A combined receiver front-end for Bluetooth and HiperLAN/2

A Software Defined Radio is a radio receiver that is reconfigurable by software. This reconfigurability leads to flexibility that can be used to offer more functionality to the user. Also, because common reconfigurable hardware can be used for very diverse radio interfaces, production and logistics can be faster and cheaper. In our Software Defined Radio project we aim at a receiver that is able to receive signals of any contemporary or future radio standard. However, because we need tangible specifications in order to design, we have chosen to implement a combination of two rather different standards: Bluetooth and HiperLAN/2. Both the analogue and the digital/software parts are included in the design. A CMOS integrated wideband analogue front-end containing a low noise amplifier, downconversion mixers and filters has been designed. This front-end\ud is connected to a PCB that contains two analogue-to-digital convertors and a sample rate convertor (SRC). The output of this board is connected to a standard PC through a digital I/O board with PCI bus. Software on this PC performs the demodulation.\ud We conclude that an analog wide-band front-end with a flexible SRC combined with appropriate software on an inherently flexible PC forms a promising architecture for Software Defined Radio

An emulator framework for a new radio resource management for QoS guaranteed services in W-CDMA

In the context of third-generation (3G) systems a mix of services with different requirements are expected. Consequently, packet scheduling mechanisms for quality of service (QoS) guarantees will play a key role. This paper proposes a new scheduling strategy that makes consistent the target quality in the radio link with the priority level assigned to each user. The performance of such a strategy is assessed by system level simulations and, in order to gain more insight into the difficulties of this optimization problem, it is compared to other alternatives. This work is part of the Wineglass project, within the Fifth Framework Program of the European Commission (IST), where a real time demonstrator including the radio resource management tasks is being developed. Thus, an implementation approach of the proposed scheduling is also described. The implementation is based on lookup tables and this approach is validated by simulation.Peer Reviewe

Performance Analysis of the Cognitive Radio Network with Opportunistic Spectrum Access

Efficient access to the spectral resources becomes a challenge for future military wireless communication systems. It requires spectral situation awareness, knowledge of current regulations, local policies and hardware platform limitations. It can be achieved by cognitive radios, realizing cognitive cycle, consisting typically of continuous observation, orientation, reasoning and decision making. All these elements must be realized in parallel and shouldn't interfere with each other. Even more difficult issue is related with cooperation between different nodes, especially in wireless domain, in harsh propagation conditions. Unpredictable phenomena create hard conditions for all deterministic behavior models, and their reproduction is a key element for efficient operation of the network. Very popular computer simulations are always simplified, and real time implementation gives an opportunity to make the next step in system elaboration. This paper presents a real-time demonstrator of cognitive radio network. It can work both in wired mode, using radio channel emulator and in mobile mode, to verify influence of real conditions on proposed cognitive solutions and assess their effectiveness

"Automation Surprise" in Aviation

Conflicts between the pilot and the automation, when pilots detect but do not understand them, cause “automation sur- prise” situations and jeopardize flight safety. We conducted an experiment in a 3-axis motion flight simulator with 16 pi- lots equipped with an eye-tracker to analyze their behavior and eye movements during the occurrence of such a situation. The results revealed that this conflict engages participant’s at- tentional abilities resulting in excessive and inefficient visual search patterns. This experiment confirmed the crucial need to design solutions for detecting the occurrence of conflict- ual situations and to assist the pilots. We therefore proposed an approach to formally identify the occurrence of “automa- tion surprise” conflicts based on the analysis of “silent mode changes” of the autopilot. A demonstrator was implemented and allowed for the automatic trigger of messages in the cock- pit that explains the autopilot behavior. We implemented a real-time demonstrator that was tested as a proof-of-concept with 7 subjects facing 3 different conflicts with automation. The results shown the efficacy of this approach which could be implemented in existing cockpits

Zero-Energy-Device for 6G: First Real-Time Backscatter Communication thanks to the Detection of Pilots from an Ambient Commercial Cellular Network

