Multi-carrier transmitter back-off estimation
First Claim
1. A method in a wireless communication transmitter configured to transmit a multi-carrier signal, the multi-carrier signal being an aggregation of two or more separately modulated carriers occupying distinct frequency regions, comprising:
- obtaining, for each of the two or more carriers, a carrier-specific metric indicative of an amount by which the maximum transmit power on that carrier should be reduced from a pre-determined nominal maximum transmit power, if transmitted alone, to achieve a pre-determined out-of-band emission requirement; and
estimating, by the wireless communication transmitter, a multi-carrier transmitter back-off metric for reducing the multi-carrier signal'"'"'s maximum transmit power, based on the two or more carrier-specific metrics obtained.
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Accused Products
Abstract
Methods and apparatus taught herein estimate the amount by which to reduce a multi-carrier signal'"'"'s maximum transmit power based on metrics specific to each carrier of the multi-carrier signal. These carrier-specific metrics may include a maximum-power reduction or cubic metric determined for that carrier as if it would be transmitted alone. In one embodiment, estimation of the required back-off is based on a weighted sum of the carrier-specific metrics, where the weights applied depend on a power ratio. Only a few relatively small look-up tables or simple computations are required in this case: one for obtaining the carrier-specific metrics based on configuration parameters of each carrier, and another for obtaining the weights based on the power ratio. Accordingly, methods and apparatus herein advantageously require less computational complexity and/or memory usage than that needed if estimating the required back-off based on similar metrics obtained for the multi-carrier signal as a whole.
20 Citations
22 Claims
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1. A method in a wireless communication transmitter configured to transmit a multi-carrier signal, the multi-carrier signal being an aggregation of two or more separately modulated carriers occupying distinct frequency regions, comprising:
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obtaining, for each of the two or more carriers, a carrier-specific metric indicative of an amount by which the maximum transmit power on that carrier should be reduced from a pre-determined nominal maximum transmit power, if transmitted alone, to achieve a pre-determined out-of-band emission requirement; and estimating, by the wireless communication transmitter, a multi-carrier transmitter back-off metric for reducing the multi-carrier signal'"'"'s maximum transmit power, based on the two or more carrier-specific metrics obtained. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A wireless communication transmitter configured to transmit a multi-carrier signal, the multi-carrier signal being an aggregation of two or more separately modulated carriers occupying distinct frequency regions, comprising:
a multi-carrier transmitter back-off metric estimation circuit configured to; obtain, for each of the two or more carriers, a carrier-specific metric indicative of the amount by which the maximum transmit power on that carrier should be reduced from a pre-determined nominal maximum transmit power, if transmitted alone, to achieve a pre-determined out-of-band emission requirement; and estimate a multi-carrier transmitter back-off metric for reducing the multi-carrier signal'"'"'s maximum transmit power, based on the two or more carrier-specific metrics obtained. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
Specification