Indoor trilateralization using digital off-air access units

Abstract

A system for indoor localization using satellite navigation signals in a Distributed Antenna System. The system includes a plurality of Off-Air Access Units (OAAUs), each operable to receive an individual satellite navigation signal from at least one of a plurality of satellite navigation systems (e.g., GPS, GLONASS, Galileo, QZSS, or BeiDou) and operable to route signals optically to one or more DAUs. The system further includes a plurality of remote DRUs located at a Remote location that are operable to receive signals from a plurality of local DAUs. Moreover, the system includes an algorithm to delay each individual satellite navigation signal for providing indoor localization at each of the plurality of DRUs.

1 . A system for indoor localization using satellite navigation signals in a Distributed Antenna System, the system comprising:
 a plurality of Off-Air Access Units (OAAUs), each having at least one directional antenna and each being operable to receive at least one of a plurality of satellite navigation signals from a plurality of satellites;   one or more Digital Access Units (DAUs), wherein the plurality of OAAUs are communicatively coupled to at least one of the one or more DAUs; and   a plurality of Digital Remote Units (DRUs) located at a remote location, wherein each individual DRU of the plurality of DRUs is operable to:
 receive one or more of the plurality of satellite navigation signals from the one or more DAUs; 
 delay the one or more of the plurality of satellite navigation signals based on a positional offset for the individual DRU; and 
 broadcast, using an antenna of the individual DRU, the delayed one or more of the plurality of satellite navigation signals. 
   
     
     
         2 . The system of  claim 1 , further comprising:
 a feedback system communicatively coupled to a first DRU of the plurality of DRUs; and   a GPS receiver at the remote location communicatively coupled to the feedback system, wherein the GPS receiver transmits a measured GPS position to the feedback system.   
     
     
         3 . The system of  claim 2 , wherein the one or more satellite signals are delayed further based on a difference between the measured GPS position and a known position of the GPS receiver. 
     
     
         4 . The system of  claim 1 , wherein the positional offset for the individual DRU is based on a position of the individual DRU within the remote location. 
     
     
         5 . The system of  claim 1 , wherein the plurality of satellite navigation signals include at least one of GPS, GLONASS, Galileo, QZSS, or BeiDou signals. 
     
     
         6 . The system of  claim 1 , wherein the one or more DAUs are coupled via at least one of a Ethernet cable, Optical Fiber, or Wireless Link. 
     
     
         7 . The system of  claim 1 , wherein the plurality of OAAUs are connected to the one or more DAUs via at least one of Ethernet cable, Optical Fiber, or Wireless Link. 
     
     
         8 . The system of  claim 1 , wherein the plurality of OAAUs are connected together via a daisy chain configuration. 
     
     
         9 . The system of  claim 8 , wherein the plurality of OAAUs are coupled via at least one of Ethernet cable, Optical Fiber, or Wireless Link. 
     
     
         10 . The system of  claim 1 , wherein a mobile device at the remote location is configured to receive the delayed one or more of the plurality of satellite navigation signals. 
     
     
         11 . A method for indoor localization using satellite navigation signals, the method comprising:
 receiving, by a plurality of Off-Air Access Units (OAAUs) each having at least one directional antenna, a plurality of satellite navigation signals from a plurality of satellites;   receiving, by one or more Digital Access Units (DAUs), the plurality of satellite navigation signals from the plurality of OAAUs;   for each individual Digital Remote Unit (DRU) of a plurality of DRUs located at a remote location:
 receiving one or more of the plurality of satellite navigation signals from the one or more DAUs; 
 delaying the one or more of the plurality of satellite navigation signals based on a positional offset for the individual DRU; and 
 broadcasting, using an antenna of the individual DRU, the delayed one or more of the plurality of satellite navigation signals. 
   
     
     
         12 . The method of  claim 11 , wherein a feedback system communicatively coupled to a first DRU of the plurality of DRUs, and wherein the method further comprises:
 measuring, by a GPS receiver at the remote location, a GPS position; and   transmitting, by the GPS receiver, the measured GPS position to the feedback system.   
     
     
         13 . The method of  claim 12 , wherein the one or more satellite signals are delayed further based on a difference between the measured GPS position and a known position of the GPS receiver. 
     
     
         14 . The method of  claim 11 , wherein the positional offset for the individual DRU is based on a position of the individual DRU within the remote location. 
     
     
         15 . The method of  claim 11 , wherein the plurality of satellite navigation signals include at least one of GPS, GLONASS, Galileo, QZSS, or BeiDou signals. 
     
     
         16 . The method of  claim 11 , wherein the one or more DAUs are coupled via at least one of a Ethernet cable, Optical Fiber, or Wireless Link. 
     
     
         17 . The method of  claim 11 , wherein the plurality of OAAUs are connected to the one or more DAUs via at least one of Ethernet cable, Optical Fiber, or Wireless Link. 
     
     
         18 . The method of  claim 11 , wherein the plurality of OAAUs are connected together via a daisy chain configuration. 
     
     
         19 . The method of  claim 18 , wherein the plurality of OAAUs are coupled via at least one of Ethernet cable, Optical Fiber, or Wireless Link. 
     
     
         20 . The method of  claim 11 , wherein a mobile device at the remote location is configured to receive the delayed one or more of the plurality of satellite navigation signals.