KR101043789B1 - Power Detector and Power Detecting Method using Digital Signal Processing, and Recording Media Recording Program for Implementation thereof - Google Patents

Abstract

The present invention provides a power meter capable of accurately measuring power and standing standing wave ratio (VSWR) without changing characteristics due to temperature change by using digital signal processing, a method for measuring the power, and a method for realizing the method. The present invention relates to a computer-readable recording medium for recording a program, which is applied to a base station or a repeater and is a power measuring device using digital signal processing, wherein the received RF (Radio Frequency) signal is converted into an IF (Intermediate Frequency) band. An analog downconverter for downconverting the signal to the first; A digital power measurement unit converting the down-converted IF band analog signal into a digital signal of the IF band and then down-converting to a baseband digital signal to measure the strength of the baseband digital signal; And a power meter controller which calculates power and standing wave ratios of the received signal based on the strength of the baseband digital signal measured by the digital power measurement unit using digital signal processing. The strength of the digital signal is measured using the predetermined control signal such that the product of the baseband digital signal and the predetermined control signal maintains a threshold.

Power Meter, Power Measurement, Digital Signal Processing, Signal Strength Meter, Loop Filter

Description

Power detector and power detection method using digital signal processing, and a computer-readable recording medium recording a program for performing the method and a method for performing the method {Power Detector and Power Detecting Method using Digital Signal Processing, and Recording Media Recording Program for Implementation}

1 is an exemplary configuration of a base station to which a power meter according to the prior art is applied.

2 is a block diagram of a base station to which a digital power meter according to the present invention is applied;

3 is a detailed block diagram of an embodiment of the analog down converter of FIG. 2;

4 is a detailed configuration diagram of an embodiment of the digital power measurement unit of FIG. 2.

FIG. 5 is a detailed block diagram of an embodiment of the signal strength meter of FIG. 4. FIG.

FIG. 6 is a detailed flowchart illustrating a control operation process, a power calculation process, and a frequency analysis process performed in the power meter controller of FIG. 2.

* Explanation of symbols for the main parts of the drawings

110: directional coupler

120, 310, 410: part for measuring standing wave ratio

130, 320, 420: part for measuring received power                 

140: control unit 121, 131, 312, 322: fixed attenuator

122, 316: amplifiers 123, 132: detectors

124, 133, 411, 421: Analog-Digital Converter (ADC)

210: directional coupling means

220: power detector (Power Detector, PD)

221: Analog Down Conversion Module (ADCM)

222: Digital Power Detector Module (DPDM)

223: Power Detector Control Module (PDCM)

230: modem means or display means

311, 313, 321, 323: Band Pass Filter (BPF)

314, 324,: mixer

315, 325: Low Pass Filter (LPF)

330: frequency synthesizer

421, 422: Numercal Controlled Oscillator (NCO)

423 digital filter

413, 424: Signal Strength Indicator (SSI)

510 loop filter 511 integrator

512 loop gain 513, 530 multiplier

520: comparator 521: threshold                 

522: adder

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power meter using digital signal processing (DSP), a method of measuring the power thereof, and a computer readable recording medium having recorded thereon a program for realizing the method. Power meter that can measure power and standing standing wave ratio (VSWR) precisely without changing the characteristic by temperature change, and the power measuring method and the program to realize the method can be read by computer. To a recording medium.

In general, the base station or the relay device of the mobile communication system measures the power of the signal transmitted by the mobile terminal in order to control the power. That is, if the power of the mobile terminal measured at the base station or the relay device is small, more power is required, and if the measured power of the mobile terminal is large, the power is required to be reduced.

In order to control power in the base station or the relay device as described above, the power of the signal transmitted from the mobile terminal must be accurately measured, and this role is a power detector (PD).

1 is an exemplary configuration diagram of a base station to which a power meter according to the prior art is applied. As shown in FIG. 1, the signal transmitted from the mobile terminal is distributed in both directions by the directional coupler 110 between the portion 120 for measuring the standing wave ratio and the portion 130 for measuring the received power.

The portion 120 for measuring the standing wave ratio includes: a fixed attenuator 121 for attenuating the signal strength to an appropriate intensity for signal processing; an amplifier 122 for amplifying the attenuated signal; And a detector 123 for converting power into a voltage and an analog-digital converter 124 for converting the analog signal converted to the voltage into a digital signal.

On the other hand, the portion 130 for measuring the power of the signal includes a fixed attenuator 131 for attenuating the signal strength to an appropriate intensity for signal processing, and a detector 132 for converting the power of the attenuated signal into voltage. And an analog-digital converter 133 for converting the analog signal converted into the voltage into a digital signal.

