JP2000165261A - Transmission output control circuit for radio communication terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a transmission output control circuit for a radio communication terminal that has a simple circuit configuration and offers ease of design with enhanced reliability. SOLUTION: A memory 23 stores the reference values of a radio communication terminal, that is, standard control variables corresponding to the reference value of power supply voltage, a transmission channel and temperature. Furthermore, the memory 23 stores a Vss correction value corresponding to a change in a power supply voltage Vss from the reference value, a channel correction value corresponding to a change in the transmission channel from the reference value (reference channel) and a temperature correction value corresponding to a change in the temperature from its reference value. An arithmetic unit obtains a calculated control variable by reading a correction value corresponding to a current power supply voltage, a current transmission channel and a current temperature among the correction values above, and calculates the correction value on the basis of the standard control variable. The calculated control variables are used to control a high output power amplifier 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission output control circuit for a radio communication device used for a mobile radio communication device or the like and for controlling the transmission output of the radio communication device to a constant value.

[0002]

2. Description of the Related Art A transmission output of a radio communication device which is used for a mobile radio communication device such as GSM and which constantly controls the transmission output of the radio communication device irrespective of changes in the temperature, power supply voltage, etc. of the radio communication device. Conventionally, the control circuit has generally been configured as a closed loop as shown in FIG. This method uses V
SWR (Voltage Standing Wave)
(Ratio) The output power of the high output power amplifier 11 is detected by a direct coupler 12 for detecting a reflected wave for detection, and the detection output is detected by a detection circuit 13. Then, the detected voltage and a reference voltage (constant voltage) obtained by D / A conversion of the reference parameter value of the memory 14 by the D / A converter 15 are compared by the differential amplifier 16, and both voltages are compared. By generating an error voltage from the differential amplifier 16 and controlling the amplification factor of the high output power amplifier 11 with the error voltage, the transmission output of the high output power amplifier 11 is controlled to be constant.

[0003]

However, in the conventional transmission output control circuit as described above, in addition to the memory 14 and the D / A converter 15, the direct coupler 12, the detection circuit 13, and the temperature compensation of the detection voltage. A large number of circuits and differential amplifiers 16 are required, which causes problems in terms of the number of components and cost, and also increases the board mounting area, making it difficult to further miniaturize small wireless communication devices such as GSM. . Also, when designing, the detection voltage is determined in consideration of the temperature compensation, the gain is determined while evaluating the output frequency and the power supply voltage fluctuation, and the differential amplifier 1 is determined in consideration of the ramping and the transient characteristics.
The design efficiency was poor, such as determining the time constant of 6.

[0004] The present invention has been made in view of the above points,
An object of the present invention is to provide a transmission output control circuit of a wireless communication device that can have a simple circuit configuration and can be easily designed.

[0005]

A transmission output control circuit for a wireless communication device according to the present invention includes means for storing a standard control value corresponding to a reference value of an operation state of the wireless communication device; Means for storing the corrected value, and means for reading out the corrected value according to the current operation state, performing an operation between the standard control value, and determining the control value of the transmission output. And In the transmission output control circuit of the wireless communication device, the transmission output of the wireless communication device can be switched to a plurality, the standard control value and the correction value are stored for each output, and the control value of the transmission output is calculated by performing further calculations. You can also decide. In addition, the wireless communication device can correspond to a plurality of bands, store a standard control value and a correction value corresponding to each band, and determine the control value of the transmission output by performing a calculation. The operation state of the wireless communication device is at least one of a power supply voltage, a transmission channel, and a temperature. Further, the determined control value of the transmission output is D / A converted, and the amplification factor of the amplifier is controlled by the D / A conversion output.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a transmission output control circuit (open loop system) of a wireless communication device according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a circuit diagram showing an embodiment of a transmission output control circuit of a wireless communication device according to the present invention. In this figure, reference numeral 21 denotes a high output power amplifier for amplifying a transmission signal. The output of a D / A converter 22 is connected to an amplification factor control terminal of the high output power amplifier 21. The D / A converter 22 is supplied with the calculated control value from the memory 23. This calculated control value is stored in the D / A converter 2
D / A conversion at 2 and the high output power amplifier 2 at the output voltage.
By controlling the amplification factor of 1, the transmission output is controlled to be constant.

