JP3360583B2 - Phase modulation signal detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phase modulation signal detecting device used in a radio wave searching device and the like, which accurately determines whether a received radio wave is phase-modulated even in a noisy radio wave environment.

[0002]

2. Description of the Related Art FIG. 15 shows a configuration of a conventional phase modulation signal detecting device. In FIG. 15, reference numeral 1 denotes a frequency measuring device for measuring the frequency of an input signal (a period measuring device for measuring a period);
Reference numeral 2 denotes an A / D converter for converting an input signal (generally represented by a complex number in a mathematical expression) into a digital signal;
Reference numeral denotes a delay element capable of controlling the amount of phase delay of the input signal in accordance with the frequency (period) value of the input signal. Reference numeral 4 denotes an adder for adding the input signal and the output signal of the delay element.

Note that the complex representation of a signal is a signal (electromagnetic wave)
Is represented by a complex number (combination of a real part and an imaginary part), which is a general method for expressing an electromagnetic wave.

In a conventional phase modulation signal detection, in short, a "value of a certain input signal" and a signal obtained by delaying the phase of the certain input signal by 1/2 wavelength (the output signal of the delay element 3) ) Is added to make the phase-modulated portion stand out.

Next, the operation of the conventional phase modulation signal detecting device will be described with reference to FIG. First, an input signal is input to the frequency measurement device 1 and the A / D converter 2, respectively. The signal input to the A / D converter 2 has a sampling period (that is, the reciprocal of the frequency) unique to the A / D converter 2.
Each time it is converted to a digital signal. Here, for example,
It is assumed that the sampling period specific to the A / D converter 2 is 10 ns (frequency is 100 MHz).

On the other hand, the frequency measuring device 1 measures the frequency of an input signal. Here, for example, it is assumed that the frequency of the input signal is 8 MHz (the cycle is 125 ns). The frequency measuring device 1 measures the frequency (8 MHz) of the measured input signal, that is,
The period (125 ns) is output to the delay element 3.

The delay element 3 calculates how many times the period (125 ns) of the input signal is longer than the sampling period (10 ns), and obtains a half of the value. In this case, 125 (ns) ÷ 10 (ns) ÷ 2 = 6.25, and 6 is obtained by rounding off.

Next, the delay element 3 has an A / D converter 2
The input signal subjected to the / D conversion is converted to a sampling cycle (10n
s) × 6 (= 60 ns) is delayed (1/2 wavelength delayed) and output.

Finally, the adder 4 determines that the A / D converter 2
The value of the / D converted signal and the value of the output of the delay element 3 are added and output. That is, "the value of a certain input signal" and "the value of a signal obtained by delaying the phase of a certain input signal by 1/2 wavelength" are added and output.

An example of the above operation of the phase modulation signal device will be described with reference to FIG. FIG. 16 shows an example of a waveform of an input signal that is phase-modulated. In FIG. 16, the vertical axis indicates the signal voltage, the horizontal axis indicates the time, and one scale on the horizontal axis indicates the sampling period (10 ns) of the A / D converter 2. In the vicinity of the center of FIG. 16, the portion where the waveform changes is the portion where the input signal is phase modulated.

The phase of the input signal is delayed by １ ／ wavelength and output from the delay element 3. FIG. 17 shows an input signal (signal a) and a signal (signal b) from the delay element 3 (both have undergone A / D conversion), and the adder 4 calculates the “value of a certain input signal” and the “phase of the certain input signal”. And the value of a signal (output signal of the delay element 3) obtained by delaying the signal by 波長 wavelength.

In general, a signal without phase modulation has one signal.
If the signal is delayed by 1/2 wavelength, the sign is inverted while the absolute value of the signal value remains unchanged. Therefore, "the value of a certain input signal" and "the value of a signal obtained by delaying the wavelength of a certain input signal by 1/2 wavelength" Is added, the signal value becomes a value close to 0.

Further, in a portion where phase modulation is performed, if the signal is delayed by １ ／ wavelength, the sign of the signal tends to be uniform. Therefore, the “value of a certain input signal” and the “phase of a certain input signal are reduced by １ ／.
The signal value becomes a value apart from 0 by adding the "wavelength-delayed signal value".

FIG. 18 shows the output of the adder 4 obtained by adding the "value of a certain input signal" shown in FIG. 17 and the "value of a signal obtained by delaying a certain input signal by 1/2 wavelength". It can be seen that the value of the part where the modulation is present is extremely far from 0.

[0015]

Since the conventional phase modulation signal detecting device is configured as described above, it has the following problems. The data used to determine the presence or absence of phase modulation is “value of a certain input signal” and “the value of a certain input signal is 1”.
However, the actual input signal always contains noise interference. To suppress the influence of such noise, use more data at the time of determination. It is well-known that statistics are valid.

