KR20000066140A - Apparatus for error compensation as to transmittion power of mobile communication terminal - Google Patents

Abstract

PURPOSE: A device for compensating a transmission output error of a mobile communication terminal, is provided to compensate a transmission output error caused by a temperature change with simple hardware. So that the communication incapability and the deterioration of speech quality between a terminal and a system due to the lowering of a transmission output when the terminal is in a high temperature, can be previously prevented. CONSTITUTION: A central processing unit(110) outputs control data for compensating a transmission output changed according to temperatures. A digital-to-analog(D/A) converter(120) converts the control data into corresponding analog voltages. A temperature sensor(130) detects the temperatures of a power amplifier and a mobile communication terminal, and outputs the detected temperature values into DC voltage values. A voltage adder(140) adds voltages outputted from the temperature sensor(130) and the D/A converter(120). A phase inverter(150) inverts the phases of the voltages outputted from the voltage adder(140), and outputs the inverted phases into control voltages. An auto gain controller(160) controls the gain of an amplifier in order to compensate the transmission output change according to temperature changes by the control voltages outputted in the phase inverter(150).

Description

Apparatus for error compensation as to transmittion power of mobile communication terminal

The present invention relates to temperature compensation of mobile communication terminals (D-TRS terminal, DCS terminal, PCS terminal), in particular, the transmission output error compensation device of the mobile communication terminal to compensate the transmission output error according to the temperature change by simple hardware It is about.

In general, a mobile communication terminal power amplifies a transmission high frequency signal and transmits the same through an antenna. In this case, a power amplifier is used for power amplification.

The power amplifier is very sensitive to temperature, and the output power is low when the temperature is high, and the output power is increased when the temperature is low. Therefore, in order to prevent the output change of the power amplifier that changes with temperature, in the related art, a temperature compensation circuit is added separately to prevent the output of the power amplifier from being changed.

Transmission error compensation device of the conventional mobile communication terminal having the temperature compensation circuit as described above is as shown in FIG.

As shown here, the temperature sensor 10 for detecting the temperature of the power amplifier and the terminal, and the analog-to-digital converter for converting the analog temperature detection voltage detected by the temperature sensor 10 to the corresponding digital temperature data ( 20), the temperature detection data output from the analog-to-digital converter 20 is searched, and the temperature of the power amplifier and the terminal is recognized, and the detected temperature is compared with the temperature set as a reference to change the output power by the difference value. A central processing unit (30) for generating control data to compensate for the above, a digital to analog converter (40) for converting temperature data generated in the central processing unit (30) into analog voltage values, and the digital Automatic gain control section 5 for automatically controlling the gain of the transmission high frequency in accordance with the analog voltage value obtained from the analog converter 40 0).

The transmission output error compensating apparatus of the conventional mobile communication terminal configured as described above first detects the temperature of the power amplifier and the mobile communication terminal by the temperature sensor 10. The analog voltage corresponding to the detected temperature is converted into digital temperature data corresponding to the analog / digital converter 20 and transferred to the central processing unit 30.

The CPU 30 calculates the difference by comparing the temperature data detected according to the program stored in the internal memory with the temperature data stored in advance. After that, the control data is output to compensate for the transmission output change by the difference value.

The control data output in this way is converted into an analog voltage corresponding to the digital-to-analog converter 40 and transferred to the automatic gain control unit 50. The automatic gain control unit 50 amplifies the transmission RF according to the control voltage. The gain of the amplifier is controlled to compensate for the change in transmit power over temperature.

However, the conventional transmission output error compensation device of the mobile communication terminal compensates for the change in the transmission output according to the temperature based on the software stored in the central processing unit, so it is difficult to compensate for the real-time transmission output change by the control by the feedback. There was this.

In addition, in the well-known software method, the transmission output compensation method uses an analog / digital converter to convert the voltage corresponding to the detected temperature into a digital, and the temperature sensor output voltage value is constant due to the device characteristics of the analog / digital converter. Because of the conversion to discrete (digital) values of the intervals, this has the disadvantage of being less accurate than continuous (analog) control.

Accordingly, the present invention has been proposed in order to solve various problems occurring in the transmission output error compensation device of the conventional mobile communication terminal as described above.

SUMMARY OF THE INVENTION An object of the present invention is to provide a transmission output error compensating device of a mobile communication terminal which compensates for transmission output error due to temperature change by simple hardware.

