JP4599313B2 - Transmission power control circuit and transmission power control method - Google Patents

Description

  The present invention relates to a transmission power control circuit and a transmission power control method, and more particularly, to a transmission power control circuit and a control method thereof that improve start-up performance until reaching a target transmission power value.

  The transmitter of the wireless communication device is configured to be accurately controlled so that the transmission power value does not deviate from the specified range. In addition, mobile radio communication devices are configured to be used by switching the transmission power value to several values or used in multi-access mobile radio communication systems. The transmission power of the mobile radio communication device is controlled so that the electric field levels of the plurality of radio signals transmitted to the base station and the relay station are substantially constant regardless of the separation distance between the base station and the mobile radio communication device. Some of them are also configured. Under such circumstances, the wireless transmitter is provided with an automatic power control (APC) circuit as a transmission power control circuit for switching the transmission power or keeping the target power value constant.

As means related to the APC circuit, for example, Patent Document 1, Patent Document 2, and Patent Document 3 by the same applicant are known. As shown in FIG. 7, the APC circuits disclosed therein extract a part of the output of the transmission power amplifier 50 by a directional coupler 51 and extract the high-frequency signal from a diode 52, a capacitor 53, a resistor 54, and the like. The signal is converted into a DC signal by a detection circuit (smoothing circuit), and this DC signal is supplied to one input terminal of the comparator 55, and a reference signal Vref for transmission power setting output from the control circuit 56 is supplied to the comparator 55. The output power value of the transmission power amplifier 50 is controlled by a control signal Vcont that is supplied to the other input terminal and output from the comparator 55. As described above, when the transmission power is switched to several values and used, the value of the reference signal supplied from the control circuit 56 of FIG. 7 to the comparator 55 is set to each target transmission power value. It is possible to set a desired transmission power value by changing it correspondingly, and it is also possible to use it as an APC circuit having both a transmission power setting function and an automatic power control function.
As a method of controlling the output of the transmission power amplifier, the input signal level of the transmission power amplifier is controlled by a variable gain amplifier or an attenuator, or the power supply voltage value or power supply current value supplied to the transmission power amplifier is controlled. Various methods are known, such as a method to do.
Japanese Patent Laid-Open No. 10-173454 JP 2002-76950 A JP 2001-339318 A

  However, in the conventional transmission power control circuit and control method, the time required to reach the set target power value, that is, the Ramp Up (rise) time may vary depending on the magnitude of the transmission power setting value. In general, it is known that the larger the set transmission power value, the shorter the rise time and the longer the rise time as the set transmission power value decreases. FIG. 8 illustrates this state, in which FIG. 8A is an example of a control signal voltage waveform when the transmission power is 5 W, and FIG. 8B is a diagram illustrating a state of rising of the output of the power amplifier. FIG. 4C is an example of a control signal voltage waveform when the transmission power is 0.5 W, and FIG. 4D is a diagram showing the rise of the output of the power amplifier at that time. As described above, the rise time varies depending on the set transmission power value depending on the circuit method. However, when the high-frequency signal level branched from the directional coupler 51 is reduced, the order of the diodes in the detection circuit is reduced. As a result of the reduction in detection efficiency in relation to the direction potential (0.7 V), the rise of the signal supplied to the comparison circuit 55 as the detection circuit output can be considered as one cause, and the setting can be made. As shown in FIGS. 2B and 2D, the activation time differs depending on the transmission power value.

In this way, if a difference occurs in the rise time of the APC circuit due to the magnitude of the set transmission power value, a prompt call will be hindered. Therefore, an APC circuit having a uniform and quick rise performance as much as possible. Realization of is desirable.
The present invention has been made in view of such problems of the conventional APC circuit, and is activated so that the rise of the APC circuit is quick and uniform regardless of the magnitude of the transmission power value to be set. An object of the present invention is to provide a transmission power control circuit with improved performance and a control method thereof.

