A Real Time Locating System based on TDOA estimation of UWB pulse sequences

L'abstract è presente nell'allegato / the abstract is in the attachmen

Integration and Prototyping of a Pulsed RF Oscillator with an UWB Antenna for Low-Cost, Low-Power RTLS Applications

The goal of this paper is to present a compact low-cost and low-power prototype of a pulsed UltraWide Band (UWB) oscillator and an UWB elliptical dipole antenna integrated on the same Radio Frequency (RF) Printed Circuit Board (PCB) and its digital control board for Real Time Locating System (RTLS) applications. The design is compatible with IEEE 802.15.4 high rate pulse repetition UWB standard being able to work between 6 GHz and 8.5 GHz with 500 MHz bandwidth and with a pulse duration of 2 ns. The UWB system has been designed using the CST Microwave Studio transient Electro-Magnetic (EM) circuit co-simulation method. This method integrates the functional circuit simulation together with the full wave (EM) simulation of the PCB’s 3D model allowing fast parameter tuning. The PCB has been manufactured and the entire system has been assembled and measured. Simulated and measured results are in excellent agreement with respect to the radiation performances as well as the power consumption. A compact, very low-power and low-cost system has been designed and validated

A low-cost indoor real time locating system based on TDOA estimation of UWB pulse sequences

One of the most popular technologies adopted for indoor localization is ultrawideband impulse radio (IR-UWB). Due to its peculiar characteristics, it is able to overcome the multipath effect that severely reduces the capability of receivers (sensors) to estimate the position of transmitters (tags) in complex environments. In this article, we introduce a new low-cost real-time locating system (RTLS) that does not require time synchronization among sensors and uses a one-way communication scheme to reduce the cost and complexity of tags. The system is able to evaluate the position of a large number of tags by computing the time difference of arrival (TDOA) of UWB pulse sequences received by at least three sensors. In the presented system, the tags transmit sequences of 2-ns UWB pulses with a carrier frequency of 7.25 GHz. Each sensor processes the received sequences with a two-step correlation analysis performed first on a field-programmable gate array (FPGA) chip and successively on an on-board processor. The result of the analysis is the time of arrival (TOA) of the tag sequence at each sensor and the ID of the associated tag. The results are sent to a host PC implementing trilateration algorithm based on the TDOA computed among sensors. We will describe the characteristics of the custom hardware that has been designed for this project (tag and sensor) as well as the processing steps implemented that allowed us to achieve an optimum localization accuracy of 10 cm

Integrated Design and Prototyping of a 77 GHz Automotive Medium Range Radar into Car Rear Lamp

The continuing trend of increasing the frequency adopted for automotive radar application has permitted an overall increase of performances and reduction of the dimensions of this type of device. This last feature could permit new ways of installation with respect to the standards adopted today by car manufacturer (behind bumpers or in car body). Instead of seeing the radar as an external device to be installed on the car it could be part of the initial project and included into the design process of a plug-in part. In this paper the integrated design and prototyping of 77 GHz automotive radar into a modern car rear lamp is presented. The radar Printed Circuit Board (PCB) has been designed to fit into the lamp without affecting the external look; the optimization of the material thickness of the radar cover and temperature tests have been performed on the system. The embedded radar processing has been implemented on a monolithic chip to perform target tracking and the main processing steps are reported. The results obtained from tests in controlled environment and on the road in traffic scenarios show that including the radar into the design of a lamp from the beginning is a feasible solution. This approach brings some advantages such as: improved placing and connections, undisturbed view, better protection from disturbances and accidents and provides more customized solutions for the car makers

An innovative harmonic radar prototype for miniaturized lightweight passive tags tracking

Harmonic radars can be generally used to track very small (1.5 cm) and lightweight (15 mg) passive tags; as an example, they have been adopted to track various insects for almost 30 years now. In most of the cases, their usage was motivated by the entomological interest in better knowing the habits of the observed insect; in fewer applications, like ours, prevailed the need of protecting the environment from invasive species. However, despite the purpose of the research involving entomological radars, not a lot of engineering resources have been invested during the last decades with the aim of improving what was basically considered a mere tool in the hands of entomologists. The goal of this paper is to show how modern radar techniques, the progresses in the available hardware and a three years long design effort helped us to build and test an harmonic radar system with considerably improved performances. The prototype herein described is able to detect the flight of tagged insects in real time, up to 500 meters with a quite large field of view in elevation, and can be therefore adopted also in harsh environments