Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: precision personnel locator; digital systems; embedded systems; waveform generation; data communication. Includes bibliographical references (leaves 108-110).

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: hardware accelerator; SVD; digital signal processing; FPGA. Includes bibliographical references (leaves 115-117).

"This thesis describes a co-processor system that has been designed to accelerate computations associated with Singular Value Array Reconciliation Tomography (SART), a method for locating a wide-band RF source which may be positioned within an indoor environment, where RF propagation characteristics make source localization very challenging. The co-processor system is based on field programmable gate array (FPGA) technology, which offers a low-cost alternative to customized integrated circuits, while still providing the high performance, low power, and small size associated with a custom integrated solution. The system has been developed in VHDL, and implemented on a Virtex-4 SX55 FPGA development platform. The system is easy to use, and may be accessed through a C program or MATLAB script. Compared to a Pentium 4 CPU running at 3 GHz, use of the co-processor system provides a speed-up of about 6 times for the current signal matrix size of 128-by-16. Greater speed-ups may be obtained by using multiple devices in parallel. The system is capable of computing the SART metric to an accuracy of about -145 dB with respect to its true value. This level of accuracy, which is shown to be better than that obtained using single precision floating point arithmetic, allows even relatively weak signals to make a meaningful contribution to the final SART solution."

"The Precision Personnel Locator project is an ongoing research project funded by the Department of Justice, the goal of which is to provide sub-meter accuracy tracking and location of first responders inside of buildings with no pre-existing infrastructure, especially in emergency situations. The PPL system consists of wearable, battery-powered Locator devices that transmit a multi-carrier “ranging signal” waveform and Reference Units that receive this ranging signal and relay the information to a Base Station for location estimation processing and display. This thesis describes the design and implementation of a subset of the Locator devices’ functionality, including: the digital generation of the ranging signal waveform; the coordination of the transmissions of many Locator devices using time-sharing methods to prevent overlap of the signals; and finally, the gathering of environmental data such as temperature and movement of the wearer and the relaying of this data back to the Base Station. To perform these tasks, two subsystems were designed and implemented as printed circuit boards. The first of these is the Data Channel, which is a low power, general-purpose communications platform that is capable of controlling the transmissions of the Locator devices with support for up to 100 Locators transmitting every second, and it can control the power of the Locator devices by switching portions of the system off when they are not in use. It also includes sensors to measure the ambient temperature, movement of the device, and a “distress button” that a first responder can press to trigger a distress signal to be transmitted to the outside of the building. The second subsystem is the Digital Waveform Generator, which consists of a Field-Programmable Gate Array (FPGA) and Digital-to-Analog Converter (DAC) that are capable of generating waveforms of up to 200 MHz bandwidth. The new Locator hardware can operate on battery power for many days. The two subsystems were successfully tested and will serve as an important step towards the goal of developing a deployable location and tracking system."