JPH10210509A - Tone signal detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the presence of phase inversion by finding a phase change through an arithmetic operation and comparing the phase change with a prescribed value because a phase of a PCM signal is changed when there is a prescribed relationship between a sample number of the PCM signal and a period of a tone signal being a detection object and phase inversion takes place in the PCM signal. SOLUTION: A discrete Fourier transform DFT arithmetic section 11, once receiving a sample stream of PCM signals performs DFT arithmetic operation to the signal to find the PCM signals is a frequency region and provides outputs of the result, a real part R and an imaginary part Q to a phase calculation section 12. The phase calculation section 12 calculates a phase PH of the PCM signal by using an arithmetic equation relating to the polarity of the real part R and the imaginary part Q. A phase inversion discrimination section 13 calculates a change in the phase PH based on a difference between the current phase PH and the phase PH calculated for a preceding processing frame. When a sampling number and a period of a tone signal have a prescribed relationship and no phase inversion takes place in the PCM signal, since the phase PH is constant, the phase difference is compared with a threshold. When the difference is higher than the threshold, it is discriminated that there is phase inversion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tone signal detecting device for detecting a tone signal from a pulse code modulated signal (hereinafter, referred to as a PCM signal) transmitted using a telephone line or the like.

[0002]

2. Description of the Related Art FIG.
FIG. 1 is a configuration diagram showing a conventional tone signal detection device disclosed in Japanese Patent Application Publication No. 0-105, in which reference numeral 1 denotes a discrete Fourier transform (hereinafter, referred to as DFT) of a PCM signal in a time domain to obtain a power component of a frequency domain. A DFT calculator for extracting a power W1 having a frequency f1; a DFT calculator 2 for performing a DFT calculation using a PCM signal in a time domain as an input signal; and extracting a power W2 having a frequency f2 among power components in a frequency domain; Reference numeral 3 denotes an integrator for integrating the entire PCM signal in the time domain to calculate the power Wb of the entire PCM signal. Reference numeral 4 denotes a power ratio W2 / W1 of the power W2 to the power W1 and a power ratio Wb / W2 of the power Wb to the power W2. W2 is a comparator that compares W2 with predetermined thresholds a and b and determines the presence or absence of a tone signal based on the comparison result.

Next, the operation will be described. A PCM signal transmitted using a telephone line may include a voice signal and the like in addition to a modem signal transmitted and received by a facsimile apparatus. Therefore, when a facsimile apparatus or the like performs transmission and reception of a modem signal, it is necessary to detect a training signal appearing at the head of the modem signal and then execute a process such as demodulation at a subsequent stage. Incidentally, FIG. 37 shows the power spectrum of the PCM signal. In general, the power component of the audio signal is represented as shown by a solid line in FIG. 29
The power component of the training signal of the modem is represented as a dotted line in the figure. As can be seen from the figure, this training signal is substantially equivalent to a signal obtained by superimposing three tone signals having power components of respective frequencies of 0.5 kHz, 1.7 kHz and 2.9 kHz.

As is apparent from FIG. 37, when the frequency is around 1 kHz, the power component of the audio signal is relatively large, but the power component of the tone signal does not exist. On the other hand, when the frequency is around 2.9 kHz, the power component of the tone signal is relatively large.
It has the characteristic that the power component of the audio signal is extremely small.

Therefore, a conventional tone signal detecting device detects a tone signal as described below by utilizing such a feature. First, the DFT operator 1 calculates P in the time domain.
When a CM signal is input, a DFT operation is performed using the PCM signal as an input signal, and power W1 having a frequency of 1 kHz is extracted from power components in the frequency domain.

[0006] On the other hand, the DFT operation unit 2 has a PC in the time domain.
When the M signal is input, the P signal
A DFT operation is performed using the CM signal as an input signal, and the power W2 having a frequency of 2.9 kHz among the power components in the frequency domain.
Is extracted.

[0007] The integrator 3 integrates the entire PCM signal in the time domain to calculate the power Wb of the entire PCM signal. When the powers W1, W2, and Wb are obtained in this way, the comparator 4 obtains the power ratio W2 / W1 of the power W2 to the power W1, and also obtains the power ratio Wb / W2 of the power Wb to the power W2. And the comparator 4
If the power ratio W2 / W1 is larger than the threshold a and the power ratio Wb / W2 is smaller than the threshold b, it can be determined that the PCM signal has the above-described characteristics.
It determines that the tone signal has arrived, and outputs a signal indicating that fact.

[0008]

Since the conventional tone signal detecting device is constructed as described above, the tone signal can be extracted from the PCM signal. However, the tone signal detecting device has means for detecting the phase inversion of the tone signal. However, even if a tone signal with phase inversion is included in the PCM signal, there is a problem that it is not possible to determine the presence or absence of phase inversion.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a tone signal detecting device capable of determining the presence or absence of a phase inversion of a tone signal.

[0010]

According to a first aspect of the present invention, there is provided a tone signal detecting apparatus for comparing the change in the phase amount calculated by the phase amount calculating means with a predetermined value to determine whether or not the input signal is inverted. Is determined.

According to a second aspect of the present invention, there is provided a tone signal detecting apparatus for specifying a signal form of an input signal based on a result of determination by a tone signal presence / absence determination means and a phase inversion presence / absence determination means.

According to a third aspect of the invention, there is provided a tone signal detecting apparatus for selecting an arithmetic expression in accordance with a result of the determination by the polarity determining unit and a result of the comparison by the absolute value comparing unit, and real numbers calculated by the absolute value calculating unit. The absolute value of the part and the imaginary part is substituted into the arithmetic expression to calculate the phase amount of the input signal.

According to a fourth aspect of the present invention, there is provided a tone signal detecting apparatus which selects an arithmetic expression according to a result of the determination by the polarity determining unit and a result of the comparison by the absolute value comparing unit, and a real number calculated by the absolute value calculating unit. The absolute value of the part or the imaginary part and the square root of the sum of squares calculated by the square-sum calculation unit are substituted into the arithmetic expression to calculate the phase amount of the input signal.

According to a fifth aspect of the present invention, there is provided a tone signal detecting apparatus for dividing a real part by an imaginary part or dividing an imaginary part by a real part based on a comparison result of an absolute value comparing part.
The division result is compared with a predetermined value, and the inverse trigonometric function is linearly approximated based on an arithmetic expression selected based on the comparison result.

According to a sixth aspect of the present invention, there is provided a tone signal detecting apparatus which divides a real part or an imaginary part by a square root of a sum of squares based on a comparison result of an absolute value comparing unit, and sets the division result to a predetermined value. The comparison is performed, and the inverse trigonometric function is linearly approximated based on an arithmetic expression selected based on the comparison result.

According to a seventh aspect of the present invention, there is provided a tone signal detecting device, wherein a difference value between a current phase amount calculated by the phase amount calculating means and a past phase amount delayed by a plurality of frames by the delay unit is set to a predetermined value. And the presence or absence of phase inversion of the input signal is determined.

In the tone signal detecting device according to the present invention, the difference value between the current phase amount calculated by the phase amount calculating means and the past phase amount delayed by the delay unit is smoothed. The calculated difference value is added to the past phase amount.

According to a ninth aspect of the present invention, there is provided a tone signal detecting device, wherein the phase amount delayed by the first delay circuit and the second
And smoothes the difference value with the phase amount delayed by the delay circuit, multiplies the smoothed difference value by a predetermined coefficient, and adds the multiplication result to the phase amount delayed by the delay unit. It was done.

According to a tenth aspect of the present invention, there is provided a tone signal detecting apparatus comprising: a plurality of phase amount compensating units for compensating past phase amounts by means different from each other; and an input signal based on outputs of the plurality of phase amount compensating units. And a plurality of difference value comparing sections for determining the presence or absence of the phase inversion of the input signal, and finally determining the presence or absence of the phase inversion of the input signal based on the determination results of the plurality of difference value comparing sections.

In the tone signal detecting device according to the present invention, when the determination result of the tone signal presence / absence determination means changes from no tone signal to presence and the first set time elapses, the phase amount calculation means calculates the tone signal. A first storage unit for storing the calculated phase amount, and a phase value calculated by the phase amount calculation means when the determination result of the tone signal presence / absence determination means changes from no tone signal to presence and a second set time elapses. A second storage unit for storing the amount, calculating a difference value between the phase amount stored by the first storage unit and the phase amount stored by the second storage unit, and calculating the difference value by a predetermined value. In this case, the presence or absence of the phase inversion of the input signal is determined.

According to a twelfth aspect of the invention, there is provided a tone signal detecting device which finally inverts the phase of an input signal based on the present judgment result by the difference value comparing section and the past judgment result held in the result holding section. Is determined.

According to a thirteenth aspect of the present invention, there is provided a tone signal detecting device, wherein a signal form of an input signal is changed to a phase inverted tone signal,
The non-phase inverted tone signal or the non-tone signal is specified.

According to a fourteenth aspect of the present invention, when the determination result of the tone signal presence / absence determination means changes from no tone signal to presence, the presence of phase inversion inputted within a certain period after the change is determined. The determination result of the phase inversion presence / absence determination means shown in FIG.

According to a fifteenth aspect of the present invention, in the case where the signal form is specified as the validity of the determination result of the phase inversion presence / absence determining means, the input is performed within a certain period after the determination result is input. The determination result of the phase inversion presence / absence determination means indicating the presence of the phase inversion is invalidated.

In the tone signal detecting device according to the present invention, only when the determination result of the phase inversion presence / absence determination means indicating the presence of the phase inversion is input at least twice or more,
The signal form is specified as having phase inversion.