Transmission output error compensation apparatus of the present invention for achieving the above object,

In the transmission output error compensation device of the mobile communication terminal,

A central processing unit for outputting control data for compensating a transmission output that varies with temperature;

A digital / analog converter for converting control data output from the central processing unit into a corresponding analog voltage;

A temperature sensor detecting a temperature of the power amplifier and the mobile communication terminal;

A voltage adder configured to add a voltage output from the temperature sensor and a voltage output from the digital / analog converter;

A phase inversion unit inverting the phase of the voltage output from the voltage adding unit and outputting the voltage as a control voltage;

It is characterized in that the automatic gain control unit for controlling the gain of the amplifier to compensate for the change in the transmission output according to the temperature change in accordance with the control voltage output from the phase inversion unit.

The voltage adding unit may include an inverting amplifier configured to invert and amplify the voltage output from the temperature sensor and the voltage obtained from the digital / analog converter.

The phase inverting unit may be configured as an inverting amplifier for inverting and amplifying the voltage output from the voltage adding unit to invert the phase of the input voltage.

Transmission output error compensation apparatus of the present invention for achieving the above object,

In the transmission output error compensation device of the mobile communication terminal,

A central processing unit for outputting control data for compensating a transmission output that varies with temperature;

A digital / analog converter for converting control data output from the central processing unit into a corresponding analog voltage;

A control voltage generator for generating a control voltage for compensating a transmission output change by varying an output voltage level with a resistance value change;

A voltage selector configured to select one of a voltage output from the digital / analog converter and a voltage generated from the control voltage generator;

A temperature sensor detecting a temperature of the power amplifier and the mobile communication terminal;

A voltage adder configured to add a voltage output from the temperature sensor and a voltage output from the voltage selector;

A phase inversion unit inverting the phase of the voltage output from the voltage adding unit and outputting the voltage as a control voltage;

It is characterized in that the automatic gain control unit for controlling the gain of the amplifier to compensate for the change in the transmission output according to the temperature change in accordance with the control voltage output from the phase inversion unit.

In the above, the control voltage generation unit is characterized by having a variable resistor for varying the control voltage output by varying the resistance value in accordance with manual operation.

The voltage selector may include a switch configured to select and output one of a control voltage output from the control voltage generator and a voltage output from the digital / analog converter.

The voltage adding unit may include an inverting amplifier configured to invert and amplify a voltage output from the temperature sensor and a voltage obtained from the digital / analog converter.

The phase inverting unit may be configured as an inverting amplifier for inverting and amplifying the voltage output from the voltage adding unit to invert the phase of the input voltage.

Transmission output error compensation apparatus of the present invention for achieving the above object,

In the transmission output error compensation device of the mobile communication terminal,

A central processing unit for outputting control data for compensating a transmission output that varies with temperature;

A digital / analog converter for converting control data output from the central processing unit into a corresponding analog voltage;

A temperature sensor detecting a temperature of the power amplifier and the mobile communication terminal;

A voltage amplifying and dividing unit for amplifying the voltage output from the temperature sensor and dividing the amplified voltage and the voltage output from the digital / analog converter to output the RF gain control voltage;

It is characterized in that the automatic gain control unit for controlling the gain of the amplifier to compensate for the change in the transmission output according to the temperature change in accordance with the control voltage output from the voltage amplification and distribution unit.

The voltage amplification and distribution unit includes a non-inverting amplifier for non-inverting and amplifying the voltage output from the temperature sensor, and a voltage division resistor for distributing the output voltage of the non-inverting amplifier and the output voltage of the digital / analog converter. It is characterized by.

1 is a block diagram of a transmission output error compensator of a conventional mobile communication terminal;

2 is a block diagram of a first embodiment of a transmission output error compensation device of a mobile communication terminal according to the present invention;

3 is a characteristic graph of a temperature sensor applied to the present invention;

4 is a characteristic graph of an automatic gain control circuit applied to the present invention;

5 is a configuration diagram of a second embodiment of a transmission output error compensation device of a mobile communication terminal according to the present invention;

6 is a configuration diagram of a third embodiment of a transmission output error compensation device of a mobile communication terminal according to the present invention;

<Description of the code | symbol about the principal part of drawing>

110: central processing unit (CPU) 120: digital to analog converter

130: temperature sensor 140: voltage adder

150: phase inversion unit 160: automatic gain control unit

170: control voltage generator 180: voltage selector

190: voltage amplification and distribution unit

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention according to the technical spirit as described above in detail.

<Example 1>

2 is a circuit diagram of a transmission output error compensation device of a mobile communication terminal according to the present invention.

