Spectrum Sensing Research Papers - Academia.edu (original) (raw)

"James Joyce, as a postcolonial Irishman, understands the connection between Ireland and the Orient . In his texts, his characters often contemplate the Orient while numbly living out their routines in Ireland, but Joyce’s Irish Oriental aesthetic goes far beyond his characters’ small mindedness and paralysis. My intent in this paper is to discover how Joyce interacts with the commonly understood category of Irish Orientalism through his texts, characters, and styles of writing. I begin my argument by defining Irish Orientalism in the context of Orientalism and history. Next, I analyze select elements of “Araby” from Dubliners and “Lotus Eaters” from Ulysses, demonstrating how they either confirm or subvert traditional conceptions of Irish Orientalism. I conclude my essay with a contemplation of other critics’ views on Joyce’s Irish Oriental aesthetic and establish my own argument in light of my close readings of the texts “Araby” and “Lotus Eaters.” I propose that Joyce neither fully confirms nor subverts the concept of Irish Orientalism; ultimately, I argue that Joyce’s works promote a new vision of Irish Orientalism that is organic and transformative and that demonstrates bravely how a postcolonial entity like Ireland (or the Orient) can begin to recreate its own identity separate from imperialism."

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- Aesthetics, Irish Literature, James Joyce, Post-Colonialism
- by Yonghong Zeng
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- Computer Science, Cognitive radio, Spectrum Sensing, Displays

This report focuses on the Access network implementation of a 5G small-cell communication system using Cognitive Radio. 5G systems are the next major wireless communications standard and Cognitive Radio is being heralded as a valid implementation method when the wireless communications industry finally concludes on a fifth generation standard. The project is concerned with implementing a Beyond-Next-Generation (5G) communications network based on Cognitive Radio. A functioning model is developed in matlab, the purpose of which is to show that Cognitive Radio based 5G systems will give acceptable Quality-of-Service and energy efficiency levels.
The Access network implementation of the system involves channel assignment for the access links which provide network access to mobile subscribers. Suitable channels to service call requests are determined based on cognition.
The system performance is evaluated by estimating the system blocking and dropping probabilities and the percentage of energy saved.

The increasing demand of wireless applications has put a lot of limitations on the use of available radio spectrum is limited and precious resource. Many survey of spectrum utilization shows that entire spectrum is not used at all the times, so many of the radio spectrum is underutilized. Some of the frequency bands in the spectrum are unoccupied, some of the frequency bands less occupied and few bands are over utilized. Cognitive radio system is a technique which overcomes that spectrum underutilization. Cognitive radio is a technique where secondary user looks for a free band to use when primary user is not in use of its licensed band. A function of cognitive radio is called Spectrum sensing which enables to search for the free bands and it helps to detect the spectrum hole (frequency band which is free enough to be used) which can be utilized by secondary user with high spectral resolution capability. The idea of simulation and analysis of Cognitive Radio System to reuse unused spectrum to increase the total system capacity was brought in this paper and this work digs into the practical implementation of a Cognitive radio system. MATLAB R2007b (version7.5) has been used to test the performance of Cognitive radio dynamically

- by Kiruthikha Chandrasekaran
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- Spectrum Sensing, Spectrum
- by Jonathan Verlant-Chenet
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- Spectrum Sensing, Higher Order Thinking
- by Akhil Jumade
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- Biomedical Engineering, Cognitive radio, Spectrum Sensing, Computer Simulation
- by Ravikumar Balakrishnan
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- Engineering, Distributed Computing, Technology, Computational Complexity
- by Nasser Aliraqi
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- Distributed Computing, Dynamic Spectrum Access, Cognitive radio, Spectrum Sensing

TVWS represent an alternative to various problems, such as spectrum scarcity; The challenge of connecting to remote locations or even the deployment of community networks through the use of portions of unused spectrum. TVWS are spaces that have been left unoccupied by the transition from analogue to digital television or simply because in some regions television operators do not see a return on investment and as a consequence these frequencies are available for use; However in order to declare them as underutilized space, a technical verification of the spectrum must be carried out. I made a census of the electromagnetic spectrum of 300 MHz to 900 MHz, belonging to the band Ultra High Frequency (UHF), that was realized with low cost measurement devices so that these measurements are replicable, in developing countries, which lack of the costly technology generally required to perform such censuses. A measurement framework based on this experience and previous experiences is constructed, taking a census of the spectrum with different low cost devices that show that it is possible to carry out an organized and structured census of a portion of the spectrum that serves as a valid source of the state of the art, and therefore a valid source for the justification of the use of these frequencies in function of the deployment of community networks or cognitive radio.