In the tone signal detecting apparatus according to the present invention, the power calculated by the power calculating means on the transmitting side and the power calculated by the power calculating means on the receiving side are compared, and the Fourier on the higher power side is compared. The output of the conversion means is selected.

The tone signal detecting device according to the eighteenth aspect compares the total band power on the transmitting side and the total band power on the receiving side calculated by the full band power calculating means, and compares the total band power on the receiving side with the larger total band power. The output of the Fourier transform means is selected.

In the tone signal detecting apparatus according to the nineteenth aspect, the signal-to-noise ratio on the transmitting side and the signal-to-noise ratio on the receiving side calculated by the noise ratio calculating means are compared, and the signal-to-noise ratio is high. The output of the Fourier transform means on the side is selected.

The tone signal detecting device according to the twentieth aspect of the present invention includes a Fourier transform unit, a power calculating unit, a tone signal presence / absence determining unit, and a signal type specifying unit for each channel, while selecting a channel for specifying a signal type. This is provided with a selecting means for selecting.

A tone signal detecting apparatus according to a twenty-first aspect of the present invention comprises a power calculating means, a tone signal presence / absence determining means, and a signal form specifying means for each channel, while selecting means for selecting a channel for specifying a signal form. It is provided with.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a block diagram showing a tone signal detecting device according to Embodiment 1 of the present invention.
Reference numeral 1 denotes a DFT operation unit (Fourier transform means) for performing a discrete Fourier transform (hereinafter referred to as DFT) on a time domain PCM signal to obtain a frequency domain PCM signal.
A phase amount calculator (phase amount calculator) that calculates the phase amount PH of the PCM signal based on the values of the real part R and the imaginary part Q of the PCM signal obtained by the calculator 11, and 13 is calculated by the phase amount calculator 12. A phase inversion presence / absence determination unit (phase inversion presence / absence determination means) that determines the presence / absence of phase inversion of the PCM signal by comparing the obtained change in the phase amount PH with the threshold a.

Next, the operation will be described. First, DFT
The arithmetic unit 11 generates a PCM signal in the time domain, that is, a sample sequence x [0], x [1],..., X [2N of the PCM signal.
-1], a DFT operation is performed using the sample sequence of the PCM signal as an input signal, and PCM in the frequency domain is performed.
Find the signal X [k].

[0033]

(Equation 1)

Where the values of N and k in the equation (1) are integers, and the values of N and k are as follows when the number of samples is 2N.
The number of samples 2N is k of the period of the tone signal to be detected.
It shall be selected to be doubled. That is, when the frequency of the tone signal to be detected is f and the sampling frequency is fs, values of N and k satisfying the following equation (2) are selected. 2N = (fs / f) × k (2)

The DFT operation unit 11 calculates D
When the FT operation is performed, the operation result is output to the phase amount calculation unit 12. Since the operation result is usually a complex number, the operation result is divided into a real part R and an imaginary part Q and output. The DFT operation unit 11 performs a DFT operation and outputs the operation result every time 2N samples are input. Therefore, the 2N samples are regarded as one processing unit. Called.

When the calculation result is output from the DFT calculation unit 11, the phase amount calculation unit 12 determines the polarity of the real part R and the imaginary part Q of the calculation result. When the polarities of the real part R and the imaginary part Q are determined, an arithmetic expression according to the determination result is selected as described below. When R> 0 Phase amount PH = tan ^-1 (Q / R) When R <0 and Q ≧ 0 Phase amount PH = π + tan ^-1 (Q / R) When R <0 and Q <0 Phase amount PH = −π + tan ⁻¹ (Q / R) When R = 0 and Q> 0 Phase amount PH = π / 2 When R = 0 and Q <0 Phase amount PH = −π / 2

Then, when an operation formula is selected according to the determination result, the phase amount calculation unit 12 calculates the phase amount PH of the PCM signal by substituting the real part R and the imaginary part Q into the operation expression,
The phase amount PH, which is the result of the calculation, is used to determine whether phase inversion exists
Output to 3.

When the phase amount PH is output from the phase amount calculation unit 12, the phase inversion presence / absence determination unit 13
The change amount of H is calculated. That is, the current phase amount PH output from the phase amount calculation unit 12 and the past phase amount PH output from the phase amount calculation unit 12 in the previous processing frame.
Is calculated as the amount of change.

The phase inversion presence / absence determining unit 13 compares the amount of change with the threshold value a, and if the amount of change is larger, determines that the PCM signal has phase inversion, and determines the threshold value a.
Is larger, it is determined that there is no phase inversion in the PCM signal. When the values of N and k are selected so as to satisfy Equation (2), usually, if there is no phase inversion in the PCM signal,
This is because the phase amount PH has a constant value, whereas if the PCM signal has a phase inversion, the phase amount PH has a property of changing by π before and after the phase inversion. When the phase inversion presence / absence determination unit 13 determines the presence / absence of the phase inversion, the determination result RJ is output, and a series of processing ends.

As is clear from the above, the first embodiment
According to the above, the phase amount P calculated by the phase amount calculation unit 12
Since the change in H is compared with the threshold value a to determine whether or not the PCM signal has phase inversion, if the PCM signal includes a tone signal, it is determined whether or not the tone signal has phase inversion. It has the effect of being able to.

Embodiment 2 FIG. 2 is a block diagram showing a tone signal detecting apparatus according to Embodiment 2 of the present invention. In the figure, the same reference numerals as those in FIG. 1 denote the same or corresponding parts, and a description thereof will be omitted. Reference numeral 14 denotes a power calculation unit (power calculation unit) that calculates the power PW of the PCM signal from the real part R and the imaginary part Q of the PCM signal obtained by the DFT calculation unit 11, and 15 denotes the P calculated by the power calculation unit 14.
A tone presence / absence determination unit (tone signal presence / absence determination means) for determining the presence / absence of a tone signal by comparing the power PW of the CM signal with a threshold value b, and a determination result TJ of the tone presence / absence determination unit 15 and a phase inversion presence / absence determination unit 13 P based on the determination result RJ of
It is a determination result output unit (signal form specifying unit) for specifying the signal form of the CM signal.

Next, the operation will be described. The operations of the DFT operation unit 11, the phase amount calculation unit 12, and the phase inversion presence / absence determination unit 13 are the same as those in the first embodiment, and thus the description is omitted. When the real part R and the imaginary part Q of the PCM signal in the frequency domain are output from the DFT operation part 11, the power calculating part 14 substitutes the real part R and the imaginary part Q into the following equation (3), Calculate the signal power PW. Power PW = (real part R) ² + (imaginary part Q) ² ... (3)

When the power calculating section 14 outputs the power PW of the PCM signal, the tone presence / absence determining section 15
The power PW of the PCM signal is compared with the threshold value b. If the power PW of the PCM signal is higher, it is determined that a tone signal is present. If the threshold value b is higher, it is determined that there is no tone signal. I do.

In this manner, when the judgment result TJ indicating the presence / absence of a tone signal is output from the tone presence / absence determination section 15 and the determination result RJ indicating the presence / absence of phase inversion is output from the phase inversion existence determination section 13, The result output unit 16 specifies the signal form of the PCM signal based on the determination result TJ and the determination result RJ.

Specifically, as shown in FIG. 3, the determination result TJ is "1" (determination that there is a tone signal),
When the determination result RJ is “1” (determination that the phase inversion exists), the signal form of the PCM signal is specified as “the phase inversion tone is present”. Also, the judgment result TJ
Is "0" (determination that there is no tone signal) and the determination result RJ is "1" (determination that phase inversion is present), the signal form of the PCM signal is changed to "phase inverted tone". None ".

If the judgment result TJ is "1" (judgment that there is a tone signal) and the judgment result RJ is "0" (judgment that there is no phase inversion),
Holds the signal form specified in the previous processing frame (for example, if the signal form specified in the previous processing frame is “with phase inversion tone”, this time also specifies the signal form as “with phase inversion tone” Do). Further, when the determination result TJ is “0” (determination that there is no tone signal) and the determination result RJ is “0” (determination that there is no phase inversion), the signal form of the PCM signal As “no phase inversion tone”.

As is clear from the above, the second embodiment
According to the above, the PCM based on the determination result TJ of the tone presence / absence determination unit 15 and the determination result RJ of the phase inversion presence / absence determination unit 13
Since the signal form of the signal is specified, it is possible to detect the tone signal included in the PCM signal and to determine whether or not the tone signal has phase inversion.

Embodiment 3 FIG. 4 is a configuration diagram showing a phase amount calculation unit 12 of a tone signal detection device according to Embodiment 3 of the present invention. In the figure, reference numeral 21 denotes an absolute value for calculating an absolute value | R | of a real part R of a PCM signal. Arithmetic unit, 22 is P
An absolute value calculator 23 calculates the absolute value | Q | of the imaginary part Q of the CM signal. The absolute value | R | of the real part R calculated by the absolute value calculator 21 and the absolute value | R | A comparator (absolute value comparing unit) that compares the absolute value | Q | of the imaginary part Q, 24 is a polarity determining unit that determines the polarity of the real part R of the PCM signal, and 25 is the polarity of the imaginary part Q of the PCM signal. It is a polarity determination unit for determination.

Reference numeral 26 denotes a determination result R of the polarity determination unit 24.
PO, the determination result QPO of the polarity determination unit 25 and the comparator 23
An arithmetic expression is selected according to the comparison result CP, and the absolute value | R of the real part R calculated by the absolute value calculation unit 21
And the absolute value | Q | of the imaginary part Q calculated by the absolute value calculation unit 22 is substituted into the arithmetic expression to calculate the phase amount PH of the PCM signal.

