LTE Spectrum Sharing Research Testbed: Integrated Hardware, Software, Network and Data

This paper presents Virginia Tech's wireless testbed supporting research on long-term evolution (LTE) signaling and radio frequency (RF) spectrum coexistence. LTE is continuously refined and new features released. As the communications contexts for LTE expand, new research problems arise and include operation in harsh RF signaling environments and coexistence with other radios. Our testbed provides an integrated research tool for investigating these and other research problems; it allows analyzing the severity of the problem, designing and rapidly prototyping solutions, and assessing them with standard-compliant equipment and test procedures. The modular testbed integrates general-purpose software-defined radio hardware, LTE-specific test equipment, RF components, free open-source and commercial LTE software, a configurable RF network and recorded radar waveform samples. It supports RF channel emulated and over-the-air radiated modes. The testbed can be remotely accessed and configured. An RF switching network allows for designing many different experiments that can involve a variety of real and virtual radios with support for multiple-input multiple-output (MIMO) antenna operation. We present the testbed, the research it has enabled and some valuable lessons that we learned and that may help designing, developing, and operating future wireless testbeds.Comment: In Proceeding of the 10th ACM International Workshop on Wireless Network Testbeds, Experimental Evaluation & Characterization (WiNTECH), Snowbird, Utah, October 201

A Unified Multi-Functional Dynamic Spectrum Access Framework: Tutorial, Theory and Multi-GHz Wideband Testbed

Dynamic spectrum access is a must-have ingredient for future sensors that are ideally cognitive. The goal of this paper is a tutorial treatment of wideband cognitive radio and radar—a convergence of (1) algorithms survey, (2) hardware platforms survey, (3) challenges for multi-function (radar/communications) multi-GHz front end, (4) compressed sensing for multi-GHz waveforms—revolutionary A/D, (5) machine learning for cognitive radio/radar, (6) quickest detection, and (7) overlay/underlay cognitive radio waveforms. One focus of this paper is to address the multi-GHz front end, which is the challenge for the next-generation cognitive sensors. The unifying theme of this paper is to spell out the convergence for cognitive radio, radar, and anti-jamming. Moore’s law drives the system functions into digital parts. From a system viewpoint, this paper gives the first comprehensive treatment for the functions and the challenges of this multi-function (wideband) system. This paper brings together the inter-disciplinary knowledge

A heterogeneous short-range communication platform for internet of vehicles

The automotive industry is rapidly accelerating toward the development of innovative industry applications that feature management capabilities for data and applications alike in cars. In this regard, more internet of vehicles solutions are emerging through advancements of various wireless medium access-control technologies and the internet of things. In the present work, we develop a short-range communication–based vehicular system to support vehicle communication and remote car control. We present a combined hardware and software testbed that is capable of controlling a vehicle’s start-up, operation and several related functionalities covering various vehicle metric data. The testbed is built from two microcontrollers, Arduino and Raspberry Pi 3, each of which individually controls certain functions to improve the overall vehicle control. The implementation of the heterogeneous communication module is based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 and IEEE 802.15 medium access control technologies. Further, a control module on a smartphone was designed and implemented for efficient management. Moreover, we study the system connectivity performance by measuring various important parameters including the coverage distance, signal strength, download speed and latency. This study covers the use of this technology setup in different geographical areas over various time spans

