Admir Burnic

System implementation study on RSSI based positioning in UWB networks

The Ultra-Wideband Radio Technology (UWB-RT) enables accurate Location and Tracking (LT) applications. However, the required and sophisticated time of arrival (ToA) ranging procedure relies on accurate synchronizations and time measurements. Non-cooperative nodes, not supporting the ToA feature, cannot be localized with this LT approach. Other LT approaches exploit the received signal strength (RSS) or received signal strength difference (RSSD). Simulations of RSS based localization in UWB networks showed promising performance results. In this paper, the authors introduce a RSS based LT demonstrator, build up with conventional Certified Wireless USB (CWUSB) sticks, using multiband UWB-RT. Different LT algorithms are tested. In a small UWB network, measurements of the localization accuracy show a root mean square error (RMSE) of about 0.33 meters.

A DVB-T2 receiver realization based on a software-defined radio concept

When DVB-T (Digital Video Broadcasting - Terrestrial) was introduced in the 1990s, it was impossible to foresee the upcoming demand for HDTV devices. Thus, a revision of this broadcasting standard, namely DVB-T2, was necessary. Recently finalized, this standard is targeting to high-definition television (HDTV). To pave the way to commercialization, an appropriate implementation concept and its corresponding validation are of utmost importance. Without a doubt, the most challenging requirements introduced by the DVB-T2 specification are an FFT (Fast Fourier Transform) size of up to 32k samples, 256-QAM (Quadrature Amplitude Modulation) and LDPC (Low-Density Parity-Check) coding with a block size of 64800 bits. Within this manuscript, the authors present a software-defined radio based realization of a demonstrator platform. This platform employs a combined DSP (Digital Signal Processor) and FPGA (Field-Programmable Gate Array) solution being capable of meeting these requirements.

Positioning in multiband OFDM UWB utilizing received signal strength

Ultra-wideband (UWB) enables accurate Localization and Tracking (LT) applications. However, the required and sophisticated time of arrival (ToA) ranging procedure relies on accurate synchronization and time measurements. Today, only few UWB devices support the required ranging feature. Examples are pulse based low data rate (LDR) UWB devices. Conventional multiband OFDM based high data rate (HDR) UWB devices do not support the ToA ranging feature. But the ultra wide frequency bandwidth of UWB enables not only high resolution of space surrounding UWB transceivers and therefore accurate time measurements, its enormous frequency diversity also minimizes fading effects. This allows reliable distance measurements, based on measurements of the received signal strength (RSS). This paper shows, that RSS based localization can be as accurate as ToA based localization. For this purpose, measurement results of the RSS and a derived path-loss model are used to calibrate a Monte Carlo simulator for RSS based ranging and localization. The RSS measurements are done with conventional wireless USB sticks, using HDR UWB. For a small 2 × 2 meters network, the simulation results show mean localization errors between 0.1 and 0.2 meters.

Applying Zero-Crossing Demodulation to the Bluetooth Enhanced Data Rate Mode

Short range communication systems such as Bluetooth and DECT (digital enhanced cordless telecommunications) require low-cost transceiver structures. Hence, the development of appropriate receiver techniques has been a major research topic. Particularly, analog limiter-discriminator with integrate and dump filtering (LDI) techniques have received considerable attention. With the availability of digital signal processing (DSP), the digital implementation of LDI techniques has become increasingly attractive. In order to make LDI receivers more accessible, zero-crossing detection was proposed. In this communication, the authors shall focus on a novel, yet promising, approach to digital zero-crossing detection in the intermediate frequency domain. Zero-crossing demodulation is an irregular sampling technique, which replaces the commonly employed regular, i.e. temporally equidistant sampling technique in the mentioned low-cost receivers. In this manuscript, the authors will present the theoretical aspects of zero-crossing demodulation with special focus on Bluetooth enhanced data rate (EDR). Next, the obtained performance results in terms of the bit error ratio (BER). Comparisons with theoretical bounds show the advantageous performance. Furthermore, a demonstrator concept termed HAWK shall be discussed and first measurement results will be presented

UWB coverage in public transport scenarios

In the near future, wireless connectivity will become a commodity in aircrafts. For the planning of the reliable network a detail analysis of the coverage is required. This paper studies the coverage in an AIRBUS A380 cabin for a OFDM UWB system based on the ECMA 368 standard. For this purpose, based on real measurement in an AIRBUS A380 airplane cabin, a Saleh-Valenzuela channel model and a path-loss model are presented. This models are used to obtain the block error rates and the throughput in an in-cabin environment.

