Drone-based radio-over-fiber system

Abstract

The drone-based radio-over-fiber system provides an unmanned aerial vehicle (AV), preferably a multi-rotor drone, connected to a base station by a tether including an optical fiber. A radio frequency-over-fiber system is used for bidirectional data communications between at least one radio frequency (RF) transmitter at the base station and at least one antenna mounted on the drone through the optical fiber in the tether. The system includes wave division multiplexers/demultiplexers that permit ultrahigh bandwidth communication over the tether. An embodiment of the system for 2×2 multiple-input, multiple-output (MIMO) signals in the 700 MHz LTE band is described.

We claim: 
     
         1 . A drone-based radio-over-fiber system, comprising:
 a base station having:
 a pair of base station radio frequency transceivers; 
 a first pair of optical modulator-demodulators, respectively, in communication with the pair of base station radio frequency transceivers; and 
 a first wavelength division multiplexer in communication with the pair of optical modulator-demodulators; 
   a tether including an optical fiber having a first end in optical communication with the first wavelength division multiplexer;   an aerial drone having an on-board communication system, the on-board communication system including:
 a second wavelength division multiplexer in optical communication with a second end of the tether; 
 a second pair of optical modulator-demodulators in communication with the second wavelength division multiplexer; and 
 a multiple-input, multiple-output antenna system having a pair of antennas, respectively, in communication with the second pair of optical modulator-demodulators. 
   
     
     
         2 . The drone-based radio-over-fiber system as recited in  claim 1 , wherein said base station further comprises a first pair of duplexers in respective communication with the pair of base station radio frequency transceivers and the first pair of optical modulator-demodulators. 
     
     
         3 . The drone-based radio-over-fiber system as recited in  claim 2 , wherein said base station further comprises a dual-pass fiber optic rotary joint coupling the first wavelength division multiplexer to the first end of the tether. 
     
     
         4 . The drone-based radio-over-fiber system as recited in  claim 3 , wherein said on-board communication system further comprises a second pair of duplexers in respective communication with the second pair of optical modulator-demodulators and the pair of antennae of the multiple-input and multiple-output antenna system. 
     
     
         5 . The drone-based radio-over-fiber system as recited in  claim 4 , wherein said on-board communication system further comprises a pair of low noise amplifiers in respective communication with the second pair of duplexers and the second pair of optical modulator-demodulators. 
     
     
         6 . The drone-based radio-over-fiber system as recited in  claim 5 , wherein said on-board communication system further comprises a dual channel power amplifier coupling the second pair of optical modulator-demodulators and the second pair of duplexers. 
     
     
         7 . The drone-based radio-over-fiber system as recited in  claim 1 , wherein each of the pair of base station radio frequency transceivers comprises an analog radio frequency transceiver. 
     
     
         8 . A drone-based radio-over-fiber system, comprising:
 a base station having:
 a pair of base station radio frequency transceivers; 
 a first pair of optical modulator-demodulators, respectively, in communication with the pair of base station radio frequency transceivers; and 
 a first wavelength division multiplexer in communication with the pair of optical modulator-demodulators; 
   a tether, the tether including an optical fiber;   a dual-pass fiber optic rotary joint optically coupling the first wavelength division multiplexer to a first end of the tether;   an aerial drone having an on-board communication system, the on-board communication system including:
 a second wavelength division multiplexer in optical communication with a second end of the tether; 
 a second pair of optical modulator-demodulators in communication with the second wavelength division multiplexer; and 
 a multiple-input and multiple-output antenna system having a pair of antennas, respectively, in communication with the second pair of optical modulator-demodulators. 
   
     
     
         9 . The drone-based radio-over-fiber system as recited in  claim 8 , wherein said base station further comprises a first pair of duplexers in respective communication with the pair of base station radio frequency transceivers and the first pair of optical modulator-demodulators. 
     
     
         10 . The drone-based radio-over-fiber system as recited in  claim 9 , wherein said on-board communication system further comprises a second pair of duplexers in respective communication with the second pair of optical modulator-demodulators and the pair of antennae of the multiple-input and multiple-output antenna system. 
     
     
         11 . The drone-based radio-over-fiber system as recited in  claim 10 , wherein said on-board communication system further comprises a pair of low noise amplifiers in respective communication with the second pair of duplexers and the second pair of optical modulator-demodulators. 
     
     
         12 . The drone-based radio-over-fiber system as recited in  claim 11 , wherein said on-board communication system further comprises a dual channel power amplifier coupling the second pair of optical modulator-demodulators and the second pair of duplexers. 
     
     
         13 . The drone-based radio-over-fiber system as recited in  claim 8 , wherein each of the pair of base station radio frequency transceivers comprises an analog radio frequency transceiver. 
     
     
         14 . A drone-based radio-over-fiber system, comprising:
 a base station having:
 a pair of base station radio frequency transceivers, each of the base station radio frequency transceivers having an analog radio frequency transceiver; 
 a first pair of optical modulator-demodulators, respectively, in communication with the pair of base station radio frequency transceivers; and 
 a first wavelength division multiplexer in communication with the pair of optical modulator-demodulators; 
   a tether, including an optical fiber having a first end in optical communication with the first wavelength division multiplexer;   an aerial drone having an on-board communication system, the on-board communication system including:
 a second wavelength division multiplexer in optical communication with a second end of the tether; 
 a second pair of optical modulator-demodulators in communication with the second wavelength division multiplexer; and 
 a multiple-input, multiple-output (MIMO) antenna system having a pair of antennas, respectively, in communication with the second pair of optical modulator-demodulators. 
   
     
     
         15 . The drone-based radio-over-fiber system as recited in  claim 14 , wherein said base station further comprises a first pair of duplexers in respective communication with the pair of base station radio frequency transceivers and the first pair of optical modulator-demodulators. 
     
     
         16 . The drone-based radio-over-fiber system as recited in  claim 15 , wherein said base station further comprises a dual-pass fiber optic rotary joint coupling the first wavelength division multiplexer to the first end of the tether. 
     
     
         17 . The drone-based radio-over-fiber system as recited in  claim 16 , wherein said on-board communication system further comprises a second pair of duplexers in respective communication with the second pair of optical modulator-demodulators and the pair of antennas of the multiple-input and multiple-output antenna system. 
     
     
         18 . The drone-based radio-over-fiber system as recited in  claim 17 , wherein said on-board communication system further comprises a pair of low noise amplifiers in respective communication with the second pair of duplexers and the second pair of optical modulator-demodulators. 
     
     
         19 . The drone-based radio-over-fiber system as recited in  claim 18 , wherein said on-board communication system further comprises a dual channel power amplifier coupling the second pair of optical modulator-demodulators and the second pair of duplexers.