Distortion compensator
AssigneeFujitsu Limited
InventorsYasuhito Funyu, Hiroaki Abe, Takeshi Ohba, Tomohiro Nakamura
Life of this patent
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Abstract
A distortion compensator updating and selecting a distortion compensation coefficient applied to a digital transmission signal so as to reduce the difference between the digital transmission signal and a digital feedback signal is disclosed. The distortion compensator includes a control part that controls the level of an input signal to an analog-to-digital conversion part outputting the digital feedback signal in accordance with the magnitude of the amplitude of the digital transmission signal.
Claims16
A distortion compensator updating a distortion compensation coefficient applied to a digital transmission signal so as to reduce a difference between the digital transmission signal and a digital feedback signal the distortion compensator comprising:
- a control part configured to control, in a feedback system, a level of an input signal to an analog-to-digital conversion part outputting the digital feedback signal to be compared with the digital transmission signal in accordance with magnitude of amplitude of the digital transmission signal.
A distortion compensator updating a distortion compensation coefficient by which a digital transmission signal is multiplied so as to reduce a difference between the digital transmission signal and a digital feedback signal, the distortion compensator comprising:
- a variable gain amplification part configured to control, in a feedback system, a level of an input signal to an analog-to-digital conversion part outputting the digital feedback signal to be compared with the digital transmission signal in response to a control signal;
- and
- a gain control part configured to output the control signal in accordance with a power value of the digital transmission signal by using a predetermined correspondence between possible power values of the digital transmission signal and gains of the variable gain amplification part.
A radio transmitter with a distortion compensation function, comprising:
- a distortion compensator configured to update a distortion compensation coefficient applied to a digital transmission signal so as to reduce a difference between the digital transmission signal and a digital feedback signal,
- the distortion compensator including a controller configured to control, in a feedback system, a level of an input signal to an analog-to-digital conversion part outputting the digital feedback signal to be compared with the digital transmission signal in accordance with magnitude of amplitude of the digital transmission signal.
A radio transmitter with a distortion compensation function, comprising:
- a distortion compensator configured to update a distortion compensation coefficient by which a digital transmission signal is multiplied so as to reduce a difference between the digital transmission signal and a digital feedback signal,
- the distortion compensator including:
- a variable gain amplification part configured to control, in a feedback system, a level of an input signal to an analog-to-digital conversion part outputting the digital feedback signal to be compared with the digital transmission signal in response to a control signal;
- and
- a gain control part configured to output the control signal in accordance with a power value of the digital transmission signal by using a predetermined correspondence between possible power values of the digital transmission signal and gains of the variable gain amplification part.
A radio transmitter with a distortion compensation function, comprising:
- a distortion compensator configured to update a distortion compensation coefficient by which a digital transmission signal is multiplied so as to reduce a difference between the digital transmission signal and a digital feedback signal,
- the distortion compensator including:
- a variable gain amplification part configured to autonomously control a level of an input signal to an analog-to-digital conversion part outputting the digital feedback signal to be compared with the digital transmission signal;
- and
- a control part configured to control an amplitude level of the digital transmission signal for calculating the difference in response to the controlling of the level of the input signal by the variable gain amplification pan.
A distortion compensator updating a distortion compensation coefficient by which a digital transmission signal is multiplied so as to reduce a difference between the digital transmission signal and a digital feedback signal, the distortion compensator comprising:
- a variable gain amplification part configured to autonomously control a level of an input signal to an analog-to-digital conversion part outputting the digital feedback signal to be compared with the digital transmission signal;
- and
- a control part configured to control an amplitude level of the digital transmission signal for calculating the difference in response to the controlling of the level of the input signal by the variable gain amplification part.
A distortion compensator operable to update compensating coefficient applied to a digital transmission signal, which is converted into an analog signal input to an amplifier, after applying the compensating coefficient, the distortion compensator comprising:
- a level control unit operable to control input level of a feedback signal, which is obtained based on an output signal from the amplifier, in a feedback system in accordance with a change of a level of the digital transmission signal;
- and
- an analog to digital converting unit operable to convert a digital signal of which level is controlled by the level control unit into a digital feedback signal to be compared with the digital transmission signal.
Dependencies are inferred from the claim text.