Evaluation of Sigma-Delta-over-Fiber for High-Speed Wireless Applications

Future mobile communication networks aim to increase the communication speed,\ua0provide better reliability and improve the coverage. It needs to achieve all of these enhancements, while the number of users are increasing drastically. As a result, new base-station (BS) architectures where the signal processing is centralized and wireless access is provided through multiple, carefully coordinated remote radio heads are needed. Sigma-delta-over-fiber (SDoF) is a communication technique that can address both requirements and enable very low-complexity, phase coherent remote radio transmission, while transmitting wide-band communication signals with high quality. This thesis investigates the potential and limitations of SDoF communication links as an enabler for future mobile networks.In the first part of the thesis, an ultra-high-speed SDoF link is realized by using state-of-the-art vertical-cavity surface-emitting-lasers (VCSEL). The effects of VCSEL characteristics on such links in terms of signal quality, energy efficiency and potential lifespan is investigated. Furthermore, the potential and limitations of UHS-SDoF are evaluated with signals having various parameters. The results show that, low-cost, reliable, energy efficient, high signal quality SDoF links can be formed by using emerging VCSEL technology. Therefore, ultra-high-speed SDoF is a very promising technique for beyond 10~GHz communication systems.In the second part of the thesis, a multiple-input-multiple-output (MIMO) communication testbed with physically separated antenna elements, distributed-MIMO, is formed by multiple SDoF links. It is shown that the digital up-conversion, performed with a shared local-oscillator/clock at the central unit, provides excellent phase coherency between the physically distributed antenna elements. The proposed testbed demonstrates the advantages of SDoF for realizing distributed MIMO systems and is a powerful tool to perform various communication experiments in real environments.In general, SDoF is a solution for the downlink of a communication system, i.e. from central unit to remote radio head, however, the low complexity and low cost requirement of the remote radio heads makes it difficult to realize the uplinks of such systems. The third part of this thesis proposes an all-digital solution for realizing complementary uplinks for SDoF systems. The proposed structure is extensively investigated through simulations and measurements and the results demonstrate that it is possible realize all-digital, duplex, optical communication links between central units and remote radio heads.In summary, the results in this thesis demonstrate the potential of SDoF for wideband, distributed MIMO communication systems and proposes a new architecture for all-digital duplex communication links. Overall, the thesis shows that SDoF technique is powerful technique for emerging and future mobile communication networks, since it enables a centralized structure with low complexity remote radio heads and provides high signal quality

EVA Radio DRATS 2011 Report

In the Fall of 2011, National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) participated in the Desert Research and Technology Studies (DRATS) field experiments held near Flagstaff, Arizona. The objective of the DRATS outing is to provide analog mission testing of candidate technologies for space exploration, especially those technologies applicable to human exploration of extra- terrestrial rocky bodies. These activities are performed at locations with similarities to extra-terrestrial conditions. This report describes the Extravehicular Activity (EVA) Dual-Band Radio Communication System which was demonstrated during the 2011 outing. The EVA radio system is designed to transport both voice and telemetry data through a mobile ad hoc wireless network and employs a dual-band radio configuration. Some key characteristics of this system include: 1. Dual-band radio configuration. 2. Intelligent switching between two different capability wireless networks. 3. Self-healing network. 4. Simultaneous data and voice communication

6G Radio Testbeds: Requirements, Trends, and Approaches

The proof of the pudding is in the eating - that is why 6G testbeds are essential in the progress towards the next generation of wireless networks. Theoretical research towards 6G wireless networks is proposing advanced technologies to serve new applications and drastically improve the energy performance of the network. Testbeds are indispensable to validate these new technologies under more realistic conditions. This paper clarifies the requirements for 6G radio testbeds, reveals trends, and introduces approaches towards their development

Soil Moisture and Permittivity Estimation

The soil moisture and permittivity estimation is vital for the success of the variable rate approaches in the field of the decision agriculture. In this chapter, the development of a novel permittivity estimation and soil moisture sensing approach is presented. The empirical setup and experimental methodology for the power delay measurements used in model are introduced. Moreover, the performance analysis is explained that includes the model validation and error analysis. The transfer functions are reported as well for soil moisture and permittivity estimation. Furthermore, the potential applications of the developed approach in different disciplines are also examined

A taxonomy and evaluation for developing 802.11‐based wireless mesh network testbeds

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/92433/1/dac1299.pd

Open source software radio platform for research on cellular networked UAVs: It works!

Cellular network-connected unmanned aerial vehicles (UAVs) experience different radio propagation conditions than radio nodes on the ground. Therefore, it has become critical to investigate the performance of aerial radios, both theoretically and through field trials. In this article, we consider low-altitude aerial nodes that are served by an experimental cellular network. We provide a detailed description of the hardware and software components needed to establish a broadband wireless testbed for UAV communications research using software radios. Results show that a testbed for innovation in UAV communications and networking is feasible with commercial off-the-shelf hardware, open source software, and low-power signaling.This work was in part supported by NSF award CNS-1939334.Peer ReviewedPostprint (author's final draft