JPH1197938A - Ssb modulating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce power consumption, to reduce a circuit scale, to increase efficiency, and to reduce distortion by realizing an amplification control amplifying means, envelope detecting means, and phase equalizing means by a digital circuit. SOLUTION: An inputted modulated signal is converted into an SSB modulated wave by a SSB generator 1, and converted into a digital signal by an A/D converter 11. A DSP 12 extracts phase modulation components and envelop components from the inputted signal by using an amplitude control amplifying means 21 and an envelop detecting means 23. Moreover, the signal of the phase modulation components is equalized by a phase equalizing means 22 so as to be made coincident with the phase of the envelop components. A frequency converter 8 mixes an analog signal inputted from a D/A converter 13 with a signal oscillated by a local oscillator 9, and converts it into a prescribed high frequency signal. Then, a modulation amplifier 15 amplitude-modulates the signal of the phase modulation components by the signal of the envelop components inputted from the DSP 12, and outputs it as an amplitude SSB modulated wave.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an SSB (Single SideBand) for generating a signal to be transmitted in a single sideband of a radio wave.
The present invention relates to a modulator, and more particularly, to an SSB modulator including an amplifier employing an envelope erasure reproduction method capable of performing amplification with high efficiency and small distortion.

[0002]

2. Description of the Related Art A so-called "envelope erasure reproduction method" has been known as an amplification method with high efficiency and small distortion for SSB modulated waves. Hereinafter, this will be briefly described.

In an amplitude modulated wave, only the amplitude changes according to the modulation signal, and the frequency and phase do not change.
The B modulated wave changes not only in amplitude but also in phase and frequency. That is, it can be considered that the SSB modulated wave is a wave obtained by simultaneously modulating the phase and the amplitude. The envelope erasing reproduction method is a method of increasing the efficiency of a power amplifier by dividing an SSB modulated wave into a phase modulation component and an amplitude modulation component (envelope component) and amplifying the phase modulation component by a non-linear amplifier.

An example of an amplifier circuit for realizing the envelope erasing and reproducing method will be described with reference to FIG. FIG. 4 is a configuration block diagram illustrating an example of an amplifier circuit that implements the envelope erasing and reproducing method. As shown in FIG. 4, the amplifier circuit for realizing the envelope erasing and reproducing method includes an SSB generator 1, an amplitude limiting amplifier 2, a non-linear amplifier 3, a modulation amplifier 4, an envelope detector 5, a low frequency An amplifier 6 and an amplifier 6 are conceivable.

[0005] Therefore, each part will be specifically described below. S
The SB generator 1 generates an SSB modulation wave based on a modulation signal input from the outside, and outputs the SSB modulation wave to the amplitude limiting amplifier 2 and the envelope detector 5. The amplitude limiting amplifier 2
The amplitude of the SSB modulated wave input from the SSB generator 1 is limited to a constant amplitude, and only the phase modulation component is extracted and output to the nonlinear amplifier 3.

[0006] The nonlinear amplifier 3 amplifies the SSB modulated wave having only the phase modulation component input from the amplitude limiting amplifier 2 and outputs the amplified signal to the modulation amplifier 4. The modulation amplifier 4 amplifies the SSB modulated wave of only the phase modulation component amplified by the non-linear amplifier 3 with the amplified envelope component input from the low-frequency amplifier 6, which will be described later, and amplifies the output. It is. Specifically, the modulation amplifier 4
In general, amplitude modulation is performed by a method called collector (plate) modulation.

The envelope detector 5 detects the envelope of the SSB modulated wave input from the SSB generator 1, extracts only the amplitude of the SSB modulated wave, and outputs it to the low frequency amplifier 6. The low frequency amplifier 6 amplifies the SSB modulated wave having only the amplitude input from the envelope detector 5 and outputs the amplified SSB modulated wave to the modulation amplifier 4.

Next, the operation of the amplifier circuit for realizing this envelope erasing and reproducing method will be described. The amplitude of the SSB modulated wave generated by the SSB generator 1 is limited by the amplitude limiting amplifier 2 and becomes only a phase modulation component, and is amplified by the nonlinear amplifier 3. On the other hand, the SSB modulated wave generated by the SSB generator 1 is also output to the envelope detector 5, where only the envelope component is extracted and amplified by the low frequency amplifier 6.