As shown, a central processing unit (110) for outputting control data for compensating for the transmission output that changes with temperature; A digital / analog converter (120) for converting control data output from the central processing unit (110) into an analog voltage corresponding thereto; A temperature sensor 130 for detecting a temperature of the power amplifier and the mobile communication terminal; A voltage adder 140 for adding a voltage output from the temperature sensor 130 and a voltage output from the digital / analog converter 120; A phase inversion unit 150 for inverting the phase of the voltage output from the voltage adding unit 140 and outputting the control voltage; The automatic gain control unit 160 controls the gain of the amplifier to compensate for the change in the transmission output according to the temperature change according to the control voltage output from the phase inversion unit 150.

In the above description, the voltage adding unit 140 includes an inverting amplifier 141 that inverts and amplifies the voltage output from the temperature sensor 130 and the voltage obtained by the digital / analog converter 140.

In addition, the phase inverting unit 150 includes an inverting amplifier 150 for inverting and amplifying the voltage output from the voltage adding unit 140 to invert the phase of the input voltage.

The first embodiment of the transmission output error compensation device according to the present invention configured as described above,

First, the central processing unit 110 outputs an output change error control data according to a preset temperature when producing a mobile communication terminal product. Here, the output change error control data is a value adjusted to equalize the deviation of the smallest maximum output for each terminal at room temperature for all terminals in the terminal production stage. It is fixed once in production and cannot be changed during operation.

The output change error control data output in this way is converted into an analog DC voltage value corresponding to the digital-to-analog converter 120 and output.

On the other hand, the temperature sensor 130 is installed in close proximity to the power amplifier detects the ambient temperature, and outputs the detected temperature value as a DC voltage value. 3 is a characteristic graph of the temperature sensor 130. As shown in the characteristic graph, the temperature sensor 130 outputs a low voltage at low temperature and a high voltage at high temperature. Here, the installation of the temperature sensor 130 is installed as close as possible to the power amplifier, and share the ground plane so that the temperature change of the power amplifier can be as sensitive as possible.

Next, the voltage adding unit 140 adds the voltage output from the digital / analog converter 120 and the voltage output from the temperature sensor 130, and inverts and amplifies the voltage by the inverting amplifier 141. When the value finally outputted from the voltage adding unit 140 is expressed by a formula, it becomes "-{(P1 / R1) + (P2 / R2)} * R3". In the above, P1 is the voltage output from the digital-to-analog converter, and P2 represents the output voltage of the temperature sensor. In this case, the inverting amplifier 141 is used to add voltages to prevent the two voltages P1 and P2 input from interfering with each other.

The phase inverting unit 150 inverts and amplifies the voltage P3 output from the voltage adding unit 140 by the inverting amplifier 151 to output a voltage having the same absolute level value and inverting only the phase.

The output phase inverted voltage is transmitted to the automatic gain control unit 160, and the automatic gain control unit 160 converts the level of the RF by a gain control method that varies the attenuation level of the RF signal existing on the transmitter RF path. Compensate for power amplifier output changes with temperature. 4 is a characteristic graph of the automatic gain control unit 160.

The automatic gain control unit 160 is an AGC circuit generally used in the RF transmitter circuit.

Summarizing the first embodiment of the present invention described above, the voltage adding unit 140 adds the initial value P1 and the temperature detection voltage P2, which are given during production based on the output level at room temperature, and inverts the phase. The control voltage is applied to the AGC circuit. In this case, when the temperature rises during the operation of the terminal, the value of the control voltage input to the AGC increases, and as a result, the transmission output level finally output increases. On the contrary, when the temperature of the terminal decreases, the value of the control voltage input to the AGC decreases relatively, and as a result, the final output power output level drops.

Here, the change of the final transmission output level according to the temperature, that is, the rise and fall varies according to the design model of the terminal, which is considered by the designer in consideration of the linearity and the slope of the AGC circuit and the resistance (R1, R2, R3) in the voltage adder. By adjusting only the value, the design model difference of the terminal can be sufficiently overcome.

When the present invention is applied to a digital TRS portable terminal, the expected output power error values are shown in the following [Table 1].

Table 1

Temperature (Celsius) Output power error (dB) without temperature compensation circuit Output power error (dB) with temperature compensation circuit -20 degrees 2.5 0.5 25 degrees (standard) 0 0 60 degrees -1.8 -0.2

For reference, the temperature sensor is 0.1V at -20 ° C, 0.5V at 25 ° C, 0.9V at 60 ° C, and the control voltage input to AGC circuit is 2.2V at -20 ° C, 3V at 60 ° C, 60 ° C. At 3.8V.

<Example 2>

5 is a circuit diagram of a second embodiment of a transmission output error compensating device according to the present invention.