A selector 27 refers to the comparison result CP of the comparator 23 and selects and outputs the smaller one of the absolute value | R | or the absolute value | Q |. A selector which selects and outputs the absolute value of the absolute value | R | or the absolute value | Q | which is not smaller, and 29 outputs the absolute value output from the selector 27 from the selector. A divider 30 that divides by the obtained absolute value, 30 is an inverse trigonometric function operation unit that substitutes the division result DV of the divider 29 into an arc tangent function, and performs an inverse trigonometric function operation, 31 is a determination result RPO of the polarity determination unit 24, An arithmetic expression according to the determination result QPO of the polarity determination unit 25 and the comparison result CP of the comparator 23 are selected, and the operation result TF of the inverse trigonometric function operation unit 30 is substituted into the operation expression to substitute the phase amount P of the PCM signal.
This is a calculation result output unit for calculating H.

Next, the operation will be described. Since the configuration other than the phase amount calculation unit 12 is the same as that of the first embodiment and the like, the operation of the phase amount calculation unit 12 will be mainly described. First, when the real part R of the PCM signal is output from the DFT operation part 11, the absolute value calculating part 21 calculates and outputs the absolute value | R | of the real part R. Further, when the imaginary part Q of the PCM signal is output from the DFT calculating part 11, the absolute value calculating part 22 calculates and outputs the absolute value | Q | of the imaginary part Q.

On the other hand, the polarity judging section 24 includes the DFT calculating section 1
When the real part R of the PCM signal is output from 1, the polarity of the real part R is determined, and the determination result RPO is output.
However, if the real part R is greater than or equal to 0, “0” is output, and if the real part R is smaller than 0, “1” is output. Further, when the imaginary part Q of the PCM signal is output from the DFT operation unit 11, the polarity determination unit 25 determines the polarity of the imaginary part Q,
The result QPO is output. Where the imaginary part Q is 0
If this is the case, “0” is output, and if the imaginary part Q is smaller than 0, “1” is output.

The comparator 23 includes an absolute value calculating section 21
When the absolute value | R | of the real part R is output from the control unit and the absolute value | Q | of the imaginary part Q is output from the absolute value calculation unit 22, the absolute value | R | is compared with the absolute value | Q | The comparison result CP is output. However, if the absolute value | R | is greater than the absolute value | Q |, “0” is output, and the absolute value | R |
If smaller, "1" is output. When the absolute value | R | is equal to the absolute value | Q |, even if “0” is output, “1” is output.
May be output.

When the comparison result CP is output from the comparator 23, the selector 27 refers to the comparison result CP and determines the absolute value | R | or the absolute value | Q | Select and output. Also, the selector 28
When the comparison result CP is output from the comparator 23, the comparator 23 refers to the comparison result CP and selects and outputs the absolute value | R | or the absolute value | Q | whichever is smaller.

When the absolute value is output from both the selector 27 and the selector 28, the divider 29 converts the absolute value output from the selector 27 by the absolute value output from the selector 28, as described below. Divide. Since the absolute value output from the selector 28 is equal to or greater than the absolute value output from the selector 27, the division result DV becomes a value of 0 or more and 1 or less. When absolute value | R | ≧ absolute value | Q | DV = | Q | / | R | • When absolute value | R | <absolute value | Q | DV = | R | / | Q |

When the division result 29 is output from the divider 29, the inverse trigonometric function operation section 30 outputs the division result D
V is substituted into the following inverse tangent function to perform an inverse trigonometric function operation. TF = tan ^-1 (DV) (4) As a method of easily performing this inverse trigonometric function operation, for example, a TF value for a representative value of the division result DV is calculated in advance and stored on a storage medium such as a memory. Is prepared, and the value of TF is obtained by reading the value of this table every time the division result DV is output.

The operation result output unit 31 outputs the determination results RPO and QPO from the polarity determination unit 24 and the polarity determination unit 25, respectively, and outputs the comparison result CP from the comparator 23 as described above. As shown in FIG. 5, an arithmetic expression according to these determination results is selected. When the calculation formula is selected in this way, the calculation result TF of the inverse trigonometric function calculation unit 30 is substituted for the calculation formula, the phase amount PH of the PCM signal is calculated, and the processing of the phase calculation unit 12 is completed.

Here, the operation of the operation result output unit 31 is shown in FIG.
This will be described more specifically with reference to FIG. First, the polarities of the real part R and the imaginary part Q are both positive and the absolute value |
If R | is smaller than the absolute value | Q |
When plotted on the −Y plane (X indicates a real part and Y indicates an imaginary part), the plot is made at the position of point A in FIG.
H can be represented by the angle between the point A, the origin, and the positive X axis. The calculation result TF of the inverse trigonometric function calculation unit 30 is the point B
And the angle between the origin and the positive X-axis. Therefore, between the phase amount PH and the calculation result TF, PH = π / 2
It is geometrically clear that the relationship has a relationship of −TF. In this case, the determination result RPO is “0”, the determination result QPO is “0”, and the comparison result CP is “1”. From 5, the arithmetic expression of PH = π / 2-TF is selected, and an arithmetic expression that satisfies the above-described geometric relationship is selected. Therefore, the calculation result output unit 31 calculates the phase amount PH by substituting the calculation result TF into the calculation formula.

Next, when the polarities of the real part R and the imaginary part Q are both positive and the absolute value | R | is larger than the absolute value | Q |, the phase amount PH and the calculation result TF match. So
In this case, an arithmetic expression of PH = TF is simply selected to obtain the phase amount PH.

Next, when the polarity of the real part R is negative and the polarity of the imaginary part Q is positive and the absolute value | R | is larger than the absolute value | Q |, the PCM signal is expressed on the XY plane ( X is the real part, Y
Is plotted at the position of point A in FIG. 7, and the phase amount PH can be represented by the angle between point A, the origin, and the positive X axis. The inverse trigonometric function operation unit 3
The calculation result TF of 0 can be represented by the angle between the point B, the origin, and the positive X axis. Accordingly, it is geometrically clear that the phase amount PH and the calculation result TF have a relationship of PH = π-TF. In this case, the determination result RPO is “1” and the determination result QPO Is "0" and the comparison result CP is "0", so that the arithmetic expression of PH = π-TF is selected from FIG. 5, and an arithmetic expression satisfying the above-described geometric relationship is selected. Therefore, the calculation result output unit 31
The calculation result TF is substituted into the calculation formula to calculate the phase amount PH.

Next, when the polarity of the real part R is positive and the polarity of the imaginary part Q is negative and the absolute value | R | is larger than the absolute value | Q |, the PCM signal is expressed on the XY plane ( X is the real part, Y
Is plotted at the position of the point A in FIG. 8, and the phase amount PH can be represented by the angle between the point A, the origin, and the positive X-axis. The inverse trigonometric function operation unit 3
The calculation result TF of 0 can be represented by the angle between the point B, the origin, and the positive X axis. Therefore, it is geometrically clear that there is a relationship of PH = −TF between the phase amount PH and the calculation result TF. In this case, the determination result RPO is “0” and the determination result QPO is Since “1” and the comparison result CP are “0”, the arithmetic expression of PH = −TF is selected from FIG. 5, and an arithmetic expression satisfying the above-described geometric relationship is selected. Therefore, the calculation result output unit 31 calculates the phase amount PH by substituting the calculation result TF into the calculation formula.

It should be noted that although other combinations of the determination results and the like are not particularly described, the results shown in FIG. 5 can be obtained by combining all the determination results and the like in consideration of the above-described geometric relationship.

As is apparent from the above, the third embodiment
According to the method described above, when a method of reading a value of a table created in a storage medium in advance is used as a method of performing an inverse trigonometric function operation on a DV output from the divider 29, the value of the division result DV is 0 or more. , The size of the table created in the storage medium can be reduced.

Embodiment 4 FIG. 9 is a configuration diagram showing the phase amount calculation unit 12 of the tone signal detection device according to the fourth embodiment of the present invention. In the figure, the same reference numerals as in FIG. Reference numeral 32 denotes a square-sum operation unit for calculating the square root SQ of the sum of squares of the real part R and the imaginary part Q of the PCM signal, and 33 denotes the determination results RPO and QPO of the polarity determination units 24 and 25 and the comparison result CP of the comparator 23. And the absolute value | R | of the real part R calculated by the absolute value calculation unit 21 or the absolute value | Q | of the imaginary part Q calculated by the absolute value calculation unit 22 and the square. This is a phase amount calculation unit that calculates the phase amount PH of the PCM signal by substituting the square root SQ of the sum of squares calculated by the sum calculation unit 32 into the calculation expression.

A divider 34 divides the absolute value output from the selector 27 by the square root SQ of the sum of squares calculated by the square sum calculator 32, and 35 denotes an inverse sine of the division result DV of the divider 34. An inverse trigonometric function operation unit that substitutes for a function and performs an inverse trigonometric function operation.
O, an arithmetic expression according to the determination result QPO of the polarity determination unit 25 and the comparison result CP of the comparator 23 are selected, and the arithmetic result TF of the inverse trigonometric function arithmetic unit 35 is substituted into the arithmetic expression to determine the phase of the PCM signal. This is a calculation result output unit for calculating the quantity PH.

