| 摘要 |
<p>A wireless location system receives signals transmitted by wireless telephone at a plurality of signal collection sites (scs 10A, SCS 10B, SCS 10C). To improve the accuracy of the location information, the system synthesizes greater bandwidth, and thus greater time resolution, than would otherwise be available. The location system commands an MTSO to make the wireless transmitter to be located change frequency channels, and a doubly-differenced carrier phase of the transmitted signal, or the time difference of arrival, is observed at each of many frequencies spanning the widest possible bandwidth. The phase-measurement data from these many frequencies are combined to resolve the inherent integer-wavelength ambiguity. To begin the process of ambiguity resolution, single-frequency channel, doubly-differenced group delay measurements are used to resolve the ambiguity in the doubly-differenced phase difference between the most closely spaced frequency channels.</p> |
