Wireless Alliance for Testing Experiment and Research (WALTER) Experts Workshop

The purpose of the publication is to describe the WALTER experts workshop and related results and findings. The workshop was conducted in Ispra, Varese, Italy from the 2nd to the 3rd of July 2008 at the European Commission JRC facilities. The workshop was organized as part of the FP7 WALTER project, which has the objective of define a networked test bed laboratory to evaluate UltraWideBand (UWB) technology and equipment. The purpose of WALTER workshop was to present and discuss the current regulatory, standardization and research status of UltraWideBand (UWB) technology with special focus on the definition of requirements, methodologies and tools for UWB measurements and testing. The WALTER workshop had the following main objectives: - Identify the main regulatory and standardization challenges for the adoption of UWB in Europe and the world. Support the identification and resolution of conflicting requirements. - Identify the main challenges in the UWB testing and measurements. Describe how the current industrial and research activity could support the resolution of these challenges. - Discuss the future developments like UWB at 60 GHz and innovative interference and mitigation techniques including Detect And Avoid (DAA). A number of international experts in the UltraWideBand field have been invited to participate to this workshop, to encourage bi-directional communication: in one direction to disseminate the information on WALTER project and its activities, in the other direction to collect the input and feedback on the regulatory and standardization work, industrial activity and research studies.JRC.G.6-Sensors, radar technologies and cybersecurit

Ultra-Wideband Secure Communications and Direct RF Sampling Transceivers

Larger wireless device bandwidth results in new capabilities in terms of higher data rates and security. The 5G evolution is focus on exploiting larger bandwidths for higher though-puts. Interference and co-existence issues can also be addressed by the larger bandwidth in the 5G and 6G evolution. This dissertation introduces of a novel Ultra-wideband (UWB) Code Division Multiple Access (CDMA) technique to exploit the largest bandwidth available in the upcoming wireless connectivity scenarios. The dissertation addresses interference immunity, secure communication at the physical layer and longer distance communication due to increased receiver sensitivity. The dissertation presents the design, workflow, simulations, hardware prototypes and experimental measurements to demonstrate the benefits of wideband Code-Division-Multiple-Access. Specifically, a description of each of the hardware and software stages is presented along with simulations of different scenarios using a test-bench and open-field measurements. The measurements provided experimental validation carried out to demonstrate the interference mitigation capabilities. In addition, Direct RF sampling techniques are employed to handle the larger bandwidth and avoid analog components. Additionally, a transmit and receive chain is designed and implemented at 28 GHz to provide a proof-of-concept for future 5G applications. The proposed wideband transceiver is also used to demonstrate higher accuracy direction finding, as much as 10 times improvement

CROSS-LAYER RESOURCE ALLOCATION SCHEME UNDER HETEROGENEOUS CONSTRAINTS FOR NEXT GENERATION HIGH RATE WPAN

International audienceIn the next generation wireless networks, the growing demand for new wireless applications is accompanied with high expectations for better quality of service (QoS) fulfillment especially for multimedia applications. Furthermore, the coexistence of future unlicensed users with existing licensed users is becoming a challenging task in next generation communication systems to overcome the underutilization of the spectrum. A QoS and interference aware resource allocation is thus of special interest in order to respond to the heterogeneous constraints of the next generation networks. In this work, we address the issue of resource allocation under heterogeneous constraints for unlicensed multi-band ultra-wideband (UWB) systems in the context of Future Home Networks, i.e. WPAN. The problem is first studied analytically using a heterogeneous constrained optimization problem formulation. After studying the characteristics of the optimal solution, we propose a low-complexity suboptimal algorithm based on a cross-layer approach that combines information provided by the PHY and MAC layers. While the PHY layer is responsible for providing the channel quality of the unlicensed UWB users as well as their interference power that they cause on licensed users, the MAC layer is responsible for classifying the unlicensed users using a two-class based approach that guarantees for multimedia services a high-priority level compared to other services. Combined in an efficient and simple way, the PHY and MAC information present the key elements of the aimed resource allocation. Simulation results demonstrate that the proposed scheme provides a good tradeoff between the QoS satisfaction of the unlicensed applications with hard QoS requirements and the limitation of the interference affecting the licensed users

Indoor wireless communications and applications

Chapter 3 addresses challenges in radio link and system design in indoor scenarios. Given the fact that most human activities take place in indoor environments, the need for supporting ubiquitous indoor data connectivity and location/tracking service becomes even more important than in the previous decades. Specific technical challenges addressed in this section are(i), modelling complex indoor radio channels for effective antenna deployment, (ii), potential of millimeter-wave (mm-wave) radios for supporting higher data rates, and (iii), feasible indoor localisation and tracking techniques, which are summarised in three dedicated sections of this chapter

Performance Enhancement Of Ultra-Wideband Power Control Using Ranging And Narrowband Interference Mitigation

Power control is a critical parameter for the design and evaluation of ultra-wideband (UWB) based ad-hoc networks due to its distributed control nature and non-fixed topology. Since the ad-hoc networks are infrastructure-less only local information is available for each node to maintain the limited resources available in the network. In UWB indoor networks the main issues in power control are the channel gain fluctuations induced by dense multipath and interference arising from the narrowband systems. In this thesis we have introduced a joint UWB physical/ medium access control layer (PHY/MAC) design for direct-sequence-based UWB (DS-UWB) power control design by exploiting the high time resolution of the UWB signal for channel gain improvement and mitigates the narrowband interference to reduce bit error rate (BER) and so enhance the throughput.The fine time resolution of UWB signals enables high ranging estimation resolution, which leads to more accurate transmitted power control. However, in dense multipath fading an accurate ranging is a problematic due to non-line-of-sight (NLOS) propagation environments. In this thesis we propose a maximum likelihood algorithm enhanced with synchronization scheme to estimate the time delay of direct-path signal in NLOS multi-path fading environment and mean acquisition time. The algorithm is examined under various doublet Gaussian pulse widths and bit energy-noise ratio )(pT)(0NEb and gives lower ranging error (0.32m) compared to others (eg. CRLB is 0.84m). The closer the narrowband interference band to the centre frequency of the UWB signal, the more signal-to-interference-noise ratio degrades. In this thesis we discussed a mitigation approach by using the flexibility of the doublet Gaussian pulse generation, where a notched band is contributed in the pulse spectrum to avoid the narrowband interferer frequencies. In this case worldwide interoperability for microwave access (WIMAX) and wireless local area network (WLAN) are used. The results are compared with orthogonal frequency division multiplexing-based UWB (OFDM-UWB) before and after mitigation. It was observed that DS-UWB shows better performance after pulse adaptation (1dB better than cognospectrum). The performance of power control using the proposed ranging and pulse adaptation schemes is investigated for different number of nodes. It is seen that, bit error rate of 10-4 can be achieved for 20 users maintaining 14.2dB SINR. Also the same bit error rate can be achieved for bit error rate for SINR using 40 pulses per bit (). The results have been indicated that the proposed approach is able to achieve better BER (1.6 dB) and throughput (12% more for 40 users) than previous related research works. dB3.12s