OVERVIEW OF POSITION LOCATION TECHNIQUES
The two most widely known network-based location technologies used in proposed mobile phone location systems are TDOA and AOA. TDOA systems use the principle that the emitter location can be estimated by intersection of the hyperbolae of constant differential TOAs of t e signal at two or more pairs of base stations. AOA systems u, e simple triangulation based on estimated AOA of a signal at o or more base stations to estimate the location of a desired transmitter. Variations of both of these approaches have been proposed for cellular location and are discussed in [3]. Below e discuss key characteristics relevant to both cellular phone an noncellular applications.
Conventional TDOA technologies require that the desired signal be captured and digitized at three or more base stations, timetagged