Next, the operation will be described. In the third embodiment, the division result DV of the divider 29 is substituted for the arctangent function to perform an inverse trigonometric function operation, and the phase amount PH is obtained based on the operation result TF. The function operation does not necessarily need to be the operation of the arctangent function, and may be, for example, the operation of the inverse sine function or the operation of the inverse cosine function. Therefore, a fourth embodiment will be described in which an inverse trigonometric function operation is performed using an inverse sine function.

First, when the real part R of the PCM signal is output from the DFT operation part 11, the absolute value calculating part 21 calculates and outputs the absolute value | R | of the real part R. Further, when the imaginary part Q of the PCM signal is output from the DFT calculating part 11, the absolute value calculating part 22 calculates and outputs the absolute value | Q | of the imaginary part Q. Further, when the real part R and the imaginary part Q of the PCM signal are output, the square sum calculating part 32 calculates the square root SQ of the square sum of the real part R and the imaginary part Q as described below. SQ = (R ² + Q ² ) ^1/2 (5)

On the other hand, the polarity judging section 24 has the DFT operation section 1
When the real part R of the PCM signal is output from 1, the polarity of the real part R is determined, and the determination result RPO is output.
However, if the real part R is greater than or equal to 0, “0” is output, and if the real part R is smaller than 0, “1” is output. Further, when the imaginary part Q of the PCM signal is output from the DFT operation unit 11, the polarity determination unit 25 determines the polarity of the imaginary part Q,
The result QPO is output. Where the imaginary part Q is 0
If this is the case, “0” is output, and if the imaginary part Q is smaller than 0, “1” is output.

The comparator 23 includes an absolute value calculating section 21
When the absolute value | R | of the real part R is output from the control unit and the absolute value | Q | of the imaginary part Q is output from the absolute value calculation unit 22, the absolute value | R | is compared with the absolute value | Q | The comparison result CP is output. However, if the absolute value | R | is greater than the absolute value | Q |, “0” is output, and the absolute value | R |
If smaller, "1" is output. When the absolute value | R | is equal to the absolute value | Q |, either "0" or "1" may be output.

When the comparison result CP is output from the comparator 23, the selector 27 refers to the comparison result CP and determines the absolute value | R | or the absolute value | Q | Select and output. Then, the divider 34
When the absolute value is output from the selector 27, the absolute value output from the selector 27 is divided by the square root SQ of the sum of squares calculated by the square sum calculation unit 32, as described below. The square root SQ of the sum of squares output by the square sum operation unit 32 is compared with the absolute value output by the selector 27, and is calculated by (absolute value output by the selector 27) ×） 2 ≦ square root SQ of the sum of squares. Is satisfied, the division result DV is 0 or more, and 1 / √2
The values are as follows. If absolute value | R | ≧ absolute value | Q | DV = | Q | / SQ · If absolute value | R | <absolute value | Q | DV = | R | / SQ

When the division result DV is output from the divider 34, the inverse trigonometric function operation section 35 outputs the division result D
V is substituted into the following inverse sine function to perform an inverse trigonometric function operation. TF = sin ^-1 (DV) (6) As a simple method of performing the inverse trigonometric function operation, a method of reading a value of a table created in a storage medium in advance in the same manner as in the third embodiment is used. is there.

The operation result output unit 36 outputs the determination results RPO and QPO from the polarity determination unit 24 and the polarity determination unit 25, respectively, and outputs the comparison result CP from the comparator 23, as described above. As shown in FIG. 5, an arithmetic expression according to these determination results is selected. When the calculation formula is selected in this way, the calculation result TF of the inverse trigonometric function calculation unit 35 is substituted for the calculation formula, the phase amount PH of the PCM signal is calculated, and the processing of the phase calculation unit 12 is completed.

As is apparent from the above, the fourth embodiment
According to the above, when a method of reading a value of a table created in a storage medium in advance is used as a method of performing an inverse trigonometric function operation on the division result DV output from the divider 34, the value of the division result DV is Since it is limited to the range of 0 or more and 1 / √2 or less, there is an effect that the capacity of the table created in the storage medium can be reduced.

Embodiment 5 FIG. 10 shows an inverse trigonometric function operation unit 3 of the tone signal detecting device according to the fifth embodiment of the present invention.
0 is a block diagram showing the configuration of the divider 29 in FIG.
The comparator 42 compares the division result DV with the threshold value c, 42 is a selector that selects the coefficient d or the coefficient e based on the comparison result C1 of the comparator 41, and 43 is the coefficient f or the coefficient f based on the comparison result C1 of the comparator 41. A selector for selecting a coefficient g; 44, a multiplier for multiplying the division result DV of the divider 29 by the coefficient selected by the selector 42; 45, a selector 43 for the multiplication result MU of the multiplier 44; This is an adder for adding coefficients.

Next, the operation will be described. Since the configuration other than the inverse trigonometric function operation unit 30 is the same as that of the third embodiment, the operation of the inverse trigonometric function operation unit 30 will be mainly described. First, when the division result DV is output from the divider 29, the comparator 41 compares the division result DV with the threshold value c and outputs the comparison result C1. When the division result DV is larger than the threshold value c, “1” is output, and when the division result DV is smaller than or equal to the threshold value c, “0” is output.

Then, the selector 42 refers to the comparison result C1 of the comparator 41, and selects the coefficient d when the division result DV is larger than the threshold value c, and otherwise selects the coefficient e. Further, the selector 43 refers to the comparison result C1 of the comparator 41, and selects the coefficient f when the division result DV is larger than the threshold c, and selects the coefficient g otherwise.

When the coefficient is selected from the selector 42 and the selector 43 in this way, first, the multiplier 44 multiplies the division result DV of the divider 29 by the coefficient selected by the selector 42 and then adds Unit 45 is a multiplier 44
And the coefficient selected by the selector 43 is added to the multiplication result MU, and the addition result is output as the calculation result TF of the inverse trigonometric function calculation unit 30.

Accordingly, the operation result TF of the inverse trigonometric function operation unit 30 is equivalent to linear approximation. To clarify the reason, the operation of the inverse trigonometric function operation unit 30 will be described more specifically. I do. First, for convenience of explanation, for example,
The threshold value c, coefficient d, coefficient e, coefficient f, and coefficient g are set as shown below. Threshold c = 0.5 Coefficient d = 0.542 Coefficient e = 0.929 Coefficient f = 0.143 Coefficient g = 0

The original operation expression of the inverse trigonometric function operation unit 30 is as shown in Expression (4) as described above. However, when the value of the threshold value c or the like is set as described above, the division result DV becomes 0.5. In the following case, since the coefficient e and the coefficient g are selected, the equation (4) is replaced by the following linear approximation equation. TF = tan ^-1 (DV) (4) TF = 0.928 x DV (7) On the other hand, when the division result DV is larger than 0.5, the coefficient d and the coefficient f are selected. , (4) is replaced by the following linear approximation. TF = 0.642 × DV + 0.143 (8)

FIG. 11 is an explanatory diagram for explaining the linear approximation. In the drawing, the solid line A shows the equation (4), the dotted line B shows the equation (7), and the dotted line C shows the equation (8). Is shown.

As is clear from the above, the division result DV of the divider 29 is compared with the threshold value c, and the inverse trigonometric function is linearly approximated based on the operation formula selected based on the comparison result C1. This has the effect of easily calculating trigonometric function operations.

In the fifth embodiment, the range of the division result DV is divided into two by comparison with the threshold value c, and the inverse trigonometric function is approximated by two straight lines.
The number of divisions is not limited to this.
You may make it more than one. Further, the division need not be performed.

In the fifth embodiment, the linear tangent function of the inverse tangent function is shown. However, the present invention is not necessarily limited to the arc tangent function. Can be approximated by a straight line. Incidentally, the inverse trigonometric function operation unit 3 in the fourth embodiment
When the inverse sine function of No. 5 is linearly approximated, the division result DV of the divider 34 may be compared with a threshold value c, and the inverse sine function may be linearly approximated based on the comparison result C1.

Embodiment 6 FIG. FIG. 12 is a block diagram showing the phase inversion presence / absence determining unit 13 of the tone signal detecting apparatus according to Embodiment 6 of the present invention. In the figure, reference numeral 51 denotes a phase amount PH calculated by the phase amount A delay memory (delay section) 52 for delaying, a delay memory (delay section) for delaying the phase amount PH delayed by the delay memory 51 by one frame, and 53 a phase amount calculation section 1
A difference unit (difference value comparison unit) for obtaining a difference value ΔPH between the current phase amount PH calculated by 2 and the past phase amount PH delayed by the delay memories 51 and 52, and 54 is obtained by the difference unit 53. A comparator (difference value comparison unit) that compares the difference value ΔPH with the threshold value a and determines whether or not the phase of the PCM signal is inverted.

Next, the operation will be described. Since the configuration other than the phase inversion presence / absence determination unit 13 is the same as that in the first embodiment, the operation of the phase inversion presence / absence determination unit 13 will be mainly described. When the current phase amount PH is output from the phase amount calculation unit 12, first, the delay memory 51 delays the current phase amount PH by one frame, and then the delay memory 52 further delays the phase amount PH by one frame. I do. Accordingly, the phase amount PH output from the delay memory 52 is delayed by two frames from the current phase amount PH.

In this way, when the current phase amount PH is delayed by two frames, the differentiator 53 sets the phase amount
2 and the delay memory 5
The difference value from the phase amount PH two frames before, which is the output of 2 ２
Calculate PH. However, in order to keep the difference value ΔPH always within the following range, when the difference value ΔPH is larger than π, 2π is subtracted from the difference value ΔPH, and the difference value ΔPH is −π or less. In this case, the difference value △ PH is 2π
Is added. π ≧ difference value △ PH> −π (9)

When the difference value ΔPH is output from the differentiator 53, the comparator 54 compares the difference value ΔPH with the threshold value a in the same manner as in the first embodiment, and Although the presence / absence of phase inversion is determined, erroneous determination due to the influence of noise or the like is reduced as compared with the first embodiment, and an effect that phase inversion can be detected more accurately is achieved.