  In order to solve such a problem, the present invention provides a transmission power control circuit according to claim 1, wherein a coupling means for branching a part of a transmission output signal of a transmitter or the like and detection for smoothing the branched high-frequency signal into a DC signal. Means, comparing means for comparing the detected DC signal with a reference signal and generating a signal corresponding to the difference, and control means for supplying a reference signal for setting the transmission output value to a target value to the comparison means In the transmission power control circuit, the reference signal is set as a plurality of values whose reference values at the time of transmission activation change in time series, and the reference value at the initial stage of activation corresponds to a target power value It is characterized in that it includes a reference value for a larger power value, is set so as to gradually decrease with time and finally become a reference value for a target power value.

According to a second aspect of the present invention, in the transmission power control circuit according to the first aspect, the reference signal is provided for each of a plurality of transmission power setting values, and each reference value is the transmission power setting value. It is characterized in that it is set in such a manner that the power value changes in time series according to the above and finally becomes a target power value.
According to a third aspect of the present invention, in the transmission power control circuit according to the first or second aspect, a reference signal time table for at least two transmission power setting values is provided for the plurality of transmission power setting values. A means for generating a reference signal for a transmission power set value based on the two reference signal time tables is provided.
According to a fourth aspect of the present invention, in the transmission power control apparatus according to the first to third aspects of the present invention, the time-series change width of the reference signal is set to be small so that spurious components generated when the transmission signal rises are reduced. It is characterized by that.

  The invention according to claim 5 relates to a method invention, wherein a coupling means for branching a part of a transmission output signal of a transmitter, a detection means for smoothing a branched high-frequency signal into a DC signal, and a detected DC signal Comparing means for generating a signal corresponding to a difference between the reference signal and a reference signal, and control means for supplying a reference signal for setting a transmission output value to the comparing means, wherein the reference signal includes a plurality of transmission signals. Each reference value is provided in correspondence with the power setting value, and each reference value at the time of transmission activation is set as a plurality of values that change in time series, and the initial reference value for activation corresponds to the target power value In a method for controlling a transmission power control circuit that includes a reference value for a power value larger than that, decreases sequentially as time elapses, and finally becomes a reference value for each target power value , Send Sometimes determining a set transmission output value; identifying the reference signal data corresponding to the determined transmission output value; sequentially reading data corresponding to the identified reference signal; and a read reference A step of converting the signal data into an analog signal, a step of supplying the converted analog signal to the comparator, and a power value targeted for a transmission power value when it is determined that the data of the reference signal is a final value. And a step of ending the transmission activation process.

  The transmission power control method according to claim 6, wherein the transmission power control method according to claim 5 includes reference signal data for at least two transmission power setting values for the plurality of transmission power setting values, and other transmission power settings. Generating reference signal data for the value based on the two reference signal data.

  Since the present invention is configured as described above, the following effects can be obtained. That is, the invention according to claim 1 compares the coupling means for branching a part of the transmission output signal of the transmitter, the detection means for smoothing the branched high-frequency signal into a DC signal, and comparing the detected DC signal with the reference signal. A transmission power control circuit comprising: comparison means for generating a signal corresponding to the difference between the control means; and a control means for supplying a reference signal for setting a transmission output value to the comparison means. The reference value at startup is set as multiple values that change in time series, and the initial value includes a reference value for a power value that is larger than that for the target power value, and decreases sequentially as time passes However, since the reference value for the target power value is finally set, even when the set power is small, a large reference signal for transmission power setting is set at the beginning of the rise. As in the case of the power value, a quick rise characteristic can be obtained.

According to a second aspect of the present invention, the reference signal is provided corresponding to each of a plurality of transmission power setting values, and each of the reference values changes in time series according to the transmission power setting value. Therefore, in a transmitter that is operated by switching to a plurality of transmission power values, it has substantially the same rapid rise characteristics for all transmission power setting values, and the same effect as the invention of claim 1 is obtained. be able to.
According to a third aspect of the present invention, a reference signal time table for at least two transmission power setting values is provided for the plurality of transmission power setting values, and reference signals for other transmission power setting values are used as the two reference signal times. Since the means for generating based on the table is provided, in the transmitter having a large number of set power values, the memory capacity can be reduced, and the address processing and the like can be reduced, so that the effect of reducing the processing amount can be expected.