Platform Based Design of Termninals and Infrastructure Components for Cognitive Wireless Networks

Cooperation in wireless networks will facilitate a new dimension in the evolution of multimedia communications, sCtting out from the todays situation with a multitude of communication standards and radio interfaces both in the licensed and thC unlicensed domain. In order to pave the way towards cooperative networks, the deployment of cognitive wireless solutions, which will form the communication platforms, will be a key asset. In the future, we expect to see an increasingly flexible, ad-hoc utilization of the available spectrum in the unlicensed domain and a co-existence of communication standards in the licensed bands. In this communication, the authors will illustrate a platform based approach towards cognitive wireless communications. Also, the authors will present three software defined radio concepts designed by the members of the Lehrstuhl für KommunikationsTechnik, namely the HAWK (Highly Adaptable Wireless Kit), the FALCON (Flxible Access Logic for COmmunication Networks), and the MUSTANG (MUlti-STAndard single chip transceiver for the Next Generation), finally, giving an outlook on their wireless optical communication device, termed ARGOS. HAWK, FALCON, MUSTANG and ARGOS form the basis of the cognitive wireless platform, developed by the authors, termed PROMETHEUS. The setup of PROMETHEUS and its functionality shall be illustrated together with selected measurement results.

Petri Net Based Controller Concept For Cognitive Radios in Wireless Access Networks

This paper will give a detailed discussion about the authors view on Software Defined and Cognitive Radio. After an introduction on different aspects of software radio and a novel approach on cognitive radio is presented. As proof of concept a software defined cognitive radio demonstrator termed Falcon was built up which is described afterwards. The Falcon is entirely based on a modular signal processing concept. In particular, the receiver deploys modules which process and generate log-likelihood ratio (LLR) signals, hence, providing the capability of a plug-and-play-type reconfigurability. To the best knowledge of the authors, such a reconfigurability approach has not yet been pursued as consequently before.

UWB applications in public transport

Wireless connectivity will become an integral component of the aircraft cabin in the near future. For the planning of the reliable network a detail analysis of the coverage is required. This paper observes the coverage in an aircraft cabin for an OFDM UWB system based on the ECMA-368 standard. For this purpose, based on real measurement in an airplane cabin mock-up, a Saleh-Valenzuela channel model and a path-loss model are presented. These models are used to obtain the block error rates and the throughput in an in-cabin environment.

Cognitive Radio Prototyping

Future wireless systems have been evolving toward a broadband and open architecture for efficient multi-service operation, which will have a great impact on the terminal and infrastructure component design methodology for supporting multiple radio schemes. Cooperation in wireless networks, requiring cognitive radio implementations, will facilitate a new dimension in the evolution of multimedia communications. The growing price pressure requires ever increasing high levels of integration efficiency, of flexibility and of future proofness at the same time, setting out in the digital baseband domain. In this communication, the authors will illustrate a platform based prototyping process, setting out from the paradigm developed in the IST-27960 STREP URANUS (UNIVERSAL RADIO-LINK PLATFORM FOR EFFICIENT USER-CENTRIC ACCESS). URANUS investigates the design of a universal radio link platform able to be incorporated in any existing proprietary and standardized wireless system in a seamless way, to ease the introduction of future personalized communications and reconfigurable air interfaces.

An implementation-friendly synchronization algorithm for multimedia HDTV receivers

To support high definition television (HDTV), the revision of DVB-T, the terrestrial digital video broadcasting standard, has recently been developed under the abbreviation DVB-T2. The provision of the anticipated high data rate services requires a highly accurate synchronization and frequency acquisition and tracking. Setting out from the procedure defined by the DVB-T2 implementation guidelines provided by the DVB-T2 standardization community, the authors have developed a modified, thus novel and yet implementation-friendly synchronization algorithm which is proposed in this manuscript. Simulation results show a promising performance improvement for synchronization, frequency offset estimation as well as the detection of the signaling information contained in the preamble P1.