Performance Estimation of Improved Cooperative Spectrum Sensing in Cognitive Radio

The applications of wireless communication are growing day by day; utilization of the spectrum is one of the prime challenges. Cognitive radio is the new era of wireless communication and acts as an immerging solution to the problem. It senses, analyzes and, allocates the vacant frequency band to secondary users (cognitive Radios). Energy detection (E.D.) has been accepted as the most suitable spectrum sensing technique due to its lower complexity, simplicity and majorly because of its blind detection.  But the performance of the E.D. is limited by low SNR,  shadowing, and multipath fading, so there is a tradeoff between complexity and performance in this conventional Energy detection technique. In this paper improved version of E.D. –Improved Energy Detection (IED)is used as a significant method for the case of cooperative sensing scenario. The proposed framework is also analyzed and compared for the case of different SNR and decision fusion rules. The Simulation result shows that the proposed framework gives excellent performance compared to conventional energy detection (CED) technique with lower complexity which meets the real-time requirement of cooperative spectrum sensing in wireless communication

Sensing and Sharing Schemes for Spectral Efficiency of Cognitive Radios

Increase in data traffic, number of users and their requirements laid to a necessity of more bandwidth. Cognitive radio is one of the emerging technology which addresses the spectrum scarcity issue. In this work we study the advantage of having collaboration between cognitive enabled small cell network and primary macrocell. Different from the existing works at spectrum sensing stage we are applying enhanced spectrum sensing to avoid probability of false alarms and missed detections which has impact on spectral efficiency. Later power control optimization for secondary users known as Hybrid spectrum sharing is used for further improvement of spectral efficiency. Furthermore, the failed packets of Primary users are taken care by high ranked relays which in turn decreases the average Primary user packet delay by 20% when compared between assisted Secondary user method and non-assisted Secondary user method.

Quantitative estimation of TV white space in Southwest Nigeria

The demand for bandwidth has increased in recent years with the advent of new technologies in the wireless systems which have resulted into spectrum crunch. Utilizing the free ultra high frequency (UHF), television (TV) channels also known as TV white space (TVWS) has been proposed as a strategy for increasing spectral efficiency. Deploying TVWS requires the knowledge of the estimate of the available TVWS. In this paper, a quantitative estimation of the available TVWS in South West, Nigeria is computed using the protection view point approach, the pollution viewpoint approach and the Federal Communication Commission (FCC) rule. Results from the estimation shows that the pollution view point approach will guarantee enough protection from the primary users and hence prevent interference from the secondary users. The findings also reveal that there are abundant TVWS in the considered states for the deployment of TVWS devices

On Employing a Savitzky-Golay Filtering Stage to Improve Performance of Spectrum Sensing in CR Applications Concerning VDSA Approach

Abstract In this paper, a filtering stage based on employing a Savitzky-Golay (SG) filter is proposed to be used in the spectrum sensing phase of a Cognitive Radio (CR) communication paradigm for Vehicular Dynamic Spectrum Access (VDSA). It is used to smooth the acquired spectra, which constitute the input for a spectrum sensing algorithm. The sensing phase is necessary, since VDSA is based on an opportunistic approach to the spectral resource, and the opportunities are represented by the user-free spectrum zones, to be detected through the sensing phase. Each filter typology presents peculiarities in terms of its computational cost, de-noising ability and signal shape reconstruction. The SG filtering properties are compared with those of the linear Moving Average (MA) filter, widely used in the CR framework. Important improvements are proposed

Improved Sensing Accuracy using Enhanced Energy Detection Algorithm with Secondary User Cooperation in Cognitive Radios

Spectrum sensing is indispensable for cognitive radio to identify the available white spaces. Energy detection is considered as a preferred technique for spectrum sensing in cognitive radio networks. It is because of its simplicity, applicability and low computational complexity, energy detection is employed widely for spectrum sensing. This paper proposes an enhanced energy detection based spectrum sensing algorithm which incorporates the features of traditional energy detection and cooperative detection. The false alarm and detection probabilities of the proposed algorithm are derived theoretically under AWGN channel conditions. The performance of the proposed algorithm is evaluated analytically for various decision thresholds. The performance evaluations indicate that the proposed enhanced energy detection algorithm outshines the traditional energy detection algorithm and greatly improves the spectrum sensing accuracy under varying SNR conditions

Three-Event Energy Detection with Adaptive Threshold for Spectrum Sensing in Cognitive Radio Systems

Implementation of dynamic spectrum access (DSA) in cognitive radio (CR) systems requires the unlicensed secondary users (SU) to implement spectrum sensing to monitor the activity of the licensed primary users (PU). Energy detection (ED) is one of the most widely used methods for spectrum sensing in CR systems, and in this paper we present a novel ED algorithm with an adaptive sensing threshold. The three-event ED (3EED) algorithm for spectrum sensing is considered for which an accurate approximation of the optimal decision threshold that minimizes the decision error probability (DEP) is found using Newton’s method with forced convergence in one iteration. The proposed algorithm is analyzed and illustrated with numerical results obtained from simulations that closely match the theoretical results and show that it outperforms the conventional ED (CED) algorithm for spectrum sensing

Improved Collaborative Spectrum Sensing Scheme for Maritime Cognitive Radio

603-612Expeditious growth in wireless networks for numerous wireless services and applications lead to the increase in demand for radio spectrum in both terrestrial and marine wireless communications. Radio spectrum is scarce as the available spectrum is already been allocated to various applications. Cognitive radio technology is an optimistic solution for the spectral scarcity. In Cognitive Radio Networks (CRN), the unused licensed bands are dynamically accessed by the unlicensed secondary users for data transmission. Spectrum Sensing (SS) is the key technique to detect the presence or absence of the primary users. SS for terrestrial wireless communication have been studied vastly. This paper is aimed to study SS for Maritime Cognitive Radio Networks (MCRN) which is daunting as SS in MCRN depends on the sea state. Existing work on SS in MCRN deals with Classical Energy Detection (CED) which is a straight forward procedure with low complexity and can be applied generally to any signal irrespective of its format. Here we intend to perform SS in MCRN using Improved Energy Detection (IED) which surpasses the performance of CED without ruining its general attributes. Evaluations and analysis are carried out using detection probability performance metric for both CED and IED, simulated and compared for different sea states