That is, in general, when N pieces of data are used, the influence of noise can be suppressed to (1 / N) ^1/2 . Therefore, in the conventional device configuration, the noise is suppressed to (1/2) ^1/2 = 0.7, but if the determination can be made using ten data, (1/10) ^1/2 = 0 .3 can suppress noise.

However, in the conventional apparatus configuration, since the number of data used at the time of determination is small, the possibility of erroneous determination when noise is mixed is high and the determination process is not efficient. Therefore, in order to perform the determination process efficiently, it is desirable to increase the number of data used at the time of the determination to minimize the influence of noise.

The present invention has been made to solve such a problem, and uses a large amount of data when determining phase modulation.
It is an object of the present invention to provide a phase modulation signal detection device capable of reducing the influence of noise included in an input signal as much as possible, eliminating the possibility of erroneous determination as much as possible, and efficiently performing determination processing.

[0019]

According to the present invention, there is provided a phase modulation signal detecting apparatus for detecting a phase modulation of an input signal based on a signal obtained by delaying the phase of the input signal in accordance with the wavelength of the input signal and the input signal. In a phase modulation signal detection device for detecting the presence or absence, a plurality of delay means for outputting an input signal with a predetermined phase delayed and an output selected from the outputs of the plurality of delay means according to the wavelength of the input signal are selected. And an adding means for adding the selected output and the input signal.

Further, the apparatus further comprises an A / D converter for A / D converting the input signal, and the plurality of delay means are arranged such that the phase amounts to be delayed for each phase corresponding to the sampling period of the A / D converter are shifted from each other. It is as if it were.

Further, the apparatus further comprises output validity judging means for judging whether or not the output of the adding means is valid based on the magnitude of the reference signal amplitude and the magnitude of the input signal amplitude.

Further, there is further provided an area calculating means for calculating the area of the locus drawn by the output of the adding means on the complex plane based on the output of the adding means.

Further, the apparatus further comprises output display means for outputting and displaying a locus drawn by the output of the adding means on the complex plane and the complex plane.

[0024] The output display means outputs the area value calculated by the area calculation means.

Further, the apparatus further comprises signal amplitude normalizing means for normalizing the signal amplitude of the input signal.

The area calculating means includes a first area calculating means for obtaining an area based on an input signal and a second area calculating means for obtaining an area based on a signal obtained by squaring the input signal. And phase modulation judging means for judging the presence or absence of phase modulation of the input signal based on the output of the area calculating means.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Unless the input signal is phase-modulated, the waveform of the input signal draws a regular sine wave as shown in FIG. 1. Therefore, if this input signal is integrated with respect to time over one cycle, It becomes 0. Therefore, if the input signal is very finely divided with respect to time as compared with the cycle of this signal and the signal values are added over one cycle, the above-described integration and the situation become the same.

Even though it is very finely divided, it is not possible to practically infinitely finely subdivide it. Therefore, it is appropriate to consider the number of data that can determine the presence or absence of phase modulation without any problem.

Therefore, in the present invention, the A / D converter 2
Pays attention to A / D conversion of an input signal for each sampling cycle peculiar to the A / D converter 2, and determines each division point in one cycle of the input signal for each sampling cycle to set the subdivision width. The sampling period is used, and the presence or absence of phase modulation is determined based on the result of adding the signal values at each division point over one period.

FIG. 1 shows a case where one cycle of a sine wave is divided into, for example, six equal parts for easy understanding. Actually, there is no problem if the sampling period is sufficiently smaller than the period of the input signal.

Therefore, in order to obtain the value of the input signal at each of these division points, a delay element for delaying the phase of the A / D-converted input signal by a phase corresponding to this sampling period and outputting the same is provided. A signal value at each division point is obtained by preparing a plurality of pieces corresponding to each division point and obtaining outputs from each delay element.

Embodiment 1 Next, FIG.
FIG. 1 is a configuration diagram of a phase modulation signal detection device according to the first embodiment. In FIG.
As a new configuration according to the first embodiment, the delay elements 31 to 3n as a plurality of delay units are prepared for each signal added by the adder 4 as the addition unit as described later. To the input signal period / (A
/ D converters 2) sampling periods.

The delay elements 31 to 3n delay the phase of the A / D-converted input signal in order corresponding to the "sampling period of the A / D converter 2" and output the delayed signal. Similarly to the above, since the sampling cycle of the A / D converter 2 is 10 ns, the input signal is output after being delayed by a phase corresponding to 10 ns.

That is, for a certain time, the delay element 31
0 ns, the delay element 32 delays the phase of the input signal by a corresponding phase for 20 ns, and outputs the delayed signal.
Is (10 × n) ns, and the input signal is output with its phase delayed by the corresponding phase. The frequency of the input signal is also 8 MHz (period 125) as in the conventional example.
ns).