The signals digitally converted by the analog-digital converters 124 and 133 are input to the controller 140, and the controller 140 calculates power and standing wave ratios of the received signals using the digitally converted signals. This is done.

That is, in the conventional power meter after detecting the signal using the detector (123, 132) implemented as an integrated circuit (IC) without down-converting the radio frequency (RF) signal transmitted through the air to the baseband The power is measured by converting the detected signal into digital.                         

However, since ICs are sensitive to temperature changes, conventional power detectors are also sensitive to temperature changes, and since the step of detecting a signal is performed in an analog manner, the resolution capable of expressing power is lowered to accurately measure power. There is a problem that cannot be done.

SUMMARY OF THE INVENTION The present invention has been proposed to solve the above problems, and a power meter capable of accurately measuring power and standing wave ratio (VSWR) without changing characteristics due to temperature change by using digital signal processing and its power It is an object of the present invention to provide a computer-readable recording medium recording a measuring method and a program for realizing the method.

A power meter according to an embodiment of the present invention for achieving the above object, is applied to a base station or a repeater, in the power meter using digital signal processing (Digital Signal Processing), the received RF (Radio Frequency) signal IF ( An analog downconverter for downconverting to an intermediate frequency band; A digital power measurement unit converting the down-converted IF band analog signal into a digital signal of the IF band and then down-converting to a baseband digital signal to measure the strength of the baseband digital signal; And a power meter controller which calculates power and standing wave ratios of the received signal based on the strength of the baseband digital signal measured by the digital power measurement unit using digital signal processing. The strength of the digital signal is measured using the predetermined control signal such that the product of the baseband digital signal and the predetermined control signal maintains a threshold.

On the other hand, the power measurement method according to an embodiment of the present invention, a method for measuring power in a power meter applied to a base station or a repeater, the method comprising the steps of: down converting the received RF signal into a first analog IF signal; Converting the first analog IF signal into a first digital IF signal and then down converting the first analog IF signal into a first digital baseband signal; Measuring the strength of the first digital baseband signal; Down converting and amplifying the received RF signal into a second analog IF signal; Converting the amplified second analog IF signal to a second digital IF signal and then down converting the second analog IF signal to a second digital baseband signal; Measuring the strength of the second digital baseband signal; And measuring the power of the received signal using the measured strength of the first digital baseband signal, and measuring the standing wave ratio using the measured strength of the second digital baseband signal. The strength of the first digital baseband signal is measured using the first control signal such that a first result of the product of the first digital baseband signal and the first control signal maintains a first threshold value, The first control signal is obtained by multiplying a first loop gain by multiplying a difference between the first result value and the first threshold value, and the strength of the second digital baseband signal is obtained by integrating the second digital baseband signal. A second resultant value of a product of a band signal and a second control signal is measured using the second control signal to maintain a second threshold value, wherein the second control signal is measured using the second resultant value and the second resultant signal. Difference from threshold This value is multiplied by a second loop gain and then integrated.

On the other hand, the present invention provides a computer-readable recording medium recording a program for performing the power measuring method according to an embodiment of the present invention.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram of a base station to which a digital power meter according to the present invention is applied, and a signal transmitted from the mobile terminal is received by the directional combining means 210 and input to the power detecting means 220. The power detection unit 220 is an analog down conversion module (Analog Down Conversion Module, ADCM, 221) for down-converting the input received signal, for converting the down-converted signal to digital and then measuring the power of the signal. A digital power detector module (DPDM) 222 and the power of the measured signal are used to calculate the power and standing wave ratio of the received signal, and the analog downconverter 221 and the digital power measurer 222 It includes a power detector control unit (Power Detector Control Module, PDCM, 223) for generating a control signal required by the. Then, the power measured by the power detecting means 220 is transmitted to the modem means or the display means 230 to be modulated or displayed.

FIG. 3 is a detailed block diagram illustrating an analog downconverter of FIG. 2. FIG. As shown in FIG. 3, the analog down-conversion unit 221 applied to the present invention includes two portions, a portion 310 for measuring the standing wave ratio of the received signal and a portion 320 for measuring the power of the received signal. Are largely distinguished.

First, the portion 310 for measuring the standing wave ratio of the received signal is a signal of a band supported by the power amplifier (hereinafter referred to as 'PA') in the signal received by the directional coupling means 210. Band pass filter (BPF, 311) to remove the signal components excluded, fixed attenuator 312 for attenuating the signal strength to a suitable strength for signal processing, PA in the signal attenuated by the fixed attenuator Mixer for downconverting the RF (Radio Frequency) signal through the bandpass filter 313 and the bandpass filter 313 to remove signal components except the signal of the supporting band into an intermediate frequency (IF) signal 314, Low Pass Filter, LPF, for removing unwanted signal components and noise in bands other than the band of interest in the signal downconverted by mixer 314. 5) and an amplifier 316 for amplifying the signal from which noise or the like has been removed by the low pass filter 315.

