SYSTEM AND METHOD FOR DETECTING TEMPORARILY UNUSED BANDWIDTH IN THE RF SPECTRUM
First Claim
1. A method (200) of detecting temporarily available channels in a frequency band, comprising:
- (a) selecting (205) a channel among a plurality of channels in a frequency band;
(b) measuring (210) an energy received in the selected channel;
(c) comparing (215) the measured energy received in the selected channel to a threshold established for the selected channel;
(d) when the measured energy received in the selected channel exceeds the threshold established for the selected channel, determining (220) the selected channel is unavailable for transmission, otherwise determining (225) that the selected channel is available for transmission;
(e) repeating steps (a) through (d) (205-225) for each of a plurality of channels in the frequency band (230);
(f) selecting (250) one of the channels that was determined in step (d) to be unavailable;
(g) correlating (255) a signal received in the selected unavailable channel with a known feature of a signal conforming to a particular transmission format;
(h) comparing (260) the correlation result to a second threshold;
(i) when the correlation result in the selected unavailable channel exceeds the second threshold, determining (265) that a signal conforming to the particular transmission format is present in the selected unavailable channel, otherwise determining (270) that the signal conforming to the particular transmission format is not present in the selected unavailable channel; and
(j) repeating steps (f) through (i) (250-270) for each channel that was determined in step (d) (220) to be unavailable.
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Abstract
A method (200) and system (300) for detecting temporarily available bandwidth in a frequency band: select (205) a channel in the frequency band; measure (210) an energy received in the selected channel; compare (215) the measured energy to a first threshold; when the measured energy exceeds the first threshold, determine that the channel is unavailable (220) for transmission, otherwise determine (225) that the channel is available for transmission; correlate (255) a signal received in the channel with a known feature of a signal conforming to a particular transmission format; compare (260) the correlation result to a second threshold; when the correlation result in the channel exceeds the second threshold, determine (265) that a signal conforming to the particular transmission format is present in the channel, otherwise determine (270) that the signal conforming to the particular transmission format is not present in the channel.
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Citations
20 Claims
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1. A method (200) of detecting temporarily available channels in a frequency band, comprising:
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(a) selecting (205) a channel among a plurality of channels in a frequency band; (b) measuring (210) an energy received in the selected channel; (c) comparing (215) the measured energy received in the selected channel to a threshold established for the selected channel; (d) when the measured energy received in the selected channel exceeds the threshold established for the selected channel, determining (220) the selected channel is unavailable for transmission, otherwise determining (225) that the selected channel is available for transmission; (e) repeating steps (a) through (d) (205-225) for each of a plurality of channels in the frequency band (230); (f) selecting (250) one of the channels that was determined in step (d) to be unavailable; (g) correlating (255) a signal received in the selected unavailable channel with a known feature of a signal conforming to a particular transmission format; (h) comparing (260) the correlation result to a second threshold; (i) when the correlation result in the selected unavailable channel exceeds the second threshold, determining (265) that a signal conforming to the particular transmission format is present in the selected unavailable channel, otherwise determining (270) that the signal conforming to the particular transmission format is not present in the selected unavailable channel; and (j) repeating steps (f) through (i) (250-270) for each channel that was determined in step (d) (220) to be unavailable. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A system (300) for detecting temporarily available bandwidth in a frequency band, comprising:
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a receiver front-end (310) adapted to select a portion of spectrum in a frequency band; an energy detector (350) adapted to measure energy present in the selected portion of spectrum; a first comparator (360) adapted to compare the measured energy in the selected portion of spectrum to a threshold established for the selected portion of spectrum; a correlator (380) adapted to correlate a signal received in the selected portion of spectrum with a known feature of a signal conforming to a particular transmission format; and a second comparator (390) adapted to compare the correlation result to a second threshold. - View Dependent Claims (13, 14, 15, 16)
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17. A method (200) of detecting temporarily available bandwidth in a frequency band, comprising:
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(a) selecting (205) a portion of spectrum in a frequency band; (b) measuring (210) an energy received in the selected portion of spectrum; (c) comparing (215) the measured energy received in the selected portion of spectrum to a threshold established for the selected portion of spectrum; (d) when the measured energy received in the selected portion of spectrum exceeds the threshold established for the selected portion of spectrum, determining (220) that the selected portion of spectrum is unavailable for transmission, otherwise determining (225) that the selected portion of spectrum is available for transmission; (e) correlating (255) a signal received in the selected portion of spectrum with a known feature of a signal conforming to a particular transmission format; (f) comparing (260) the correlation result to a second threshold; (g) when the correlation result in the selected portion of spectrum exceeds the second threshold, determining (265) that a signal conforming to the particular transmission format is present in the selected portion of spectrum, otherwise determining (270) that the signal conforming to the particular transmission format is not present in the selected portion of spectrum; and (h) repeating steps (a) through (g) for each of a plurality of spectrum portions spanning the frequency band. - View Dependent Claims (18, 19, 20)
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Specification