The operation of the thus configured phase modulation signal device according to the first embodiment will be described with reference to FIG. The measurement of the frequency of the input signal by the frequency measuring device 1 and the A / D conversion of the input signal by the A / D converter 2 are the same as those in the above-described conventional example, and a description thereof will be omitted.

The delay elements 31 to 3n delay the A / D-converted input signals by 10 ns, respectively, in accordance with the sampling period (10 ns) of the A / D converter 2 by the corresponding phase. Output.

For example, the A / D converter 2 A / D converts the input signal at a specific sampling period (10 ns), and
The D-converted input signals are sequentially output to the delay element 31, and the delay element 31 outputs one of the signals captured by the delay element 31.
The first signal (a signal delayed by 10 ns from a certain time) is output, and the remaining signal is sent to the delay element 32, and the delay element 3
2 outputs the first signal (a signal delayed by 20 ns from a certain time) of the signal captured by the delay element 32 and sends the remaining signal to the delay element 33. The delay element 3n is the first signal of the signal captured by the delay element 3n ((10 × n) from a certain time)
ns corresponding to the phase corresponding to ns).

Then, based on the measurement result of the frequency measuring device 1 and the sampling period of the A / D converter 2, the adder 4 selects the number of data (delay elements) from the output results of the delay elements 31 to 3n. Out of the outputs of 31 to 3n, it is determined how many delay elements (outputs of the delay elements) are added in order from the delay element 31 to output.

Specifically, “input signal cycle / (A / D
The sampling period data of the converter 2) is added and output. If this number is k, the outputs of the delay elements 31 to 3k are added by the adder 4.

In this example, (125 ns) ÷ (10n
s) = 12.5, which is rounded to 13, and eventually the adder 4 adds the values of the output signals of the delay elements 31 to 313.

Actually, the value of "the period of the input signal / the sampling period of the (A / D converter 2)" is not always an integer, and the output value of the adder 4 does not become zero.

However, when the input signal is not phase-modulated, if the value of “period of input signal / sampling period of (A / D converter 2)” is approximated by a rounded value, the value becomes “input signal”. Can be mathematically easily proved (this proof itself is not an essential part of the present invention and will be omitted).

On the other hand, if the input signal is phase modulated,
When the value of the signal is added to “the period of the input signal / the sampling period of the (A / D converter 2)” (this is N), the value increases in proportion to N. Specifically, it can be mathematically easily proved that the value is “maximum amplitude of signal × N × 0.6” (this proof itself is not an essential part of the present invention, and will be omitted). .

Therefore, when the input signal is not phase-modulated, the output (signal value) of the adder is “maximum amplitude of input signal × 1”.
/ 2 or less "When phase modulation is performed," maximum amplitude of input signal × N ×
About 0.6 ”In this example, since N = 13, these two values are 0.5 (= 1/1) when the maximum amplitude of the input signal is 1.
2) and 7.8 (13 × 0.6) are greatly different from each other, and the presence or absence of phase modulation is emphasized.

FIG. 3 shows a graph of the output of the adder actually using the apparatus configuration shown in FIG. 2. As can be seen from a comparison between FIG. 3 and FIG. The value of the central part is larger in the case of FIG.
It can be seen that the presence or absence of phase modulation is more emphasized than that of FIG.

Therefore, according to the first embodiment, a large amount of data is used when determining the presence or absence of phase modulation, and the influence of noise included in the input signal is reduced as much as possible to eliminate the possibility of erroneous determination as much as possible. The determination process can be performed efficiently.

Further, the device is composed of simple components such as the A / D converter 2 and the adder 4, so that the configuration of the device can be simplified.

Embodiment 2 In general, an input signal is subjected to amplitude modulation (AM modulation) in addition to mixing of noise. In particular, in the radio wave searching device, the sensitivity of the receiving antenna varies in noise, which is a major factor of amplitude modulation.

As described above, when the amplitude-modulated input signal is directly processed by the configuration of the first embodiment, even if the input signal is not phase-modulated due to the influence of the amplitude modulation, the output of the adder 4 disappears and remains. And this is the factor that causes the wrong decision.

In the second embodiment, in order to solve such a problem, an amplitude normalizing device for removing amplitude modulation applied to an input signal before performing A / D conversion is provided, and unnecessary amplitude modulation is removed. It is intended to increase the efficiency of determining the presence or absence of modulation.

FIG. 4 is a block diagram of a phase modulation signal detection device according to the second embodiment. In FIG. 4, reference numeral 5 denotes a new configuration according to the second embodiment. (Modulation) before the A / D conversion.