According to the fourth aspect of the present invention, the change width of the time-series value of the reference signal is set to be small so that the spurious component generated at the rising edge of the transmission signal is reduced. This is effective in reducing transmission power loss.
The inventions according to claims 5 and 6 relate to a method, and since the transmission power control circuit according to claims 1 to 3 is used as a processing procedure, if the process is realized, it is the same as the apparatus according to claims 1 to 3. Can achieve the same effect.

  Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. However, the components, types, combinations, shapes, relative arrangements, and the like described in this embodiment are merely illustrative examples and not intended to limit the scope of the present invention only unless otherwise specified. .

  FIG. 1 is a block diagram showing an embodiment of a transmission power control circuit of the present invention. In FIG. 1, reference numeral 1 denotes a transmission power amplifier to be controlled. In this example, it is assumed that transmission can be performed by switching to four target powers of 5 W, 3 W, 1 W, and 0.5 W. The APC circuit (transmission power control circuit) 10 according to the present invention for controlling the transmission power of the transmission power amplifier 1 includes a coupling unit (coupling unit) 2 for branching a part of the transmission output signal of the transmission power amplifier 1, and A detection unit (detection unit) 3 that smoothes the branched high-frequency signal into a DC signal, a comparison unit (comparison unit) 4 that compares the detected DC signal with a reference signal and generates a signal corresponding to the difference, and target transmission A control unit (control means) 5 for supplying a reference signal for setting an output value to the comparison unit 4 and a memory 6 attached to the control 5 are provided. The memory 6 stores reference signal data to be supplied to the comparison unit 4, and four memory areas of the memory 6 correspond to four transmission power setting values as reference value signal data for 5 W. A memory 6-1, a memory 6-2 for 3W, a memory 6-3 for 1W, and a memory 6-4 for 0.5W are provided. The reference signal data in these memory areas is selectively switched by controlling the changeover switch 7 with the control unit 5 and supplied to the comparison unit 4. The output signal (control signal) of the comparison unit 4 is supplied. : Vcont) controls the transmission power value of the transmission power amplifier 1. When the reference signal output from the control unit 5 is obtained as a digital signal, it is converted into an analog signal and supplied to the comparison unit 4. However, if the comparison unit 4 is a digital processing circuit, it may be a digital signal, but it is necessary to generate the control signal Vcont in such a form that the transmission power amplifier 1 can be controlled.

  FIG. 2 is a diagram showing an example of reference signal data stored in the memory 6, where (a) is for transmission power 5 W, (b) is for transmission power 3 W, (c) is for 1 W, ( d) shows the value for 0.5 W, the upper part t of the table shows the time-series order, and the lower part shows the reference signal data value, which is expressed in hexadecimal in this example. Hexadecimal notation is already well known, but the correspondence with decimal notation is the same from 0 to 9, but 10 is A, 11 is B, 12 is C, 13 is D, 14 Is expressed as E, 15 is expressed as F, and beyond that, 16 is expressed as 10, 17 is expressed as 11,. For example, in decimal notation, FF is 255, FE is 254, FD is 253, FB is 251, F9 is 249,.

  A feature of the present invention is that, as a reference signal supplied to the comparison unit 4 at the time of startup when starting up the transmitter, a plurality of values that change in time series are set, and the reference value at the start-up is the target power A reference value corresponding to a power setting value larger than that for the value is set so as to sequentially decrease as time elapses and finally become a reference value for the target power value. The time t is preferably sampled finely at the highest possible frequency.

