Hybrid analog/digital method and apparatus for controlling the transmission power level of a radio transceiver
First Claim
1. A method for controlling the transmission power level of a modulated carrier signal comprising the steps of:
- compressing a digital signal to be transmitted by multiplying said digital signal by a first predetermined value;
converting the compressed digital signal to an analog signal;
modulating a carrier signal based on the analog signal;
inputting the modulated carrier signal to an analog transmission power amplifier;
adjusting the gain of said transmission power amplifier for the modulated carrier signal on the basis of a second predetermined value; and
transmitting the amplifier modulated carrier signal;
wherein said first and second predetermined values are derived from a digital transmission power control word without feedback, said power level control word comprising a plurality of bits and said first and second predetermined values being derived from different combinations of said bits.
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Accused Products
Abstract
A technique for controlling the transmission power level of a transmitter, particularly in a wireless personal communication system, is disclosed. This technique assists in the prevention of interference between transceivers from degrading the quality of transmissions. Transmission power level is controlled through a hybrid circuit containing both digital and analog electronics. The transmission power level is set by controlling both the amount by which a data stream is compressed and the gain of an analog transmit power amplifier. This approach allows adequate control over the transmission power level; it avoids the need for utilizing excessively wide data paths for the digital transmit signals (which may compromise portable terminal battery consumption), or utilizing expensive, hard-to-calibrate analog electronics.
151 Citations
11 Claims
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1. A method for controlling the transmission power level of a modulated carrier signal comprising the steps of:
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compressing a digital signal to be transmitted by multiplying said digital signal by a first predetermined value; converting the compressed digital signal to an analog signal; modulating a carrier signal based on the analog signal; inputting the modulated carrier signal to an analog transmission power amplifier; adjusting the gain of said transmission power amplifier for the modulated carrier signal on the basis of a second predetermined value; and transmitting the amplifier modulated carrier signal; wherein said first and second predetermined values are derived from a digital transmission power control word without feedback, said power level control word comprising a plurality of bits and said first and second predetermined values being derived from different combinations of said bits. - View Dependent Claims (2, 3)
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4. A method for controlling the transmission power level of a modulated carrier signal comprising the steps of:
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compressing a digital signal to be transmitted by multiplying said digital signal by a first predetermined value; modulating a carrier signal based on the compressed digital signal; inputting said modulated carrier signal to a transmission power amplifier; adjusting the gain of said transmission power amplifier on the basis of a second predetermined value; and transmitting the amplified modulated carrier signal; said first and second predetermined values being derived from a digital power level control word which comprises n bits, where n is an integer; said first predetermined value is derived from k bits of said n bits, where k is an integer that is less than n; and said second predetermined value is derived from the remaining n-k bits of said n bits.
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5. A method for controlling the transmission power level of a modulated carrier signal comprising the steps of:
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applying a bit stream to an information symbol mapper to produce a digital signal to be transmitted, the information symbol mapper being a baseband quadrature symbol mapper and the digital signal produced by said baseband quadrature symbol mapper comprising an in-phase digital signal and a quadrature digital signal; compressing said digital signal by multiplying said digital signal by a first predetermined value, including multiplying both the in-phase and the quadrature signals by the first predetermined value; modulating a carrier signal based on the compressed digital signal; inputting said modulated carrier signal to a transmission power amplifier; adjusting the gain of said transmission power amplifier on the basis of a second predetermined value; and
transmitting the amplified modulated carrier;
said method further comprisingmultiplexing the in-phase and the quadrature signals prior to said compressing step and converting said signals from digital to analog; and demultiplexing the in-phase and quadrature signals following compression and digital-to-analog conversion.
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6. A system for controlling the transmission power level of a modulated carrier signal transmitter comprising:
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means for compressing a digital signal to be transmitted by multiplying said digital signal by a first predetermined value; means for converting the compressed digital signal to an analog signal; means for modulating a carrier signal based on the analog signal; means for inputting said modulated carrier signal to an analog transmission power amplifier; means for adjusting the gain of said analog transmission power amplifier on the basis of a second predetermined value; and means for transmitting the amplified modulated carrier signal; wherein said first and second predetermined values are derived from a digital transmission power level control word without feedback. - View Dependent Claims (7, 8, 9)
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10. A system for controlling the transmission power level of a modulated carrier signal transmitter comprising:
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means for compressing a digital signal to be transmitted by multiplying said digital signal by a first predetermined value; means for modulating a carrier signal based on the compressed digital signal; means for inputting said modulated carrier signal to a transmission power amplifier; means for adjusting the gain of said transmission power amplifier on the basis of a second predetermined value; and means for transmitting the amplified modulated carrier signal; said first and second predetermined values being derived from a digital transmission power level control word which comprises n bits, wherein n is an integer; said first predetermined value is derived from k bits of said n bits, where k is an integer that is less than n; and said second predetermined value is derived from the remaining n-k bits of said n bits.
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11. A system for controlling the transmission power level of a modulated carrier signal transmitter comprising:
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means for applying a bit stream to an information symbol mapper to produce a digital signal to be transmitted, said information symbol mapper being a baseband quadrature symbol mapper and the digital signal produced by said baseband quadrature symbol mapper comprises an in-phase digital signal and a quadrature digital signal; means for compressing said digital signal by multiplying said digital signal by a first predetermined value including means for multiplying both the in-phase and quadrature signals by said predetermined value; means for modulating a carrier signal based on the compressed digital signal; means for inputting said modulated carrier signal to a transmission power amplifier; means for adjusting the gain of said transmission power amplifier on the basis of a second predetermined value; and means for transmitting the amplified modulated signal;
said system further comprisingmeans for multiplexing the in-phase and quadrature signals prior to compressing said digital signal and converting the signals from digital to analog; and means for demultiplexing the in-phase and quadrature signals following compression and digital to analog-conversion.
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Specification