JP2008187550A - Level control apparatus and method thereof, and transmitter using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten the time until a desired transmission analog output is provided when a digital signal generating unit of which an output amplitude has been changed is connected to a digital signal generating unit optimized to the desired transmission analog output in a transmitter. <P>SOLUTION: In a transmitter which is configured to transmit a digital signal S1 to be transmitted while converting the digital signal into an analog signal and amplifying it and in which an amplitude value of the digital signal is optimized to a desired transmission analog output by an ALC control function, when a digital signal generating unit 1 is changed and the amplitude value S1 of the digital signal is changed, first of all, an arithmetic unit 2 performs rough adjustment by adding a differential before and after the change of the amplitude value of the digital signal to a changed amplitude value. Next, a comparative control unit 18 and a gain correction unit 3 perform ALC control on a digital signal S2 after the addition for fine adjustment. Thus, the time for the ALC control is shortened. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a level control apparatus and method, and a transmission apparatus using the level control apparatus, and more particularly to a level control method in a transmission apparatus that performs analog conversion and transmits a digital signal to be transmitted.

  The gain control of the transmission output correction method in the transmission apparatus having the conventional level control function will be described with reference to the block diagram of FIG. The conventional transmission apparatus includes a digital signal generation unit 1 that generates a digital signal S1 to be transmitted, a digital analog (D / A) conversion unit 4 to which the digital signal S1 is input, and the D / A conversion unit 4. The transmission amplifying unit 5 to which the analog signal is input, the detection unit 14 for converting the transmission analog signal into a voltage, and the analog digital (A / D) that converts the feedback analog signal S3 into the feedback digital signal S8 and inputs it to the comparison control unit 18 ) The conversion unit 16, the comparison control unit 18 that compares and controls the transmission digital signal S 1 and the feedback digital signal S 8, and the transmission control information S 6 that is the comparison result are converted into analog signals, and the variable attenuator 8 of the transmission amplification unit 5 is converted. And a D / A converter 17 for controlling the amount of attenuation.

  The transmission amplifier 5 includes a frequency converter 6 to which an analog signal from the D / A converter 4 is input, a band pass filter (BPF) 7 that receives the frequency conversion output, and a variable that receives the BPF output. The attenuator 8 includes an amplifying unit 9 that amplifies a transmission analog signal that is a variable attenuation output, and a distribution unit 10 that distributes the amplified transmission analog signal to a feedback analog signal S3 and an antenna supply signal.

  In such a configuration, the transmission digital signal S1 and the feedback digital signal S8 are compared by the comparison control unit 18, and the attenuation amount of the variable attenuator 8 is controlled according to the comparison result, so that a preset transmission analog signal is obtained. ALC control (Auto Level Control) is performed so as to achieve a level.

  Thus, the transmission apparatus generally has an ALC control function so that the transmission analog output becomes constant. This ALC control function is optimized so that the gain relationship from the amplitude value of the transmission digital signal S1 that is the output of the digital signal generation unit 1 to the transmission analog output of the transmission amplification unit 5 is fixed. It has become.

As related conventional examples, there are Patent Documents 1 to 3.
JP 2000-183851 A JP 2002-094394 A JP-A-9-027723

  In the prior art shown in FIG. 4, when the amplitude of the digital signal generator is changed with respect to the digital signal generator 1 optimized for a desired transmission analog output, for example, the digital signal generator When the specification is changed and the amplitude value of the transmission digital signal S1 becomes small, the gain control of the difference in the amplitude of the transmission digital signal is performed by the transmission amplifier 5 by ALC.

  However, as the ALC function, when the gain difference is multiplied by a coefficient and gain control is performed in stages, as the difference increases, the desired transmission analog output is reached as shown in FIG. There is a problem that time t is required until the time t. In FIG. 5, the ALC control amount is shown as β, and the case where eight-level control is performed is shown.

  The reason why the gain control is performed step by step is to prevent deterioration of the distortion component. That is, in this apparatus, distortion compensation control is performed in addition to ALC control. This is because distortion occurs in a configuration in which a signal is transmitted while being amplified, and it is necessary to cancel the distortion. At this time, if the input signal to the amplifying unit changes abruptly, distortion more than distortion compensation occurs and the transmission characteristic deteriorates for a certain period, so gain control is performed in stages.

  In the prior art of FIG. 4, the ALC function is realized by the analog signal portion using the variable attenuator 8 and the D / A converter 17 of the transmission amplifying unit 5. There is a disadvantage that adjustment is complicated.

  Note that all of the techniques disclosed in Patent Documents 1 to 3 have this digital signal generation for the digital signal generation unit 1 that has a specification change in the digital signal generation unit and is optimized for a desired transmission analog output. No consideration is given to the case where the amplitude of the part is changed.

