Performance Estimation of Improved Cooperative Spectrum Sensing under Fading Environment (original) (raw)
Related papers
Energy Detection Based Cooperative Spectrum Sensing in Cognitive Radio Networks
IEEE Transactions on Wireless Communications, 2000
Detection performance of an energy detector used for cooperative spectrum sensing in a cognitive radio network is investigated over channels with both multipath fading and shadowing. The analysis focuses on two fusion strategies: data fusion and decision fusion. Under data fusion, upper bounds for average detection probabilities are derived for four scenarios: 1) single cognitive relay; 2) multiple cognitive relays; 3) multiple cognitive relays with direct link; and 4) multi-hop cognitive relays. Under decision fusion, the exact detection and false alarm probabilities are derived under the generalized " -outof-" fusion rule at the fusion center with consideration of errors in the reporting channel due to fading. The results are extended to a multi-hop network as well. Our analysis is validated by numerical and simulation results. Although this research focuses on Rayleigh multipath fading and lognormal shadowing, the analytical framework can be extended to channels with Nakagami-multipath fading and lognormal shadowing as well.
2015
Article History: Received 14, July, 2015 Received in revised form 23, July, 2015 Accepted 13, August, 2015 Published online 28, August, 2015 In this paper we focus on spectrum sensing in cognitive radio to sense the presence of primary user and effectively use the available radio bandwidth. Cognitive users are allowed to share the licensed spectrum allotted to the primary user, when kept unutilized by it. Here energy detection technique is usedfor spectrum sensing overthe Rayleigh fading channel.Multiple cognitive radios actively participate to enhance the sensing capability of channel by collecting all sensed data at one central place. This collected data is processedand decision is made for the availability of spectrum, and thus can overcome the flaws of individual sensing. Comparison of cooperative and non-cooperative spectrum sensing for same number of cognitive radios is carried out under the centralized fusion procedure.
A Novel Energy Detection Technique for Cooperative Spectrum Sensing in Cognitive Radio
Journal of Green Engineering
Cooperative spectrum sensing is used as a promising solution to detect the primary user effectively in a highly noisy environment, where the multiple secondary users make a global decision in relation to the primary user. The Bayesian Estimation Energy Detection (BEED) technique is one of the elegant spectrum sensing techniques available in a non-cooperative environment. So an attempt was made in this paper by incorporating the BEED in a cooperative environment, which yields the detection of primary user effectively up to a Signal to Noise Ratio (SNR) of-19 dB, when the Rayleigh fading effects are considered.
Performance of Cooperative Spectrum Sensing in Fading Channels
Detection is compromised when a cognitive radio (CR) user experiences deep shadowing or fading effects. In order to detect the primary user (PU) more accurately, we allow the CR users to cooperate by sharing their information. In this paper we investigate performance of cooperative spectrum sensing scheme using energy detection (ED-CSS) to improve the sensing performance in channels such as log-normal shadowing and Nakagami fading channels. Hard decision combining rule (ORrule, AND-rule and MAJORITY-rule) is performed at fusion center (FC) to make the final decision about primary user present or not. Comparison among data fusion rules has been investigated for a wide range of average SNR values. The performance has been assessed in terms of miss detection (Pm) and false detection probabilities (Pf). A simulation model has been developed to evaluate performance of ED-CSS in different fading environments. A comparative performance of ED-CSS has been studied for various data fusion rules in Nakagami fading as well as shadow faded channels.
Study on Energy Detection-based Cooperative Sensing in Cognitive Radio Networks
Journal of Networks, 2013
Cognitive radio (CR) technology aims to achieve efficient radio spectrum utilization based on overlay spectrum sharing. Therefore, one of the main requirements of CR systems is the capability to detect and sense the presence of primary transmissions. However, sensing is affected by the behavior of the wireless channel, i.e., hidden node, interference, shadowing, and fading, which may result in wrong detection decisions. Consequently, CRs may introduce harmful interference to primary radios. Cooperative spectrum sensing can improve detection decisions by obtaining sensing information from different sources, which has been recently proposed to overcome this problem. This paper reviews cooperative sensing aspects, approaches, architecture, as well as problematic aspect and drawbacks of the control channel and associated fusion methods.
