1,295 research outputs found
Implementation Aspects of a Transmitted-Reference UWB Receiver
In this paper, we discuss the design issues of an ultra wide band (UWB) receiver targeting a single-chip CMOS implementation for low data-rate applications like ad hoc wireless sensor networks. A non-coherent transmitted reference (TR) receiver is chosen because of its small complexity compared to other architectures. After a brief recapitulation of the UWB fundamentals and a short discussion on the major differences between coherent and non-coherent receivers, we discuss issues, challenges and possible design solutions. Several simulation results obtained by means of a behavioral model are presented, together with an analysis of the trade-off between performance and complexity in an integrated circuit implementation
A VHDL-AMS Simulation Environment for an UWB Impulse Radio Transceiver
Ultra-Wide-Band (UWB) communication based on the impulse radio paradigm is becoming increasingly popular. According to the IEEE 802.15 WPAN Low Rate Alternative PHY Task Group 4a, UWB will play a major role in localization applications, due to the high time resolution of UWB signals which allow accurate indirect measurements of distance between transceivers. Key for the successful implementation of UWB transceivers is the level of integration that will be reached, for which a simulation environment that helps take appropriate design decisions is crucial. Owing to this motivation, in this paper we propose a multiresolution UWB simulation environment based on the VHDL-AMS hardware description language, along with a proper methodology which helps tackle the complexity of designing a mixed-signal UWB System-on-Chip. We applied the methodology and used the simulation environment for the specification and design of an UWB transceiver based on the energy detection principle. As a by-product, simulation results show the effectiveness of UWB in the so-called ranging application, that is the accurate evaluation of the distance between a couple of transceivers using the two-way-ranging metho
Fly-By-Wireless for Next Generation Aircraft: Challenges and Potential solutions
âFly-By-Wirelessâ paradigm based on wireless connectivity in aircraft has the potential to improve efficiency and flexibility, while reducing weight, fuel consumption and maintenance costs. In this paper, first, the opportunities and challenges for wireless technologies in safety-critical avionics context are discussed. Then, the assessment of such technologies versus avionics requirements is provided in order to select the most appropriate one for a wireless aircraft application. As a result, the design of a Wireless Avionics Network based on Ultra WideBand technology is investigated, considering the issues of determinism, reliability and security
Technology Implications of UWB on Wireless Sensor Network-A detailed Survey
In todayâs high tech âSMARTâ world sensor based networks are widely used. The main challenge with wireless-based sensor networks is the underneath physical layer. In this survey, we have identified core obstacles of wireless sensor network when UWB is used at PHY layer. This research was done using a systematic approach to assess UWBâs effectiveness (for WSN) based on information taken from various research papers, books, technical surveys and articles. Our aim is to measure the UWBâs effectiveness for WSN and analyze the different obstacles allied with its implementation. Starting from existing solutions to proposed theories. Here we have focused only on the core concerns, e.g. spectrum, interference, synchronization etc.Our research concludes that despite all the bottlenecks and challenges, UWBâs efficient capabilities makes it an attractive PHY layer scheme for the WSN, provided we can control interference and energy problems. This survey gives a fresh start to the researchers and prototype designers to understand the technological concerns associated with UWBâs implementatio
Ultra Wideband Impulse Radio Systems with Multiple Pulse Types
In an ultra wideband (UWB) impulse radio (IR) system, a number of pulses,
each transmitted in an interval called a "frame", is employed to represent one
information symbol. Conventionally, a single type of UWB pulse is used in all
frames of all users. In this paper, IR systems with multiple types of UWB
pulses are considered, where different types of pulses can be used in different
frames by different users. Both stored-reference (SR) and transmitted-reference
(TR) systems are considered. First, the spectral properties of a multi-pulse IR
system with polarity randomization is investigated. It is shown that the
average power spectral density is the average of the spectral contents of
different pulse shapes. Then, approximate closed-form expressions for the bit
error probability of a multi-pulse SR-IR system are derived for RAKE receivers
in asynchronous multiuser environments. The effects of both inter-frame
interference (IFI) and multiple-access interference (MAI) are analyzed. The
theoretical and simulation results indicate that SR-IR systems that are more
robust against IFI and MAI than a "conventional" SR-IR system can be designed
with multiple types of ultra-wideband pulses. Finally, extensions to
multi-pulse TR-IR systems are briefly described.Comment: To appear in the IEEE Journal on Selected Areas in Communications -
Special Issue on Ultrawideband Wireless Communications: Theory and
Application
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