Method and apparatus for determining the frequency of a radio signal during periods of stability and monitoring communications with a radio receiver
First Claim
1. A method of determining stability of frequency and frequency of a frequency-stable electrical signal, the method comprising:
- counting amplitude transitions of an electrical signal during a primary sampling period;
counting the amplitude transitions of the electrical signal during each of at least two secondary sampling periods, wherein the secondary sampling periods are shorter than the primary sampling period and at least one of the secondary sampling periods partially overlaps, in time, the primary sampling period;
comparing counts of the amplitude transitions of two of the secondary sampling periods to each other to produce a difference;
comparing the difference to a threshold and determining that the frequency of the electrical signal is unstable if the difference exceeds the threshold; and
if the difference does not exceed the threshold, determining the frequency of the electrical signal from an accumulated count of the amplitude transitions accumulated during the primary sampling period.
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Abstract
A method and apparatus provide for monitoring radio frequency signals and, in conjunction with the monitoring, determining frequency of a received dominant radio frequency signal. Zero amplitude transitions of the signal are counted in primary and secondary sampling periods to determine frequency and frequency stability. The method and apparatus can be used to tune to radio frequency signals having frequencies in a list of frequencies to be monitored and detecting signals in the radio frequency spectrum on other frequencies. The monitoring and scanning may occur simultaneously, sequentially, or in any order or sequence. The frequencies of dominant signals received are determined and added to the list for monitoring. The receiver may be tuned to a frequency determined immediately upon determination of the frequency determined, after storage of the frequency determined, only after a signal on the currently monitored frequency terminates, or upon other conditions. A user of the apparatus can build a list of frequencies to be monitored automatically without sophisticated knowledge or equipment.
71 Citations
38 Claims
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1. A method of determining stability of frequency and frequency of a frequency-stable electrical signal, the method comprising:
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counting amplitude transitions of an electrical signal during a primary sampling period; counting the amplitude transitions of the electrical signal during each of at least two secondary sampling periods, wherein the secondary sampling periods are shorter than the primary sampling period and at least one of the secondary sampling periods partially overlaps, in time, the primary sampling period; comparing counts of the amplitude transitions of two of the secondary sampling periods to each other to produce a difference; comparing the difference to a threshold and determining that the frequency of the electrical signal is unstable if the difference exceeds the threshold; and if the difference does not exceed the threshold, determining the frequency of the electrical signal from an accumulated count of the amplitude transitions accumulated during the primary sampling period. - View Dependent Claims (2, 3, 4, 5)
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6. A method of determining stability of frequency and frequency of a frequency-stable signal received from the ambient electromagnetic environment, the method comprising:
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receiving a dominant signal from ambient electromagnetic signals; counting amplitude transitions of the dominant signal during a primary sampling period; counting the amplitude transitions of the dominant signal during each of at least two secondary sampling periods, wherein the secondary sampling periods are shorter than the primary sampling period and at least one of the secondary sampling periods partially overlaps, in time, the primary sampling period; comparing counts of the amplitude transitions of two of the secondary sampling periods to each other to produce a difference; comparing the difference to a threshold and determining that the frequency of the dominant signal is unstable if the difference exceeds the threshold; and if the difference does not exceed the threshold, determining the frequency of the dominant signal from an accumulated count of the amplitude transitions accumulated during the primary sampling period. - View Dependent Claims (7, 8, 9, 10, 11, 12)
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13. A method of monitoring signals on established radio frequencies and detecting radio frequency signals on frequencies not being monitored, the method comprising:
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tuning a radio receiver to one of a plurality of established frequencies stored in a data base, to monitor any signals on the established frequency to which the radio receiver is tuned; in conjunction with monitoring any signals on the established frequency to which the radio receiver is tuned, detecting a dominant radio frequency signal, and counting the amplitude transitions of the dominant radio frequency signal detected during each of at least two secondary sampling periods, wherein the secondary sampling periods are shorter than the primary sampling period and at least one of the secondary sampling periods partially overlaps, in time, the primary sampling period, comparing counts of the amplitude transitions of two of the secondary sampling periods to each other to produce a difference, and comparing the difference to a threshold and determining that the frequency of the dominant radio frequency signal detected is unstable if the difference exceeds the threshold, and, if the difference does not exceed the threshold;