The reason is that, in the first embodiment, the difference value △ between the current phase amount PH and the phase amount PH one frame before is given by
Since the PH is compared with the threshold a, when the phase inversion occurs in the middle of the processing frame n as shown in FIG. 14, the difference value ΔPH becomes only π / 2 at the maximum, and In order to be able to detect the phase inversion even when it occurs in the middle of a frame, the threshold value a is set to π /
Must be less than 2. On the other hand, in the sixth embodiment, the difference value ΔPH between the current phase amount PH and the phase amount PH two frames before is compared with the threshold value a. Even when the phase inversion occurs in the middle of the frame n, the difference value ΔPH increases up to π at the maximum, and the phase inversion can be detected even when the threshold value a is larger than π / 2. Since the threshold value a can be increased as compared with the above, when the value of the difference value ΔPH increases due to the influence of noise or the like, the difference value ΔPH exceeds the threshold value a and is erroneously determined to have phase inversion. The danger is reduced.

Although the sixth embodiment has been described with reference to the case where the difference value ΔPH between the current phase amount PH and the phase amount PH two frames before is obtained, the present invention is not limited to this. A difference value ΔPH from the phase amount of the above may be obtained.

Embodiment 7 FIG. 15 is a block diagram showing the phase inversion presence / absence determining unit 13 of the tone signal detecting apparatus according to Embodiment 7 of the present invention. In the figure, the same reference numerals as those in FIG. . 55 smoothes the difference value ΔP1 between the current phase amount PH calculated by the phase amount calculation unit 12 and the past phase amount PH delayed by the delay memory 51, and converts the smoothed difference value ΔP1A into the past value. A phase amount compensator 56 to be added to the phase amount PH is a subtractor for calculating a difference value ΔP1 between the current phase amount PH calculated by the phase amount calculator 12 and the past phase amount PH delayed by the delay memory 51. , 57
Is a smoothing circuit composed of a low-pass filter or the like for smoothing the difference value ΔP1, and 58 is a difference value obtained by smoothing the past phase amount PH delayed by the delay memory 51 by the smoothing circuit 57. Adder for adding ΔP1A, 5
Reference numeral 9 denotes a current phase amount P calculated by the phase amount calculation unit 12.
H + addition result PH of the adder 58+ {difference value between P1A}
This is a differentiator (difference value comparison unit) for obtaining PH.

Next, the operation will be described. In the first embodiment described above, the values of N and k are selected such that the number of samples 2N is k times the period of the tone signal to be detected. In this case, however, as described above,
If there is no phase inversion in the PCM signal, the phase amount PH becomes a constant value. However, when the values of N and k cannot be selected, that is, when the values of N and k that satisfy Expression (2) cannot be selected, N that approximately satisfies the relationship of Expression (2) as much as possible is used. And the value of k must be selected. In this case, the phase amount PH increases or decreases at a constant rate even if the PCM signal does not have phase inversion.

Therefore, in such a case, the difference value ΔPH between the current phase amount PH and the past phase amount PH is simply obtained and compared with the threshold value a as in the first embodiment. An error occurs when the phase amount PH changes at a constant rate, and the presence or absence of phase inversion cannot be accurately detected. Therefore,
The seventh embodiment compensates for such an error so that the presence or absence of phase inversion can be accurately detected.

Specifically, when the current phase amount PH is output from the phase amount calculating section 12, first, the delay memory 51
Delays the current phase amount PH by one frame. And
When the past phase amount PH delayed by one frame from the delay memory 51 is output from the delay memory 51, the subtractor 56 compares the current phase amount PH output from the phase amount calculation unit 12 with the past phase amount one frame before. The difference value ΔP1 from the PH is calculated.

When the difference value ΔP1 is output from the subtractor 56, the smoothing circuit 57 smoothes the difference value ΔP1 in order to obtain an average phase change amount between one processing frame. When the smoothed difference value ΔP1A, which is the average amount of phase change, is output from the smoothing circuit 57, the adder 58 compares the phase amount PH of the previous frame output from the delay memory 51 with respect to the phase amount PH output from the delay memory 51. The smoothed difference value △ P1
Add A. As a result, 1 input to the differentiator 59
The past phase amount PH + ΔP1A before the frame is a value in which a change that increases or decreases between one processing frame is considered. Therefore, when the differentiator 59 compares the current phase amount PH with the past phase amount PH, the influence of the change is removed.

As is apparent from the above, the seventh embodiment
According to this, the difference value ΔP1 between the current phase amount PH calculated by the phase amount calculation unit 12 and the past phase amount PH one frame before delayed by the delay memory 51 is smoothed, and the smoothed difference The value △ P1A is converted to the past phase amount PH.
, The phase inversion can be accurately detected even when the phase amount PH increases or decreases at a constant rate even though there is no phase inversion.

Embodiment 8 FIG. FIG. 16 is a block diagram showing the phase inversion presence / absence determining unit 13 of the tone signal detecting device according to the eighth embodiment of the present invention. In the figure, the same reference numerals as those in FIG. . Reference numerals 61 to 63 denote delay memories (delay units) for delaying the phase amount PH by one frame.
63 delays the current phase amount PH by h frames. Reference numeral 64 denotes a delay memory (first delay circuit) that delays the phase amount PH delayed by the delay memory 63 by at least one frame, and 65 denotes a delay memory that delays the phase amount PH delayed by the delay memory 64 by one frame ( (A second delay circuit).

The reference numeral 66 smoothes the difference value ΔP1 between the phase amount PH delayed by the delay memory 64 and the phase amount PH delayed by the delay memory 65, and adds a coefficient to the smoothed difference value ΔP1A. h,
A phase amount compensation circuit 67 for adding the multiplication result △ P1A × h to the phase amount PH delayed by the delay memory 63;
Is a subtractor that calculates a difference value ΔP1 between the phase amount PH delayed by the delay memory 64 and the phase amount PH delayed by the delay memory 65, and 68 is a low-pass filter or the like that smoothes the difference value ΔP1. Smoothing circuit, 6
9 is a difference value ΔP1A smoothed by the smoothing circuit 68
Is a multiplier which multiplies the multiplication result △ P1A × h of the multiplier 69 to the past phase amount PH delayed by the delay memory 63.

Next, the operation will be described. In the seventh embodiment, the case where the phase value PH one frame before is compensated for and the difference value ΔPH from the current phase amount PH is calculated is described. The difference value ΔPH from the phase amount PH may be obtained, and the same effect as in the seventh embodiment can be obtained.

Specifically, first, the delay memories 61 to 61
63 delays the current phase amount PH by h frames, then the delay memories 64 and 65 further delay the phase amount, and a phase amount PH delayed by n-1 frames from the current phase amount PH; The phase amount PH delayed by n frames from the current phase amount PH is output to the subtractor 67.

When the past phase amount PH delayed by n-1 frames and the past phase amount PH delayed by n frames are output, the subtracter 67 outputs the past phase amount delayed by n-1 frames. The difference value ΔP1 between the phase amount PH and the past phase amount PH delayed by n frames is calculated.

Thus, the difference value △
When P1 is output, a smoothing circuit 68 smoothes the difference value ΔP1 to obtain an average phase change amount between one processing frame in order to obtain a change amount between the h processing frames. The smoothed difference value ΔP1A is multiplied by a predetermined coefficient h. Then, the adder 70 calculates the multiplication result {P1A × h} which is the change amount between the h processing frames from the multiplier 69.
Is output, h output from the delay memory 63 is output.
The multiplication result △ P1A for the phase amount PH before the frame
× h is added. As a result, the past phase amount PH + １P1A × h before the h frame input to the differentiator 59 is represented by h
The value takes into account a change that increases or decreases between processing frames. Therefore, when the differentiator 59 compares the current phase amount PH with the past phase amount PH, the influence of the change is removed.

As is clear from the above, the eighth embodiment
According to, the difference value △ P1 between the phase amount PH before the (n-1) th frame and the phase amount PH before the nth frame is smoothed, and the smoothed difference value △ P1A is multiplied by a coefficient h,
Since the multiplication result △ P1A × h is added to the phase amount PH delayed by the delay memory 63, even if the phase amount PH increases or decreases at a constant rate despite no phase inversion, There is an effect that the phase inversion can be accurately detected.

Embodiment 9 FIG. FIG. 17 is a block diagram showing a phase inversion presence / absence determining section 13 of a tone signal detecting device according to Embodiment 9 of the present invention. In the figure, the same reference numerals as those in FIG. . 71 is a delay memory (delay unit), 72 is a multiplier for multiplying the difference value △ P1A smoothed by the smoothing circuit 68 by a coefficient (h-1), and 73 is a delay memory 7
The adder 74 adds the multiplication result △ P1A × (h−1) of the multiplier 72 to the phase amount PH before the h−1 frame delayed by 1. The reference numeral 74 denotes a current value calculated by the phase amount calculation unit 12. Addition result PH + 加 算 P1 of phase amount PH and adder 73
A difference unit (difference value comparison unit) for obtaining a difference value ΔPH from A × (h−1), 75 compares the difference value ΔPH obtained by the difference unit 74 with a threshold value m, and inverts the phase of the PCM signal. (Differential value comparing unit) for determining the presence or absence of
4 is a determination circuit (final determination unit) that calculates the logical product of the comparison result C2 of No. 4 and the comparison result C3 of the comparator 75.