[0007] A memory 23 such as an EEPROM stores reference values for the operating state of the wireless communication device, that is, standard control values corresponding to the reference values of the power supply voltage, the transmission channel, and the temperature. The memory 23 stores a Vss correction value corresponding to a change in the power supply voltage Vss from the reference value, a channel correction value corresponding to a change in the transmission channel from the reference value (reference channel), and a temperature reference value. Is stored. Among these correction values, a correction value according to the current power supply voltage, the current transmission channel, and the current temperature is read out, and the calculated control value is calculated by performing an arithmetic operation with a standard control value by an arithmetic unit (not shown). By calculating and controlling the amplification factor of the high output power amplifier 21 via the D / A converter 22 with the calculated control value, the transmission output is always kept constant irrespective of power supply voltage fluctuations, channel changes, and temperature changes. Can control.

[0008] Such a control method will be described more specifically with reference to FIGS. 2 to 6. As a mobile radio terminal, G
SM (The GSM System for Mobile)
When a terminal (leCommunication) terminal is used, for example, as a 1800 MHz band terminal (DCS1800), the transmission power level is switched in 16 steps according to the distance from the base station. So, in this specific example,
The output can be switched in 16 stages of “0 to 15”, and the standard control value and the correction value are stored at each output level, and the output can be controlled to be constant.

FIG. 2 shows standard control values, and the power supply voltage Vss
= 3.9 V, transmission channel = middle channel, temperature 2
Standard control values of "450" to "100" are set for each output level on condition that the reference value is 5 degrees.

FIG. 3 shows a Vss correction value, Vss = 3.9V.
A correction value of "+10 to +20" or "-5" is set for each output level depending on whether the power supply voltage is "lower" or "higher" than the reference value.

FIG. 4 shows channel correction values, which are "+5 to +10" or "+2" depending on whether the transmission channel is "lower" or "higher" than the intermediate reference channel.
A channel correction value of "0 to +30" is set for each output level.

FIG. 5 shows a temperature correction value. A temperature correction value of "-5" or "+5" is set depending on whether the temperature is "lower" or "higher" than the reference value of temperature = 25 degrees.

Using these standard control values and correction values, the current operation state of the wireless communication device is changed to the power supply voltage Vss = 3.6.
Consider the case where V, transmission channel = low channel, and temperature is 35 degrees. At this time, “+10 to +20” of “low” is selected in the Vss correction value of FIG. Further, “+5” of “low” in the channel correction values of FIG.
"+10" is selected, and "+5" of "high" is selected in the temperature correction value of FIG. Then, the selected correction value and the standard control value of FIG. 2 are added for each output level as shown in FIG. 6, and the addition result becomes a calculated control value (470 to 135) of each output level. The calculated control value is D / A converted by the D / A converter 22 in FIG.
Open-loop high output power amplifier 2 with A conversion output
1 is controlled, and as a result, the transmission output is controlled to be constant irrespective of the fluctuation of the power supply voltage Vss from the reference value, the change of the transmission channel from the reference channel, and the change of the temperature from the reference value, and at the same time accurate. It is possible to obtain excellent ramping characteristics and transient characteristics.

According to the transmission output control circuit of FIG. 1 in which such control is performed, the circuit configuration is simple, the number of parts and cost are advantageous, and the board mounting area is small, so that the radio communication device Can be further miniaturized. In addition, since the number of components can be reduced, variations between components can be suppressed, and reliability can be improved. Furthermore, design becomes easy.

FIG. 7 is a circuit diagram showing another embodiment of the present invention. In another embodiment, the GSM (900 MH
z) and the DCS1800 (1800 MHz) dual band mobile radio communication apparatus according to the present invention, the memory 23 stores a standard control value, a Vss correction value, and a channel correction corresponding to each band (GSM and DCS1800). value,
Each of the temperature correction values is stored. Therefore, the calculation of the standard control value and the correction value for each band is performed by an arithmetic unit (not shown) as described above to obtain a calculated control value for each band,
The transmission output can be controlled to be constant for each band as described above.

FIG. 8 shows an actual circuit of a GSM and DCS1800 dual band mobile radio communication apparatus employing the transmission output control circuit of the present invention. In this circuit, D
The two analog signals (I and Q components) converted by the / A converter 45 are modulated by the modulator 38 together with the signal of the second local oscillator 40 to become a transmission signal, which is supplied to the phase detector 36 via the buffer 37. Is done. Further, the reference wave of the first local oscillator 41 and the transmission wave of the transmission voltage control oscillator (hereinafter referred to as dual TXVCO) 34 corresponding to two bands (GSM and DCS1800) are The frequency is converted to the same frequency as the transmission signal modulated by the modulator 38, and the phase detector 36
Supplied to If there is a phase difference between the two signal inputs to the phase detector 36, the dual TXVCO
An error signal is generated indicating how much the S.34 deviates from the standard. The error signal generated by the phase detector 36 is input to the loop filter 35. This loop filter 35
Denotes a low-pass filter, which is configured by an RC circuit that removes fluctuations in the AC signal of the phase detector 36. The input to the loop filter 35 is a DC error signal having an AC ripple, which controls the dual TXVCO 34. A phase-locked loop circuit is configured to control the dual TXVCO 34.

