Digital receiving system for dense environment of aircraft
AssigneeLockheed Martin Corporation
InventorsJohn Erik Hershey, Ralph Thomas Hoctor, Richard August Korkosz, Charles McDonald Puckette, IV
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Abstract
The capacity of a Mode-S ADS-B surveillance radar system is increased by sectorizing the radar system by the use of a directional array of Mode-S, quarter wavelength, single element, stub antennas. The ensemble of signals from the array of Mode-S antenna elements is processed electronically. The signal processing/receiver architecture increases the capacity of the Mode-S ADS-B system to be capable of effectively functioning within a highly congested airspace.
Claims15
A Mode-S digital receiving system for receiving and processing Mode-S signals in an aircraft operating in a dense environment of aircraft comprising:
- a. a spatial array of Mode-S antenna elements mounted on the aircraft;
- b. a signal processing receiver for producing and processing a separate signal for each separate antenna element;
- c. at least one analog to digital (A/D) converter for converting the signals for the separate antenna elements to corresponding digital signals;
- d. a multiplexer for sequentially and periodically coupling at least one signal or digital signal from the separate antenna elements;
- e. a squitter filter for determining the presence of a squitter preamble in a Mode-S signal received by the receiving system;
- f. a digital signal processing unit, responsive to the determined presence of the Mode-S signal, for processing and adjusting complex weights of the digital signals for the separate antenna element to maximize the signal-to-noise ratio of the received Mode-S signal;
- g. a Mode-S receiver, coupled to the output of the digital signal processing unit, for processing and identifying technical data conveyed by the Mode-S signal.
A method for receiving and processing Mode-S signals in an aircraft operating in a dense environment of aircraft comprising:
- a. mounting a spatial array of Mode-S antenna elements on the aircraft;
- b. producing and processing a separate signal for each separate antenna element;
- c. converting the signals for the separate antenna elements to corresponding digital signals;
- d. sequentially and periodically coupling at least one signals or digital signals from the separate antenna elements;
- e. determining the presence of a squitter preamble in a Mode-S signal received by a receiving system;
- f. in response to the determined presence of the Mode-S signal, processing and adjusting complex weights of the digital signals for the separate antenna element to maximize the signal-to-noise ratio of the received Mode-S signal;
- g. processing and identifying technical data conveyed by the maximized signal-to-noise ratio Mode-S signal.
Dependencies are inferred from the claim text.