Ambient backscatter communication technology (AmBC) and a novel device category called zero-energy devices (ZED) have recently emerged as potential components for the forthcoming 6th generation (6G) networks. A ZED communicates with a smartphone without emitting additional radio waves, by backscattering ambient waves from base stations. Thanks to its very low consumption, a ZED powers itself by harvesting ambient light energy. However, the time variations of data traffic in cellular networks prevents AmBC to work properly. Recent works have demonstrated experimentally that a backscatter device could be detected by listening only ambient pilot signals (which are steady) instead of the whole ambient signal (which is bursty) of 4G. However, these experiments were run with a 4G base station emulator and a bulky energy greedy backscatter device. In this paper, for the first time, we demonstrate real-time AmBC on the field, with Orange commercial 4G network as ambient source and Orange Zero-Energy Device.Comment: 3 pages, 7 figures , 6Get202

A knowledge-based flight status monitor for real-time application in digital avionics systems

The Dryden Flight Research Facility of the National Aeronautics and Space Administration (NASA) Ames Research Center (Ames-Dryden) is the principal NASA facility for the flight testing and evaluation of new and complex avionics systems. To aid in the interpretation of system health and status data, a knowledge-based flight status monitor was designed. The monitor was designed to use fault indicators from the onboard system which are telemetered to the ground and processed by a rule-based model of the aircraft failure management system to give timely advice and recommendations in the mission control room. One of the important constraints on the flight status monitor is the need to operate in real time, and to pursue this aspect, a joint research activity between NASA Ames-Dryden and the Royal Aerospace Establishment (RAE) on real-time knowledge-based systems was established. Under this agreement, the original LISP knowledge base for the flight status monitor was reimplemented using the intelligent knowledge-based system toolkit, MUSE, which was developed under RAE sponsorship. Details of the flight status monitor and the MUSE implementation are presented

Real-Time Experimental Demonstration of Multi-band CAP Modulation in a VLC System with Off-the-Shelf LEDs

We demonstrate, for the first time, m-CAP modulation using off-the-shelf LEDs in a VLC in real time experimental setup using field programmable gate arrays based in universal software radio peripherals (USRPs). We demonstrate transmission speeds up to ~30 Mb/s can be achieved, which supports high definition television streaming.Comment: 2 pages, 4 figures, IEEE INFOCOM Demonstration

Experimental Investigations of Millimeter Wave Beamforming

The millimeter wave (mmW) band, commonly referred to as the frequency band between 30 GHz and 300 GHz, is seen as a possible candidate to increase achievable rates for mobile applications due to the existence of free spectrum. However, the high path loss necessitates the use of highly directional antennas. Furthermore, impairments and power constraints make it difficult to provide full digital beamforming systems. In this thesis, we approach this problem by proposing effective beam alignment and beam tracking algorithms for low-complex analog beamforming (ABF) systems, showing their applicability by experimental demonstration. After taking a closer look at particular features of the mmW channel properties and introducing the beamforming as a spatial filter, we begin our investigations with the application of detection theory for the non-convex beam alignment problem. Based on an M-ary hypothesis test, we derive algorithms for defining the length of the training signal efficiently. Using the concept of black-box optimization algorithms, which allow optimization of non-convex algorithms, we propose a beam alignment algorithm for codebook-based ABF based systems, which is shown to reduce the training overhead significantly. As a low-complex alternative, we propose a two-staged gradient-based beam alignment algorithm that uses convex optimization strategies after finding a subregion of the beam alignment function in which the function can be regarded convex. This algorithm is implemented in a real-time prototype system and shows its superiority over the exhaustive search approach in simulations and experiments. Finally, we propose a beam tracking algorithm for supporting mobility. Experiments and comparisons with a ray-tracing channel model show that it can be used efficiently in line of sight (LoS) and non line of sight (NLoS) scenarios for walking-speed movements

Radio Environment Map for the Cognitive Radio Network Simulator

Military wireless tactical systems has faced the problem of limited spectrum resources. This is a reason why Cognitive Radio (CR) is one of the most popular topic studied by research institutes in the field of mobile telecommunications. CR technology is based on cognitive cycle, used for making decisions based on observation and orientation. To support this activity, radios need also information on current position, electromagnetic situation, legal issues etc. These functions can be provided by Radio Environment Map (REM) database. It enables more flexible spectrum utilization and coexistence of Primary and Secondary Users (PUs, SUs) without harmful interferences. This paper presents a proposal of REM database structure and graphical user interface (GUI). It also describes GUI implementation in MATLAB and data structure. Database was implemented using the database engine – SQLite. The proposed REM database is a part of cognitive radio network simulator developed in the Institute of Telecommunications