Next, the second embodiment configured as described above
The operation of the phase modulation signal device according to the above will be described with reference to FIG. Here, the device shown in FIG. 4 has the same basic operation as the operation of the device described in the first embodiment, and thus the detailed description is omitted, but the operation is different from the operation of the device described in the first embodiment. Is a part of the operation of the amplitude normalizing device 5, and the operation related to this part will be described.

The input / output signal of the amplitude normalizing device 5 is represented by s (t) (t is time and s () is a complex number).
Can be expressed as follows. Input signal to amplitude normalizing device 5: s (t) Output signal from amplitude normalizing device 5: s (t) / | s
(T) | (| x | is the absolute value of x)

When the amplitude modulation is applied to the input signal,
The input signal can be expressed as A (t) · sin (t) (A (t) is an amplitude modulation portion), but A (t) · sin (t) becomes → A ( t) · sin (t) / | A (t) · sin (t) | = A (t) · sin (t) / (| A (t) | · | sin (t) |) = A (t) Sin (t) / A (t) = sin (t), and the amplitude modulation portion of the input signal can be eliminated.

Therefore, according to the second embodiment, an amplitude normalizing device for removing unnecessary amplitude modulation applied to a force signal before performing A / D conversion is provided, and unnecessary amplitude modulation applied to an input signal is provided. The amplitude modulation can be removed, and even if the amplitude-modulated signal is taken in as an input signal, even if the input signal is not phase-modulated due to the influence of the amplitude modulation, the output of the adder 4 will remain and an error will occur. This makes it possible to increase the efficiency of determining the presence or absence of phase modulation.

Embodiment 3 In the device of the second embodiment to which the amplitude normalizing device 5 is added, when only noise is input, it is not possible to discriminate between noise and an effective desired input signal, and only noise is input. In this case as well, the amplitude is normalized, and an erroneous judgment result is obtained using the normalized result as a judgment material.

That is, for any input signal, the amplitude value is normalized (that is, set to 1). Therefore, the size of the input signal after the normalization is determined by the effective desired input signal and noise. Cannot be distinguished from each other, and this is a factor that causes an incorrect determination.

In the third embodiment, in order to solve such a problem, noise is distinguished from a desired input signal based on the magnitude of the input signal before normalization, and the efficiency of determining the presence or absence of phase modulation is improved. The purpose is.

FIG. 5 is a block diagram of a phase modulation signal detecting apparatus according to the third embodiment. In FIG. 5, as a new configuration according to the third embodiment, reference numeral 6 denotes a case where only noise is input as an input signal. Then, the maximum amplitude of the input signal is compared with the magnitude of a predetermined value (reference signal amplitude) stored as a criterion for determining whether or not the input signal is a noise. An amplitude value determination device as output validity determination means for determining an input signal.

The specified value serving as a criterion for determining whether or not noise is present is stored in the amplitude value determining device 6 in advance. 7 is the A of the output of the adder 4 and the output of the amplitude value judging device 6.
An AND circuit that performs an ND operation.

Next, the third embodiment configured as described above
The operation of the phase modulation signal detecting device according to the above will be described with reference to FIG. Here, the basic operation of the device shown in FIG. 5 is the same as that of the device described in the second embodiment, and therefore the detailed description is omitted, but the operation is different from that of the device described in the second embodiment. Is the operation of the portion of the amplitude value judging device 6 and the operation of the subsequent portion of the AND circuit 7, and the operation related to this portion will be described.

The magnitude of the reference (amplitude) of the input signal, which is originally valid, is stored in the amplitude value determination device 6 as a specified value in advance. Then, the amplitude value judging device 6 measures, for example, the magnitude (amplitude) of the input signal with the amplitude value judging device 6, and is effective if the measured value is larger than a predetermined value stored in the amplitude value judging device 6. It is determined as a desired input signal (output is 1), and if it is less than that, it is determined as noise (output is 0). That is, when the amplitude of the input signal is larger than the specified value, a graph in which the presence or absence of phase modulation is emphasized as shown in FIG. 3 is obtained.

The AND circuit 7 ANDs the result of the judgment by the amplitude value judging device 6 and the output of the adder 4 to make the amplitude of the input signal larger than the specified value (output: 1). By outputting only the output result of the adder 4 which is large, a graph as shown in FIG. 3 in which the presence or absence of the phase modulation is emphasized can be obtained.

Therefore, according to the third embodiment, when only noise is input as an input signal, it is possible to distinguish between noise and an effective desired input signal, and only noise is input. Also in this case, since the result of normalizing the amplitude is not output, an erroneous judgment result is not obtained using the normalized result as a judgment material.

Embodiment 4 The fourth embodiment attempts to more accurately determine the presence or absence of phase modulation using all signal values of an input signal, and utilizes the fact that a signal is expressed on a complex plane.