  The object of the present invention is to connect a digital signal generator whose output amplitude is changed to a digital signal generator optimized for a desired transmission analog output until the desired transmission analog output is obtained. It is an object to provide a level control device and method, and a transmission device using the same, which can reduce time and analog components.

  The level control apparatus according to the present invention is configured to transmit a digital signal to be transmitted while converting it into an analog signal, and the amplitude value of the digital signal is optimized to a desired transmission analog output by an automatic level control function. A level control device in the transmission device, the addition / subtraction means for adding / subtracting the difference before and after the change of the amplitude value of the digital signal to the amplitude value after the change when the amplitude value of the digital signal is changed; Automatic level control means for performing the automatic level control on the digital signal after addition / subtraction.

  A transmission apparatus according to the present invention uses the above-described level control apparatus.

  The level control method according to the present invention is configured so that a digital signal to be transmitted is analog-converted and transmitted while being amplified, and the amplitude value of the digital signal is optimized to a desired transmission analog output by an automatic level control function. A level control method in the transmission device, wherein when the amplitude value of the digital signal is changed, an addition / subtraction step of adding / subtracting a difference before and after the change of the amplitude value of the digital signal to the amplitude value after the change, And an automatic level control step for performing the automatic level control on the digital signal after addition / subtraction.

  According to the present invention, even when a digital signal generation unit whose output amplitude is changed is connected to a digital signal generation unit optimized for a desired transmission analog output, the transmission digital signal is corrected. Thus, there is an effect that the time until the desired transmission analog output is obtained by the ALC function can be shortened. Also, by realizing the ALC function with digital signals, there is an effect that analog parts can be reduced.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of an embodiment of the present invention, and the same parts as those in FIG. 4 are denoted by the same reference numerals. The embodiment of the present invention includes a digital signal generation unit 1 that outputs a transmission digital signal S1, a calculation unit 2 that receives the transmission digital signal S1, and a transmission control information S6 of the comparison control unit 18 that receives the calculation output S2. , The gain correction unit 3 that corrects the gain of the transmission amplification unit 5, the D / A conversion unit 4 that receives the output of the gain correction unit, and the transmission amplification that uses the D / A conversion output as an input 5, a detection unit 14 for detecting the feedback analog signal S 3 that is a demultiplexed output of the transmission amplification unit 5, an A / D conversion unit 16 that performs a digital conversion on the detection output, and a feedback digital that is the output of the digital conversion A comparison control unit 18 that compares the signal S8 and the calculation output S2 of the calculation unit 2 is included.

  The transmission amplifying unit 5 amplifies the frequency converting unit 6 to which the analog signal from the D / A converting unit 4 is input, the BPF 7 having the frequency converted output as an input, and the amplifying unit 9 having the BPF output as an input. The distribution unit 10 distributes the transmission analog signal to the feedback analog signal S3 and the antenna supply signal.

  FIG. 2 is a block diagram of a specific example of the comparison control unit 18 in FIG. A delay unit 181 that accumulates the input transmission digital signal S2, and an average processing unit 182 that accumulates and averages the transmission digital signal S2 from the delay unit 181 and outputs an average transmission power data S31; An average processing unit 183 that accumulates and averages the feedback digital signal S8 to be averaged and outputs the averaged transmission power data S32, and the average transmission power data S31 that is synchronized with the timing by being delayed by the delay unit 181. The comparator 184 that compares the transmission power data S32 and the transmission gain information S33 output from the comparator 184 are input, and the transmission reference gain set individually for the transmission amplifier 5 in advance in the transmission reference gain information memory unit 187 The comparison control unit 18 is composed of an arithmetic unit 185 that calculates and outputs transmission control information S6 that is a difference from the information S35. There.

  The operation of the embodiment of the present invention shown in FIGS. 1 and 2 will be described below. In the case of a transmission digital signal whose amplitude is changed to be small with respect to a digital signal generation unit optimized for a desired transmission analog output, the transmission digital signal S1 output from the digital signal generation unit 1 is calculated by the calculation unit 2 The correction information of the amplitude value for the transmission digital signal S1 stored in advance is added by the calculation unit 2 and output as the transmission digital signal S2.

  The transmission digital signal S2 is subjected to correction of the gain change of the transmission amplification unit 5 by the gain correction unit 3, and is output to an antenna (not shown) via the D / A conversion unit 4 and the transmission amplification unit 5. The feedback analog signal S3 distributed by the distribution unit 10 is input to the comparison control unit 18 as the feedback digital signal S8 via the detection unit 14 and the A / D conversion unit 16. The comparison control unit 18 calculates the gain correction value of the transmission amplifier 5, and the gain correction unit 3 adds the correction value to the amplitude value of the transmission digital output S2.