Then, the modulation amplifier 4 is connected to the nonlinear amplifier 3
The amplitude of the signal of the phase modulation component inputted from the low frequency amplifier 6 is amplified by the envelope component inputted from the low frequency
An SSB modulated wave equivalent to the linearly amplified modulated wave is output.

To match the phase of the signal of the phase modulation component output from the nonlinear amplifier 3 with the signal of the envelope component output from the low frequency amplifier 6, as shown in FIG.
The phase equalizer 7, the frequency converter 8, and the local oscillator 9 may be arranged at a stage subsequent to the amplitude limiting amplifier 2. FIG.
FIG. 10 is a configuration block diagram illustrating an example of an amplifier circuit that implements a conventional envelope erasure reproduction method in an SB modulation device.

Further, in consideration of the fact that the average level of the input signal is not constant, an output level control circuit 10 which is a DC amplifier for controlling the power supply voltage of the modulation amplifier 4 is provided in order to keep the level of the output signal constant. It is also considered to add. The output level control circuit 10 includes the envelope detector 5
Are amplified and output to the modulation amplifier 4. The modulation amplifier 4 controls the gain using the signal input from the output level control circuit 10.

[0012]

As described above, in the above-mentioned conventional SSB modulator, amplitude modulation is performed by a method called collector modulation. However, in this method, the efficiency of the last stage of the amplifying element (the efficiency with respect to the DC input) is increased. Modulated wave output) is about 5
Since the output is only about 0 to 60%, an output almost equal to the output of the modulated wave is required for the low-frequency amplifier, and there is a problem that the power consumption of the low-frequency amplifier increases and the circuit scale increases. Was.

Further, since the processing of the envelope detector, the phase equalizer, the amplitude limiting amplifier, etc. is realized by an analog circuit,
In addition to the necessity of a large number of adjustment circuits for correcting the characteristics of the elements, there is a problem that influences such as the setting of adjustment points and changes in the characteristics of the elements themselves due to aging cannot be avoided.

The present invention has been made in view of the above circumstances, and realizes an amplifier circuit digitally to reduce the power consumption of a low-frequency amplifier and the like, and reduce the circuit scale.
It is an object of the present invention to provide an SSB modulator having high efficiency and low distortion.

[0015]

According to a first aspect of the present invention, there is provided an SSB modulation apparatus for extracting a phase modulation component with a constant amplitude of an SSB modulation wave. A limiting amplifier, an envelope detector for extracting an envelope component of the SSB modulated wave, and the amplitude limiting amplifier extracting the envelope component so as to match the phase of the envelope component signal extracted by the envelope detector. Phase equalization means for changing the phase of the phase-modulated component signal is realized by a digital circuit, eliminating the need for element adjustment, reducing distortion, increasing efficiency, and reducing power consumption. And the circuit scale can be reduced.

According to a second aspect of the present invention, there is provided an SSB modulator according to the first aspect, wherein the envelope detecting means comprises: a first band-limiting filter;
AGC means, a Hilbert transform filter, first multiplication means, second multiplication means, addition means, delay means,
An envelope detecting means comprising an AGC detecting means and a second band-limiting filter, wherein the first band-limiting filter is a first band-limiting filter for band-limiting an externally input signal. The AGC means controls the gain of a signal input from the first band-limiting filter in accordance with a signal input from the AGC detection means at a subsequent stage, and the Hilbert transform filter includes: A Hilbert transform filter that shifts the output signal by 90 degrees; the first multiplying means is a first multiplying means for squaring the signal output by the Hilbert transform filter; and the delay means is the AGC means. Is a delay means for delaying a signal output by the delay means for a predetermined time, and the second multiplication means is a second multiplication for squaring the signal delayed by the delay means. A stage, it said adding means is said first multiplying means and the second multiplying means and adding means for adding and combining the squared signals respectively by the A
The GC detection means is an AGC detection means for detecting the signal level of the signal added and synthesized by the addition means and outputting the feedback to the AGC means, and the second band-limiting filter is a signal output from the addition means. Is a second band-limiting filter that limits the band of the signal, and outputs as an envelope component of the signal input from the outside,
No element adjustment is required, distortion can be reduced, efficiency is high, power consumption can be reduced, and the circuit scale can be reduced.

