Method and apparatus for generating transmitting wave
AssigneeNEC Corporation
InventorSatoshi Kowaguchi
Life of this patent
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Abstract
In a method for generating a transmitting wave, a power supply voltage to be supplied to a transmission power amplifier is detected by a voltage detector, and a modulating signal is controlled so that a peak value of a modulated wave is lowered in accordance with a reduction amount of the power supply voltage. Since the peak value of the modulated wave input to the power amplifier is lowered, it is possible to obtain a transmitting wave without a distortion of the wave form or an increased bandwidth even when the reduction in the power supply voltage involves the lowering of the driving capability of the power amplifier.
Claims29
A method for generating a modulated wave in a transmitter having a power supply, the modulated wave including at least an amplitude component, the method comprising the steps of:
- a) detecting a power supply voltage of the power supply;
- b) determining an amplitude limit based on the power supply voltage;
- c) generating a modulating signal based on transmitting data such that an amplitude of the modulated wave is restricted within the amplitude limit;
- and
- d) performing a modulation in accordance with the modulating signal to generate the modulated wave.
An apparatus for generating a modulated wave in a transmitter having a power supply, the modulated wave including at least an amplitude component, the apparatus comprising:
- detecting means for detecting a power supply voltage of the power supply;
- determining means for determining an amplitude limit based on the power supply voltage;
- generating means for generating a modulating signal based on transmitting data such that an amplitude of the modulated wave is restricted within the amplitude limit;
- and
- modulating means for modulating a carrier wave in accordance with the modulating signal to generate the modulated wave.
A transmitter comprising:
- a modulator for performing a modulation in accordance with a modulating signal to output a modulated wave which includes at least an amplitude component;
- a power amplifier for amplifying the modulated wave in power to output a transmitting wave;
- a power supply for supplying power to at least the power amplifier;
- detecting means for detecting a power supply voltage of the power supply;
- determining means for determining an amplitude limit based on the power supply voltage;
- and
- generating means for generating the modulating signal based on transmitting data such that an amplitude of the modulated wave is restricted within the amplitude limit.
Dependencies are inferred from the claim text.