Position location using ghost canceling reference television signals

Abstract

Provided is a method, apparatus, and computer-readable media for determining the position of a user terminal comprises generating a correlation reference signal based on known characteristics of a chirp-type signal present in a broadcast analog television signal; receiving, at the user terminal, a broadcast analog television signal comprising the chirp-type signal; and correlating the broadcast analog television signal with the correlation reference signal, thereby producing a pseudorange; and wherein the location of the user terminal is determined based on the pseudorange and a location of the transmitter of the broadcast analog television signal.

Description

[0001] Cross References to Related Applications [0002] This application claims the benefit of the following U.S. Provisional Patent Application: Serial No. 60 / 265,675, filed February 2, 2001, by Rabinowitz and James J. Spilker, "System and Method for Navigation and / or Data Communication Using Satellite and / or Terrestrial Infrastructure "(Systems and Methods for Navigation and / or Data Communications Using Satellites and / or Land Lower Constructs); Serial No. 60 / 281,270, filed April 3, 2001, by James J. Spilker," Use of the ETSI DVB Terrestrial Digital TV Broadcast Signals For High AccuracyPosition Location in Mobile Radio Links” (Use of ETSI DVB Terrestrial Digital TV Broadcast Signals for High Accuracy Position Positioning in Mobile Radio Links); 2. By James J. Spilker and Matthew Rabinowitz32 April 2001 Serial No. 60 / 281,269 filed on 3rd, "AnATSC Standard DTV Channel For Low Data Rate Broadcast to MobileReceivers" Serial No. 60 / 293,812" DTV Monitor System Unit filed on May 25,...

AI Technical Summary

Problems solved by technology

Those techniques cannot use severely attenuated signals, so that conventional analog television receivers cannot extract sync timing from horizontal sync signals or chrominance bursts

those techniques cannot accommodate the frequency offset and short-term instabilities of the analog transmitter clock, which will cause severe position errors because the user must sequentially sample one channel after another

Those techniques cannot resolve periodic ambiguities in chroma carriers, especially in the presence of multipath

In addition, this technique precludes the use of signals with variable characteristics that do not affect the performance of analog television receivers but significantly affect the performance of navigation systems (e.g., variations in blanking pulses, horizontal sync pulses, and chroma bursts). shape and duration)

Additionally, these techniques do not use signals that allow for precise ranging to a few meter accuracy in the presence of multipath

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