System and method for power control calibration and a wireless communication device
First Claim
1. A system for the control of transmit power in a wireless communication device having a transmitter and a receiver, the system comprising:
- a power control reference circuit to generate a power control signal indicative of a desired transmit power;
a variable gain transmitter amplifier having an amplifier input and an amplifier output and a variable gain control input;
a transmit power control circuit to generate a control signal coupled to the control input to thereby control the variable gain;
a transmit power processor coupled to the amplifier output to detect a transmit power level and to generate a feedback signal related thereto; and
a summing circuit to combine the feedback signal and power control signal wherein the combined feedback and power control signal are provided as an input to the power control circuit.
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Accused Products
Abstract
A technique for calibrating the open-loop transmit power of a wireless communication device overcomes the inherent nonlinearities in the gain control input of a variable gain amplifier (VGA). In one embodiment, a feedback circuit generates a signal indicative of the transmit power. This signal is compared with a desired transmit power level, which comprises an open-loop gain component and a closed-loop gain component. The desired transmit power level is compared with the actual transmit power level and an error signal is generated. The error signal is used to alter the gain of the VGA in the transmitter to thereby adjust the actual transmit power level to correspond with the desired transmit power level. In alternative embodiment, the receiver portion, which also contains a VGA, is pre-calibrated in a conventional manner. During a transmitter calibration process, the transmitter is coupled to the receiver input through a mixer and filter. The pre-calibrated receiver determines the actual transmit power level. The difference is used to generate error correction data to adjust for non linearities in the gain control input of the transmitter VGA.
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Citations
40 Claims
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1. A system for the control of transmit power in a wireless communication device having a transmitter and a receiver, the system comprising:
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a power control reference circuit to generate a power control signal indicative of a desired transmit power;
a variable gain transmitter amplifier having an amplifier input and an amplifier output and a variable gain control input;
a transmit power control circuit to generate a control signal coupled to the control input to thereby control the variable gain;
a transmit power processor coupled to the amplifier output to detect a transmit power level and to generate a feedback signal related thereto; and
a summing circuit to combine the feedback signal and power control signal wherein the combined feedback and power control signal are provided as an input to the power control circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A system for the control of transmit power in a wireless communication device having a transmitter and a receiver, the system comprising:
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a variable gain transmitter amplifier having an amplifier input and an amplifier output and a variable gain control input;
a power control reference circuit to generate a power control signal indicative of a desired transmit power, the power control signal having an open-loop gain component and a closed-loop gain component;
a transmit power processor coupled to the amplifier output to detect a transmit power level and to generate a feedback signal related thereto; and
an error circuit to compare the feedback signal and power control signal and generated an error signal based thereon, the error signal being coupled to the power control circuit. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31)
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18. A system for the control of transmit power in a wireless communication device having a transmitter and a receiver, the receiver having a calibrated receiver signal pathway capable of determining the strength of a received signal, the system comprising:
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a variable gain radio frequency (RF) transmitter amplifier having an amplifier input and an amplifier output and a variable gain control input, the variable gain control input initially receiving a control signal indicative of a desired transmit power level;
a mixer coupled to the amplifier output and receiving a local oscillator signal having an oscillator frequency corresponding to an operational frequency of the receiver, the mixer generating a signal at operational frequency of the receiver and corresponding to a signal at the amplifier output; and
a coupling circuit to couple the signal generated by the mixer to the receiver signal pathway to permit power measurement of the signal using the calibrated receiver signal pathway.
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32. A method for the control of transmit power in a wireless communication device having a transmitter and a receiver, the method comprising:
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generating a power control signal indicative of a desired transmit power, the power control signal having an open-loop gain component and a closed-loop gain component;
coupling the power control signal to a gain control input of a variable gain transmitter amplifier having an amplifier input and an amplifier output;
detecting a transmit power level at the amplifier output and generating a feedback signal related thereto; and
comparing the feedback signal and power control signal and generating an error signal based thereon, the error signal being used to generate the power control signal. - View Dependent Claims (33, 34, 35, 36, 38, 39, 40)
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37. A method for the control of transmit power in a wireless communication device having a transmitter and a receiver, the receiver having a calibrated receiver signal pathway capable of determining the strength of a received signal, the method comprising:
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setting a desired gain level of a variable gain radio frequency (RF) transmitter amplifier;
detecting an output of the variable gain transmitter amplifier indicating an actual gain level;
converting the frequency of the detected output to a frequency corresponding to an operational frequency of the receiver;
coupling the converted signal to the receiver signal pathway to permit power measurement of the signal using the calibrated receiver signal pathway.
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Specification