Analysis of radio frequency spectrum usage using cognitive radio

This paper presents the analysis of radio frequency (RF) spectrum usage using cognitive radio. The aim was to determine the unused spectrum frequency bands for efficiently utilization. A program was written to reuse a range of vacant frequency with different model element working together to produce a spectrum sensing in MATLAB/Simulink environment. The developed Simulink model was interfaced with a register transfer level - software defined radio, which measures the estimated noise power of the received signal over a given time and bandwidth. The threshold estimation performed generates a 1\0 output for decision and prediction. It was observed that some spectrum, identified as vacant frequency, were underutilized in FM station in Benin City. The result showed that when cognitive radio displays “1” output, which is decision H1, the channel is occupied and cannot be used by the cognitive radio for communication. Conversely, when “0” output (decision H0) is displayed, the channel is unoccupied. There is a gradual decrease in the probability of detection (Pd), when the probability of false alarm (Pfa) is increased from 1% to 5%. In the presence of higher Pfa, the Pd of the receiver maintains a high stability. Hence, the analysis finds the spectrum hole and identifies how it can be reuse

Wireless Audio Interactive Knot

Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2001.Includes bibliographical references (leaves 44-45).The Sound Transformer is a new type of musical instrument. It looks a little like a saxophone, but when you sing or "kazoo" into it, astonishing transforms and mutations come out. What actually happens is that the input sound is sent via 802.11 wireless link to a net server that transforms the sound and sends it back to the instrument's speaker. In other words, instead of a resonant acoustic body, or a local computer synthesizer, this architecture allows sound to be sourced or transformed by an infinite array of online services, and channeled through a gesturally expressive handheld. Emerging infrastructures (802.11, Bluetooth, 3G and 4G, etc) seem to aim at this new class of instrument. But can such an architecture really work? In particular, given the delays incurred by decoupling the sound transformation from the instrument over a wireless network, are interactive music applications feasible? My thesis is that they are. To prove this, I built a platform called WAI-KNOT (for Wireless Audio Interactive Knot) in order to examine the latency issues as well as other design elements, and test their viability and impact on real music making. The Sound Transformer is a WAI-KNOT application.Adam Douglas Smith.S.M

An overview of bluetooth device discovery and fingerprinting techniques – assessing the local context

The ubiquitous nature of portable communication devices presents a number of opportunities for automated device discovery, tracking and possible owner identification. Consumer devices such as smartphones, tablets, wearables, laptops and vehicle entertainment systems commonly support the 802.15.1 (Bluetooth) wireless communication protocol that enables a variety device discovery and fingerprinting techniques. We provide an overview of these techniques encompassing those native to the protocol as well as those that are possibly protocol-agnostic due to their inherently generic nature. We then introduce an opportunity for a comparison study that sets out to examine and quantify the effectiveness of selected techniques in the field. To assess the potential viability of such study in the local context, we employ location-aware inquiry scanning and discuss the results of the exploratory data collection. We conclude that in this context the simplest technique being inquiry scanning can be used to establish a baseline for comparison with other techniques

The Mobile Generation: Global Transformations at the Cellular Level

Every year we see a new dimension of the ongoing Digital Revolution, which is enabling an abundance of information to move faster, cheaper, in more intelligible forms, in more directions, and across borders of every kind. The exciting new dimension on which the Aspen Institute focused its 2006 Roundtable on Information Technology was mobility, which is making the Digital Revolution ubiquitous. As of this writing, there are over two billion wireless subscribers worldwide and that number is growing rapidly. People are constantly innovating in the use of mobile technologies to allow them to be more interconnected. Almost a half century ago, Ralph Lee Smith conjured up "The Wired Nation," foretelling a world of interactive communication to and from the home that seems commonplace in developed countries today. Now we have a "Wireless World" of communications potentially connecting two billion people to each other with interactive personal communications devices. Widespead adoption of wireless handsets, the increasing use of wireless internet, and the new, on-the-go content that characterizes the new generation of users are changing behaviors in social, political and economic spheres. The devices are easy to use, pervasive and personal. The affordable cell phone has the potential to break down the barriers of poverty and accessibility previously posed by other communications devices. An entire generation that is dependant on ubiquitous mobile technologies is changing the way it works, plays and thinks. Businesses, governments, educational institutions, religious and other organizations in turn are adapting to reach out to this mobile generation via wireless technologies -- from SMS-enabled vending machines in Finland to tech-savvy priests in India willing to conduct prayers transmitted via cell phones. Cellular devices are providing developing economies with opportunities unlike any others previously available. By opening the lines of communication, previously disenfranchised groups can have access to information relating to markets, economic opportunities, jobs, and weather to name just a few. When poor village farmers from Bangladesh can auction their crops on a craigslist-type service over the mobile phone, or government officials gain instantaneous information on contagious diseases via text message, the miracles of mobile connectivity move us from luxury to necessity. And we are only in the early stages of what the mobile electronic communications will mean for mankind. We are now "The Mobile Generation." Aspen Institute Roundtable on Information Technology. To explore the implications of these phenomena, the Aspen Institute Communications and Society Program convened 27 leaders from business, academia, government and the non-profit sector to engage in three days of dialogue on related topics. Some are experts in information and communications technologies, others are leaders in the broader society affected by these innovations. Together, they examined the profound changes ahead as a result of the convergence of wireless technologies and the Internet. In the following report of the Roundtable meeting held August 1-4, 2006, J. D. Lasica, author of Darknet and co-founder of Ourmedia.org, deftly sets up, contextualizes, and captures the dialogue on the impact of the new mobility on economic models for businesses and governments, social services, economic development, and personal identity