The increasing demand of wireless applications has put a lot of limitations on the use of available radio spectrum is limited and precious resource. Many survey of spectrum utilization shows that entire spectrum is not used at all the times, so many of the radio spectrum is underutilized. Some of the frequency bands in the spectrum are unoccupied, some of the frequency bands less occupied and few bands are over utilized. Cognitive radio system is a technique which overcomes that spectrum underutilization. Cognitive radio is a technique where secondary user looks for a free band to use when primary user is not in use of its licensed band. A function of cognitive radio is called Spectrum sensing which enables to search for the free bands and it helps to detect the spectrum hole (frequency band which is free enough to be used) which can be utilized by secondary user with high spectral resolution capability. The idea of simulation and analysis of Cognitive Radio System to reuse unused spectrum to increase the total system capacity was brought in this paper and this work digs into the practical implementation of a Cognitive radio system.MATLAB R20 07b (version7.5) has been used to test the performance of Cognitive radio dynamically

- by Mohd Adib Sarijari
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- Software Defined Radio, Cognitive radio, Spectrum Sensing, Wireless Network
- by abdessamad ELRHARRAS
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- FPGA, Cognitive radio, Vhdl, Spectrum Sensing

In emerging cognitive radio (CR) networks, the first cognitive task preceding any dynamic spectrum management is the sensing and identification of spectrum holes in wireless environments. This paper develops a distributed compressed spectrum sensing approach for (ultra-)wideband CR networks. First, compressive sampling is performed at local CRs to scan the very wide spectrum at practical signal-acquisition complexity. Then, measurements or states from multiple CR detectors are fused to collect spatial diversity gain, which improves the detection quality especially under fading channels. Distributed fusion algorithms are derived to effect collaborative fusion at low communication and computation load scalable to the network size. Multiple performance metrics are identified to evaluate the proposed spectrum sensing techniques, as well as to assess those performance-determining factors in system design. Computer simulations corroborate the effectiveness of the proposed techniques in id...

- by Erik Blasch
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- Computer Science, Distributed Algorithms, Data Compression, Fading Channel
- by Ogechi A K U D O Nwogu
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- Cognitive radio, Spectrum Sensing, Random Matrix Theory, Eigenvalues

Los espacios en blanco de televisión representan una alternativa a diversos problemas, tales como, la escasez de espectro; el reto de llevar conexión a lugares remotos y la potencial saturación de los operadores de telefonía móvil impulsa a utilizar estos espacios para aliviar cada uno de estos problemas. Los espacios en blanco de televisión son espacios que han quedado desocupados debido a la transición de la televisión analógica a la digital o simplemente porque en ciertas regiones los operadores de televisión no ven un retorno de inversión y en consecuencia estas frecuencias están disponibles para su uso.
En este trabajo de grado se realizó un censo del espectro electromagnético de 300 MHz a 900 MHz, pertenecientes a la banda Ultra High Frequency (UHF), con dispositivos de medición de bajo costo de manera que estas mediciones sean replicables, en países en vías de desarrollo, que carecen de la costosa tecnología generalmente requerida para realizar dichos censos. De igual manera, se construye un marco de medición basado en esta experiencia y experiencias previas. Se obtiene entonces un censo del espectro con diferentes dispositivos de bajo costo que demuestran que es posible realizar un censado organizado y estructurado de una porción del espectro que sirva como una fuente valida del estado del mismo.

Fruit peel coloring is one of the most important measures of commercial values in various citrus fruits. It is well documented that a gaseous plant hormone, ethylene, regulates the peel color changes associated with fruit ripening. To handle the peel color quality, it is necessary to develop a universal measure of ethylene-directed color changes. Here, we proposed a novel colorimetric formula: y* = [ (L* n • max-L* t) 2 + (a* n • max-a* t) 2 + (b* n • max-b* t) 2 ] 1/2 (y* > 0), based the CIE 1976 L*a*b* colour space units, which reflect the wholistic changes in fruit color. Since all known colorimetric values are specialized for estimation of the changes in certain single pigment, our formula may be useful for assessing the total fruit color development in a controlled atmosphere.