FIG. 6 is a block diagram of a phase modulation signal detecting device according to the fourth embodiment. In the fourth embodiment, a phase modulation signal detecting device different from those of the first to third embodiments is described for ease of explanation. The basic configuration is shown. Therefore, the basic configuration (A / D converter 2 to adder 40) of the phase modulation signal detection device may be the device shown in FIG. 2 as described later.

In FIG. 6, as a new configuration according to the fourth embodiment, an adder 40 sequentially accumulates and accumulates input signals sequentially A / D converted by the A / D converter 2, and 8 is an adder. This is a display as output validity determination means for displaying the accumulation results (complex numbers) of 40 on a two-dimensional coordinate plane (complex plane). Here, in the two-dimensional coordinate plane (complex plane), the real part of the complex number is represented on the horizontal axis, and the imaginary part is represented on the vertical axis.

The operation of the thus configured phase modulation signal device according to Embodiment 4 will be described with reference to FIG. The signal input to the A / D converter 2 is set to A at every sampling period (also 10 ns) unique to the A / D converter 2.
The output of the A / D converter 2 is output to the adder 40 every sampling period.

The adder 4 sequentially adds and integrates the A / D converted input signals, and accumulates the latest value in an internal memory. The display 8 sequentially reads out the latest accumulation result of the adder 40 and displays the value (complex number representation) on a two-dimensional coordinate plane (complex plane) on the screen.

How the presence or absence of phase modulation can be expressed by the above processing will be described. If the signal is a simple signal without phase modulation, the input signal can be expressed as sin (2πFt) + i · cos (2πFt) (complex number expression).

Therefore, the accumulation result of the adder 40 is as follows: Σ (sin (2πFt) + i · cos (2πFt)) = Σsin (2πFt) + i · Σcos (2πFt) = (constant 1) × (−cos (2πFt) + i Sin (2πFt)) + (constant 2)

If the above (constant 1) and (constant 2) are ignored and attention is paid to the other parts, this expression showing the accumulation result of the adder 40 expresses a circular motion on a complex plane.
That is, when the input signal is a simple signal that is not phase-modulated, as a result of adding the signal values, a “one circle” is drawn on the complex plane of the display 8 as shown in FIG.

On the other hand, if the input signal is a simple signal that is phase-modulated, the sign of the signal stored in the adder 40 is inverted during the integration, and is displayed on the complex plane of the display 8 as shown in FIG. "Multiple circles" are drawn. In this case, if there is a phase-modulated portion, a new circle is drawn. Therefore, FIG. 8 shows a case where the phase is modulated once.

The drawing direction of the plurality of circles (the traveling direction of the trajectory) is reversed every time the phase is modulated. This is a phenomenon that occurs because the sign of the signal stored in the adder 40 is inverted when phase-modulated.

Therefore, according to the fourth embodiment, a signal value is expressed by using a complex number which is a general expression method, and an integrated value of the signal value expressed by a complex number (also a complex number)
Is displayed on the complex plane of the display 8, so that whether or not the input signal is phase-modulated can be seen at a glance according to the shape of the figure (circle) drawn on the complex plane of the display 8. Thus, the efficiency of determining the presence / absence of phase modulation increases.

Even when noise is mixed in the input signal, the data used for drawing the figure on the complex plane uses all the data input so far, so that the noises cancel each other out. Thus, the adverse effects of noise can be minimized.

As described above, it goes without saying that the same output display form and effect can be obtained even when the output signal of the device shown in FIG.

Embodiment 5 Generally, a figure (X (i), Y (i)) on an XY plane (where i = 1, 2,...)
, N) can be calculated by the following equation. (Area) = (Σx (i) × y (i + 1) −Σx (i +
1) × y (i)) / 2 However, when i = N, i + 1 is set to 1.

This area has a direction (sign) such as a so-called integration direction. For example, this is a positive sign when a figure (for example, a circle) is drawn counterclockwise, and a negative sign when it is drawn clockwise. . As described in the fourth embodiment, in the case of phase modulation, the drawing direction (increase / decrease direction of the area value) of the figure changes, and in the fourth embodiment, the figures drawn on the complex plane are integrated. The presence or absence of phase modulation can be detected based on the direction in which the area increases or decreases.

FIG. 9 is a block diagram of a phase modulation signal detecting apparatus according to the fifth embodiment. For ease of explanation, the fifth embodiment differs from the first to third embodiments in the same way as the fourth embodiment. 3 shows a basic configuration of a different phase modulation signal detection device. Therefore, the basic configuration of the phase modulation signal detection device (A / D converter 2
The adder 40) may be the device shown in FIG. 2 as described later.

