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US 7,095,802 B1Granted
Apparatus and method for GPS-based digital compensation of radio frequencies
AssigneeGeneral Dynamics Advanced Information Systems, Inc.
InventorsAndrew J. Wardrop, Stephen W. Fuchs
Life of this patent
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Abstract
An apparatus and method for controlling the communication frequencies of a software controlled radio by using GPS to calibrate one or more local oscillators and compensating within the digital radio processing for the local oscillator inaccuracies.
Claims11
An apparatus for digitally compensating received radio frequency signals, comprising:
- a first oscillator;
- a downconverter for receiving the received radio frequency signals, the downconverter being driven by the first oscillator and having a mixer;
- a first frequency monitor adapted to measure the frequency of the first oscillator;
- a second oscillator;
- an analog-to-digital converter driven by the second oscillator;
- a digital receiver driven by the second oscillator, the digital receiver having a numerically controlled oscillator;
- a second frequency monitor adapted to measure the frequency of the second oscillator;
- a digital demodulator;
- and
- a computer adapted to receive the frequency measurement of the first oscillator from the first frequency monitor, to receive the frequency measurement of the second oscillator from the second frequency monitor, to calculate the errors of the first oscillator and the second oscillator, and to calculate a numerically controlled oscillator setting based on the calculation of the errors of the first oscillator and the second oscillator;
- wherein the numerically controlled oscillator is adapted to receive the numerically controlled oscillator setting from the computer to cause the digital receiver to transmit a signal of a desired frequency to the digital demodulator.
8 more elements
An apparatus for digitally compensating transmitted radio frequency signals, comprising:
- a first oscillator;
- a digital modulator having a numerically controlled oscillator and a mixer, wherein the digital modulator and the numerically controlled oscillator are driven by the first oscillator;
- a first frequency monitor that is adapted to measure the frequency of the first oscillator;
- a digital to analog converter driven by the first oscillator;
- a second oscillator;
- an upconverter driven by the second oscillator;
- a second frequency monitor adapted to measure the frequency of the second oscillator;
- a computer adapted to receive the frequency measurement of the first oscillator from the first frequency monitor, to receive the frequency measurement of the second oscillator from the second frequency monitor, to calculate the errors of the first oscillator and the second oscillator, and to calculate a numerically controlled oscillator setting based on the calculation of the errors of the first oscillator and the second oscillator;
- wherein the numerically controlled oscillator is adapted to receive the numerically controlled oscillator setting from the computer to cause said upconverter to transmit a radio frequency signal of a desired frequency.
6 more elements
Dependencies are inferred from the claim text.