As shown, a central processing unit (110) for outputting control data for compensating for the transmission output that changes with temperature; A digital / analog converter (120) for converting control data output from the central processing unit (110) into an analog voltage corresponding thereto; A control voltage generator 170 for generating a control voltage for compensating a transmission output change by varying an output voltage level with a resistance change; A voltage selector 180 which selects and outputs one of a voltage output from the digital / analog converter 120 and a voltage generated from the control voltage generator 170; A temperature sensor 130 for detecting a temperature of the power amplifier and the mobile communication terminal; A voltage adder 140 for adding a voltage output from the temperature sensor 130 and a voltage output from the voltage selector 180; A phase inversion unit 150 for inverting the phase of the voltage output from the voltage adding unit 140 and outputting the control voltage; The automatic gain control unit 160 controls the gain of the amplifier to compensate for the change in the transmission output according to the temperature change according to the control voltage output from the phase inversion unit 150.

In the above, the control voltage generation unit 170 includes a variable resistor for varying the control voltage output by varying the resistance value in accordance with manual operation.

In addition, the voltage selector 180 includes a switch 181 that selects and outputs one of a control voltage output from the control voltage generator 170 and a voltage output from the digital / analog converter 120. .

The second embodiment of the transmission output error compensating device of the mobile communication terminal according to the present invention configured as described above is to select a hardware transmission output error compensation method and a software transmission output error compensation method according to the user's selection.

That is, the software transmission output error compensation method stores control data in a memory in the central processing unit 110 in advance when producing a terminal product. Then, in use, the central processing unit 110 outputs the control data to compensate for the change in the transmission output according to the temperature, and the output control data is converted into the analog voltage corresponding thereto in the digital / analog converter 120. .

In addition, in the transmission output error compensation method of hardware, the variable resistor of the variable resistor (not shown in the drawing) in the control voltage generation unit 170 in advance in the production of the terminal to output a control voltage according to the resistance value is changed.

Then, the user manipulates the switch 181 in the voltage selector 180 to select a desired compensation voltage.

On the other hand, the temperature sensor 130 detects the temperature of the terminal or the temperature of the power amplifier as shown in Figure 2, and outputs a voltage corresponding to the detected temperature, the voltage adding unit 140 as described above The voltage output from the temperature sensor 130 and the voltage selected by the voltage selector 180 are added.

Hereinafter, since the operations of the phase inversion unit 150 and the automatic gain control unit 160 are the same as those of <Example 1> already described, detailed description thereof will be omitted.

<Example 3>

6 is a third embodiment of a transmission output error compensation device of a mobile communication terminal according to the present invention.

As shown, a central processing unit (110) for outputting control data for compensating for the transmission output that changes with temperature; A digital / analog converter (120) for converting control data output from the central processing unit (110) into an analog voltage corresponding thereto; A temperature sensor 130 for detecting a temperature of the power amplifier and the mobile communication terminal; A voltage amplification and distribution unit 190 for amplifying the voltage output from the temperature sensor 130 and dividing the amplified voltage and the voltage output from the digital / analog converter 120 to output the RF gain control voltage; It is composed of an automatic gain control unit 160 for controlling the gain of the amplifier to compensate for the change in the transmission output according to the temperature change in accordance with the control voltage output from the voltage amplification and distribution unit 190.

The voltage amplification and distribution unit 190 includes a non-inverting amplifier 191 for non-inverting and amplifying the voltage output from the temperature sensor 130, an output voltage of the non-inverting amplifier 191 and the digital / And a voltage divider resistor R9 and R10 for dividing the output voltage of the analog converter 120.

According to the third exemplary embodiment of the present invention configured as described above, the voltage adding unit 140 and the phase inverting unit 150 of the first embodiment are compared to the first embodiment, and the voltage amplifying and distributing unit 190 ) Is replaced by

First, the central processing unit 110 outputs an output change error control data according to a preset temperature when producing a mobile communication terminal product. Here, the output change error control data is a value adjusted to equalize the deviation of the smallest maximum output for each terminal at room temperature for all terminals in the terminal production stage. It is fixed once in production and cannot be changed during operation.

The output change error control data output in this way is converted into an analog DC voltage value corresponding to the digital-to-analog converter 120 and output.

On the other hand, the temperature sensor 130 is installed in close proximity to the power amplifier detects the ambient temperature, and outputs the detected temperature value as a DC voltage value.

Then, the voltage amplification and distribution unit 190 non-inverts and amplifies the voltage output from the temperature sensor 130 by the non-inverting amplifier 191, and the non-inverted amplified voltage by the distribution resistors R90 and R10. The output voltage of the digital-to-analog converter 120 is distributed and applied as a control voltage to the automatic gain control unit 160 at a later stage.