In FIG. 9, as a new configuration according to the fifth embodiment, reference numeral 9 denotes a figure showing the accumulation result of the adder 40 drawn on the complex plane of the display 8 based on the integrated value of the adder 40 ( This is an area calculation device as area calculation means for sequentially calculating the area of (circle). The area calculation device 9 calculates the area with the area of the figure drawn leftward as positive and the area of the figure drawn rightward as negative (see FIG. 10). In FIG. 10, when figures are drawn in the order of the numbers, the signs of the areas are different from each other.

Next, the fifth embodiment configured as described above
The operation of the phase modulation signal device according to the above will be described with reference to FIG. Here, the device shown in FIG. 9 has the same basic operation as the operation of the device described in the fourth embodiment, and thus the detailed description is omitted, but the operation is different from the operation of the device described in the fourth embodiment. Is the operation of the part of the area calculation device 9, and the operation related to this part will be described.

The area calculating device 9 sets the area of the figure drawn leftward to be positive and the area of the figure drawn rightward to negative from the locus (coordinate point) indicating the accumulation result of the adder 41.
The area of the figure is sequentially calculated, and the display 8 outputs and displays the value of the calculated area.

First, consider a case where a simple signal that is not phase-modulated is an input signal. As described in the fourth embodiment, the figure on the complex plane in this case is a circle, which has a shape that is drawn in a certain direction. Therefore, the output value of the area calculation device 8 is “monotonically increasing or monotonically decreasing”.

On the other hand, consider the case where a simple signal subjected to phase modulation is an input signal. As described in Embodiment 4,
In this case, the figure on the coordinate plane is a plurality of circles, and the drawing directions of the adjacent circles are reversed. Therefore, the output of the area calculation device 9 repeats “from increase to decrease or from decrease to increase” every time phase modulation is performed. FIG. 11 shows a graph of the output state of the area calculator 9. The graph of FIG. 11 may be displayed on the display 8 instead of the area value.

Therefore, according to the fifth embodiment, a signal value is expressed by using a complex number which is a general expression method, and a circle which is a change in shape of a figure drawn on a complex plane of the display 8 is displayed. Is calculated as a numerical value by the area calculating device 8 and the change (numerical value) is output and displayed on the display 8, so that the operator may erroneously determine the shape output and displayed on the display 8. Thus, it becomes clear at a glance whether or not the input signal is phase-modulated, and the efficiency of determining the presence or absence of phase modulation is increased.

As described above, it is needless to say that the same output display form and effect can be obtained even when the output signal of the device shown in FIG.

Further, as shown in FIG.
In the same manner as in the second embodiment, an amplitude normalizing device 5 for removing amplitude modulation applied to an input signal before A / D conversion is provided, unnecessary amplitude modulation is removed, and the efficiency of determining the presence or absence of phase modulation is provided. May be increased.

Embodiment 6 FIG. When an input signal is represented by s (t) and a complex number, ｛s (t) is generally Δs regardless of whether the signal is phase-modulated or non-phase-modulated. (T)｝ ² is a non-phase modulated signal having a frequency twice as high as s (t).

This is a process of multiplying an original signal represented by a complex number by "-1" in the equation, so that the component of "-1" disappears by squaring to perform the original phase modulation. This is because there is no signal.

Since the value of the area S (t) described in the fifth embodiment increases in proportion to the frequency of the signal, s (t) and {s (t)} ^{2 for a} signal that is not phase-modulated. (S1 (t) and S2 (t), respectively)
Is S1 (t) / S2 (t) = 2.

This is for the following reason. {S (t)} ²
Is １ ／ of the radius of the circle corresponding to s (t) on the complex plane (since the signal frequency is doubled).
Double. Therefore, the area drawn by a circle making a circuit about {s (t)} ² is １ ／ of the area drawn by a circle making a circuit about s (t). Since {s (t)} ² draws a circle twice while drawing, the total area of {s (t)} 2 is 1/4 + ／ = 1/2, so that the area of s (t) is 1 / 2, and the area ratio is S1 (t) / S2 (t) = 1 / (1/2) = 2.

On the other hand, if the input signal is a signal that is phase-modulated, S2 (t) takes the same value as a signal that is not phase-modulated, but the shape of the graph showing the area value for S1 (t) is 11 shows a "graph in which the area value monotonically increases", and the area value is smaller than that in the case where the input signal is a signal that is not phase-modulated. Accordingly, the area ratio is S1 (t) / S2 (t) = X (X is 2 or more).

Therefore, after calculating S1 (t) / S2 (t), it is possible to determine the presence or absence of phase modulation by comparing the ratio and determining whether the ratio is 2 or more.

