Automatic information acquisition system
First Claim
1. An information acquisition process of scanning a range of radio frequency signals to identify and store frequency shift key signals which are transmitted on a particular radio frequency signal, said information acquisition process comprising the steps of:
- retuning an adjustable radio receiver incrementally within said range of radio frequency signals until a radio signal with a strong signal tone is located;
a first evaluation step in which said radio signal is measured to determine if it has any frequency shift key characteristics;
a first abandoning step in which said radio signal is abandoned and said retuning step is reachieved, said first abandoning step being performed only when said radio signal is determined not to have any frequency shift key characteristics in said first evaluation step;
a dither step in which said radio receiver marginally adjusts its frequency reception in order to maximize the signal tone of the radio signal, said dither step including a second evaluation step in which mark and space signal characteristics are counted in order to determine if there is a frequency shift key signal transmitted within the radio signal;
a lockon step in which said radio receiver is directed to terminate scanning and lock onto the radio signal, said lockon step being performed when said second evaluation step indicates that there is a frequency shift key signal transmitted in said radio signal; and
a second abandoning step in which said radio signal is abandoned and said retuning step is reachieved, said second abandoning step being performed only when said radio signal determined not to have frequency shift key characteristics in said second evaluation step.
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Accused Products
Abstract
The automatic information acquisition system includes a process for the control of a tunable radio receiver to automatically receive, decode, and store digitally-coded information which has been transmitted by radio. Key elements of the system include a general-purpose digital computer, a tunable radio receiver, a hardware signal decoder (multi-mode data controller), a hardware interface (Mark/Space detector), and controlling software. The software causes the radio receiver to scan a pre-set range of frequencies in search of suitably formatted signals, as determined by the Mark/Space detector. When a suitable signal is located, the receiver scanning stops, the specific signal coding is identified, and the signal is decoded, with the received information being recorded on computer storage media. If the transmitted frequency shifts, the software will retune the receiver to prevent loss of signal. If the signal is lost due to termination, fading, or interference, the software will abandon it in search of a new signal. This process continues indefinitely.
23 Citations
1 Claim
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1. An information acquisition process of scanning a range of radio frequency signals to identify and store frequency shift key signals which are transmitted on a particular radio frequency signal, said information acquisition process comprising the steps of:
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retuning an adjustable radio receiver incrementally within said range of radio frequency signals until a radio signal with a strong signal tone is located; a first evaluation step in which said radio signal is measured to determine if it has any frequency shift key characteristics; a first abandoning step in which said radio signal is abandoned and said retuning step is reachieved, said first abandoning step being performed only when said radio signal is determined not to have any frequency shift key characteristics in said first evaluation step; a dither step in which said radio receiver marginally adjusts its frequency reception in order to maximize the signal tone of the radio signal, said dither step including a second evaluation step in which mark and space signal characteristics are counted in order to determine if there is a frequency shift key signal transmitted within the radio signal; a lockon step in which said radio receiver is directed to terminate scanning and lock onto the radio signal, said lockon step being performed when said second evaluation step indicates that there is a frequency shift key signal transmitted in said radio signal; and a second abandoning step in which said radio signal is abandoned and said retuning step is reachieved, said second abandoning step being performed only when said radio signal determined not to have frequency shift key characteristics in said second evaluation step.
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Specification
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- Resources
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Current AssigneeUnited States Of America As Represented By The Secretary Of The Air Force
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Original AssigneeUnited States Of America As Represented By The Secretary Of The Air Force
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InventorsFuhrman, Thomas A.
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Primary Examiner(s)Chin, Stephen
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Application NumberUS07/648,247Time in Patent Office782 DaysField of Search375/7, 375/8, 375/78, 375/81, 375/88, 375/89, 375/90, 375/91, 455/161.1, 455/161.2, 455/161.3, 358/181US Class Current375/334CPC Class CodesH04L 27/14 Demodulator circuits; Recei...