  Specifically, the contents of each reference signal data in FIG. 2 will be described. (A) is reference signal data for a transmission output of 5 W, and the reference signal value for finally setting the transmission power of 5 W is FF (decimal system). 255), since 5 W is the maximum output of this transmitter, in this case, all values that change in time series are set to FF. (B) is reference signal data for 3 W. In this case, the first reference signal data value at the rising edge is set to FF corresponding to a reference value of 5 W larger than 3 W, and thereafter, FE, FD,. It is reduced to 9C for Max-2, 9B for Max-1, and 9A indicating the target value for the final value Max. This 9A is a value for obtaining a transmission output of 3W. Similarly, for 1 W transmission output, as shown in (c), the initial value starts with FF which is the reference value of the maximum power value, and finally becomes 37, 35, 33. A value 33 is a value for obtaining a transmission power of 1 W. Similarly, for the minimum value of 0.5 W, as shown in (d), the value starts with FF and finally ends with Max 25 at a transmission power of 0.5 W.

  As described above, when a reference signal value indicating a large transmission power value is set as the initial value with the passage of time and the reference signal is changed to the reference value of the target value with the passage of time, the output corresponding to each reference signal is output. As a result, the entire control system operates so that the instantaneous operation at the start of transmission is driven to generate an output larger than the final set power, resulting in an increase in the ramp-up speed. It becomes possible. In addition, as an example in the case of controlling transmission power with the control voltage Vcont generated in the comparison unit 4, for example, the circuit shown in FIG. FIG. 3 includes a differential amplifier including transistors Q1 and Q2 as the comparison unit 4, and a voltage difference between two signals of the signal from the detection unit 3 and the reference signal for setting transmission power supplied from the control unit 5 The collector current of the transistor Q1 is controlled so that becomes zero, the collector-emitter current of the transistor Q3 is controlled by the current, and the power supply voltage Vamp supplied to the preamplifier 8 of the transmitter changes, resulting in Thus, the level of the high-frequency signal input to the transmission power amplifier 1 is controlled, and the transmission power finally changes. In this example, the voltage control method is shown. However, since there are a current control method, a method of controlling an attenuator for adjusting the level of the high-frequency signal, etc., it can be used for designing as appropriate. The control unit 4 is supplied with a transmission power value switching, a transmission activation signal, and the like by a signal from a main control unit of a wireless communication device (not shown).

  FIG. 4 is a diagram for explaining the situation at the time of start-up of the transmitter including the transmission power control circuit configured as described above, where (a) is 5 W, (b) 3 W, (c) is 1 W, (d ) Is for 0.5W. As shown in FIG. 2, since all the reference signal data set to 5W are arranged with FF and the maximum value, there is no difference from the conventional control method. Therefore, the control system reacts so that the transmission power instantaneously becomes 5 W transmission power, the control signal Vcont becomes the same as that of 5 W, and then the reference signal data value decreases. The reference voltage becomes a control voltage corresponding to the target power value to be finally set when each reference signal data value becomes t = Max when the reference signal data value becomes t = Max. Secure to. If the control is performed based on the control voltage Vcont set in this way, the transmission power Po for each set value exhibits a rising characteristic at substantially the same time timing as shown in the right diagram of FIG. In addition, although these figures have shown the ideal state typically for outline | summary description, it becomes a complicated waveform with a transient phenomenon actually.

FIG. 5 is a flowchart showing a control example of the transmission power control circuit according to the present invention configured as described above.
In the figure, when the flow starts, the set transmission power value is determined. In this example, it is first determined whether it is 5 W. If the setting is 5 W (S 1 Yes), the reference signal data corresponding to 5 W of the memory 6 is read from the memory area 6-1 and t = 0. Data is extracted (S2). Since the extracted data is a digital signal, it is converted into an analog signal (S3), and the converted signal is supplied to the comparison unit 4. Next, the time parameter t is incremented to +1 (S4), and it is determined whether the value is t = Max indicating the final value shown in FIG. 2 (S5). Returning to S3 (S5 No), data corresponding to the time is taken out, and then converted into an analog signal by a digital / analog converter (D / A) (not shown). By repeating the above steps S3 to S5, the reference signal data shown in FIG. 2 is converted into an analog signal while being sequentially read and supplied to the comparison unit 4. In S5, when the time parameter is the final value t = Max, the data corresponding to the target 5W is read out, converted to analog, supplied to the comparison unit 4, and the flow ends.

