913 research outputs found

    Implementation Aspects of a Transmitted-Reference UWB Receiver

    Get PDF
    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 1-bit Synchronization Algorithm for a Reduced Complexity Energy Detection UWB Receiver

    Get PDF
    This work investigates the possibility of performing synchronization in a reduced complexity Energy Detection receiver. A new receiver scheme employing a single comparator only is defined and the related synchronization algorithm is presented. The possibility of synchronizing has been analyzed both for an idealized Dirac Delta input signal and for realistic UWB signals obtained through the TG4a channel model. The matlab simulations show that it is possible to obtain coarse synchronization using a simple maximum detection algorithm computed on collected energies for the ideal case of Dirac Delta pulses. For realistic UWB signals better synchronization performances are possible by employing a searchback algorithm. Due to the low complexity of the receiver scheme, the synchronization algorithm requires a long locking time

    Novel wireless modulation technique based on noise

    Get PDF
    In this paper, a new RF modulation technique is presented. Instead of using sinusoidal carriers as information bearer, pure noise is applied. This allows very simple radio architectures to be used. Spread-spectrum based technology is applied to modulate the noise bearer. Since the transmission bandwidth of the noise bearer can be made very wide, up to ultra-wideband regions, extremely large processing gains can be obtained. This will provide robustness in interference-prone environments. To avoid the local regeneration of the noise reference at the receiver, the Transmit-Reference (TR) concept is applied. In this concept, both the reference noise signal and the modulated noise signal are transmitted, together forming\ud the bearer. The reference and modulated signals are separated by applying a time offset. By applying different delay times for different channels (users) a new multiple access scheme results based on delay: Delay Division Multiple Access (DDMA). A theoretical analysis is given for the link performance of a single-user and a multi-user system. A testbed has been built to demonstrate the concept. The demonstrator operates in a 50 MHz bandwidth centered at 2.4 GHz. Processing gains ranging from 10Âż30 dB have been tested. The testbed confirms the basic behavior as predicted by the theory

    A VHDL-AMS Simulation Environment for an UWB Impulse Radio Transceiver

    Get PDF
    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

    Timing Acquisition Performance Metrics of Tc-DTR UWB Receivers over Frequency-Selective Fading Channels with Narrow-Band Interference: Performance Analysis and Optimization

    No full text
    International audienceThe successful deployment of Impulse Radio (IR) Ultra Wide Band (UWB) wireless communication systems requie that they coexist and contend with a variety of interfering signals co–located over the same transmission band. In fact, if on the one hand the large transmission bandwidth of IR–UWB signals allows them to resolve multipath components and exploit multipath diversity, on the other hand it yields some new coexistence challenges for both unlicensed commercial and military communication systems, which are required to be robust to unintentional and intentional jammers, respectively. In particular, the design and analysis of low–complexity receiver schemes with good synchronization capabilities and high robustness to Narrow–Band Interference (NBI) is acknowledged as an important issue in IR–UWB research. Motivated by this consideration, in [1] we have recently proposed a low–complexity receiver design, the so–called Chip–Time Differential Transmitted–Reference (Tc–DTR) scheme, and have shown that it is more robust to NBI than other non–coherent receiver schemes available in the literature. In this paper, we aim at generalizing the results in [1] and at developing the enabling analytical tools for the analysis and design of timing acquisition algorithms for non–coherent receivers over frequency–selective fading channels with NBI. Furthermore, we move from the proposed analytical framework to tackle the optimization problem of devising optimal signature codes to reduce the impact of NBI on the performance of the Tc–DTR synchronizer. Analytical frameworks and findings are substantiated via Monte Carlo simulations
    • …
    corecore