KR20000001305A - Distortion compensation device due to voltage shift and method thereof - Google Patents

Abstract

PURPOSE: A distortion compensation device due to voltage shift and method thereof is provided to perform stable operation and improve reliability though great voltage shift is generated in the transmitter using cartesian feedback loop. CONSTITUTION: The distortion compensation device due to power shift comprises: a voltage recognition unit(100) lowering input voltage within the operation voltage of an A/D converter(200); an A/D converter(200) generating digital signals corresponding to the voltage; a controller(300) controlling a attenuation/amplification unit(420) if input voltage is out of allowable range; a demodulator(410) restoring signals inputted from the attenuation/amplification unit(420) and a phase controller(700) into I/Q signals; a down converter(400) consisted of the attenuation/amplification unit(420) controlling level according to the signal inputted from the controller(300); a loop filter(500) filtering the I/Q signals and feed back signals; au up converter(600) consisted of a modulator(610), an attenuator(620) and an amplifier(630); and a phase controller(700) controlling the pulse phase generated from a local oscillator and inputting it to the demodulator(410).

Description

Distortion Compensation Device and Method According to Power Voltage Variation

The present invention relates to an apparatus and method for compensating for distortion caused by fluctuations in power supply voltage in a Cartesian feedback loop, and more particularly, to a power source in a Cartesian feedback loop circuit that removes distortion components generated during transmission modulation and amplification. The present invention relates to a distortion compensating apparatus and method according to power supply voltage fluctuation, which can compensate for distortion components caused by voltage fluctuation.

In general, the power amplification module in the up-converter of the Cartesian feedback loop circuit uses a power supply voltage input from a battery, and when the power supply voltage of the battery is changed, the output of the power amplifier is also changed.

In other words, as the power supply voltage decreases, the output decreases. As the power supply voltage increases, the output increases. When the output of the power amplifier is changed in this way, the input level of the demodulator coupled and supplied from the output of the power amplifier is also changed.

This is because the attenuator and amplifier in the downconverter portion of the Cartesian feedback loop circuit operate on the basis of the normal power supply voltage, and thus the output change due to the power supply voltage change cannot be compensated.

In addition, when the demodulator input level of the Cartesian feedback loop circuit is changed, normal demodulation output is not performed. Therefore, modulation using the demodulation output cannot be performed properly, resulting in distortion of the output, thereby preventing normal communication. There was a problem.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems, and in a device in which normal communication is not performed because the modulation is distorted in the conventional Cartesian feedback loop circuit, it is input from the battery of the Cartesian feedback loop circuit. It is an object of the present invention to provide an apparatus and method for recognizing a voltage by a controller to adjust an attenuation value by an output change caused by a change in power supply voltage and to perform an accurate operation regardless of an operating range of the power supply voltage.

In order to achieve the above object, the distortion compensating apparatus according to the power supply voltage variation of the present invention, in a Cartesian feedback loop circuit, reduces a power supply voltage input from a battery supplying power to the circuit within an operating voltage of an A / D converter. A voltage recognizing unit; An A / D converter for making a digital signal corresponding to the voltage input from the voltage recognizer; A control unit which monitors the input voltage and controls the attenuation / amplifying unit when it is determined that the output is fluctuated outside the allowed range; A down converter comprising a demodulation unit for receiving an input signal from the attenuation / amplification unit and a modulation signal input from the phase adjustment unit to restore an I / Q signal, and an attenuation / amplification unit for adjusting a level according to the signal input from the control unit; A loop filter for filtering the frequency of the I / Q signal inputted from the controller and the signal fed back; A modulator for modulating the TX / LO signal fed back with the I / Q signal input from the loop filter and demodulated by the demodulator, and receiving a signal output from the modulator to adjust an output level. An up converter comprising an attenuator configured to achieve an output level, and an amplifier configured to amplify a signal input from the attenuator to generate a transmission output of the terminal; Characterized in that it comprises a phase adjuster for adjusting the phase of the pulse generated by the local oscillator and input to the demodulator.