- by Tomonori Kawano
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- Agricultural Engineering, Biochemistry, Botany, Food Science
- by Arumugam Nallanathan
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- Cognitive radio, Spectrum Sensing, Primary User, Detection Probability
- by Asad Javied
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- Cognitive radio, Spectrum Sensing, Cooperative Spectrum Sensing, Outlier detection
- by Nam Nguyen
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- Wireless Communications, Cognitive radio, Cooperative Communications, Spectrum Sensing
- by Kamran Arshad
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- Distributed Computing, Monte Carlo Simulation, Cognitive radio, Probability

Limited spectrum resources and dramatic growth of high data rate applications have motivated opportunistic spectrum access utilizing the promising concept of cognitive networks. Although this concept has emerged primarily to enhance spectrum utilization and to allow the coexistence of heterogeneous network technologies, the importance of energy consumption imposes additional challenges, because energy consumption and communication performance can be at odds. In this paper, the approaches for energy efficient spectrum sensing and spectrum handoff, fundamental building blocks of cognitive networks is investigated. The tradeoff between energy consumption and throughput, under local as well as under cooperative sensing are characterized, and what further aspects need to be investigated to achieve energy efficient cognitive operation under various application requirements are discussed.

- by Waleed Ejaz
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- Spectrum Sensing, Cognitive Radio Network
- by Ian Akyildiz and +1
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- Distributed Computing, Cognitive radio, Spectrum Sensing, Wireless Network

Ultrawideband and cognitive radio are two of the most important approaches that are shaping the future of wireless communication systems. At a first glance, the aims of UWB and cognitive radio do not seem to be overlapping significantly, however, there is a strong synergy between the capabilities of UWB and the goals of cognitive radio. One of the objectives of

- by Mustafa Şahin
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- Cognitive radio, Spectrum Sensing, Spectrum, Wireless communication systems
- by Vahid Jamali
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- Engineering, Distributed Computing, Technology, Computational Complexity

This report reviews Cognitive Radio technology starting from when the term Cognitive Radio was coined by Dr Joseph Mitola in the late 90s. Basic concepts about CR technology as well as different features of CR alongside principles behind CR more importantly from the cognitive cycle perspective were discussed in this report. Certain applications and test-beds across the United States and Europe like CORNET and ORBIT were identified. Several emerging research topics which could lead to major innovative CR approach were also discussed before giving a personal opinion on when CR technology is likely to be widely used.

Wireless technology is expanding its domain and with it is growing the need for more frequencies for communication. Cognitive radio offers a solution to this problem by using the concept of Dynamic spectrum access instead of fixed spectrum allocation. Such radios are capable of sensing the RF spectrum for identifying idle frequency bands. It then transmits opportunistically so as to avoid interference with primary user over same band. In cognitive radio, intelligent spectrum sensing forms the major and most important part. Out of the various sensing techniques, we will give an overview of some of the prominent non-cooperative techniques. The paper deals with comparative study of these methods.

The need for Digital Transmission has been on the increase over the years. Spectrums are basically a range of electromagnetic waves for digital transmission. Digital Transmission has poised great economic benefits to Networks Transmission Industries. However, with the wide spread demand for networks transmission, appropriate supervision of utilization and management is adequately required. A key component of the study is based on the input from the operational regions, industry stakeholders and Government Commissions. The study observed that, digital transmission has helped in managing the rate at which available spectrums are been utilized. Indeed, it takes 8MHz (Eight Mega Hertz) of Spectrum to carry a single Analogue Transmission, but with, Digital Transmission, it take the same 8MHz (Eight Mega Hertz) of Spectrum to carry as much as 20 (twenty) Digital Transmissions. This research work focused on providing solution to the need for a proper Analysis of Digital Spectrum Utilization. The concept of a Fuzzy Set, and a robust analytic tool (MATLAB) was used as the analytic system model for a more scientific and feasible solution to sensitivity analysis and spectrum utilization. The system was developed and evaluated using a scientific field data obtained from Nigerian Television Authority (NTA) Jos, for analysis purpose. Results obtained from the analysis shows that the use of Spectrum for Digital Transmission in Nigeria (Jos) has periodically increased, however not up to 50% (fifty per cent) were in use as at the end of December 2016. Recent concerns for conversion of Analogue Transmission to Digital are expected to bring about significant increase to Spectrum Utilization in Nigeria.

- by Solomon Mbak
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- Spectrum Sensing, Spread Spectrum, Spectrum Management, Spectrum
- by Vahid Jamali
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- Engineering, Distributed Computing, Technology, Computational Complexity