According to a third aspect of the present invention, there is provided an SSB modulation apparatus including an envelope detector for extracting an envelope component of an SSB modulated wave, wherein the SSB modulated wave comprises: An amplitude limiting amplifier for extracting a phase modulation component with a constant amplitude, and the amplitude limiting amplifier extracting so as to match the phase of the envelope component signal extracted and output by the envelope detector. The phase equalizer for changing the phase of the signal of the phase modulation component is realized by a digital circuit, which eliminates the need for element adjustment, reduces distortion, increases efficiency, and reduces power consumption. The circuit scale can be reduced.

According to a fourth aspect of the present invention for solving the problems of the above conventional example, a modulated signal input from the outside
An SSB modulator that realizes an SSB generator for converting into a B modulation wave by a digital circuit, wherein the SSB generator receives an input of a modulation signal that has been converted into a digital signal in advance,
A band-limiting filter for band-limiting the modulated signal, AGC means for adjusting the gain of the band-limited modulated signal, a Hilbert transform filter for phase-shifting the signal input from the AGC means by 90 degrees, and a reference signal A reference signal generating unit that divides the reference signal into a cosine component and a sine component, and outputs the signal, a signal input from the Hilbert transform filter, and a cosine component of the reference signal input from the reference signal generating unit. First multiplying means for multiplying, delay means for delaying a signal inputted from the AGC means for a fixed time, sine components of a signal inputted from the delay means and a reference signal inputted from the reference signal generating means And the signal input from the first multiplication means and the signal input from the second multiplication means are added to each other, and SSB It is characterized in that it is an SSB generator having an addition means for outputting as a harmonic, and no element adjustment is required, distortion can be reduced, efficiency is high, power consumption can be reduced, and the circuit scale can be reduced. Further, if the envelope detection means at the subsequent stage is realized by a digital circuit, the processing of each section can be reused for the processing of the envelope detection means, and the digital circuit can be simplified.

The invention according to claim 5 for solving the problem of the above-mentioned conventional example is to separate and amplify an SSB modulated wave into a signal of a phase modulation component and a signal of an envelope component, and to synthesize the SSB modulated wave. An SSB modulator that reproduces a modulated wave, wherein a modulation amplifier that receives an input of the separated and amplified phase modulation component signal and an envelope component signal and reproduces an SSB modulated wave includes the envelope component. A D / A converter that converts lower-order bits of the signal into an analog signal, an amplitude modulator that amplitude-modulates the signal of the phase modulation component with an analog signal input from the D / A converter, A first power amplifier that amplifies and outputs a signal input from the converter, and a signal corresponding to each of the remaining bits of the envelope component signal that are not input to the D / A converter. The value of the bit provided As a switch, if the value of the bit indicates ON, a second power amplifier that amplifies and outputs the phase modulation component with the weight of the bit, and a signal input from the first power amplifier And a combiner for combining and outputting a signal input from the second power amplifier and outputting the combined signal.
With a small circuit scale, the signal of the phase modulation component can be amplitude-modulated by the signal of the envelope component input as a digital signal, so that the efficiency is high and the power consumption can be reduced.

[0020]

Embodiments of the present invention will be described with reference to the drawings. S according to the embodiment of the present invention
The SB modulation device (this device) digitally amplifies the SSB modulated wave. In particular, the circuit scale is reduced by realizing the amplitude limiting amplifying means, the phase equalizing means, and the envelope detecting means with a DSP. In addition, highly efficient amplification can be performed without aging.

This apparatus will be described with reference to FIG. FIG.
1 is a configuration block diagram of the present apparatus. As shown in FIG. 1, the present apparatus includes an SSB generator 1, an A / D converter 11,
DSP 12, D / A converter 13, frequency converter 8
, Local oscillator 9, nonlinear amplifier 3, modulation amplifier 1
The DSP 12 includes an amplitude limiter 21, a phase equalizer 22, and an envelope detector 23.

Hereinafter, each part will be described in detail. Since the SSB generator 1 is the same as the conventional one, the description is omitted. However, since the SSB generator 1 can be embodied by using the DSP 12, this case will be described in detail later. The A / D converter 11 converts the SSB modulated wave input from the SSB generator 1 into a digital signal,
Is output to

The DSP 12 extracts a phase modulation component from the input digital signal by an amplitude limiting means 21 and a phase equalizing means 22 which will be described later, and makes the phase of the phase modulation component and the D / A signal coincide with each other. In addition to the output to the converter 13, the envelope detection means 23 extracts the envelope component of the input digital signal and outputs it to the modulation amplifier 15.

