scholarly journals Spectrum Sensing for Cognitive Vehicular Networks over Composite Fading

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Haroon Rasheed ◽  
Nandana Rajatheva
Keyword(s):  
Cognitive Radio ◽  
Spectrum Sensing ◽  
Large Scale ◽  
Vehicular Networks ◽  
Multipath Fading ◽  
Energy Detection ◽  
Shadow Fading ◽  
Radio System ◽  
Composite Fading ◽  
Hidden Terminal

Recent advancement in vehicular wireless applications is also a major contributing factor in spectrum scarcity. Cognitive radio system is a mechanism which allows unlicensed cognitive users (CUs) to utilize idle unused bands. Fast and reliable detection of primary legacy user is the key component of cognitive radio networks. However, hidden terminal and low SNR problems due to shadow fading put fundamental limit to the sensing performance and practical entailments in design of the cognitive vehicular networks. Extensive modeling is being carried out to specify varying channel characteristics, particularly multipath fading and shadowing. Energy detection-(ED-) based spectrum sensing is a viable choice for many vehicle-to-vehicle (V2V) and vehicle to-road-side infrastructure (V2I) communications. This paper examines the performance of spectrum sensing using ED over Gamma-shadowed Nakagami-m composite fading channel to cater for both small-and-large scale fading. The results highlight the notable impact of shadowing spread and fading severity on detection performance. The relevant simulation results are presented to support our analytical results for average detection probability. Furthermore, these results are investigated and compared to other compound and classical channels.

scholarly journals 5G cognitive radio system design with new algorithm asynchronous spectrum sensing

2021 ◽  
Vol 10 (4) ◽  
pp. 2046-2054
Author(s):  
Mohammed Mehdi Saleh ◽  
Ahmed A. Abbas ◽  
Ahmed Hammoodi
Keyword(s):  
Cognitive Radio ◽  
Spectrum Sensing ◽  
Energy Detection ◽  
Primary User ◽  
Spectrum Access ◽  
Secondary Users ◽  
Radio System ◽  
Wireless Applications ◽  
Fifth Generation ◽  
Time Required

Due to the rapid increase in wireless applications and the number of users, spectrum scarcity, energy consumption and latency issues will emerge, notably in the fifth generation (5G) system. Cognitive radio (CR) has emerged as the primary technology to address these challenges, allowing opportunist spectrum access as well as the ability to analyze, observe, and learn how to respond to environmental 5G conditions. The CR has the ability to sense the spectrum and detect empty bands in order to use underutilized frequency bands without causing unwanted interference with legacy networks. In this paper, we presented a spectrum sensing algorithm based on energy detection that allows secondary user SU to transmit asynchronously with primary user PU without causing harmful interference. This algorithm reduced the sensing time required to scan the whole frequency band by dividing it into n sub-bands that are all scanned at the same time. Also, this algorithm allows cognitive radio networks (CRN) nodes to select their operating band without requiring cooperation with licensed users. According to the BER, secondary users have better performance compared with primary users.

scholarly journals Estimation of Best Spectrum Sensing Concept in Cognitive Radio Networks

2019 ◽  
Vol 8 (12) ◽  
pp. 1159-1163
Keyword(s):  
Cognitive Radio ◽  
Spectrum Sensing ◽  
Cognitive Radio Networks ◽  
Specific Energy ◽  
Spectrum Sharing ◽  
Matched Filter ◽  
Energy Detection ◽  
Radio Networks ◽  
Radio System ◽  
Spectrum Detection

Cognitive radio is a versatile and sharp radio system learning that can naturally recognize accessible divert in a remote range and change correspondence parameters empower more data to run at the same time. Psychological radio is estimated as a point towards which a product characterized radio stage ought to create. The significant elements of CR incorporate Spectrum detecting, Spectrum portability, Spectrum choice, Spectrum sharing. Range detecting frames the base of subjective radios and is one of the principle strategies that empower the intellectual radios to improve the range use. Range detecting is for the most part done in the recurrence and time area. In this paper we will analyze about and investigate four noteworthy range detecting systems to be specific Energy detection, Matched filter spectrum detection, Cyclostationary spectrum detection and Waveform based spectrum detection. In view of the similar outcomes we can appraise the best spectrum detection for remote portable applications

scholarly journals A novel double threshold-based spectrum sensing technique at low SNR under noise uncertainty for Cognitive Radio Systems