FIG. 13 is a block diagram of a phase modulation signal detecting apparatus according to the sixth embodiment. For simplicity of explanation, the sixth embodiment is similar to the first to third embodiments in the same manner as the fourth to fifth embodiments. Shows the basic configuration of a different phase modulation signal detection device. Accordingly, the basic configuration of the phase modulation signal detection device (A / D converter 2 to adder 41, A / D converter 2 to adder 42 (excluding the squarer)) is shown in FIG. 2 as described later. It may be a device.

In FIG. 13, as a new configuration according to the sixth embodiment, reference numeral 10 denotes a squarer which removes a phase modulation component by squaring an input signal (represented by a complex number). An area ratio judging device as phase modulation judging means for judging whether an input signal is phase-modulated by comparing output results of two systems.

Next, the sixth embodiment configured as described above will be described.
Will be described with reference to FIG. Here, the device shown in FIG. 13 has the same basic operation as the operation of the device described in the fifth embodiment, and thus the detailed description is omitted, but the operation is different from the operation of the device described in the fifth embodiment. Is the operation of the squarer 10 and the area ratio determination device 11, and the operation related to this portion will be described.

The input signal A / D converted by the A / D converter 2 is branched into two systems and input to the adder 41 and the squarer 10, respectively. The signal input to the squarer 10 is input to the adder 42 after the square processing as described above.

In the adders 41 and 42, the integration of the signal values (sequential calculation of the coordinate points on the trajectory) is performed in the same manner as in the fifth embodiment.
1 and 92, and the area calculators 91 and 92 calculate the area in the same manner as in the fifth embodiment, and output the area to the area ratio determination device 11.

Then, the area ratio determination device 11 compares the two areas and determines S1 (t) / S2 based on the above description.
After calculating (t), the area ratio is compared and the value is “2”.
, Or whether the value is greater than or equal to the value. The determination result may be output and displayed on the display 8 by the area ratio determination device 11, for example.

Therefore, according to the sixth embodiment, a signal value is expressed using a complex number, which is a general expression method, and the area of a circle which is the shape of a figure drawn on a complex plane is calculated by an area calculating apparatus. It is calculated as a numerical value from 91 and 92, and it is determined whether or not the input signal is phase-modulated by comparing the two, so that the operator does not erroneously determine the shape displayed and displayed on the display 8, The efficiency of determining the presence or absence of phase modulation increases.

Embodiment 7 FIG. The amplitude normalizing device 2 described in the second embodiment is newly added to the device of the sixth embodiment,
Even if the amplitude normalizing device 2 removes unnecessary amplitude modulation applied to the input signal before performing A / D conversion, if only noise is input as an input signal, the new device configuration will be used to reduce noise. Is erroneously treated as a valid signal and the presence or absence of phase modulation is determined.

In the third embodiment, an apparatus configuration for preventing such erroneous determination based on the level of an input signal by providing an amplitude value determination apparatus 6 has been proposed. In the sixth embodiment, an area for detecting the presence or absence of phase modulation is proposed. Focusing on the provision of the calculation device 8,
In the seventh embodiment, a method will be described in which the input signal is determined to be noise from a change in the output value of the area calculation device 8.

The method will be described specifically. As described in the fifth embodiment, the area value is monotonically increased or decreased when the input signal is a simple signal that is not phase-modulated, and is fixed at a fixed interval when the input signal is a simple signal that is phase-modulated. Repeat from increase to decrease and decrease to increase.

Therefore, when only the noise is the input signal, the area value is irregularly and irregularly repeated from decrease to increase and decrease to increase. If this change in the area value is detected, it can be easily determined that the input signal is noise.

FIG. 14 is a block diagram of a phase modulation signal detecting device according to the seventh embodiment. In the seventh embodiment, the first to third embodiments are similar to the fourth to sixth embodiments for ease of explanation.
3 shows a basic configuration of a phase modulation signal detection device different from that of FIG.
Therefore, the basic configuration (A / D converter 2 to adder 40) of the phase modulation signal detection device may be the device shown in FIG. 2 as described later. In addition, the area calculation devices 91 and 92 are the first,
It corresponds to a second area calculating means.

In FIG. 14, as a new configuration according to the seventh embodiment, reference numeral 12 denotes a noise determination device that determines whether or not an input signal is noise based on the output of the area determination device 9.

Next, the second embodiment configured as described above
Will be described with reference to FIG. Here, the device shown in FIG. 14 has the same basic operation as the operation of the device described in the sixth embodiment, and thus the detailed description is omitted, but the operation is different from the operation of the device described in the sixth embodiment. Is the operation of the noise determination device 12, and the operation related to this portion will be described.

The area calculating device 9 calculates the area of the figure drawn by the locus (circle) moving on the complex plane, and its output is taken into the noise judging device 12. When the input signal is only noise, the area value taken into the noise determination device 12 is irregularly and irregularly repeated from decrease to increase and decrease to increase.

