Augmentation of commercial wireless location system (WLS) with moving and/or airborne sensors for enhanced location accuracy and use of real-time overhead imagery for identification of wireless device locations
First Claim
1. A mobile LMU-enhanced wireless location system (WLS), comprising:
- a WLS comprising a plurality of stationary location measuring units (LMUs) overlaid on a commercial wireless communications system such that said plurality of LMUs are collocated with respective base transceiver stations (BTSs) of said wireless communications system; and
a mobile platform supporting a mobile LMU and a Global Positioning System (GPS) module, wherein the GPS module is configured to provide a time and frequency reference as well as data representing the position and velocity of the mobile LMU, and wherein said mobile LMU includes a downlink receiver configured to receive a downlink signal from a base transceiver station and for deriving a replica signal from said downlink signal, said replica signal representing a replica of a transmission received at said base transceiver station, and wherein said mobile LMU further includes a receiver configured to receive uplink radio frequency (RF) transmissions from a wireless device and memory for storing data samples of received transmissions, wherein said mobile platform further supports a correlation processor configured to correlate stored data representing a received transmission with a replica of said received transmission received via said downlink signal.
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Accused Products
Abstract
Mobile LMUs can be used in a Wireless Location System to provide detection coverage in areas lacking adequate receiver coverage. The mobile LMUs can be used to detect the radio frequency (RF) transmissions from wireless handsets and devices over a period of time to permit determination of their location. The mobile LMU'"'"'s time, position, and velocity is calculated and transmitted to a SMLC along with any transmissions received from wireless devices. The SMLC analyzes and resolves the Doppler component of the wireless device while compensating for the Doppler component of the mobile LMU. The position and velocity of the wireless device can be compared with real-time imagery taken by the mobile LMU platform to accurately determine the location of the wireless device. To enhance the mobile LMU'"'"'s ability to detect a signal of interest, which may be very weak and/or corrupted by noise, a process may be employed whereby the low power mobile terminals'"'"' signals are received at receiving sites and stored in memory. Then, a more powerful replica of the SOI is received at a later time from a network controller, or BTS, and this is employed to enhance the correlation processing of the SOI in memory.
113 Citations
30 Claims
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1. A mobile LMU-enhanced wireless location system (WLS), comprising:
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a WLS comprising a plurality of stationary location measuring units (LMUs) overlaid on a commercial wireless communications system such that said plurality of LMUs are collocated with respective base transceiver stations (BTSs) of said wireless communications system; and a mobile platform supporting a mobile LMU and a Global Positioning System (GPS) module, wherein the GPS module is configured to provide a time and frequency reference as well as data representing the position and velocity of the mobile LMU, and wherein said mobile LMU includes a downlink receiver configured to receive a downlink signal from a base transceiver station and for deriving a replica signal from said downlink signal, said replica signal representing a replica of a transmission received at said base transceiver station, and wherein said mobile LMU further includes a receiver configured to receive uplink radio frequency (RF) transmissions from a wireless device and memory for storing data samples of received transmissions, wherein said mobile platform further supports a correlation processor configured to correlate stored data representing a received transmission with a replica of said received transmission received via said downlink signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method for locating a mobile station (MS) operating within a region covered by a wireless location system (WLS), comprising:
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receiving a transmission from the MS at at least three geographically separated signal collection sites, including at least one mobile location measurement unit (LMU); transmitting a downlink signal from at least one signal collection site or network controller, said downlink signal including data permitting said mobile LMU, after receiving said downlink signal, to derive a replica of said transmission from the MS as received at a signal collection site; at said mobile LMU, performing correlation processing on said replica and the transmission from the MS as received at the mobile LMU to determine one of time of arrival (TOA) and time difference of arrival (TDOA) data at said mobile LMU; and using the TOA or TDOA data determined at the mobile LMU to estimate a location of the MS. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22)
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23. A mobile system for use in a wireless location system (WLS), comprising:
- a location measuring unit (LMU) borne by a mobile platform, said LMU comprising a receiver configured to receive radio frequency (RF) transmissions and memory for storing data samples of received transmissions;
a GPS module borne by said mobile platform and operatively coupled to said mobile LMU, wherein said GPS module determines the three dimensional position and velocity of the mobile LMU, as well as a frequency reference and precise time; and
a downlink receiver configured to receive a downlink signal from at least one BTS or network controller, said downlink signal including data permitting said LMU to derive a replica of a transmission from mobile station (MS) as received at a signal collection site remote from said mobile system, and a processor configured to correlate stored data representing a received transmission with a replica of said received transmission. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30)
- a location measuring unit (LMU) borne by a mobile platform, said LMU comprising a receiver configured to receive radio frequency (RF) transmissions and memory for storing data samples of received transmissions;
Specification