In FIG. 6, V1 represents an output voltage of the digital-to-analog converter 120, V2 represents an output voltage of the temperature sensor 130, and V3 represents an output voltage of the non-inverting amplifier 191. V3 is a voltage obtained by V2 * (1 + R8 / R7). And V4 represents a divided voltage with respect to the voltage difference between V3 and V1.

As described above, according to the present invention, the transmission output can be kept constant, thereby preventing the communication failure between the terminal and the system and the deterioration of the call quality that may occur due to the decrease in the transmission output at high temperature of the terminal. .

In addition, even when the terminal is low temperature, there is an effect that it is possible to prevent the generation of the interference wave to the adjacent channel caused by the increase in the transmission output.

In addition, it is possible to prevent damage or abnormal operation of the power amplifier in advance by maintaining a constant transmission output, thereby reducing the cost and reducing the current consumption of the battery.

In addition, by implementing the transmission output error compensation device in hardware, it is possible to control the transmission output constantly in response to the temperature change immediately without feedback, there is an effect capable of real-time control.

In addition, since there is a continuous transmission output error compensation by analog, there is an advantage that accurate control is possible.

Claims (10)

In the transmission output error compensation device of the mobile communication terminal, A central processing unit for outputting control data for compensating a transmission output that varies with temperature; A digital / analog converter for converting control data output from the central processing unit into a corresponding analog voltage; A temperature sensor detecting a temperature of the power amplifier and the mobile communication terminal; A voltage adder configured to add a voltage output from the temperature sensor and a voltage output from the digital / analog converter; A phase inversion unit inverting the phase of the voltage output from the voltage adding unit and outputting the voltage as a control voltage; And an automatic gain controller for controlling gain of an amplifier in order to compensate for a change in a transmission output according to a temperature change according to a control voltage output from the phase inversion unit. The apparatus of claim 1, wherein the voltage adding unit comprises an inverting amplifier configured to invert and amplify a voltage output from the temperature sensor and a voltage obtained from the digital / analog converter. The apparatus of claim 1, wherein the phase inverting unit comprises an inverting amplifier inverting and amplifying a phase of an input voltage by inverting and amplifying a voltage output from the voltage adding unit. In the transmission output error compensation device of the mobile communication terminal, A central processing unit for outputting control data for compensating a transmission output that varies with temperature; A digital / analog converter for converting control data output from the central processing unit into a corresponding analog voltage; A control voltage generator for generating a control voltage for compensating a transmission output change by varying an output voltage level with a resistance value change; A voltage selector configured to select one of a voltage output from the digital / analog converter and a voltage generated from the control voltage generator; A temperature sensor detecting a temperature of the power amplifier and the mobile communication terminal; A voltage adder configured to add a voltage output from the temperature sensor and a voltage output from the voltage selector; A phase inversion unit inverting the phase of the voltage output from the voltage adding unit and outputting the voltage as a control voltage; And an automatic gain controller for controlling gain of an amplifier in order to compensate for a change in a transmission output according to a temperature change according to a control voltage output from the phase inversion unit. 5. The apparatus of claim 4, wherein the control voltage generator comprises a variable resistor for varying a control voltage output by varying a resistance value according to a manual operation. [5] The transmission output of claim 4, wherein the voltage selector comprises a switch for selecting and outputting one of a control voltage output from the control voltage generator and a voltage output from the digital / analog converter. Error compensation device. The apparatus of claim 4, wherein the voltage adding unit comprises an inverting amplifier configured to invert and amplify a voltage output from the temperature sensor and a voltage obtained from the digital / analog converter. 5. The apparatus of claim 4, wherein the phase inverter comprises an inverting amplifier inverting and amplifying a phase of an input voltage by inverting and amplifying the voltage output from the voltage adding unit. In the transmission output error compensation device of the mobile communication terminal, A central processing unit for outputting control data for compensating a transmission output that varies with temperature; A digital / analog converter for converting control data output from the central processing unit into a corresponding analog voltage; A temperature sensor detecting a temperature of the power amplifier and the mobile communication terminal; A voltage amplifying and dividing unit for amplifying the voltage output from the temperature sensor and dividing the amplified voltage and the voltage output from the digital / analog converter to output the RF gain control voltage; Transmission output error compensation device of the mobile communication terminal characterized in that it comprises an automatic gain control unit for controlling the gain of the amplifier to compensate for the change in the transmission output according to the temperature change in accordance with the control voltage output from the voltage amplification and distribution unit . The non-inverting amplifier for non-inverting and amplifying the voltage output from the temperature sensor, a voltage for distributing the output voltage of the non-inverting amplifier and the output voltage of the digital / analog converter. Transmission output error compensation device of a mobile communication terminal, characterized in that consisting of a distribution resistor.