—In this paper, performance of cooperative spectrum sensing (CSS) has been assessed in the presence of Rayleigh fading. Cognitive radio (CR) users which employ improved energy detectors (IEDs) are censored depending on the quality of radio channels between them and a fusion center (FC). A training based channel estimator is used at the FC to estimate the fading coefficients characterizing the channels between the CRs and the FC. The CRs utilize selection combining (SC) of the decision statistics obtained by IEDs with multiple antennas for making hard decisions about the presence of primary user (PU) and transmit the information to the FC using BPSK signaling if the CR is selected to transmit. The majority logic fusion is applied at the FC for estimating the performance in terms of missed detection and total error probability for both perfect and imperfect channel estimation under different channel and network parameter conditions
6th International Symposium on Telecommunications (IST), 2012
Cognitive radio networks can improve the efficient use of spectrum through opportunistic access to the licensed bands without interfering with the primary users. Spectrum sensing, as an important functionality in cognitive radios (CRs), needs to reliably detect the signals from licensed primary radios. To achieve this, improved energy detector is proposed. By using optimum norm of the received signal samples in improved energy detector, the detection performance is improved as compared to the conventional detector. In the literature, Cooperation between CRs is proposed to avoid interference in primary users and increase the utilization of spectrum. In this paper, we assume a cooperative scheme where each CR senses a common frequency band with a different average SNR. According to Neyman-Pearson theorem, optimum norm of the received samples are compared to a predetermined threshold. Then, binary decision of each CR is sent to a fusion center (FC) to make final decision about presence or absence of primary users. The numerical results show that the performance of cooperative spectrum sensing with improved energy detector is increased considerably as compared to the conventional ones. The results also show that the OR rule outperforms the AND and the majority rules in both energy detectors. Index Terms-Cooperative spectrum sensing, cognitive radio network, improved energy detector.
Cognitive Radio Technology Applications for Wireless and Mobile Ad Hoc Networks
This chapter discusses the detection performance of relay based cognitive radio networks. Relays are assigned in cognitive radio networks to transmit the primary user's signal to cognitive coordinators or CPUs, thus achieving cooperative spectrum sensing. The purpose of the chapter is to provide mathematical analysis of energy detectors for dual hop networks. The soft fusion rule is used at the relays which acts as amplify and forward relays. For the detection purpose, the energy detector is employed at the cognitive coordinator. In the ending sections, sensing performance is analyzed for different fading channels in the MATLAB environment and simulation results present comparative performance of various relay conditions with concluding remarks.
A Performance Study of Energy Detection Based Spectrum Sensing for Cognitive Radio Networks
Spectrum scarcity is considered an impediment to the growth of wireless technologies. However, studies reveal a significant underutilization of the frequency spectrum apportioned to licensed users. An intelligent radio technology platform, termed Cognitive Radio was conceived to solve this imminent challenge by shifting the paradigm of a static spectrum allocation policy to that of dynamic (opportunistic) spectrum access. A foremost part of this technology is spectrum sensing. Among the methods espoused, Energy Detection possesses an advantage of low implementation and low computational complexity; compared to the other methods that require prior information and specific features of the signal to be detected. This study evaluates the performance of the energy detection based spectrum sensing technique in noisy and fading environments. Both single user detection and cooperative detection situations were investigated. Closed form solutions for the probabilities of detection and false alarm were derived. Analytical results were verified by numerical computations using Monte Carlo method in MATLAB. The performance of the energy detection technique was evaluated by use of Receiver Operating Characteristics (ROC) curves over AWGN and fading (Rayleigh & Nakagami-m) channels. Results show that for both single user detection and cooperative detection, the energy detection technique performs better in AWGN than in fading environment. The performance of cooperative detection in fading environment on the other hand, outperforms that of the single user detector.
2015
The ever growing wireless technologies has put a lot of demand on the usage of available spectrum, thus leading to spectrum underutilization and scarcity. To address this issue and improve spectrum utilization gave rise to the concept of the cognitive radio. The cognitive radio is known to enhance the utilization of spectrum of where a secondary user can utilize the spectrum of the primary user without causing harmful interference to the incumbent primary user. In this paper, we evaluated the performance of the energy detection based spectrum sensing in a fading and non-fading environments. Also we presented results on the single user detection and cooperative detection applying the energy detector. The performance of the energy detection technique was assessed by the use of the receiver operating characteristics (ROC) curves over additive white Gaussian noise (AWGN), Rayleigh and Nakagami channels. The cooperative detection shows better performance to the single user in the fading ...