determining the frequency of the dominant radio frequency signal detected bycounting amplitude transitions of the dominant radio frequency signal detected during a primary sampling period, and determining the frequency of the dominant radio frequency signal detected from an accumulated count of the amplitude transitions accumulated during the primary sampling period; and storing the frequency determined in the data base as an established frequency. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21)
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22. A method of monitoring signals on established radio frequencies and detecting radio frequency signals on frequencies not being monitored, the method comprising:
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tuning a radio receiver to one of a plurality of established frequencies stored in a data base, to monitor any signals on the established frequency to which the radio receiver is tuned; in conjunction with monitoring any signals on the established frequency to which the radio receiver is tuned, detecting a dominant radio frequency signal, and counting the amplitude transitions of the dominant radio frequency signal detected during each of at least two secondary sampling periods, wherein the secondary sampling periods are shorter than the primary sampling period and at least one of the secondary sampling periods partially overlaps, in time, the primary sampling period, comparing counts of the amplitude transitions of two of the secondary sampling periods to each other to produce a difference, and comparing the difference to a threshold and determining that the frequency of the dominant radio frequency signal detected is unstable if the difference exceeds the threshold, and, if the difference does not exceed the threshold;
determining the frequency of the dominant radio frequency signal detected bycounting amplitude transitions of the dominant radio frequency signal detected during a primary sampling period, and determining the frequency of the dominant radio frequency signal detected from an accumulated count of the amplitude transitions accumulated during the primary sampling period; and tuning the radio receiver to the frequency determined and monitoring any signals on the frequency determined. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30)
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31. A method of determining radio frequencies with active signals in the ambient electromagnetic environment and received through an antenna, the method comprising:
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a) receiving a dominant radio frequency signal through an antenna; b) (i) counting the amplitude transitions of the dominant radio frequency signal detected during each of at least two secondary sampling periods, wherein the secondary sampling periods are shorter than the primary sampling period and at least one of the secondary sampling periods partially overlaps, in time, the primary sampling period; (ii) comparing counts of the amplitude transitions of two of the secondary sampling periods to each other to produce a difference; (iii) comparing the difference to a threshold and determining that the frequency of the dominant radio frequency signal detected is unstable if the difference exceeds the threshold; (iv) if the difference does not exceed the threshold, calculating the frequency of the dominant radio frequency signal detected; and (v) counting amplitude transitions of the dominant radio frequency signal during a primary sampling period and calculating the frequency of the dominant radio frequency signal from the amplitude transitions counted during the primary sampling period, as an active non-established radio frequency; c) tuning a radio receiver to at least one established frequency that is stored in a data base of established frequencies, and testing for a signal on the established frequency to which the radio receiver is tuned, to identify an active established radio frequency; and repeating a), b), and c) to identify a plurality of active non-established radio frequencies and active established radio frequencies. - View Dependent Claims (32, 33)
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34. An apparatus for monitoring signals on established radio frequencies and detecting dominant radio frequency signals on non-established frequencies, the apparatus comprising:
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a frequency agile radio receiver; a memory storing a plurality of established frequencies which are to be monitored by the radio receiver; a detector for detecting a dominant radio frequency signal in conjunction with monitoring a signal on an established frequency by the radio receiver; frequency determining means for determining the frequency of the dominant radio frequency signal detected by the detector, the frequency determining means including a first counter for counting amplitude transitions of a dominant radio frequency signal during a primary sampling period, calculation means for determining the frequency of the dominant radio frequency signal from the count accumulated in the first counter, a second counter for counting the amplitude transitions of the dominant radio frequency signal during at least two secondary sampling periods, wherein the secondary sampling periods are shorter than the primary sampling period and at least one of the secondary sampling periods partially overlaps, in time, the primary sampling period, first comparing means for comparing counts of the amplitude transitions of two of the secondary sampling periods to each other to produce a difference, and second comparing means for comparing the difference to a threshold and determining that the frequency of the dominant radio frequency signal is unstable if the difference exceeds the threshold; and a controller for controlling tuning of the radio receiver, operation of the detector and frequency determining means, and storing in the memory of frequencies determined by the frequency determining means. - View Dependent Claims (35, 36, 37, 38)
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Specification