The D / A converter 13 converts a digital signal of a phase modulation component input from the DSP 12 into an analog signal and outputs the analog signal to the frequency converter 8. The frequency converter 8 mixes the signal of the phase modulation component input from the D / A converter 13 and the signal input from the local oscillator 9, converts the mixed signal into a predetermined high-frequency signal, and outputs the signal to the nonlinear amplifier 3. Things. Since the nonlinear amplifier 3 is the same as the conventional one, the description is omitted.

The modulation amplifier 15 amplitude-modulates the signal input from the non-linear amplifier 3 with the digital signal of the envelope component input from the DSP 12, and will be specifically described later.

Here, the amplitude limiting means 21 of the DSP 12
, The phase equalizing means 22 and the envelope detecting means 23 are realized by digitally implementing the conventional amplitude limiting amplifier 2, the phase equalizer 7 and the envelope detector 5 by using the DSP 12. It is.

Here, the modulation amplifier 15 will be described in detail with reference to FIG. FIG. 2 is a configuration block diagram of the modulation amplifier 15 of the present apparatus. The modulation amplifier 15 includes a D / A converter 31 and an amplitude modulator 32, as shown in FIG.
, A plurality of power amplifiers 33 and a combiner 34.

The components will be described below. The D / A converter 3
Reference numeral 1 denotes an LSB (Least Significant) of the digital signal of the envelope component input from the envelope detector 23 of the DSP 12.
The input of several bits on the (t Bit) side is converted into an analog signal and output to the amplitude modulator 32.

The amplitude modulator 32 amplitude-modulates the signal of the phase modulation component input from the non-linear amplifier 3 with the signal of the envelope component converted into the analog signal input from the D / A converter 31, and The signal is output to the amplifier 33a. The power amplifier 33 amplifies the input signal and outputs the amplified signal to the synthesizer 34. In particular, the power amplifier 33a
Is for amplifying the signal input from the amplitude modulator 32 and outputting the amplified signal to the synthesizer 34.

Further, the power amplifiers 33b to 33n
MS of digital signal of envelope component input from P12
The remaining bits on the B (Most Significant Bit) side (D
Each of the remaining bits not input to the A / A converter 31 is used as a switch, and when the switch is turned on (when the input bit is “1”), a non-linear conversion is performed at a preset amplification factor. The signal of the phase modulation component input from the amplifier 3 is amplified and output to the combiner 34. When the switch is not turned on (when the input bit is “0”), the phase input from the nonlinear amplifier 33 is output. This prevents the modulated component signal from being output to the synthesizer 34.

That is, the power amplifier 33 performs amplification at an amplification factor corresponding to the weight of each bit input as a switch, and outputs the result to the combiner 34. Synthesizer 34
Is for adding and synthesizing signals input from the power amplifiers 33a to 33n in an analog manner and outputting the resultant signals. In the claims, the power amplifier 33a is referred to as a first power amplifier, and the power amplifiers 33b to 33n are referred to as second power amplifiers.

Here, the case where the digital signal of the envelope component output by the DSP 12 is 4-bit "1001" will be specifically described as an example. Originally, the digital signal of the envelope component should be represented by a larger number of bits, but here, 4 bits are used for explanation.

The signal of the envelope component is divided into, for example, two bits on the MSB side and two bits on the LSB side, and
The two bits on the side are converted into an analog signal by the D / A converter 31 and output to the amplitude modulator 32. Here, since it is assumed that the two bits on the LSB side are “01”, a voltage signal corresponding to “01” is output to the amplitude modulator 32, and the amplitude modulator 32 receives a signal of a phase modulation component that is separately input. Is amplitude-modulated by the voltage signal and output to the power amplifier 33a. Then, the power amplifier 33 a amplifies the input signal and outputs the amplified signal to the combiner 34.

Each of the two bits on the MSB side is
Each is input to the power amplifier 33b and the power amplifier 33c. Since the bit input to the power amplifier 33b is assumed to be “0”, the power amplifier 33b does not output the signal of the phase modulation component input separately to the combiner 34. .