When the set value in S1 is not 5 W (No in S1), it is sequentially determined what the set value is, but in this example, the flow is determined in descending order of the power value. That is, the determination is made in the order of 3 W, 1 W, and 0.5 W, but the flow at each set value is almost the same as the float at the time of setting 5 W, and thus the description is omitted. If all of the instructed set values are different from preset values (No in S1-3), an error display is performed (S7). As described above, the transmission power control method of the present invention corresponds to the coupling means for branching a part of the transmission output signal of the transmitter, the detection means for smoothing to a DC signal, and the difference between the DC signal and the reference signal. As a control method of a transmission power control circuit comprising a comparison means for generating a signal and a control means for setting a transmission output level, a step of determining a set transmission output knowledge at the time of transmission activation, and a determined transmission output value The step of specifying the reference signal data corresponding to the step, the step of reading the data and converting it to an analog signal, and supplying the converted analog signal to the comparator to control the output of the transmission power amplifier to be controlled And the same processing is repeated until the reference signal data reaches the final value, and when it is determined that the reference data is final data, the transmission power value is set as a target. It is intended to include the step of terminating the transmission startup process by the force value.
Since the present invention is configured and controlled in this way, it is possible to quickly raise the transmission output almost the same regardless of the magnitude of the transmission power setting value.

FIG. 6 is a diagram showing a modification of the present invention, and suggests several modifications.
That is, the first modification is a method of preparing reference signal data for setting a larger transmission power for a maximum power setting value of 5 W, as shown in FIG. According to this, it becomes possible to expect a quicker rise even for the setting of 5 W. Furthermore, for other setting values, if a large setting reference signal data is arranged at the start point, the setting can be made quickly as well. May improve the performance. Since these effects differ depending on the circuit configuration used, etc., it is preferable to appropriately set the characteristics in consideration of the circuit characteristics.
In the second modification, the reference signal data value is set so that the rising characteristic of the control signal Vcont has a slight slope, as shown in FIG. According to this method, it is possible to obtain an effect of reducing the spurious of the high-frequency signal generated due to the steepness when the transmission power rises. The spurious reduction method at the time of starting up the transmitter is described in Japanese Patent Application Laid-Open No. 2002-76950 by the same applicant, so that it is useful to use it together with the present invention. It would also be possible to achieve this.

The third modification includes a reference signal time table for two or more transmission power setting values for a plurality of transmission power setting values, and the reference signals for other transmission power setting values are the two or more reference signals. It comprises so that the means to produce | generate based on a time table may be provided. According to this method, as shown in FIGS. 6A to 6E, it is possible to generate complementary data from two or more prepared data even for values for which reference signal data is not prepared in advance. is there. In that case, it is sufficient to prepare such a generation program in the control unit, and when the transmission power setting value is large, a memory saving effect and a processing amount reduction effect can be obtained.
In the fourth modification, the configuration of the coupling unit 2 may be a configuration in which a part of transmission power is simply branched by a small-capacitance capacitor in addition to a directional coupler using a microstrip line or the like.

  The present invention is not limited to the above-described embodiments, and various modifications can be made. Furthermore, each function / method for realizing the transmission power control circuit of the above-described embodiment and the above-described transmission power control method are each programmed and installed in a computer if written in a recording medium such as a CD-ROM in advance. The object of the present invention can be achieved by mounting the CD-ROM or the like on a medium driving device such as a CD-ROM drive and executing these programs.