On the other hand, the portion 320 for measuring the power of the received signal is a portion for measuring the standing wave ratio of the received signal except that an amplifier for amplifying a signal from which noise or the like is removed by a low pass filter. The configuration is the same as that of 310. In addition, a signal input to the mixers 314 and 324 for downconverting the RF signal into an intermediate frequency (IF) signal is generated by the signal generator 330 and jointly provided.

Meanwhile, when detecting power between the power amplifier and the input / output router, the band pass filters 311 and 321 may be removed.

4 is a detailed block diagram of an embodiment of the digital power measurement unit of FIG. 2. As shown in FIG. 4, the digital power measurement unit 222 is also largely divided into two parts, a part 410 for measuring the standing wave ratio of the received signal and a part 420 for measuring the power of the received signal.

First, the portion 410 for measuring the standing wave ratio of the received signal is an analog-to-digital converter 411 for converting the analog IF signal transmitted from the analog downconverter 221 into a digital IF signal. And a numerically controlled oscillator 412 for down-converting the converted signal into a digital baseband signal and a signal strength indicator (SSI) 413 for measuring the strength of the down-converted digital baseband signal.

On the other hand, the portion 420 for measuring the power of the received signal is an analog-to-digital converter 421 for converting the analog IF signal transmitted from the analog down-conversion unit 221 into a digital IF signal, the conversion to the digital IF signal A numerically controlled oscillator 422 for downconverting the converted signal into a digital baseband signal, a digital filter 423 and a digital filter for selecting a signal of interest for the entire band or for each channel for the downconverted digital baseband signal. A signal strength meter 424 for measuring the power of the output signal of 423.

In this case, the digital power oscillators 412 and 422 and the digital filter 423 are controlled using the control signals of the power meter controller 223 in the process of detecting the digital power to measure the power of each channel as well as the entire band. As a result, the frequency characteristics can be analyzed. That is, when the digital filter 423 selects a channel of interest by the control signal of the power meter controller 223, the power of the signal of the selected channel is measured.

5 is a detailed block diagram illustrating an exemplary embodiment of the signal strength meter of FIG. 4. The power of the signal is indirectly measured by the signal strength meter shown in FIG. 5 and the principle thereof is as follows.

In order to keep the output value of the multiplier 530 constant as a threshold, the output value of the loop filter 510 fed back to the multiplier 530 should be adjusted according to the change of the input signal of the multiplier 530. Accordingly, the comparator 520 compares the output of the multiplier 530 with the threshold value 521 and transmits the difference value to the loop filter 510, and the loop filter 510 has a loop gain ( After multiplying and integrating 512, the multiplier 530 transmits the multiplier 530 to the multiplier 530. Through this process, the output of the multiplier 530 may maintain a threshold regardless of the change in the input signal of the multiplier 530. That is, when the input signal of the multiplier 530 decreases, the output signal of the loop filter 510 increases, so that the output signal of the multiplier 530 maintains the threshold 521, and conversely, the input signal of the multiplier 530 increases. In this case, the output signal of the loop filter 510 is decreased so that the output signal of the multiplier 530 maintains the threshold 521. Therefore, using the output signal of the loop filter 510 can indirectly measure the power of the signal.

The power meter controller 223 sets the local frequency of the analog down converter 221 and controls the digital filter 423 and the signal strength meters 413 and 424 of the digital power measurer 222. The power meter controller 223 calculates power and standing wave ratios of signals using the output signals of the signal strength meters 413 and 424 of the digital power meter 222, and analyzes frequency characteristics.

6 is a detailed flowchart illustrating a control operation process, a power calculation process, and a frequency analysis process performed by the power meter controller of FIG. 2.

As shown in FIG. 6, when a signal is input to the power meter controller 223 (601), it is determined whether the set values of the analog down-converter 221 and the digital power measurer 222 are changed (602). If the set value is changed, the local frequency of the analog down-converter 221 and the digital filter 423, the numerically controlled oscillators 412 and 422, and the signal strength meters 413 and 424 of the digital power measurement unit 222. After resetting according to the changed value (603 to 606), the power of the input signal is measured and the standing wave ratio is calculated (607 and 608). However, when the set value is not changed, the power of the input signal is measured while calculating the standing wave ratio while maintaining the set values of the analog down-converter 221 and the digital power measuring unit 222 (607 and 608). . Then, the measured power is transmitted to the modem means or the display means 230 to be modulated or displayed.