In addition, in order to achieve the above object, in the distortion compensation method according to the power supply voltage variation of the present invention, a power supply voltage is input from a battery for supplying power to a Cartesian feedback loop circuit, and is converted into a digital signal in an A / D converter. A first step of recognizing the power supply voltage after the control unit; After performing the first step, the controller determines whether there is a change in the power supply voltage within the allowable range, and maintains the state of the control signal if there is no voltage change, and maintains the state of the control signal if the voltage decreases or increases. A second step of changing; And after performing the second step, a third step of adjusting the level and maintaining the output linearity according to the signal input from the controller in the attenuation and amplifying unit of the up / down converter.

1 is a functional block diagram illustrating a configuration state of a distortion compensator according to a change in power supply voltage according to an embodiment of the present invention;

2 is a control flowchart illustrating an operation state of a controller of a distortion compensation method according to a change in power supply voltage according to an embodiment of the present invention.

<Explanation of symbols for main parts of the drawings>

100: voltage recognition unit 200: A / D converter

300: control unit 400: down converter

410: demodulator 420: attenuation / amplifier

500: loop filter 600: up converter

610: modulator 620: attenuator

630: amplifier 700: phase adjuster

Hereinafter, with reference to the accompanying drawings will be described in detail the distortion compensation device and method according to the power supply voltage variation according to an embodiment of the present invention.

1 is a functional block diagram showing a configuration of a distortion compensator according to a power supply voltage variation according to an embodiment of the present invention. As shown in the figure, a battery for supplying power to a circuit in a Cartesian feedback loop circuit is shown. A voltage recognizing unit 100 for lowering the power supply voltage input from the A / D converter 200 within an operating voltage; An A / D converter 200 for making a digital signal corresponding to the voltage input from the voltage recognizer 100; A controller 300 that monitors the input voltage and controls the attenuation / amplifying unit 420 if it is determined that the output fluctuates out of the allowable range; A demodulator 410 which receives a signal input from the attenuation / amplifying unit 420 and a modulation signal input from the phase adjusting unit 700 and restores an I / Q signal; A down converter 400 composed of an attenuation / amplifying part 420 for adjusting a level according to a signal input from the control part 300; A loop filter 500 for filtering the frequency of the I / Q signal inputted from the controller 300 and the signal inputted back; A modulator 610 which feeds back the I / Q signal input from the loop filter 500 and modulates the I / Q signal demodulated by the demodulator 410 to the TX_LO signal, and the modulator 610. Attenuator 620 is configured to receive the signal output from the attenuator 620 to adjust the output level to the desired output level, amplifying unit 630 to amplify the signal input from the attenuator 620 to create a transmission output of the terminal An up converter 600; The present embodiment includes a phase adjuster 700 which adjusts a phase of a pulse generated by the local oscillator and inputs it to the demodulator 410.

FIG. 2 is a control flowchart illustrating an operation state of a controller of a distortion compensation method according to fluctuations in power supply voltage according to an embodiment of the present invention. As shown in FIG. 2, a power supply voltage of a battery for supplying power to a Cartesian feedback loop circuit is shown. A first step (S1) of receiving a signal, converting the digital signal from the A / D converter 200 and recognizing the power supply voltage in the control unit 300; After performing the first step (S1), the control unit 300 determines whether there is a change in the power supply voltage within the allowed range, if there is no voltage change, maintains the state of the control signal, the voltage decreases or increases A second step (S2) of changing the state of the control signal if it has been done; After performing the second step (S2), the attenuation and amplification units 420, 620, and 630 of the up / down converters 400 and 600 adjust levels according to signals input from the control unit 300 and output linearity. This embodiment comprises a third step (S3) to maintain the.

Hereinafter, the operation of the distortion compensating apparatus and method according to the variation of the power supply voltage configured as described above will be described in more detail with reference to the accompanying drawings.

