Distribution of Transmit Signal to Multiple Transmit Antennas for Reduction of Measured Specific Absorption Rate
First Claim
1. A method of operating a communication device, comprising:
- transmitting information, by the communication device, in a first transmission mode if a proximity signal is in a first state; and
transmitting information, by the communication device, in a second transmission mode if the proximity signal is in a second state.
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Accused Products
Abstract
Various embodiments of the present invention recognize at least two zones of operation for a communication device. In a first zone, which is sufficiently spaced away from a human head or body that SAR limits will be met, transmit power delivered to an antenna of a communication device may be maximized within any other constraints under which the communication device operates. In a second zone, which is not sufficiently spaced away from a human head or body, transmit power is redistributed such that SAR limitations are met without affecting the transmit power control loop of the communication device. For example, a second antenna physically disposed at a different location within the communication device may be used either instead of, or in addition to, the first transmit antenna in order that the SAR limits are met.
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Citations
20 Claims
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1. A method of operating a communication device, comprising:
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transmitting information, by the communication device, in a first transmission mode if a proximity signal is in a first state; and transmitting information, by the communication device, in a second transmission mode if the proximity signal is in a second state. - View Dependent Claims (2, 3, 4, 5)
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6. A method of modifying a spatial distribution of transmit power from a communication device, comprising:
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transmitting a communications signal at a power level determined by a transmit power controller from a first antenna of the communications device; asserting, within the communication device, a first signal, the first signal indicative of the presence of a human body within a predetermined range of distance from the first antenna; and responsive to the assertion of the first signal, transmitting a first portion of the communications signal at a power level determined by the transmit power controller from the first antenna and transmitting a second portion of the communications signal from a second antenna at a power level determined by the transmit power controller; wherein the power level determined by a transmit power controller may vary over time. - View Dependent Claims (7, 8, 9, 10)
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11. A method of modifying a spatial distribution of transmit power from a communications device having a plurality of transmit antennas, comprising:
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(a) determining, at the communications device, whether at least one of the plurality of transmit antennas is within a predetermined range of a human body; (b) if the determination of (a) is negative, transmitting a communications signal from a first one of the plurality of transmit antennas in accordance with a first transmission arrangement; and (c) if the determination of (a) is affirmative, transmitting at least a portion of the communications signal from one or more additional antennas of the plurality of transmit antennas in accordance with a second transmission arrangement. - View Dependent Claims (12, 13, 14, 15)
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16. A method of reducing transmitted energy from a communication device, comprising:
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(a) accumulating, by the communication device, a running average of the total energy transmitted; (b) determining, by the communication device, a delay between a transmitted request from the communication device to a base station and an action by the base station; (c) determining, by the communication device, the amount of energy associated with the transmission of required control data during the determined delay of (b); and (d) determining, by the communication device, whether the running average the total energy transmitted plus the amount of energy associated with the transmission of required control data during the determined delay is within a predetermined threshold of an SAR limit. - View Dependent Claims (17, 19, 20)
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18. A communication device, comprising:
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a plurality of antennas disposed within the communication device; a transmitter, disposed within the communication device, and switchably coupled to the plurality of antennas; at least one proximity sensor, disposed within the communication device, a first one of the at least one proximity sensors having a known spatial relationship with at least a first antenna of the plurality of antennas; a controller, disposed within the communication device, and coupled to the transmitter and to the at least one proximity sensor; wherein the controller is operable, responsive to a first state of a first signal received from the at least one proximity sensor, to direct transmit power to the first antenna, and responsive to a second state of the first signal, to direct transmit power to at least a second antenna of the plurality of antennas.
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Specification