Apparatuses, systems, and methods for determining location of a mobile device(s) in a distributed antenna system(s)

1. A distributed antenna system (DAS), comprising:

a head-end unit comprising:

at least one downlink interface unit configured to:

receive downlink radio frequency (RF) signals from a base station; and

distribute the downlink RF signals over at least one downlink communications medium to a plurality of remote antenna units;

at least one uplink interface unit configured to:

receive uplink RF signals from the plurality of remote antenna units over at least one uplink communications medium; and

distribute the received uplink RF signals to the base station;

the plurality of remote antenna units each comprising at least two antennas configured in a diversity arrangement, the plurality of remote antenna units configured to use a multiple input/multiple output (MIMO) scheme and to be installed in known locations, the a plurality of remote antenna units configured to:

receive the downlink RF signals from the head-end unit;

transmit the downlink RF signals into a respective coverage area;

receive uplink RF signals from client devices located in respective coverage areas; and

distribute the received uplink RF signals to the head-end unit; and

a location processing unit (LPU), comprising:

a plurality of signal monitoring devices configured to receive each of the uplink RF signals distributed from the plurality of remote antenna units located in the known locations; and

a controller configured to:

determine signal strengths of the received uplink RF signals;

determine which remote antenna unit among the plurality of remote antenna units is receiving the uplink RF signals from at least one client device having the greater signal strength; and

determine location information for the at least one client device based on identification of the remote antenna unit receiving the uplink RF signals having the greater signal strength.

2. The DAS of claim 1 , wherein:

the head-end unit further comprises:

at least one electrical to optical (E/O) converter configured to convert the received downlink RF signals into optical downlink RF signals; and

at least one optical to electrical (O/E) converter configured to convert the received uplink RF signals into electrical uplink RF signals;

each of the plurality of remote antenna units further comprises:

at least one optical to electrical (O/E) converter configured to convert the received optical downlink RF signals into electrical downlink RF signals to be distributed to the client devices; and

at least one electrical to optical (E/O) converter configured to convert the received electrical uplink RF signals into optical uplink RF signals to be distributed to the head-end unit.

3. The DAS of claim 1 , wherein the plurality of remote antenna units are deployed at multiple floors of a building infrastructure.

4. The DAS of claim 1 , wherein the downlink RF signals and the uplink RF signals are modulated according to the long term evolution (LTE) standard.

5. The DAS of claim 1 , wherein the received uplink RF signals are received in channels separated into frequency blocks.

6. The DAS of claim 5 , wherein the controller is configured to determine the signal strength of the uplink RF signals by measuring the signal strength of the frequency blocks in the uplink RF signals.

7. The DAS of claim 1 , wherein the received uplink RF signals are received in channels separated into temporal blocks.

8. The DAS of claim 7 , wherein the controller is configured to determine the signal strength of the uplink RF signals by measuring the signal strength of the temporal blocks in the uplink RF signals.

9. The DAS of claim 1 , wherein the controller is further configured to convert the received uplink RF signals into baseband uplink RF signals.

10. The DAS of claim 1 , wherein the controller is further configured to synchronize to a downlink RF signal received from a base station.

11. The DAS of claim 1 , wherein the controller is configured to determine the signal strengths of the uplink RF signals as a function of a fast Fourier transform (FFT) of a window of samples of the uplink RF signals.

12. The DAS of claim 1 , wherein the controller is configured to average the signal strengths of the uplink RF signals.

13. The DAS of claim 1 , wherein the received uplink RF signals are received into resource blocks (RB) separately identifiable to a particular user device.

14. The DAS of claim 1 , wherein the control system is further configured to communicate the location information to at least one base station.

15. The DAS of claim 1 , wherein the LPU is further configured to add location information for one or more of the client devices to the received uplink RF signals.