Since the value of the bit input to the power amplifier 33c is "1", the power amplifier 33c
The signal c is turned on in accordance with the value of the input bit, and the signal of the separately input phase modulation component is amplified and output to the combiner 34 in accordance with the weight of the bit. And
A combiner 34 adds and combines the amplified phase modulation component signals input from the power amplifiers 33a to 33c and outputs the combined signal to the outside.

As described above, the conversion of several bits on the LSB side to analog data is different from the method of weighting all bits as digital data in the power amplifier 33.
In order to reduce the number.

Next, the operation of the present apparatus will be described.
The modulation signal input from the outside to this device is the SSB generator 1
Is converted into an SSB modulated wave by the A / D converter 1
The signal is converted into a digital signal by 1 and output to the DSP 12.

Then, the DSP 12 controls the amplitude
And the envelope detection means 23 to extract a phase modulation component and an envelope component, respectively, from the input signal,
Further, the signal of the phase modulation component is equalized by the phase equalizing means 22 so as to match the phase of the envelope component, and is output to the D / A converter 13. Further, the signal of the envelope component is output to the modulation amplifier 15 as it is.

The D / A converter 13 converts the phase modulation component signal input from the DSP 12 into an analog signal and outputs the analog signal to the frequency converter 8, and the frequency converter 8 inputs the analog signal and the local oscillator 9 Is mixed with a signal oscillating, converted into a predetermined high-frequency signal, and output to the nonlinear amplifier 3.

Then, the nonlinear amplifier 3 amplifies the signal of the phase modulation component converted into a predetermined high-frequency signal and outputs the amplified signal to the modulation amplifier 15. Then, the modulation amplifier 15
The signal of the amplitude modulation component is modulated by the signal of the envelope component input from the envelope detection means 23 of P12, and the amplified S
Output to the outside as an SB modulated wave.

Here, the DSP 12 includes the envelope detection means 23, extracts the envelope component from the signal obtained by converting the SSB modulated wave output from the A / D converter 11 into a digital signal, and outputs it as a digital signal. However, for example, the signal of the envelope component of the SSB modulated wave may be directly extracted from the output of the SSB generator 1 by analog means similar to the related art. In this case, the signal of the envelope component input to the modulation amplifier 15 is
What is necessary is just to convert into a digital signal by an A / D converter beforehand.

According to the present apparatus, since the amplitude modulation is performed digitally, there is an effect that an SSB modulated wave amplified with small distortion and high efficiency can be generated with a small circuit scale.

The SSB generator 1 may be digitally embodied by using the DSP 12. In this case, the modulated signal is A / D converted and input to the SSB generator 1 of the DSP 12.

Therefore, the present apparatus in the case where the SSB generator 1 is embodied digitally will be described with reference to FIG. FIG. 3 is a configuration block diagram of the present apparatus when the SSB generator 1 is digitally embodied.

Here, the envelope component input to the modulation amplifier is a 12-bit digital signal, which is divided into 4 bits on the MSB side and 8 bits on the LSB side. Further, the power amplifier in the modulation amplifier has an efficiency of 9
It is assumed that the power amplifier is 0% or more. It is experimentally known that the amplitude modulation efficiency of the modulation amplifier becomes 80% or more as a whole.

As shown in FIG. 3, the SSB generator 1 digitally realized by using the DSP 12 has a BPF (band limiting filter) 41, an AGC unit 42, a Hilbert transform filter 43, a multiplication unit 44, Delay means 45;
A DSP 12 having an adding means 46;
Digital Synthesizer) 51.

Hereinafter, these components will be described in detail.
The BPF 41 is a 10th-order IIR (Infinite-duration Im
It can be realized as a pulse response) filter, receives a digital signal obtained by A / D-converting a modulated signal, limits the band, and outputs the signal to the AGC means 42.

The AGC means 42 has, for example, a maximum rating of 10 in accordance with the input level that the DSP 12 can handle.
The gain of the signal input from the BPF 41 is controlled to a level of about dB and output to the Hilbert transform filter 43 and the delay means 45.

The Hilbert transform filter 43 shifts the phase of the signal input from the AGC means 42 by 90 degrees and outputs the resulting signal to the multiplying means 44a. The multiplying means 44 a multiplies a signal input from the Hilbert transform filter 43 by a signal input from the DDS 51 described later and outputs the result to the adding means 46.