Next, the operation will be described. In the eighth embodiment, the phase compensation circuit 66, the differentiator 59, and the comparator 54 are provided as a set to compensate for the change in the phase PH before h frame. However, as shown in FIG. ,
Another set of these may be provided to make a final determination based on the comparison result of the two comparators 54 and 75, and it is possible to more reliably determine the presence or absence of phase inversion.

Specifically, in the same manner as in the eighth embodiment, the phase amount PH + △ P1A × h in which the variation of the phase amount PH before the h-frame is compensated is obtained, and then the current phase amount PH is calculated.
And the phase amount PH + ΔP1A × h before the h frame are calculated, and the comparator 54 calculates the difference ΔPH and the threshold a
And outputs the comparison result C2. On the other hand, h-1
Phase amount PH that compensates for the change in phase amount PH before the frame
+ △ P1A × (h−1), and then the current phase amount P
H and the phase amount PH before the h−1 frame PH + ΔP1A × (h−
The comparator 75 compares the difference value ΔPH with the threshold value m, and outputs a comparison result C3.

Thus, the comparator 54 and the comparator 7
When the comparison results C2 and C3 are output from No. 5 respectively, the determination circuit 76 calculates the logical product of the comparison result C2 and the comparison result C3, and makes a final determination on the presence or absence of phase inversion. That is, only when both the comparators 54 and 75 indicate the determination result indicating that the phase is inverted, the final determination result RJ indicating that the phase is inverted is output.

As is clear from the above, the ninth embodiment
According to the method described above, the final determination of the presence or absence of phase inversion is performed based on the determination results of the comparators 54 and 75. An effect that can be determined is achieved.

In the ninth embodiment, the configuration in which two sets of the phase amount compensating circuit, the differentiator, and the comparator are provided has been described. Further, in the ninth embodiment, the logical product of the comparison result C2 and the comparison result C3 has been described. However, the present invention is not limited to this. For example, a logical sum may be obtained. When three or more sets of the phase amount compensating circuit, the differentiator, and the comparator are provided, the determination circuit 76 may determine the presence or absence of phase inversion by taking a majority decision of a plurality of comparison results.

Embodiment 10 FIG. FIG. 18 is a block diagram showing a tone signal detecting apparatus according to Embodiment 10 of the present invention. In the figure, the same reference numerals as those in FIG. 2 denote the same or corresponding parts, and a description thereof will be omitted. 81 is a phase amount calculation unit 1
2 and the tone presence / absence determination unit 15
Is a phase inversion presence / absence determination unit (phase inversion presence / absence determination means) based on the determination result TJ.

FIG. 19 shows a tenth embodiment of the present invention.
Is a configuration diagram showing a phase inversion presence / absence determination unit 81 of the tone signal detection device according to the present invention. In FIG. When the signal level of the timer 82 changes from “0” to “1”, the timer 83 outputs the “0” level signal only during the set time T4 (first set time). The data holding circuit (first storage unit) 84 for storing the phase amount PH at the time when the determination result TJ of the tone presence / absence determination unit 15 changes from no tone signal to presence (changes from “0” to “1”). , Set time T5
A timer that outputs a signal of “0” level only during the (second set time).
When the data changes from “1” to “1”, the data holding circuit (second storage unit) stores the phase amount PH at the time of the change.

Reference numeral 86 denotes a difference unit (difference value comparison unit) for calculating a difference value ΔPH between the phase amount PH stored by the data holding circuit 83 and the phase amount PH stored by the data holding circuit 85. A comparator (difference value comparison unit) that compares the difference value ΔPH calculated by the differentiator 86 with a threshold value a to determine whether or not the PCM signal is inverted.

Next, the operation will be described. Since the configuration other than the phase inversion presence / absence determination unit 81 is the same as that of the second embodiment,
The operation of the phase inversion presence / absence determination section 81 will be mainly described.
First, the timer 82 constantly monitors the judgment result TJ of the tone presence / absence judging section 15, and when the judgment result TJ changes from no tone signal to present (changes from "0" to "1"), as shown in FIG. Then, a signal of "0" level is output only during the set time T4. Similarly to the timer 82, the timer 84 constantly monitors the determination result TJ of the tone presence / absence determining unit 15, and when the determination result TJ changes from no tone signal to presence (changes from "0" to "1"), As shown in FIG. 20, a "0" level signal is output only during the set time T5.

However, the set times T4 and T5 are set to values that satisfy the following relationship. 0 <T4 <T2−T3 T2−T3 <T5 <T2 × 2−T3 Here, T2 is a period of the phase inversion of the tone signal.
Reference numeral 3 denotes a tone presence / absence determining unit 1 after a tone signal is input.
Reference numeral 5 denotes a response time until the determination result TJ is changed to the presence of a tone signal.

The data holding circuit 83 is connected to the timer 8
When the signal level of the output signal of No. 2 changes from "0" to "1", the phase amount PH at the time of the change (at point A in the figure) is stored. When the signal level of the output signal of the timer 84 changes from “0” to “1”, the data holding circuit 85
The phase amount PH at the time of the change (time B in the figure) is stored.

When the phase amount PH at the time of change is stored in this way, the differentiator 86 sets the phase amount PH (the phase amount PH at the time point A) stored by the data holding circuit 83 and the data holding circuit PH. The phase amount PH stored by 85
A difference value ΔPH from (the phase amount PH at the time point B) is calculated. Then, the comparator 87 outputs the difference value ΔP
When H is output, the difference value ΔPH is compared with a threshold value a to determine whether or not the PCM signal is inverted, as in the second embodiment.

As is apparent from the above, the first embodiment
According to 0, the difference value ΔPH between the phase amount PH at the time point A and the phase amount PH at the time point B is calculated to determine the presence or absence of the phase inversion. If the value is set to a value, the presence / absence of phase inversion can be determined based on the phase amount PH when the phase is stable, instead of the phase amount PH when the phase is unstable before and after the phase inversion. As a result, the phase inversion occurs instantaneously. However, even when the phase is gradually inverted over a certain period of time, the effect of accurately detecting the phase inversion can be obtained.

Embodiment 11 FIG. FIG. 21 is a block diagram showing the phase inversion presence / absence determining unit 13 of the tone signal detecting device according to the eleventh embodiment of the present invention. In the figure, the same reference numerals as those in FIG. . Reference numeral 88 denotes a delay memory (result holding unit) for delaying the judgment result RJ of the comparator 54 by one frame, 89 denotes a delay memory (result holding unit) for delaying the judgment result RJ delayed by the delay memory 88 by 1 frame, 90 Is a decision circuit (final decision circuit) which finally decides the presence or absence of phase inversion of the PCM signal by a majority decision of the current decision result RJ outputted from the comparator 54 and the past decision results RJ outputted from the delay memories 88 and 89, respectively. Determination unit).

Next, the operation will be described. Embodiment 6 except for the delay memories 88 and 89 and the judgment circuit 90.
Therefore, the operations of the delay memories 88 and 89 and the determination circuit 90 will be mainly described. When the judgment result RJ is output from the comparator 54 in the same manner as in the sixth embodiment, first, the delay memory 88 stores the judgment result RJ in the delay memory 88.
Is delayed by one frame, and the delay memory 89 further delays the determination result RJ by one frame.

As a result, the current judgment result RJ, the past judgment result RJ one processing frame before the present, and the past judgment result RJ two processing frames before the present are input to the judgment circuit 90. Will be. Thus, 3
When one determination result RJ is input, the determination circuit 90 finally determines the presence or absence of phase inversion based on the majority of the three determination results RJ, and outputs the determination result RJ.

As is clear from the above, the first embodiment
According to No. 1, a plurality of determination results RJ with different processing frames
, The presence / absence of phase inversion is finally determined, so that there is an effect that the presence / absence of phase inversion can be accurately determined without causing erroneous determination due to the influence of noise or the like.
In the eleventh embodiment, the case where the majority of the three determination results RJ are determined to finally determine the presence or absence of the phase inversion has been described. However, a plurality of determination results RJ may be used. It is not limited to RJ. Also, it is not always necessary to make a majority decision, and a logical operation such as a logical product or logical sum may be used.

Embodiment 12 FIG. Embodiments 2 to 11 above
In FIG. 22, the determination result KJ of the determination result output unit 16 is specified for one of two signal forms (with phase inversion tone and without phase inversion tone) as shown in FIG. As shown, it may be specified to one of three signal forms (a phase-inverted tone signal, a non-phase-inverted tone signal, and a non-tone signal).

Specifically, as shown in FIG. 22, the determination result TJ is "1" (determination that there is a tone signal), and the determination result RJ is "1" (phase inversion is present). In this case, the signal form of the PCM signal is specified as “phase inverted tone signal”. If the determination result TJ is “0” (determination that there is no tone signal) and the determination result RJ is “1” (determination that phase inversion is present), the signal form of the PCM signal Is specified as a “non-tone signal”.

Further, the judgment result TJ is "1" (judgment that there is a tone signal), the judgment result RJ is "0" (judgment that there is no phase inversion), and When the signal form is “phase inverted tone signal”,
The signal form specified in the previous processing frame is held, and the signal form of the PCM signal is specified as “phase inverted tone signal”. The determination result TJ is “1” (determination that there is a tone signal) and the determination result RJ
Is “0” (determined that there is no phase inversion), and
If the signal form in the previous state is other than the “phase inverted tone signal”, the signal form of the PCM signal is specified as “non-phase inverted tone signal”. Further, the judgment result TJ is “0”
(The determination that there is no tone signal) and the determination result RJ is “0” (the determination that there is no phase inversion), the signal form of the PCM signal is changed to “non-tone signal”. Identify.

