METHOD AND APPARATUS FOR OPTIMIZING SPECTRUM UTILIZATION BY A COGNITIVE RADIO NETWORK
First Claim
1. A method for selecting a communications channel in a CR system, comprising the steps of:
- determining a maximum allowed transmit power level on each of a plurality of candidate channels;
measuring a power level on each of the plurality of candidate channels;
computing an estimated link budget for each candidate channel, wherein the estimated link budget comprises a difference between the maximum allowed transmit power level and the corresponding measured power level for the candidate channel; and
selecting the channel that has the highest estimated link budget for communications.
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Accused Products
Abstract
A technique for a secondary communication system to utilize spectrum designated to another (or primary) communication system is provided. By ranking a plurality of secondary base stations based on base station transmit power, calculated required transmit power and path loss, a set of criteria is developed for selecting a highest ranked secondary base station for operation within a primary'"'"'s spectrum. The ranking may be adapted based on mobility of the secondary'"'"'s subscriber; and as such the secondary system communicates within the primary'"'"'s spectrum using the adaptively ranked base stations. Channel selection may also be ranked. The technique and apparatus allows a cognitive radio (CR) network to operate within an incumbent network'"'"'s spectrum.
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Citations
20 Claims
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1. A method for selecting a communications channel in a CR system, comprising the steps of:
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determining a maximum allowed transmit power level on each of a plurality of candidate channels; measuring a power level on each of the plurality of candidate channels; computing an estimated link budget for each candidate channel, wherein the estimated link budget comprises a difference between the maximum allowed transmit power level and the corresponding measured power level for the candidate channel; and selecting the channel that has the highest estimated link budget for communications. - View Dependent Claims (2, 3)
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4. A method for selecting a cognitive radio (CR) channel, comprising the steps at a CR mobile subscriber:
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scanning frequency bands to determine the availability of one or more CR base stations at the location of the CR mobile subscriber; determining a transmit power level for each available CR base station; measuring a received power level for each available CR base station; computing an estimated link budget for each candidate channel, wherein the estimated link budget comprises a difference between the transmit power level of the CR base station and the corresponding measured received power level for the CR base station; calculating required transmit power by the CR mobile subscriber to reach each CR base station and avoid interference to identified incumbents; ranking the CR base stations based on the estimated link budget, required transmit power and maximum allowed transmit power level of the CR mobile subscriber; and selecting and utilizing a highest ranked CR base station and channel for transmission from the CR mobile subscriber. - View Dependent Claims (5, 6, 7, 8, 9, 10)
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11. A communication system, comprising:
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a primary system operating under regulated spectrum; a database containing regulation and geo-location information pertaining to the primary system; a secondary system having a secondary subscriber and a plurality of secondary base stations, the secondary system seeking to utilize the regulated spectrum; and the secondary subscriber selecting one of the plurality of secondary base station channels for operation within the primary system'"'"'s spectrum based on secondary base station rankings, the secondary base station rankings being based on a maximum allowed transmit power level in conjunction with active or passive channel measurements of the secondary system. - View Dependent Claims (12, 13, 14, 15)
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16. A method for optimizing spectrum sharing amongst cognitive radio systems and incumbent systems, comprising:
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scanning the spectrum for CR base stations by a CR subscriber; detecting the presence of a plurality of CR base stations; ranking the plurality of CR base stations by the CR subscriber based on CR base station transmit power, required transmit power of the CR subscriber to reach each CR base station and estimated link budgets, wherein estimated link budgets are based on path loss between the CR subscriber and each CR base station of the plurality of base stations and local noise levels; selecting a CR base station from the ranked CR base station detecting mobility of the CR subscriber and re-ranking the plurality of CR base stations based on the mobility of the CR subscriber; and maintaining CR subscriber communication within the incumbent spectrum by switching base stations when the detected mobility meets predefined criteria. - View Dependent Claims (17, 18)
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19. A method for optimizing spectrum sharing amongst cognitive radio (CR) systems and incumbent systems, comprising:
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ranking a plurality of CR base stations based on base station transmit power, calculated required CR transmit power; selecting a highest ranked CR base station for operation within the incumbent'"'"'s spectrum; adapting the ranking based on mobility of the CR subscriber; and the CR system communicating within the incumbent'"'"'s spectrum using the adaptively ranked CR base station. - View Dependent Claims (20)
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Specification