The delay means 45 delays the signal input from the AGC means 42 for a predetermined time and outputs the delayed signal to the multiplication means 44b. The multiplying unit 44b multiplies a signal input from the delay unit 45 by a signal input from the DDS 51 described later and outputs the result to the adding unit 46.

The adding means 46 adds and combines the signals input from the multiplying means 44a and 44b and outputs the resultant signal. The DDS 51 outputs a reference signal as a digital signal. The DDS 51 outputs a sine component of the reference signal to the multiplying means 44b and a cosine component to the multiplying means 44a.
In order to smooth (smoothing) the signal after A conversion,
An LPF (Low Pass Filter) is not required.

That is, in this SSB generator 1, PSN
Although a method known as (Phase Shift Network) is realized digitally, other filter methods, a Weber method, and the like can also be realized by DSP processing. In the claims, the multiplication means 44a
Are referred to as a first multiplying means, and the multiplying means 44b is referred to as a second multiplying means.

Further, in this SSB modulator, the signal output from the adding means 46, which is the output of the SSB generator 1, can be directly and continuously processed in the DSP 12. That is, the output of the adding means 46 is output to the amplitude limiting means 21 and the envelope detecting means 23.

Here, as shown in FIG. 3, the envelope detection means 23 specifically includes a first BPF means 61 for performing band limitation and a gain of a signal band-limited by the first BPF 61. AGC means 62 for controlling according to a signal inputted from AGC detection means 67 at the subsequent stage, and AGC means 6
2, a Hilbert transform filter 63 for shifting the phase of the signal output by 90 degrees, a multiplying means 64a for squaring the signal output from the Hilbert transform filter 63, a delay means 65 for delaying the signal output from the AGC means 62 for a predetermined time, Multiplying means 64b for squaring the delayed signal; adding means 66 for adding and synthesizing the signals squared by the multiplying means 64a and 64b; detecting the signal level of the added and synthesized signal; AGC detection means 67 for feedback output to 62, second BPF means 68 for limiting the band of the signal output from addition means 66 and outputting as an envelope component of the SSB modulated wave input from SSB generator 1; It is possible to construct from.

In this way, the SSB generator 1 and the envelope detection means 23 can be used in common, and the digital circuit can be simplified.

In the SSB modulator described here, the A / D converter and the D / D converter
In consideration of the case where the sampling frequency of the A-converter 14 is high, multi-rate processing is preferably performed to convert the sampling frequency.

Further, in the preceding stage of the A / D converter for converting the modulated signal into a digital signal, the band below 1/2 of the sampling frequency is band-limited by an anti-aliasing filter, and further, the latter stage of the A / D converter. In this case, it is ideal to perform decimation processing by a decimation filter, further perform rate conversion, and then perform interpolation by an interpolation filter realized by a DSP. Further, a smoothing filter may be provided downstream of the D / A converter 14 to remove harmonics.

Further, it is possible to generate a carrier by digital signal processing of DDS, and the DSP may perform the processing of waveform generation. Furthermore, without using a DSP, an FPGA (Field Programmable Gate Ar
rays), a gate array, a general-purpose logic IC, or the like can realize the same processing as that of the DSP.

[0059]

According to the first aspect of the present invention, the amplitude limiting amplifier for extracting the phase modulation component while keeping the amplitude of the SSB modulated wave constant, and the envelope detecting device for extracting the envelope component of the SSB modulated wave are provided. Since the SSB modulator is implemented by a digital circuit and the phase equalizing means for matching the phase of the signal of the phase modulation component to the phase of the signal of the envelope component, adjustment of the element is unnecessary, and the element due to aging Since the effects of changes in the characteristics of the signal are eliminated, distortion can be reduced.Moreover, since the amplitude modulation is performed by the digital circuit, the efficiency is high. Power consumption can be reduced,
This has the effect of reducing the circuit scale.