By this operation, a high level signal is output as a transmission carrier from the dual TXVCO 34, and a desired output level signal of the GSM or DCS1800 standard is output by the dual HPA 33 which is a high output power amplifier.
A transmission signal of the band is output at a desired level from the antenna 31 via the antenna switch 32. In each case, the dual TXVCO 34, the dual HPA 33, and the antenna switch 32 are all switched to the GSM standard band by the MPU and DSP 48 by the band switching signal line 50 in the case of the GSM standard, for example.

During the series of transmission operations, the power supply V
The temperature is detected by the ss 42 and the thermistor 43 that detects the temperature, and the temperature information is A / D converted by the A / D converter 44 in the codec unit 47. Further, the transmission channel and the power supply voltage can be known by the MPU and the DSP 48. Based on these information, the corresponding correction value is MP
U and the DSP 48 read out from the memory unit 49, and at the same time, the standard control value is read out from the memory unit 49, and
This is performed by the PU and the DSP 48, and the calculated control value is obtained. The calculated control value is D / A converted by the D / A converter 46, and the dual HPA 33 is controlled by the output analog signal, so that the transmission output is controlled to be constant, and at the same time, accurate ramping characteristics (Ramping) and excessive Characteristics (Transient) can be obtained.

FIG. 8 shows the present invention in GSM and DCS18.
Although the present invention is applied to the dual band mobile radio communication device of No. 00, the present invention can be widely used not only for other mobile radio communication devices but also for fixed use normal radio communication devices.

[0020]

As described above in detail, according to the transmission output control circuit of the wireless communication device of the present invention, the circuit configuration is simple, the number of parts and cost are advantageous, and the board mounting area is small. , The size of the wireless communication device can be further reduced, and the number of components can be reduced, so that variations among components can be suppressed, and reliability can be improved.
In addition, design becomes easy.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an embodiment of a transmission output control circuit of a wireless communication device according to the present invention.

FIG. 2 is a diagram specifically showing a standard control value in the present invention.

FIG. 3 is a diagram specifically showing a Vss correction value in the present invention.

FIG. 4 is a diagram specifically showing channel correction values in the present invention.

FIG. 5 is a diagram specifically showing a temperature correction value in the present invention.

FIG. 6 is a diagram specifically showing a calculated control value in the present invention.

FIG. 7 is a circuit diagram showing another embodiment of the transmission output control circuit of the wireless communication device according to the present invention.

FIG. 8 is a circuit diagram showing a GSM and DCS1800 dual band mobile wireless communication device employing the transmission output control circuit of the present invention.

FIG. 9 is a circuit diagram showing a transmission output control circuit of a conventional wireless communication device.

[Explanation of symbols]

 Reference Signs List 21 High output power amplifier 22 D / A converter 23 Memory

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5J090 AA04 AA41 AA51 CA02 CA04 CA58 CA98 CN01 CN04 DN02 FA12 FA18 FN07 FN09 HA01 HA38 HN08 HN16 HN23 KA34 KA41 KA53 KA55 KA68 MA20 SA14 TA01 5K060 BB07 DD04 HH31 HH32

Claims (5)

[Claims] A means for storing a standard control value corresponding to a reference value of an operation state of the wireless communication device; a means for storing a correction value corresponding to a change in the operation state; Means for reading a correction value, performing an operation with the standard control value, and determining a control value of the transmission output, the transmission output control circuit of the wireless communication device. 2. A transmission output of a wireless communication device can be switched to a plurality of outputs, a standard control value and a correction value are stored for each output, and a control value of the transmission output is determined by performing an operation. The transmission output control circuit for a wireless communication device according to claim 1. 3. The wireless communication device corresponds to a plurality of bands, stores a standard control value and a correction value corresponding to each band, and performs a calculation to determine a control value of a transmission output. A transmission output control circuit for a wireless communication device according to claim 1. 4. The transmission output control of a wireless communication device according to claim 1, wherein the operation state of the wireless communication device is at least one of a power supply voltage, a transmission channel, and a temperature. circuit. 5. The apparatus according to claim 1, wherein the determined control value of the transmission output is D / A converted, and the amplification factor of the amplifier is controlled by the D / A conversion output. Transmission output control circuit of the wireless communication device.