2021 ◽  
Author(s):  
Garima Mahendru
Keyword(s):  
Cognitive Radio ◽  
Spectrum Sensing ◽  
Energy Detection ◽  
Communication Link ◽  
Noise Power ◽  
Radio System ◽  
Low Snr ◽  
Detection Probabilities ◽  
Analytical Result ◽  
Novel Concept

Abstract Cognitive Radio is a novel concept that has invoked a paradigm shift in wireless communication and promises to solve the problem of spectrum underutilization. Spectrum sensing plays a pivotal role in a cognitive radio system by detecting the vacant spectrum for establishing a communication link. For any spectrum sensing method, detection probability and error probability portray a significant part in quantifying the detection performance. At low SNR, it becomes cumbersome to differentiate noise and signal due to which sensing method loses robustness and reliability. In this paper, mathematical modeling and critical measurement of detection probabilities has been done for energy detection-based spectrum sensing at low SNR in uncertain noisy environment. A mathematical model has been proposed to compute double thresholds for reliable sensing when the observed energy is less than the uncertainty in the noise power. A novel parameter “Threshold Wall” has been formulated for optimum threshold selection to overcome sensing failure. Comparative simulation and analytical result measurements have been presented that reveals improved sensing performance.

scholarly journals Analysis of Spectrum Sensing over Imperfect Channel conditions in Cognitive Vehicular Networks

2017 ◽  
Author(s):  
Xiaomin Qian ◽  
Li Hao ◽  
Dadong Ni ◽  
Quang Thanh Tran
Keyword(s):  
Cognitive Radio ◽  
Spectrum Sensing ◽  
Vehicular Networks ◽  
Radio Channel ◽  
Energy Detection ◽  
Critical Issue ◽  
Wireless Channel ◽  
Cooperative Sensing ◽  
Counting Rule ◽  
Temporally Correlated

An explosive growth in vehicular wireless services and applications gives rise to spectrum resource starvation. Cognitive radio has been used to vehicular networks to mitigate the impending spectrum starvation problem by allowing vehicles to fully exploit spectrum opportunities unoccupied by licensed users. Efficient and effective detection of licensed user is a critical issue to realize cognitive radio applications. However, spectrum sensing in vehicular environments is a very challenging task due to vehicles mobility. For instance, vehicle mobility has a large effect on the wireless channel, thereby impacting the detection performance of spectrum sensing. Thus, gargantuan efforts have been made in order to analyze the fading properties of mobile radio channel in vehicular environments. Indeed, numerous studies have demonstrated that the wireless channel in vehicular environments can be characterized by a temporally correlated Rayleigh fading. In this paper, we focus on energy detection for spectrum sensing and a counting rule for cooperative sensing based on Neyman-Pearson criteria. Further, we go into the effect of the sensing and reporting channels condition on spectrum sensing performance under temporally correlated Rayleigh sensing channel. For local and cooperative sensing, we derive some alternative expressions for average probability of miss detection. The pertinent numerical and simulating results are provided to further validate our theoretical analyses under a variety of scenarios.

scholarly journals DWT Based Energy Detection Spectrum Sensing Method for Cognitive Radio System

2020 ◽  
Vol 3 (3) ◽  
pp. 1-11
Author(s):  
Muntaser S. Falih ◽  
Hikmat N. Abdullah
Keyword(s):  
Cognitive Radio ◽  
Spectrum Sensing ◽  
Detection Probability ◽  
Signal To Noise Ratio ◽  
Energy Detection ◽  
Primary User ◽  
Radio System ◽  
Processed Sample ◽  
Simulation Results ◽  
Sensing Time

In this paper a new blind energy detection spectrum-sensing method based on Discreet Wavelet Transform (DWT) is proposed. The method utilizes the DWT sub-band to collects the received energy. The proposed method recognizes the Primary User (PU) signal from noise only signal using the differences in the collected energy in first and last sub-bands of one level DWT. The simulation results show that the proposed method achieves improved detection probability especially at low Signal to Noise Ratio (SNR) compared to Conventional Energy Detector (CED). The results also show that the proposed method has shorter sensing time and less Energy Consumption (EC) compared to CED due to using small number of processed sample. Therefore, this method is suitable for Cognitive Radio (CR) applications where only limited energy like device battery is available.

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