It is a block diagram which shows the transmission power control circuit which concerns on one Embodiment of this invention. 5A and 5B are diagrams illustrating examples of reference signal data used in the present invention, where FIG. 5A is a diagram illustrating reference signal data for 5 W setting, FIG. 5B is a diagram illustrating reference signal data for 3 W setting, and FIG. The figure which shows reference signal data, (d) is a figure which shows the 0.5W setting reference signal data. It is a principal part block diagram which concerns on one Embodiment of the transmission power control circuit of this invention. 5A and 5B are diagrams illustrating a power control status in an embodiment of the present invention, where FIG. 5A is a diagram illustrating a setting time of 5 W, FIG. 5B is a diagram illustrating a setting time of 3 W, and FIG. ) Is a diagram showing the situation when 0.5 W is set. It is a flowchart of one Embodiment of the transmission power control method of this invention. It is a figure for demonstrating the modified example of this invention, (a) is a figure which shows the time of setting more than 5W, (b) is a figure which shows the time of setting 5W, (c) is the time of setting 0.5W thru | or 5W. (D) is a figure which shows the time of 0.5W setting, (e) is a figure which shows the condition at the time of setting 0.5W or less. It is a block diagram which shows the structural example of the conventional transmission power control circuit. It is a figure which shows the transmission power rise condition by the conventional transmission power control circuit, (a) is a control signal rising waveform figure at the time of 5W setting, (b) is a rising waveform figure of the transmission signal at the time of 5W setting, (c) is 0 (D) is a rising waveform diagram of a transmission signal when 0.5 W is set.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 50 Transmission power amplifier, 2 coupling | bonding part, 3 detection part, 4 comparison part, 5,56 control part, 6, 6-1 to 6-4 memory, 7 changeover switch, 8 front stage amplifier, 51 directional coupler, 52 diode, 53, C capacitor, 54, R resistor, 55 differential amplifier.

Claims (6)

  Coupling means for branching a part of the transmission output signal; detection means for smoothing the branched high-frequency signal into a DC signal; comparison means for comparing the detected DC signal with a reference signal and generating a signal corresponding to the difference; And a control means for supplying a reference signal for setting a transmission output value to a target value to the comparison means, wherein the reference signal has a reference value in time series when the transmission is activated. The reference value at the start of startup includes a reference value for a power value that is larger than that for the target power value, and is sequentially reduced over time to finally reach the target power value. A transmission power control circuit, which is set to be a reference value for.   The reference signal is provided for each of a plurality of transmission power setting values, each reference value changes in time series according to the transmission power setting value, and finally each target power value The transmission power control circuit according to claim 1, wherein the transmission power control circuit is set so as to be a reference value for.   A means for generating a reference signal for at least two transmission power setting values for the plurality of transmission power setting values, and generating a reference signal for other transmission power setting values based on the two reference signal time tables; The transmission power control circuit according to claim 1, further comprising a transmission power control circuit.   4. The change width of a value that changes in time series of the reference signal is set to be small so that spurious components generated at the rising edge of the transmission signal are reduced. Transmission power control circuit. Coupling means for branching a part of the transmission output signal; detection means for smoothing the branched high-frequency signal into a DC signal; comparison means for comparing the detected DC signal with a reference signal and generating a signal corresponding to the difference; And a control means for supplying a reference signal for setting a transmission output value to the comparison means, wherein the reference signal is provided for each of a plurality of transmission power setting values, and each reference value is transmitted. The starting value is set as multiple values that change in time series, and the initial reference value includes a reference value for a power value larger than that for the target power value, and decreases sequentially over time. In the method of controlling the transmission power control circuit that is finally set to be a reference value for each target power value,
A step of determining a set transmission output value when starting transmission, a step of identifying the reference signal corresponding to the determined transmission output value, a step of sequentially reading data corresponding to the identified reference signal, and a read A step of converting reference signal data into an analog signal, a step of supplying the converted analog signal to the comparator, and a transmission with a target transmission power value when it is determined that the data of the reference signal is a final value A transmission power control method comprising a step of setting a power value and ending transmission start processing.   Including reference signal data for at least two transmission power setting values for the plurality of transmission power setting values, and generating reference signal data for other transmission power setting values based on the two reference signal data The transmission power control method according to claim 5, wherein:

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