Embodiment 13 FIG. FIG. 23 is a block diagram showing a judgment result output unit 16 of the tone signal detection device according to the thirteenth embodiment of the present invention. In FIG. When the change information is output from the change point detection unit 91, the change point detection unit 92 outputs the change information when the change is made (the signal level changes from “0” to “1”). Timer 93 outputs a signal of signal level “0” as long as possible, 93 is a logical product circuit for calculating the logical product of the determination result RJ of phase inversion presence / absence determination section 13 and the output of timer 92, 94 is the determination result of tone presence / absence determination section 15 The determination circuit specifies the signal form of the PCM signal based on the TJ and the output S1 of the AND circuit 93.

Next, the operation will be described. Since the configuration other than the determination result output unit 16 is the same as that of the second embodiment, the operation of the determination result output unit 16 will be mainly described. First, the change point detecting section 91 determines the determination result T of the tone presence / absence determining section 15.
J is monitored, and when there is a change from no tone signal to present (signal level changes from "0" to "1"), change information is output. Then, when the change information is output from the change point detecting section 91, the timer 92 changes the signal level of the output signal to "for a certain period of time T6 from the time when the change information is received, as shown in FIG. Change from "1" to "0". However, the fixed time T6 is set to a value that satisfies the following relationship. 0 <T6 <T2-T3

On the other hand, the logical product circuit 93 calculates the logical product of the determination result RJ of the phase inversion presence / absence determining section 13 and the output of the timer 92, and outputs the result to the determination circuit 94 as S1. As shown in FIG. 24, only when the determination result RJ is “1” (determination that phase inversion is present) and the output of the timer 92 is “1” (at the time of A),
Assuming that the determination result RJ of the phase inversion presence / absence determination unit 13 is valid, the determination result RJ is output as it is. Therefore,
At the time point B, the determination result RJ is “1”, but the output of the timer 92 is “0”, so that the determination result RJ of the phase inversion presence / absence determination unit 13 is invalidated and there is no phase inversion of the PCM signal. Is output (“0” level signal).

The determination circuit 94 specifies the signal form of the PCM signal based on the determination result TJ of the tone presence / absence determination section 15 and the output S1 of the AND circuit 93. In particular,
As shown in FIG. 25, when the determination result TJ is “1” (determination that there is a tone signal) and the output S1 of the AND circuit 93 is “1”, the signal form of the PCM signal Is specified as “with phase inversion tone”. Also,
If the determination result TJ is “0” (determination that there is no tone signal) and the output S1 of the AND circuit 93 is “1”, the signal form of the PCM signal is changed to “no phase-inversion tone”. Specify as follows.

When the judgment result TJ is "1" (judgment that there is a tone signal) and the output S1 of the AND circuit 93 is "0", it is specified in the previous processing frame. The signal form is retained (for example, if the signal form specified in the previous processing frame is “with phase inversion tone”, the signal form is also specified as “with phase inversion tone” this time). Further, the determination result TJ is “0” (determination that there is no tone signal), and
When the output S1 of the AND circuit 93 is “0”, P
The signal form of the CM signal is specified as “no phase inversion tone”.

As is clear from the above, the first embodiment
According to No. 3, when the determination result TJ of the tone presence / absence determination unit 15 changes from no tone signal to presence, the determination result of the phase inversion presence / absence determination unit 13 indicating the presence of phase inversion input within a fixed time T6 after the change. Since the RJ is invalidated, the determination result RJ indicating the presence of the phase inversion is erroneously made due to the influence of noise or the like during a period during which phase inversion cannot normally occur, that is, a period immediately after the tone signal is detected. This can be regarded as determination, and an effect that the presence / absence of phase inversion can be determined more accurately.

Embodiment 14 FIG. FIG. 26 is a configuration diagram showing the determination result output unit 16 of the tone signal detection device according to the fourteenth embodiment of the present invention. In the figure, the same reference numerals as those in FIG. A timer 95 outputs a signal of a signal level "0" only when the change information is output from the change point detection unit 91 or the change point detection unit 97 for a certain period of time T6 or T7. An AND circuit for calculating the logical product of the judgment result RJ of 13 and the output of the timer 95, and 97 is the logical product circuit 9
6 is monitored, and the signal level is changed from “1” to “0”.
The change point detecting section 98 which outputs change information when the state changes to "1."
Is a determination circuit for specifying the signal form of the PCM signal on the basis of the output S2.

Next, the operation will be described. Since the configuration other than the determination result output unit 16 is the same as that of the second embodiment, the operation of the determination result output unit 16 will be mainly described. First, the change point detecting section 91 determines the determination result T of the tone presence / absence determining section 15.
J is monitored, and when there is a change from no tone signal to present (signal level changes from "0" to "1"), change information is output. On the other hand, the change point detecting section 97 monitors the output S2 of the AND circuit 96 and outputs change information when the signal level changes from “1” to “0”.

Then, the timer 95 is connected to the change point detecting section 91.
When the change information is output from, as shown in FIG. 27, only during a certain time T6 from the time when the change information is received,
The signal level of the output signal is changed from “1” to “0”. However, the fixed time T6 is set to a value that satisfies the following relationship. 0 <T6 <T2−T3 When the change information is output from the change point detecting unit 97, the timer 95 sets the time limit for a certain period of time T7 from the time when the change information is received, as shown in FIG. The signal level of the output signal is changed from “1” to “0”. However, the fixed time T
7 is set to a value that satisfies the following relationship. 0 <T7 <T2-T8

The logical product circuit 96 calculates the logical product of the determination result RJ of the phase inversion presence / absence determining section 13 and the output of the timer 95, and outputs the result to the change point detecting section 97 and the determining circuit 98 as S2. However, specifically, as shown in FIG. 27, only when the determination result RJ is “1” (determination that there is phase inversion) and the output of the timer 95 is “1”, (A1, A2), phase inversion presence / absence determination unit 1
The judgment result RJ of 3 is regarded as valid, and the judgment result RJ
J is output as it is. Therefore, at the time points B1 and B2, the determination result RJ is “1”, but the output of the timer 95 is “0”. Therefore, the determination result RJ of the phase inversion presence / absence determination unit 13 is invalidated, and the phase of the PCM signal is A signal indicating that there is no inversion is output (“0” level signal).

The determination circuit 98 specifies the signal form of the PCM signal based on the determination result TJ of the tone presence / absence determination section 15 and the output S2 of the AND circuit 96. In particular,
As shown in FIG. 27, when the determination result TJ is “1” (determination that there is a tone signal) and the output S2 of the AND circuit 96 is “1”, in principle, the PCM
Although the signal form of the signal is specified as “with phase inversion tone”, as shown in FIG. 28, when the determination result indicating that phase inversion is present for the first time after the tone signal is detected, the signal form is set to “phase inversion”. When a determination result indicating that there is phase inversion twice is obtained instead of "with inverted tone", the signal form is set to "with phase inverted tone".

The reason for this is that the method of determining that there is a phase inversion tone only after finding the second phase inversion is an effective method for preventing erroneous determination due to the influence of noise or the like.
Recommendation G. 165. Incidentally, FIG. 28 shows that the signal form is not determined to be “with phase inversion tone” even if the first phase inversion is detected after the tone is detected from the tone non-detection state. FIG. 10 is a state transition diagram showing that the signal form is “with phase inversion tone”. In the drawing, the signal form is set to "with phase inverted tone" only when in the phase inverted tone detection state, and the signal form is set to "without phase inverted tone" when in the other three states.

The determination circuit 98 determines that the determination result TJ is “0” (determination that there is no tone signal), and
When the output S2 of the AND circuit 96 is “1”, P
The signal form of the CM signal is specified as “no phase inversion tone”. When the determination result TJ is “1” (determination that there is a tone signal) and the output S2 of the AND circuit 96 is “0”, the signal form specified in the previous processing frame is changed. It is held (for example, if the signal form specified in the previous processing frame is “with phase inversion tone”, the signal form is specified as “with phase inversion tone” this time). Further, the determination result TJ is “0” (determination that there is no tone signal), and
When the output S2 of the AND circuit 96 is “0”, P
The signal form of the CM signal is specified as “no phase inversion tone”.

As is clear from the above, the first embodiment
According to No. 4, when the signal form is specified with the determination result RJ of the phase inversion presence / absence determination unit 13 as valid, the phase indicating the presence of phase inversion input within a certain period T7 after the input of the determination result RJ Decision result RJ of reversal presence / absence judgment unit 13
Is invalidated, the determination result RJ indicating the presence of phase inversion is erroneously determined by the influence of noise or the like during a period during which phase inversion cannot normally occur, that is, during a period immediately after phase inversion is detected. Thus, it is possible to determine the presence / absence of phase inversion more accurately. Further, the signal form is identified as having phase inversion only when the determination result RJ of the phase inversion presence / absence determination section 13 indicating that phase inversion is present is input at least twice, so that an error caused by noise or the like is further caused. An effect that the determination can be effectively prevented is achieved.

In the above-described fourteenth embodiment, when the determination result TJ of the tone presence / absence determining unit 15 becomes “0” (determination that there is no tone signal), the state transits to the tone non-detection state. (See FIG. 28) Alternatively, the power of the PCM signal may be monitored, and when the power becomes smaller than a predetermined threshold, the state may be changed to a tone non-detection state.