IMPLEMENTATION OF WIRELESS LAN IN UTP

This paper, entitled Implementation ofWireless LAN in UTP environment, looks into the way to implement wireless network in UTP. The main objectives ofthis project are to provide mobile network and internet access using university's network system to students and lecturers and to make it easier and convenient for student to download lecture notes and for lecturers to upload them. Currently, there is no wireless LAN access in UTP environment that can be use by students and staff as alternative opportunity to access and share instant information. Therefore, this project research area is to find out the way to implement wireless LAN using secure Wi-Fi in UTP external environment. For this study, the scope is narrow down to the architecture and design ofwireless LAN network and its developing methodology. Anetwork simulation tool called Network Simulator version 2, or simply known as ns-2, is used to test the efficiency and functionality ofthe designed network. The outcome ofthis project is a good network architecture design that will give high network performance to all users in UTP

High-Fidelity Spectrum Characterization with Low-Cost Sensors

With the increasing use of wireless technologies, we see a heavy use of the spectrum at certain frequencies whereas it is underutilized at other frequencies. We need to utilize the currently underutilized spectrum. Hence, a paradigm called Dynamic Spectrum Access arises. Dynamic Spectrum Access looks for opportunity to utilize this underutilized spectrum by allowing devices to opportunistically access spectrum that is not actively used. DSA, however, requires spectrum sensing and spectrum characterization across time, space, and frequency for opportunistic devices to know where to operate. Spectrum sensing is the process of collecting power level traces from the radio-frequency spectrum, whereas spectrum characterization determines how many transmitters occupy a given spectrum and what are their temporal and frequency characteristics. Traditional spectrum sensing and characterization is performed with expensive sensors, which renders the task economically-infeasible. Our project introduces a low-cost alternative, which is more mobile and cost efficient. A typical issue with low cost sensors is that the scans from the low-cost sensor are of lower quality compared to scans from a higher-cost alternative. In this end, we compare the characterizations of the spectrum from the low cost sensor to the high-cost sensor across time, frequency, and space. We conduct granularity, sensitivity,transmitter pattern, and mobility experiments to compare the scans of the two sensors in different scenarios. We analyze the two characterizations from the two sensors in a controlled setting to see if the scans of the two are comparable. From the mobility and granularity experiments, we observe that scans from the low-cost sensors are comparable to the scans from the high-cost sensors. However, as expected, we do see lower sensitivity in the low-cost sensor. Comparing the two scans will help us form a better picture of the kind of ii infrastructure we can build using the two sensors that is both economically feasible and can give us high-fidelity scans

RF channel characterization for cognitive radio using support vector machines

Cognitive Radio promises to revolutionize the ways in which a user interfaces with a communications device. In addition to connecting a user with the rest of the world, a Cognitive Radio will know how the user wants to connect to the rest of the world as well as how to best take advantage of unused spectrum, commonly called white space\u27. Through the concept of Dynamic Spectrum Acccess a Cognitive Radio will be able to take advantage of the white space in the spectrum by first identifying where the white space is located and designing a transmit plan for a particular white space. In general a Cognitive Radio melds the capabilities of a Software Defined Radio and a Cognition Engine. The Cognition Engine is responsible for learning how the user interfaces with the device and how to use the available radio resources while the SDR is the interface to the RF world. At the heart of a Cognition Engine are Machine Learning Algorithms that decide how best to use the available radio resources and can learn how the user interfaces to the CR. To decide how best to use the available radio resources, we can group Machine Learning Algorithms into three general categories which are, in order of computational cost: 1.) Linear Least Squares Type Algorithms, e.g. Discrete Fourier Transform (DFT) and their kernel versions, 2.) Linear Support Vector Machines (SVMs) and their kernel versions, and 3.) Neural Networks and/or Genetic Algorithms. Before deciding on what to transmit, a Cognitive Radio must decide where the white space is located. This research is focused on the task of identifying where the white space resides in the spectrum, herein called RF Channel Characterization. Since previous research into the use of Machine Learning Algorithms for this task has focused on Neural Networks and Genetic Algorithms, this research will focus on the use of Machine Learning Algorithms that follow the Support Vector optimization criterion for this task. These Machine Learning Algorithms are commonly called Support Vector Machines. Results obtained using Support Vector Machines for this task are compared with results obtained from using Least Squares Algorithms, most notably, implementations of the Fast Fourier Transform. After a thorough theoretical investigation of the ability of Support Vector Machines to perform the RF Channel Characterization task, we present results of using Support Vector Machines for this task on experimental data collected at the University of New Mexico.\u2

High Efficiency RF Amplifier Design

High efficiency RF power amplifiers are key to the operation of modern wireless systems. From reducing power consumption at base stations to increasing battery life in handsets, high efficiency amplifiers help system designers to meet key performance criteria for their customers. The advent of the Internet of Things and 5G will lead to mass proliferation of battery operated wireless devices, increasing demand for high efficiency systems. In this project, a high efficiency 4W narrowband PA operating at 1GHz is designed, built and tested for the IMS2020 high efficiency power amplifier (HEPA) design competition. Emphasis is placed on achieving maximum power-added efficiency. The resulting amplifier provides 81.5% power added efficiency while delivering 4.8W to a 50 ohm load with 0.25W input power