When the noise determination device 12 detects a change from an irregular increase in the area value to a decrease from an irregular increase, and a change from the decrease to an increase, the noise determination device 12 determines that the input signal is noise and determines the presence or absence of phase modulation. Absent.

Therefore, according to the seventh embodiment, when the noise determination device 12 detects a change of the area value from irregular increase to decrease, and decrease to increase, the input signal is noise. Is not determined to determine the presence / absence of phase modulation, so that the efficiency of determining the presence / absence of phase modulation can be improved.

[0112]

According to the present invention, a large amount of data is used at the time of phase modulation determination, the influence of noise included in the input signal is reduced as much as possible, and the possibility of erroneous determination is eliminated as much as possible. Can be done

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a phase modulation signal detection method according to an embodiment.

FIG. 2 is an explanatory diagram of a phase modulation signal detection device according to the first embodiment.

FIG. 3 is an explanatory diagram of a phase modulation signal detection device according to the first embodiment.

FIG. 4 is an explanatory diagram of a phase modulation signal detection device according to a second embodiment.

FIG. 5 is an explanatory diagram of a phase modulation signal detection device according to a third embodiment.

FIG. 6 is an explanatory diagram of a phase modulation signal detection device according to a fourth embodiment.

FIG. 7 is an explanatory diagram of a phase modulation signal detection device according to a fourth embodiment.

FIG. 8 is an explanatory diagram of a phase modulation signal detection device according to a fourth embodiment.

FIG. 9 is an explanatory diagram of a phase modulation signal detection device according to a fifth embodiment.

FIG. 10 is an explanatory diagram of a phase modulation signal detection device according to a fifth embodiment.

FIG. 11 is an explanatory diagram of a phase modulation signal detection device according to a fifth embodiment.

FIG. 12 is an explanatory diagram of a phase modulation signal detection device according to a fifth embodiment.

FIG. 13 is an explanatory diagram of a phase modulation signal detection device according to a sixth embodiment.

FIG. 14 is an explanatory diagram of a phase modulation signal detection device according to a seventh embodiment.

FIG. 15 is an explanatory diagram of a conventional phase modulation signal detection method.

FIG. 16 is an explanatory diagram of a conventional phase modulation signal detection method.

FIG. 17 is an explanatory diagram of a conventional phase modulation signal detection method.

FIG. 18 is an explanatory diagram of a conventional phase modulation signal detection method.

[Explanation of symbols]

1 frequency measuring device, 2 A / D converter, 3, 31 to 3
n delay element, 4, 40, 41, 42 adder, 5 amplitude normalizing device, 6 amplitude value judging device, 7 AND circuit,
8 display, 9, 91, 92 area calculation device, 10 squarer, 11 area ratio judgment device, 12 noise judgment device.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04L 27/18-27/22

Claims (8)

(57) [Claims] 1. A phase modulation signal detecting device for detecting the presence or absence of phase modulation of an input signal based on a signal obtained by delaying the phase of the input signal according to the wavelength of the input signal and the input signal. A plurality of delay means for outputting a signal with a delay of a predetermined phase, and an output selected from the outputs of the plurality of delay means according to the wavelength of the input signal, and the selected output and the input signal; A phase modulation signal detecting device, comprising: an adding unit for adding the phase modulation signal. 2. An A / D converter for A / D-converting an input signal, wherein the plurality of delay units have different amounts of phase to be delayed for each phase corresponding to a sampling period of the A / D converter. The phase modulation signal detection device according to claim 1, wherein: 3. An output validity judging means for judging whether the output of the adding means is valid or not based on the magnitude of the reference signal amplitude and the magnitude of the input signal amplitude. 3. The phase modulation signal detection device according to 1 or 2. 4. An apparatus according to claim 1, further comprising an area calculating means for calculating an area of a locus drawn by an output of said adding means on a complex plane based on an output of said adding means.
The phase modulation signal detection device according to any one of the above. 5. The phase-modulated signal detection device according to claim 4, further comprising output display means for outputting and displaying a complex plane and a locus drawn by an output of the addition means on the complex plane. 6. The phase modulation signal detection device according to claim 4, wherein the output display means outputs an area value calculated by the area calculation means. 7. The apparatus according to claim 1, further comprising signal amplitude normalizing means for normalizing the signal amplitude of the input signal.
7. The phase modulation signal detection device according to any one of claims 1 to 6. 8. The area calculating means includes a first area calculating means for obtaining an area based on an input signal and a second area calculating means for obtaining an area based on a signal obtained by squaring the input signal. The phase modulation signal detection device according to claim 4, further comprising a phase modulation determination unit configured to determine whether or not phase modulation of the input signal is performed based on an output of the second area calculation unit.