Evaluating Navigation Augmentation with LTE in the Urban Signal Environment

Tall buildings that block, reflect, or diffract signals challenge GPS positioning in urban environments, resulting in positioning errors. This paper explores the use of communication signals, such as long-term evolution (LTE) signals, as signals of opportunity (SOP) leveraged to aid navigation performance. Data collected during a driving experiment in the urban center of Denver, Colorado is processed using a carrier phase tracking architecture, which provides accumulated Doppler ranging (ADR) measurements. This data is applied to the problem of characterizing LTE small cell transmitter clock and position states, a critical first step in use for navigation. Batch LLS phase profile comparisons and shadow matching techniques are used, and their combined application matches LTE transmitter locations to candidates in a known database.