The development and implementation of a localised position location strategy

[摘要] ENGLISH ABSTRACT: Location and tracking of personnel and assets is a lucrative enterprise that has seen much expansion inthe last decade or two. This expansion is coupled with the rise in popularity of GPS-based technologies.It has become common practice for businesses to track and manage vehicle fleets with GPS enableddevices. We use GPS to navigate while driving our cars, to keep track of our loved ones and we evenhave GPS receivers in our cell phones.Unfortunately, GPS technology has a few limitations. It can only be used in areas with a clear view of thesky, as line-of-sight must be maintained with at least four satellites at all times. This precludes the use ofGPS indoors or in heavily built-up areas. GPS receivers are also still quite expensive.This thesis developed and implemented a strategy for Localised Position Location. Several possiblesolutions were investigated. Spread Spectrum was selected as the best method to develop into aworking example. The characteristics of Spread Spectrum signals and Pseudo-Noise Codes wereinvestigated in some detail, which led to the proposal of several simulation models. These simulationssuggested that a simple configuration consisting of a transmitter, sliding correlator, bandpass filter andRF power detector can effectively track a stationary target.A transmitter was designed and implemented and was then used in a simplified measurement tocorroborate the predictions made by earlier simulations. With results looking positive it was decided tocontinue with the design and implementation of a receiver. A complete transmitter/receiver systemallowed for extensive measurements to be made. The physical measurements agreed with simulatedpredictions, confirming that the proposed position location strategy is effective.

[发布机构] Stellenbosch University