  Both the transmission digital signal S2 and the feedback digital signal S8 are input to the comparison control unit 18, and the transmission digital signal S2 is accumulated in the delay unit 181 and output from the average processing unit 182 as average transmission power data S31. Similarly, the input feedback digital signal S8 is output from the average processing unit 183 as average transmission power data S32. The average transmission power data S31 and the average transmission power data S32 are input to the comparator 184.

  The average transmission power data S31 is corrected by the delay unit 181 until the amount of delay until the average transmission power data S31 is output from the calculation unit 2 and fed back is synchronized with the input of the average transmission power data S32. The amplitudes of the digital signals of the average transmission power data S31 and the average transmission power data S32 are converted into transmission power levels according to a certain standard, compared by the comparator 184, and transmission gain information S33 is output. In the arithmetic unit 185, the transmission gain information S33 is compared with the transmission reference gain information S35 set in advance in the transmission reference gain memory unit 187 for each transmission amplifier 5, and the transmission control information S6 obtained by correcting the gain difference is gain corrected. Is output to the unit 3.

  In this way, in the case of a transmission digital signal whose amplitude is changed to be small with respect to the digital signal generation unit optimized for a desired transmission analog output, first, the transmission digital signal stored in advance in the calculation unit 2 By performing coarse adjustment by adding the amplitude difference of S1, the amplitude difference of the transmission digital signal S2 with respect to the transmission digital signal S1 to obtain a desired transmission transmission analog output is reduced.

  Then, by performing the fine adjustment by correcting the amplitude value of the transmission digital signal S2 by the ALC function by the comparison control unit 18, the characteristics as shown in FIG. 3 can be achieved, and the ALC control is speeded up. it can. Even if the ALC control is stepwise as described above, the correction range is reduced by the coarse adjustment in the previous step of the ALC, so that the gain control time that the ALC performs stepwise is greatly reduced. Can do it.

  In addition, since the ALC function is realized by correcting the amplitude value of the transmission digital signal, analog parts for the ALC function can be reduced.

  In the above-described embodiment, the case of the transmission digital signal whose amplitude is changed to be small with respect to the digital signal generation unit optimized for the desired transmission analog output is described. In the case of a transmission digital signal whose amplitude is greatly changed with respect to the digital signal generation unit optimized for output, the transmission digital signal S1 output from the digital signal generation unit 1 is stored in advance in the arithmetic unit 2. It is clear that the correction information of the amplitude value for the transmission digital signal S1 is subtracted by the calculation unit 2 and the transmission digital signal S2 is output.

It is a functional block diagram of the Example of this invention. It is a block diagram which shows the specific example of the comparison control part 18 of FIG. It is a figure which shows the effect of this invention. It is a functional block diagram which shows a prior art. It is a figure for demonstrating the characteristic of a prior art.

Explanation of symbols

1 Digital signal generator
2 Calculation unit
3 Gain correction section
4 D / A converter
5 Transmission amplifier
6 Frequency converter
7 BPF
9 Amplification unit
10 Distribution Department
14 detector
16 A / D converter
18 Comparison control unit
181 Delay unit 182, 183 Average processing unit
184 comparator
185 calculator
187 Transmission reference gain memory section

Claims (5)

This is a level control device in a transmission device that is configured to convert a digital signal to be transmitted after analog conversion and to amplify it, and to optimize the amplitude value of the digital signal to a desired transmission analog output by an automatic level control function. And
When the amplitude value of the digital signal is changed, correction means for adding or subtracting the difference before and after the change of the amplitude value of the digital signal to the changed amplitude value;
Automatic level control means for performing the automatic level control on the digital signal after addition and subtraction,
A level control device comprising:   The automatic level control means compares the feedback digital signal corresponding to the level of the transmission analog output with the output of the addition means so that the level of the transmission analog output becomes a predetermined value, so that the digital signal after the addition 2. The level control apparatus according to claim 1, wherein automatic level control is performed.   A transmission apparatus comprising the level control apparatus according to claim 1. This is a level control method in a transmission apparatus that is configured to convert a digital signal to be transmitted after being converted into an analog signal and amplify the signal, and to optimize the amplitude value of the digital signal to a desired transmission analog output by an automatic level control function. And
When the amplitude value of the digital signal is changed, an addition / subtraction step of adding / subtracting the difference before and after the change of the amplitude value of the digital signal to the changed amplitude value;
An automatic level control step for performing the automatic level control on the digital signal after addition / subtraction,
A level control method comprising:   The automatic level control step compares the feedback digital signal according to the level of the transmission analog output with the output of the addition / subtraction step so that the level of the transmission analog output becomes a predetermined value, so that the digital signal after the addition 5. The level control method according to claim 4, wherein automatic level control is performed.

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