Meanwhile, operations performed by the power meter controller 223 are implemented using digital signal processing.

As described above, the method of the present invention may be implemented as a program and stored in a recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.) in a computer-readable form. Since this process can be easily implemented by those skilled in the art will not be described in more detail.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be clear to those of ordinary knowledge.

The present invention as described above, by applying the digital signal processing (Digital Signal Processing, DSP) method to accurately measure the power of the received signal and the standing voltage ratio (Voltage Standing Wave Ratio, VSWR) of the antenna without changing the characteristics of the temperature change It can be effective.

In addition, the present invention has the effect of effectively diagnosing and monitoring the base station and the relay by analyzing the frequency characteristics of the signal for each band or each channel using the down-converted signal for power measurement.

Claims (8)

Applied to a base station or a repeater, the power meter using digital signal processing (Digital Signal Processing), An analog down converter for down converting a received radio frequency (RF) signal into an intermediate frequency (IF) band; A digital power measurement unit converting the down-converted IF band analog signal into a digital signal of the IF band and then down-converting to a baseband digital signal to measure the strength of the baseband digital signal; And And a power meter controller which calculates power and standing wave ratio of the received signal based on the strength of the baseband digital signal measured by the digital power measurement unit using digital signal processing. The strength of the baseband digital signal is measured using the predetermined control signal such that the product of the baseband digital signal and the predetermined control signal maintain a threshold. Power meter using digital signal processing. The method of claim 1, The analog down converter, A first analog down converter configured to down convert the received RF signal into a first analog IF signal; And A second analog downconversion unit for downconverting and amplifying the received RF signal into a second analog IF signal, The digital power measurement unit, A first analog-to-digital converter for converting the first analog IF signal into a first digital IF signal; A first numerically controlled oscillator for down converting the first digital IF signal into a first digital baseband signal; A first signal strength meter for measuring the strength of the first digital baseband signal; A second analog-to-digital converter for converting the amplified second analog IF signal to a second digital IF signal; A second numerically controlled oscillator for down converting the second digital IF signal into a second digital baseband signal; And A second signal strength meter for measuring the strength of the second digital baseband signal, The power meter controller may measure the power of the received signal using the measured strength of the first digital baseband signal, and calculate the standing wave ratio using the measured strength of the second digital baseband signal. Power meter using digital signal processing. The method of claim 2, The digital power measurement unit may further include a digital filter for filtering the entire band or the band of interest of the down-converted first digital baseband signal and outputting the filtered signal to the first signal strength meter. The first signal strength meter measures the strength of the filtered first digital baseband signal. Power meter using digital signal processing. The method of claim 3, The first signal strength meter and the second signal strength meter, Multiplier; A comparator for detecting a difference between an output of the multiplier and a threshold; And A loop filter for multiplying the difference detected by the comparator with the loop gain and integrating and outputting the multiplier to the multiplier, The multiplier multiplies a predetermined input signal by the output of the loop filter, The multiplier of the first signal strength meter receives the first digital baseband signal or the filtered first digital baseband signal as the input signal, The multiplier of the second signal strength meter receives the second digital baseband signal as the input signal. Power meter using digital signal processing. In the method for measuring power in a power meter applied to a base station or repeater, Down converting the received RF signal into a first analog IF signal; Converting the first analog IF signal into a first digital IF signal and then down converting the first analog IF signal into a first digital baseband signal; Measuring the strength of the first digital baseband signal; Down converting and amplifying the received RF signal into a second analog IF signal; Converting the amplified second analog IF signal to a second digital IF signal and then down converting the second analog IF signal to a second digital baseband signal; Measuring the strength of the second digital baseband signal; And Measuring the power of the received signal using the measured strength of the first digital baseband signal, and measuring the standing wave ratio using the measured strength of the second digital baseband signal, The strength of the first digital baseband signal is measured using the first control signal such that a first result of the product of the first digital baseband signal and the first control signal maintains a first threshold value. , The first control signal is obtained by integrating after multiplying a first loop gain by a difference value between the first result value and the first threshold value, The strength of the second digital baseband signal is measured using the second control signal such that a second result of the product of the second digital baseband signal and the second control signal maintains a second threshold value. , The second control signal is obtained by integrating after multiplying a second loop gain by a difference value between the second result value and the second threshold value. How to measure power. The method of claim 5, Filtering all bands or bands of interest of the downconverted first digital baseband signal; Measuring the strength of the first digital baseband signal, measuring the strength of the filtered first digital baseband signal How to measure power. A computer-readable recording medium having recorded thereon a program for performing the method of claim 5 or 6. delete

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