First, when a power supply voltage is input from a battery that supplies power to a Cartesian feedback loop circuit used in a digital frequency public communication (TRS), the power recognition unit 100 recognizes the power supply voltage.

When a power supply voltage is input to the voltage recognizer 300, the A / D converter 200 generates a digital signal corresponding to the input voltage and inputs the digital signal to the controller 300, and attenuates / amplifies the down converter 400. 420 adjusts the level according to the signal from the control unit 300.

The controller 300 monitors the input voltage and controls the attenuation / amplification unit 420 in the down converter 400 when it is determined that the output is out of the allowable range. In other words, when the power supply voltage is lowered, the output is lowered, so that the attenuation is controlled to be smaller as the output is lowered. When the power supply voltage is increased, the output is also increased, so the attenuation is increased as the output is increased.

At this time, the attenuation / amplification unit 420 is configured to attenuate up to 36 dB at 2 dB intervals according to the control signal input from the control unit 300. You can adjust it to 18dB, and if the output is reduced by 6dB, the attenuation is 10dB.

As described above, if the output linearity is maintained after the level is adjusted in the attenuation and amplifying units 420, 620, and 630 of the downconverter 400 and the upconverter 600, the demodulator 410 of the downconverter 400. ) To restore the I / Q signal.

Thereafter, the loop filter 500 filters the frequency of the I / Q signal inputted from the controller 300 and the signal inputted back, and the I / Q inputted from the loop filter 500 from the modulator 610. The I / Q signal demodulated by the demodulator 410 is fed back to the signal and modulates the TX_LO signal.

Meanwhile, the present invention is not limited to the above embodiments and can be variously modified within the scope not departing from the technical gist of the present invention.

As described above, the distortion compensator and method according to the present invention change the power supply voltage, so that the transmitter performs a stable operation even with a wide range of power supply voltage changes in the transmitter using the Cartesian feedback loop. There is.

Claims (2)

A Cartesian feedback loop circuit, comprising: a voltage recognition unit (100) for lowering a power supply voltage input from a battery for supplying power to the circuit within an operating voltage of an A / D converter (200); An A / D converter 200 for making a digital signal corresponding to the voltage input from the voltage recognizer 100; A controller 300 that monitors the input voltage and controls the attenuation / amplifying unit 420 if it is determined that the output fluctuates out of the allowable range; A demodulator 410 which receives a signal input from the attenuation / amplifying unit 420 and a modulation signal input from the phase adjusting unit 700 and restores an I / Q signal; A down converter 400 composed of an attenuation / amplifying part 420 for adjusting a level according to a signal input from the control part 300; A loop filter 500 for filtering the frequency of the I / Q signal inputted from the controller 300 and the signal inputted back; A modulator 610 which feeds back the I / Q signal input from the loop filter 500 and modulates the I / Q signal demodulated by the demodulator 410 to the TX_LO signal, and the modulator 610. Attenuator 620 is configured to receive the signal output from the attenuator 620 to adjust the output level to the desired output level, amplifying unit 630 to amplify the signal input from the attenuator 620 to create a transmission output of the terminal An up converter 600; And a phase adjuster (700) for adjusting the phase of the pulse generated by the local oscillator and inputting it to the demodulator (410). A first step (S1) of receiving a power supply voltage from a battery for supplying power of a Cartesian feedback loop circuit, converting the power supply voltage into a digital signal in the A / D converter 200 and recognizing the power supply voltage in the controller 300; After performing the first step (S1), the control unit 300 determines whether there is a change in the power supply voltage within the allowed range, if there is no voltage change, maintains the state of the control signal, the voltage decreases or increases A second step (S2) of changing the state of the control signal if it has been done; After performing the second step (S2), the attenuation and amplification units 420, 620, and 630 of the up / down converters 400 and 600 adjust levels according to signals input from the control unit 300 and output linearity. And a third step (S3) of maintaining the distortion.