System and method for location of mobile devices in confined environments
A distributed antenna system comprising a master unit configured for interfacing with at least one signal source, a plurality of remote units coupled with the master unit and configured for interfacing with a user device, a remote unit including filtering circuitry for decomposing uplink signals from a user device into a plurality of narrowband signals and processing circuitry for evaluating the plurality of uplink narrowband signals and providing data for a power profile that is associated with the uplink signals of a specific user device, and location measurement circuitry coupled with the remote units and configured to receive data for a plurality of different power profiles from a plurality of different remote units wherein the plurality of power profiles are associated with the same specific user device, the location measurement unit configured for processing the power profile data from the different remote units to determine the location of the specific user device with respect to the distributed antenna system.
1. A distributed antenna system comprising:
a master unit configured for interfacing with at least one signal source;
a plurality of remote units coupled with the master unit and configured for interfacing with a user device, a remote unit including:
filtering circuitry for decomposing uplink signals from the user device into a plurality of narrowband signals;
processing circuitry for evaluating the plurality of uplink narrowband signals and providing data for a power profile that is associated with the uplink signals of a specific user device;
location measurement circuitry coupled with the remote units and configured to receive data for a plurality of different power profiles from a plurality of different remote units wherein the plurality of power profiles are associated with the same specific user device, the location measurement unit configured for processing the power profile data from the different remote units to determine the location of the specific user device in an area of the distributed antenna system.
2. The distributed antenna system of claim 1 wherein the filtering circuitry is configured for decomposing a carrier signal into a plurality of narrowband signals reflective of equal divisions of the bandwidth of the carrier signal.
3. The distributed antenna system of claim 1 wherein the filtering circuitry is digital circuitry configured for providing I/Q digital representations of the narrowband signals.
4. The distributed antenna system of claim 1 wherein the filtering circuitry includes a filterbank configured for processing an uplink carrier signal into a plurality of narrowband signals, the filterbank including a plurality of demodulators for providing a plurality of frequency-shifted narrowband signals and a plurality of filters coupled with respective demodulators for defining the bandwidth of the narrowband signals.
5. The distributed antenna system of claim 1 wherein the power profile from one of the plurality of different remote units is a reference power profile, the location measurement circuitry evaluating additional power profiles against the reference power profile to determine difference values and further configured for using the difference values to determine the location of the specific user device in the area of the distributed antenna system.
6. The distributed antenna system of claim 5 wherein the processing circuitry is configured for providing data for the power profile including signal timing data, the location measurement circuitry evaluating reference timing data against timing data for additional power profiles to determine timing difference values and further configured for using the timing difference values to determine the location of the specific user device in the area of the distributed antenna system.
7. The distributed antenna system of claim 5 wherein the processing circuitry is configured for providing data for the power profile for the specific user device including power level data, the location measurement circuitry evaluating reference power level data against power level data for additional power profiles to determine power level difference values and further configured for using the power level difference values to determine the location of the specific user device in the area of the distributed antenna system.
8. The distributed antenna system of claim 5 wherein the processing circuitry is configured for providing data for the power profile including both timing data and power level data, the location measurement circuitry evaluating reference timing data against timing data for additional power profiles to determine timing difference values and evaluating reference power level data against power level data for additional power profiles to determine power level difference values, the location measurement circuitry further configured for using both the timing difference values and the power level difference values to determine the location of the specific user device in the area of the distributed antenna system.
9. The distributed antenna system of claim 1 wherein the power profile associated with the uplink signals of the specific user device is reflective of the distance of that specific user device from the remote unit providing the power profile.
10. The distributed antenna system of claim 1 wherein the uplink signals from the user device are signals according to at least one of LTE standards and GSM standards, the processing circuitry configured for providing data for the power profile that includes timing information based upon the at least one standard.
11. The distributed antenna system of claim 1 wherein the uplink signals from the user device are signals according to at least one of LTE standards and GSM standards, the processing circuitry configured for providing data for the power profile that includes power information based upon the at least one standard.
12. The distributed antenna system of claim 1 wherein the location measurement circuitry is configured for processing power profile data and using at least one of trilateration or triangulation for determining the location of the specific user device in the area of the distributed antenna system.
13. A method of determining the location of a user device within a space comprising:
with a plurality of remote units positioned around the space, interfacing with at least one user device;
decomposing uplink signals from the user device into a plurality of narrowband signals;
evaluating the plurality of uplink narrowband signals and providing data for a power profile that is associated with the uplink signals of a specific user device;
collecting data for a plurality of different power profiles from a plurality of different remote units wherein the plurality of power profiles are associated with the same specific user device;
processing the power profile data from the different remote units to determine the location of the specific user device in the space.
14. The method of claim 13 wherein further comprising providing I/Q digital representations of the narrowband signals.
15. The method of claim 13 further comprising evaluating the power profile from one of the plurality of different remote units as a reference power profile and evaluating additional power profiles against the reference power profile to determine difference values, and using the difference values to determine the location of the specific user device in the space.
16. The method of claim 15 further comprising providing data for the power profile that includes signal timing data, evaluating reference timing data against timing data for additional power profiles to determine timing difference values and using the timing difference values to determine the location of the specific user device in the space.
17. The method of claim 15 further comprising providing data for the power profile that includes power level data, evaluating reference power level data against power level data for additional power profiles to determine power level difference values and using the power level difference values to determine the location of the specific user device in the space.
18. The method of claim 15 further comprising evaluating the power profile including both timing data and power level data and evaluating reference timing data against timing data for additional power profiles to determine timing difference values and evaluating reference power level data against power level data for additional power profiles to determine power level difference values, and using both the timing difference values and the power level difference values to determine the location of the specific user device in the space.
19. The method of claim 13 wherein the uplink signals from the user device are signals according to at least one of LTE standards and GSM standards and further comprising providing data for the power profile that includes timing information based on the at least one standard.
20. The method of claim 13 wherein the uplink signals from the user device are signals according to at least one of LTE standards and GSM standards and further comprising providing data for the power profile that includes power information based on the at least one standard.