Textile UWB antennas for wireless body area networks

A new ultrawideband (UWB) textile antenna designed for UWB wireless body area network (WBAN) applications is presented. Unlike previous textile antennas, these antennas offer a direct integration into clothing due to a very small thickness (0.5 mm) and flexibility. We have realized two different designs of textile antennas: coplanar waveguide fed printed UWB disc monopole and UWB annular slot antenna. To our knowledge, these are the first textile UWB antennas reported in the open literature. Measured return loss and radiation pattern characteristics of textile UWB antennas agree well with simulations. Moreover, measured transfer functions show that these textile antennas possess excellent transient characteristics, when operating in free space as well as on the human body. They can operate in the entire UWB band approved by the Federal Communications Commission (3.1-10.6 GHz)A new ultrawideband (UWB) textile antenna designed for UWB wireless body area network (WBAN) applications is presented. Unlike previous textile antennas, these antennas offer a direct integration into clothing due to a very small thickness (0.5 mm) and flexibility. We have realized two different designs of textile antennas: coplanar waveguide fed printed UWB disc monopole and UWB annular slot antenna. To our knowledge, these are the first textile UWB antennas reported in the open literature. Measured return loss and radiation pattern characteristics of textile UWB antennas agree well with simulations. Moreover, measured transfer functions show that these textile antennas possess excellent transient characteristics, when operating in free space as well as on the human body. They can operate in the entire UWB band approved by the Federal Communications Commission (3.1-10.6 GHz

Performance of Hybrid Direct-Sequence Time-Hopping Ultrawide Bandwidth Systems over Nakagami-m Fading Channels

This paper investigates and compares the performance of various ultrawide bandwidth (UWB) systems when communicating over Nakagami-m fading channels. Specifically, the direct-sequence (DS), time-hopping (TH) and hybrid direct-sequence time-hopping (DS-TH) UWB systems are considered. The performance of these UWB systems is studied associated with employing the conventional single-user correlation detector or minimum mean-square error (MMSE) multiuser detector. Our simulation results show that the hybrid DS-TH UWB system may outperform a corresponding pure TH-UWB or pure DS-UWB system in terms of the achievable error performance. Given the total spreading gain of the hybrid DS-TH UWB system, there is an optimal setting of the TH spreading factor and DS spreading factor, which results in the best error performance

UWB microstrip filter design using a time-domain technique

A time-domain technique is proposed for ultra-wideband (UWB) microstrip-filter design. The design technique uses the reflection coefficient (S11) specified in the frequency domain. When the frequency response of the UWB filter is given, the response will be approximated by a series of UWB pulses in the time domain. The UWB pulses are Gaussian pulses of the same bandwidth with different time delays. The method tries to duplicate the reflection scenario in the time domain for very narrow Gaussian pulses (to obtain the impulse response of the system) when the pulses are passed through the filter, and obtains the value of the filter coefficients based on the number of UWB pulses, amplitudes, and delays of the pulses

Ultra-wideband radio signals distribution in FTTH networks

The use of an ultra-wideband (UWB) radio technique is proposed as a viable solution for the distribution of high-definition audio/video content in fiber-to-the-home (FTTH) networks. The approach suitability is demonstrated by the transmission of standards-based UWB signals at 1.25 Gb/s along different FTTH fiber links with 25 km up to 60 km of standard single-mode fiber length in a laboratory experiment. Experimental results suggest that orthogonal frequency-division-multiplexed UWB signals exhibit better transmission performance in FFTH networks than impulse radio UWB signals

IR-UWB Detection and Fusion Strategies using Multiple Detector Types

Optimal detection of ultra wideband (UWB) pulses in a UWB transceiver employing multiple detector types is proposed and analyzed in this paper. We propose several fusion techniques for fusing decisions made by individual IR-UWB detectors. We assess the performance of these fusion techniques for commonly used detector types like matched filter, energy detector and amplitude detector. In order to perform this, we derive the detection performance equation for each of the detectors in terms of false alarm rate, shape of the pulse and number of UWB pulses used in the detection and apply these in the fusion algorithms. We show that the performance can be improved approximately by 4 dB in terms of signal to noise ratio (SNR) for perfect detectability of a UWB signal in a practical scenario by fusing the decisions from individual detectors.Comment: Accepted for publishing in IEEE WCNC 201

Performance of MB-OFDM UWB and WiMAX IEEE 802.16e converged radio-over-fiber in PON

Experimental results about the performance of converged radio-over- fiber transmission including multiband- OFDM UWB and WiMAX 802.16e wireless over a passive optical network are reported in this paper. The experimental study indicates that UWB and WiMAX converged transmission is feasible over the proposed distribution set-up employing a single wavelength. However, the results indicate that there is an EVM penalty of 3.2 dB for a UWB 10 km SSMF transmission in presence of WiMAX wireless

Wi-PoS : a low-cost, open source ultra-wideband (UWB) hardware platform with long range sub-GHz backbone

Ultra-wideband (UWB) localization is one of the most promising approaches for indoor localization due to its accurate positioning capabilities, immunity against multipath fading, and excellent resilience against narrowband interference. However, UWB researchers are currently limited by the small amount of feasible open source hardware that is publicly available. We developed a new open source hardware platform, Wi-PoS, for precise UWB localization based on Decawave’s DW1000 UWB transceiver with several unique features: support of both long-range sub-GHz and 2.4 GHz back-end communication between nodes, flexible interfacing with external UWB antennas, and an easy implementation of the MAC layer with the Time-Annotated Instruction Set Computer (TAISC) framework. Both hardware and software are open source and all parameters of the UWB ranging can be adjusted, calibrated, and analyzed. This paper explains the main specifications of the hardware platform, illustrates design decisions, and evaluates the performance of the board in terms of range, accuracy, and energy consumption. The accuracy of the ranging system was below 10 cm in an indoor lab environment at distances up to 5 m, and accuracy smaller than 5 cm was obtained at 50 and 75 m in an outdoor environment. A theoretical model was derived for predicting the path loss and the influence of the most important ground reflection. At the same time, the average energy consumption of the hardware was very low with only 81 mA for a tag node and 63 mA for the active anchor nodes, permitting the system to run for several days on a mobile battery pack and allowing easy and fast deployment on sites without an accessible power supply or backbone network. The UWB hardware platform demonstrated flexibility, easy installation, and low power consumption