US Patent No. 9,651,652

INTERFERENCE CANCELLATION SYSTEM FOR LOCATION AND DIRECTION FINDING


Patent No. 9,651,652
Issue Date May 16, 2017
Title Interference Cancellation System For Location And Direction Finding
Inventorship Elias Bonaventure Kpodzo, Franklin Park, NJ (US)
Robert Holland, Moorestown, NJ (US)
Assignee L3 TECHNOLOGIES, INC., New York, NY (US)

Claim of US Patent No. 9,651,652

1. A method for determining a position of a device experiencing interference, the method comprising:
receiving a plurality of radio frequency (RF) signals from a plurality of transmitters each located at a known position, wherein
each respective RF signal of the plurality of RF signals is transmitted from one of the transmitters, and each respective
RF signal comprises a respective RF SOI and a respective instance of at least one RF interfering signal;

determining a sample of the at least one RF interfering signal;
converting each of the plurality of RF signals to a plurality of optical signals, and converting the sample of the at least
one RF interfering signal to at least one optical interfering signal;

applying a 180 phase shift to the at least one optical interfering signal;
variably attenuating and variably time delaying the at least one optical interfering signal;
combining an instance of the at least one optical interfering signal with each of the plurality of optical signals after variably
attenuating and variably time delaying the at least one optical interfering signal;

converting the plurality of optical signals to a second plurality of RF signals after combining the at least one optical interfering
signal with each of the plurality of interfering signals; and

estimating a current position based on the known positions of each of the transmitters and one or more of the relative amplitudes
of the second plurality of RF signals, the relative timing differences of the second plurality of RF signals, or the relative
phase differences of the second plurality of RF signals.