop cooperative diversity is discussed using an improved energy detector. We introduce a framework to derive a closed-form expression of the optimal number of multihop cooperative diversity branches by minimizing the total error rate. An efficient quick spectrum sensing algorithm is proposed, which requires fewer than the total number of cooperative multihop diversity branches. It is shown, through various numerical examples, that by using the optimal number of secondary transmission paths, it is possible to perform quick spectrum sensing while satisfying an upper bound on the total error rate.