According to the second aspect of the present invention, the envelope detecting means limits the band of the signal inputted from the outside.
BPF, AGC means for controlling the gain of a band-limited signal in accordance with a signal input from a subsequent AGC detection means, Hilbert transform filter means for shifting the gain-controlled signal by 90 degrees, and Hilbert transform filter First multiplying means for squaring the signal output by the means, delay means for delaying the signal output from the AGC means for a predetermined time, second multiplying means for squaring the delayed signal, first multiplying means and An adding means for adding and combining the signals squared by the multiplying means, an AGC detecting means for detecting a signal level of the added and combined signal, and outputting the signal to the AGC means; 2. The SSB modulation device according to claim 1, further comprising a second BPF device that limits a band and outputs the signal as an envelope component of an externally input signal. Therefore, the envelope detection means can be realized as processing performed by the DSP, and element adjustment is not required. Distortion can be reduced because there is no influence of changes in element characteristics due to aging, and amplitude can be reduced by a digital circuit. Since the modulation is performed, the efficiency is high. Therefore, the output that is almost the same as the output of the modulated wave is not required for the low-frequency amplifier, so that the power consumption can be reduced and the circuit scale can be reduced. .

According to the third aspect of the present invention, since the amplitude limiting amplifying means and the phase equalizing means are SSB modulators realized by digital circuits, the adjustment of the elements is not required, and the elements are not affected by aging. Since the effects of changes in the characteristics of the signal are eliminated, distortion can be reduced.Moreover, since the amplitude modulation is performed by the digital circuit, the efficiency is high. Therefore, power consumption can be reduced and the circuit scale can be reduced.

According to the fourth aspect of the present invention, an SSB generator for converting an externally input modulated signal into an SSB modulated wave includes a band-limiting filter, an AGC means, a Hilbert transform filter, and a reference signal generating means. , The first multiplication means, the delay means, the second multiplication means, and the addition means, the SSB modulator is realized by a digital circuit. Distortion can be reduced because the effects of changes in characteristics are eliminated, and the efficiency is high because the amplitude modulation is performed by the digital circuit. Therefore, an output almost equal to the output of the modulated wave is required for the low-frequency amplifier. Since the power consumption can be reduced and the circuit scale can be reduced, if the envelope detection means at the subsequent stage is realized by a digital circuit, the processing of each section described above can be performed by an envelope detection method. It can be reused for the processing of, there is an effect of simplified digital circuit.

According to the fifth aspect of the present invention, upon receiving the input of the separated and amplified phase modulation component signal and the envelope component signal, the D / A converter lowers the envelope component signal. A few bits are converted into an analog signal, the amplitude modulator amplitude-modulates the signal of the phase modulation component with the analog signal, and the first power amplifier amplifies and outputs the amplitude-modulated signal. , The remaining bits not input to the D / A converter are input as switches to the corresponding second power amplifiers, and if the value of the bit indicates ON, the second power The amplifier amplifies and outputs the signal of the phase modulation component with the weight of the bit, and the combiner
The SSB modulator includes a modulation amplifier that combines and outputs a signal input from the power amplifier and a signal input from the second power amplifier, so that the envelope input as a digital signal is small in circuit scale. The signal of the phase modulation component can be amplitude-modulated by the signal of the line component,
Since the amplitude modulation is performed by the digital circuit, the efficiency is high. Therefore, the output which is almost the same as the output of the modulated wave is not required for the low frequency amplifier, so that the power consumption can be reduced.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram of the present apparatus.

FIG. 2 is a configuration block diagram of a modulation amplifier 15 of the present apparatus.

FIG. 3 is a configuration block diagram of the present apparatus when the SSB generator 1 is digitally embodied.

FIG. 4 is a configuration block diagram illustrating an example of an amplifier circuit that realizes an envelope erasing and reproducing method.

FIG. 5 is a configuration block diagram illustrating an example of an amplifier circuit that realizes a conventional envelope erasure reproduction method in an SSB modulation device.

[Explanation of symbols]

1: SSB generator, 2: Amplitude limiting amplifier, 3: Nonlinear amplifier, 4: Modulation amplifier, 5: Envelope detector,
6 low frequency amplifier, 7 phase equalizer, 8 frequency converter, 9 local oscillator, 10 output level control circuit, 11 A / D converter, 12 DSP, 13
D / A converter, 15: modulation amplifier, 21: amplitude limiting means, 22: phase equivalent means, 23: envelope detection means, 30: A / D converter, 31: D / A converter,
32 amplitude modulator 33 power amplifier 34 synthesizer 41 BPF 42 AGC means 43 Hilbert transform filter 44 multiplication means 45 delay means 46 addition means 51 DDS 61: first BPF, 62: AGC means, 63: Hilbert transform means, 64: multiplication means, 66: addition means, 6
7 AGC detection means, 68 second BPF