The assignment policy of frequency spectrum which is limited, is implemented as a constant in today's wireless communications. Increasing number of users with the rapidly developing wireless technologies also increases the frequency spectrum demand. Therefore, allocation of frequency bands in the spectrum to the users as fixed causes inefficient use of the frequency spectrum. To overcome this problem, cognitive radio concept is emerged. This concept described as intelligent radio enables the current spectrum band to be used efficiently and actively. Cognitive radio detects whether or not there is any licensed (primary) users around, by sensing the full spectrum band continuously. It assigns the spectrum bands unused by primary users to unlicensed (secondary) users. To prevent interference, it empties that spectrum when the primary users start to use their own spectrum bands, or it reduces transmission power to a level that cannot communicate. Spectrum sensing which is one of the major components used to improve cognitive radio spectrum efficiency scans all licensed users and unused frequency spectrum continuously. In this study, spectrum availability is determined according to the detected energy level using Energy Detection Based Spectrum Sensing which is one of the spectrum sensing techniques. The effects of Probability of detection (Pd), Probability of false alarm (Pf), Probability of missed detection (Pm) and Signal to Noise Ratio (SNR) value to each other are analyzed. Simulation results shows that the probability of detection increases significantly when signal to noise ratio increases.

- by Can Cakir
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- Cognitive Radio Networks, Dynamic Spectrum Access, Spectrum Sensing
- by Abdur Rahim
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- Cognitive radio, Spectrum Sensing, Time-Frequency Analysis, Performance Improvement

In the last few years Compressed Sampling (CS) has been well used in the area of signal processing and image compression. Recently, CS has been earning a great interest in the area of wireless communication networks. CS exploits the sparsity of the signal processed for digital acquisition to reduce the number of measurement, which leads to reductions in the size, power consumption, processing time and processing cost. This article presents application of CS for the spectrum sensing and channel estimation in Cognitive Radio (CR) networks. Basic approach of CS is introduced first, and then scheme for spectrum sensing and channel estimation for CR is discussed. First, fast and efficient compressed spectrum sensing (CSS) scheme is proposed to detect wideband spectrum, where samples are taken at sub-Nyquist rate and signal acquisition is terminated automatically once the samples are sufficient for the best spectral recovery and then, after the spectrum sensing, in the second phase notion of multipath sparsity is formalized and a novel approach based on Orthogonal Matching Pursuit (OMP) is discussed to estimate sparse multipath channels for CR networks. The effectiveness of the proposed scheme is demonstrated through comparisons with the existing conventional spectrum sensing and channel estimation methods.

A scenario is presented in spectrum sensing for Cognitive Radio Networks based on energy detectors. Results are presented for the performance of the energy detector based on Welch periodogram. The effect of the number of signal samples and the time domain window function are demonstrated for low Signal-to-Noise Ratio values. Furthermore, the detector performance is linked to a general probabilistic scheme for sensing algorithms. Important system issues such as receiver feedback and cooperative spectrum sensing are included in this framework. Parametric computations of the probability of correct decision are presented to show the detrimental effect of the hidden node problem in a simple collaborative spectrum sensing scheme.

- by Sean F Johnston
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- Optics, Visual Studies, Spectroscopy, History of Physics
- by Vlad Popescu
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- Signal Processing, Wireless Sensor Networks, Cognitive radio, Low Frequency

Today's wireless communication systems follow fixed spectrum assignment policies which leads to overall inefficient spectrum use. Further, spectrum scarcity is an issue for operators with emerging mobile services and large number of users with even higher capacity requirements. This inefficiency and scarcity in spectrum usage necessitates a new paradigm for communications such as utilising available spectrum opportunistically. Cognitive radio (CR) is an enabling technology having potential to increase spectrum utilisation and provide desired interference protection to licenced users. This can be done by detection of spectrum opportunities by secondary users. Due to channel fading and shadowing a single user can not make a reliable decision and collaboration of and among users is required. In this paper, it has been demonstrated that for improved detection performance decision fusion algorithm for collaborative spectrum sensing must have information about channel and the mean SNR of all secondary users. Using Monte Carlo simulations it is concluded that for optimum performance it is not necessary that all users collaborate with each other.

- by Kamran Arshad
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- Monte Carlo Simulation, Cognitive radio, Spectrum Sensing, Uncertainty
- by Dr. Sesham Srinu
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- Spectrum Sensing
- by Cindy Gao
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- Algorithms, Game Theory, Cognition, Cognitive Radio Networks

The tremendous growth in wireless communication has increased the spectrum usage, thereby raised the spectrum scarcity and security issues. The real problem is the inefficient spectrum allocation and its usage. Cognitive Radio is considered to be the key enabling technology for such problems. Spectrum sensing is the main aspect of cognitive radios. In this paper, a survey of Interference mitigation techniques by using Spatial Modulation in cognitive radio is studied. To protect both the primary as well as secondary user transmission, beam forming techniques is used. Such a scheme can be employed in the 5G technologies by the deployment of GFDM. Also, a comparative study on other 5G multicarrier transmission schemes such as FBMC and UFMC is done.