Detection of signals transmitted by frequency-shift keying modulation techniques
AssigneeRockwell Collins, Inc.
InventorsJoseph T. Graf, James C. Gregory
Life of this patent
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Abstract
An apparatus and method of detecting signals transmitted via frequency-shift keying techniques. An observation window encompassing a frequency band is defined and searched for received tones, the frequency spacing between received tones is calculated and compared to known FSK modulation techniques to determine whether at least part of a transmission is potentially present. The transmission may be an automatic link establishment signal. A histogram can store data on received tones. The observation window can be shifted to center a potential FSK transmission for parallel modem processing that will attempt to demodulate and decode it.
Claims20
A method of detecting a wireless communication signal, comprising the steps of:
- defining an observation window encompassing a frequency band;
- searching the defined observation window for received tones;
- calculating a frequency spacing between at least two received tones found in said searching step;
- and
- comparing the calculated frequency spacing with a frequency spacing scheme of a known modulation technique to determine whether the at least two received tones are at least a portion of a transmission made via the known modulation technique.
A communication apparatus capable of detecting a transmission made via a frequency-shift keying modulation technique, comprising:
- a signal receiving component;
- a memory system storing data representing signals received by said signal receiving component, said memory system also storing instructions for defining an observation window encompassing a frequency band, for searching the defined observation window for received tones;
- for calculating a frequency spacing between at least two received tones found within the defined observation window, and for comparing the calculated frequency spacing with a frequency spacing scheme of a known modulation technique to determine whether the at least two received tones are at least a portion of a transmission made via the known modulation technique;
- and
- a processing component, coupled with said signal receiving component, and with said memory system, said processing component being capable of executing the instructions for defining an observation window encompassing a frequency band, for searching the defined observation window for received tones;
- for calculating a frequency spacing between at least two received tones found within the defined observation window, and the instructions for comparing the calculated frequency spacing with a frequency spacing scheme of a known modulation technique to determine whether the at least two received tones are at least a portion of a transmission made via the known modulation technique.
A communication apparatus capable of receiving a signal via a dispersive media, comprising:
- means for receiving a signal;
- means for storing information, storing information representing a signal received by said means for receiving, said means for storing information also being for storing instructions for searching a defined observation window for received tones and for determining whether received tones have been transmitted via a frequency-shift keying modulation technique;
- and
- means for processing, coupled with said means for receiving, and also coupled with said means for storing, said means for processing being capable of executing the instructions for searching a defined observation window for received tones and for determining whether received tones have been transmitted via a frequency-shift keying modulation technique.
Dependencies are inferred from the claim text.