Claims (5)

[Claims] 1. An amplitude limiting amplifying means for extracting a phase modulation component with a constant amplitude of an SSB modulated wave, an envelope detecting means for extracting an envelope component of the SSB modulated wave, and the envelope detecting means. Phase equalizing means for changing the phase of the signal of the phase modulation component extracted by the amplitude limiting amplifying means so as to match the phase of the signal of the envelope component to be extracted is realized by a digital circuit. SSB modulator. 2. An envelope detection means, comprising: a first band limiting filter, an AGC means, a Hilbert transform filter, a first multiplication means, a second multiplication means, an addition means, a delay means, An envelope detecting means including an AGC detecting means and a second band-limiting filter, wherein the first band-limiting filter is a first band-limiting filter for band-limiting an externally input signal. The AGC means is an AGC means for controlling a gain of a signal input from the first band-limiting filter in accordance with a signal input from the AGC detection means at a subsequent stage. A Hilbert transform filter that shifts the output signal by 90 degrees, wherein the first multiplying means is a first multiplier that squares the signal output by the Hilbert transform filter. Wherein the delay means is a delay means for delaying a signal output from the AGC means for a predetermined time, and the second multiplication means is a second multiplication means for squaring the signal delayed by the delay means. The adding means is an adding means for adding and combining the signals squared by the first multiplying means and the second multiplying means, respectively, and the AGC detecting means is added and combined by the adding means. AGC detection means for detecting the signal level of the signal and feeding back and outputting the signal to the AGC means. The second band-limiting filter limits the band of the signal output from the addition means and receives the signal from the outside. 2. The SSB modulator according to claim 1, wherein the SSB modulator is a second band-limiting filter that outputs the signal as an envelope component of the signal. 3. An SSB modulation device comprising an envelope detector for extracting an envelope component of an SSB modulated wave, wherein said amplitude limiting amplification means extracts a phase modulation component with the amplitude of said SSB modulated wave being a constant amplitude. A phase equalizing means for changing the phase of the signal of the phase modulation component extracted by the amplitude limiting amplifying means so as to match the phase of the signal of the envelope component extracted and output by the envelope detector, S characterized by being realized by a digital circuit
SB modulator. 4. An SSB modulator which realizes an SSB generator for converting a modulation signal input from the outside into an SSB modulation wave by a digital circuit, wherein the SSB generator is a modulation signal previously converted into a digital signal. , A band-limiting filter for band-limiting the modulated signal, AGC means for adjusting the gain of the band-limited modulated signal, and a Hilbert transform filter for shifting the signal input from the AGC means by 90 degrees A reference signal generating means for generating a reference signal, dividing the reference signal into a cosine component and a sine component, and outputting the signals, respectively; a signal input from the Hilbert transform filter and a reference input from the reference signal generating means First multiplying means for multiplying a cosine component of a signal, delay means for delaying a signal input from the AGC means for a predetermined time, The multiplying the sine component of the reference signal input signal inputted from the means and from said reference signal generating means 2
An SSB generator comprising: a multiplying means for adding a signal input from the first multiplying means and a signal input from the second multiplying means, and outputting as an SSB modulated wave. An SSB modulator characterized by the above-mentioned. 5. The SSB modulated wave is separated into a signal of a phase modulation component and a signal of an envelope component, amplified, and combined to generate a signal of SSB.
An SSB modulator that reproduces an SB modulated wave, comprising: a modulation amplifier that receives an input of the separated and amplified phase modulation component signal and an envelope component signal and reproduces an SSB modulated wave; A D / A converter that converts lower-order bits of the component signal into an analog signal; an amplitude modulator that amplitude-modulates the phase modulation component signal with an analog signal input from the D / A converter; A first power amplifier for amplifying and outputting a signal input from the modulator; and a signal corresponding to each of remaining bit signals not input to the D / A converter among signals of the envelope component. A second power amplifier that amplifies the phase modulation component with the weight of the bit and outputs the amplified power, if the value of the bit indicates ON, and the value of the bit is a switch. Power amplifier SS, which is a modulation amplifier and a signal inputted signal et inputted from the second power amplifier combining to have a combiner which outputs
B modulator.