Embodiment 15 FIG. FIG. 29 is a block diagram showing a tone signal detecting apparatus according to Embodiment 15 of the present invention. In the figure, the same reference numerals as those in FIG. 2 denote the same or corresponding parts, and a description thereof will be omitted. 101 is a transmitting unit of the tone signal detecting device, 102 is a receiving unit of the tone signal detecting device, 10
3 compares the power PW calculated by the power calculation unit 14 of the transmission unit 101 with the power PW calculated by the power calculation unit 14 of the reception unit 102, and determines the determination result of the determination result output unit 16 on the side where the power PW is larger. A comparator (selecting means) 104 that makes only KJ effective, a DFT operation unit 104 on the side where the power PW is higher based on the comparison result C4 of the comparator 103
1 and the real part R and imaginary part Q of the PCM signal
Is a selector (selecting means) for selecting.

Next, the operation will be described. When a tone signal detecting device inputs a transmitting PCM signal and a receiving PCM signal, and it is necessary to specify a signal form for both of them, the tone signals to be detected are the transmitting PCM signal and the receiving PCM signal. Under the condition that they do not simultaneously exist (for example, half-duplex communication), if the tone signal detecting device is configured as shown in FIG. 29, the processing amount of the tone signal detecting device can be reduced and the configuration can be simplified. Can be

That is, the DFT operation unit 11 and the power calculation unit 1
4, the tone presence / absence determination unit 15 and the determination result output unit 16 are provided in both the transmission unit 101 and the reception unit 102, respectively, but the phase amount calculation unit 12 and the phase inversion presence / absence determination unit 1
3 can be shared. Specifically, first, the comparator 103 compares the power PW calculated by the power calculation unit 14 of the transmission unit 101 with the power PW calculated by the power calculation unit 14 of the reception unit 102. Is output as the comparison result C4 indicating whether is larger.

When the comparator 103 outputs the comparison result C4, the selector 104 selects the real part R and the imaginary part Q of the PCM signal obtained by the DFT operation unit 11 having the higher power PW based on the comparison result C4. And outputs the real part R and the imaginary part Q to the phase amount calculation unit 12.
As a result, the phase amount calculation unit 12 calculates the phase amount PH based on the real part R and the imaginary part Q of the PCM signal obtained by the DFT calculation unit 11 on the side where the power PW is large.

The comparison result C4 of the comparator 103 is also output to the determination result output unit 16 of the transmission unit 101 and the determination result output unit 16 of the reception unit 102. , Own tone presence / absence determination unit 15
The signal form is specified based on the determination result of the phase inversion presence / absence determination unit 13, and the determination result output unit 16 on the side where the power PW is low, regardless of the determination result of the tone presence / absence determination unit 15 on its own side, The form is forcibly set to “no phase inversion tone”.

As is apparent from the above, the first embodiment
According to No. 5, the power PW calculated by the power calculation unit 14 of the transmission unit 101 is compared with the power PW calculated by the power calculation unit 14 of the reception unit 102, and the power PW calculated by the DFT calculation unit 11 on the side where the power PW is larger is calculated. Since the real part R and the imaginary part Q of the obtained PCM signal are selected and output to the phase amount calculating unit 12, the phase amount calculating unit 12 and the phase inversion existence determining unit 13 can be shared. As a result, the processing amount of the tone signal detecting device can be reduced, and the configuration can be simplified.

Embodiment 16 FIG. FIG. 30 is a block diagram showing a tone signal detecting apparatus according to Embodiment 16 of the present invention. In the figure, the same reference numerals as those in FIG. 29 denote the same or corresponding parts, and a description thereof will be omitted. Reference numeral 105 denotes an all-band power calculation unit (all-band power calculation means) for calculating the entire-band power APW of the PCM signal. The whole band power APW calculated by the whole band power calculation unit 105 is compared, and the whole band power APW is calculated.
This is a comparator (selection unit) that validates only the determination result KJ of the determination result output unit 16 on the side where W is large.

Next, the operation will be described. When a tone signal detecting device inputs a transmitting PCM signal and a receiving PCM signal, and it is necessary to specify a signal form for both of them, the tone signals to be detected are the transmitting PCM signal and the receiving PCM signal. Under the condition that they do not exist at the same time (for example, half duplex communication), if the tone signal detecting device is configured as shown in FIG. 30, the processing amount of the tone signal detecting device can be reduced and the configuration can be simplified. Can be

That is, the DFT operation unit 11 and the power calculation unit 1
4, the tone presence / absence determination unit 15 and the determination result output unit 16 are provided in both the transmission unit 101 and the reception unit 102, respectively, but the phase amount calculation unit 12 and the phase inversion presence / absence determination unit 1
3 can be shared. Specifically, first, the full-band power calculating section 105 of the transmitting section 101 and the receiving section 102 transmits the full-band power A
Calculate PW.

[0148]

(Equation 2)

Then, the full-band power calculating section 105 of the transmitting section 101 and the receiving section 102 outputs the full-band power A of the PCM signal.
When the PW is calculated, the comparator 106 calculates the total band power AP calculated by the full band power calculation unit 105 of the transmission unit 101.
W is compared with the whole band power APW calculated by the whole band power calculation unit 105 of the receiving unit 102, and a comparison result C5 indicating which side of the whole band power APW is larger is output.

When the comparator 106 outputs the comparison result C5, the selector 104 selects the real part R and the imaginary part of the PCM signal obtained by the DFT operation unit 11 having the larger total band power APW based on the comparison result C5. The part Q is selected, and its real part R and imaginary part Q are output to the phase amount calculating part 12. As a result, the phase amount calculation unit 12 outputs the entire band power A
P calculated by the DFT operation unit 11 on the side where PW is large
Phase amount PH based on real part R and imaginary part Q of CM signal
Is calculated.

The comparison result C5 of the comparator 106 is also output to the determination result output unit 16 of the transmission unit 101 and the determination result output unit 16 of the reception unit 102, and the determination result output unit on the side where the total band power APW is large. 16 specifies the signal form based on the determination results of the tone presence / absence determination unit 15 and the phase inversion presence / absence determination unit 13 on its own side. Regardless of the determination result of the presence / absence determination unit 15 or the like, the signal form is forcibly set to “no phase inversion tone”.

As is clear from the above, the first embodiment
According to No. 6, the entire band power calculation unit 105 of the transmission unit 101
And the total band power AW calculated by the whole band power calculator 105 of the receiver 102.
Since the PWs are compared, the real part R and the imaginary part Q of the PCM signal obtained by the DFT operation unit 11 on the side where the total band power APW is large are selected and output to the phase amount calculation unit 12. Amount calculation unit 12 and phase inversion presence / absence determination unit 1
3 can be shared, and as a result, the processing amount of the tone signal detection device can be reduced and the configuration can be simplified.

Embodiment 17 FIG. FIG. 31 is a block diagram showing a tone signal detecting device according to a seventeenth embodiment of the present invention. In the drawing, the same reference numerals as those in FIG. 30 denote the same or corresponding parts, and a description thereof will be omitted. 107 is a power calculator 14
PW calculated by the above and the entire band power calculation section 105
An S / N calculator (noise ratio calculator) that calculates a signal-to-noise ratio (hereinafter, referred to as an S / N ratio) of the PCM signal based on the total band power APW calculated by
1 and the S / N ratio calculated by the S / N calculation section 107 of the receiving section 102 and the S / N ratio calculated by the S / N calculation section 107 of FIG.
A comparator (selecting means) that compares the N ratio and validates only the determination result KJ of the determination result output unit 16 on the higher S / N ratio side.

Next, the operation will be described. When a tone signal detecting device inputs a transmitting PCM signal and a receiving PCM signal, and it is necessary to specify a signal form for both of them, the tone signals to be detected are the transmitting PCM signal and the receiving PCM signal. Under the condition that they do not exist at the same time (for example, half-duplex communication), if the tone signal detector is configured as shown in FIG. 31, the processing amount of the tone signal detector can be reduced and the configuration can be simplified. Can be

That is, the DFT operation unit 11 and the power calculation unit 1
4, the tone presence / absence determination unit 15 and the determination result output unit 16 are provided in both the transmission unit 101 and the reception unit 102, respectively, but the phase amount calculation unit 12 and the phase inversion presence / absence determination unit 1
3 can be shared. Specifically, first, the S / N calculation unit 10 of the transmission unit 101 and the reception unit 102
7 calculates the S / N ratio of the PCM signal as shown below. S / N ratio = PW / (APW-PW) (11)

When the S / N calculating section 107 of the transmitting section 101 and the receiving section 102 calculates the S / N ratio of the PCM signal, the comparator 108 sets the S / N calculating section 107 of the transmitting section 101.
Is compared with the S / N ratio calculated by the S / N calculation unit 107 of the receiving unit 102, and a comparison result C6 indicating which side has a higher S / N ratio is output. .

When the comparator outputs the comparison result C6, the selector 104 outputs the real part R and the imaginary part of the PCM signal obtained by the DFT operation unit 11 having the higher S / N ratio based on the comparison result C6. The part Q is selected, and its real part R and imaginary part Q are output to the phase amount calculating part 12. As a result, the phase amount calculation unit 12 sets the D / S on the side with the larger S / N ratio.
The real part R of the PCM signal obtained by the FT operation unit 11
Then, the phase amount PH is calculated based on the imaginary part Q.

The comparison result C6 of the comparator 108 is also output to the determination result output unit 16 of the transmission unit 101 and the determination result output unit 16 of the reception unit 102, and the determination result output unit of the higher S / N ratio is output. Reference numeral 16 specifies the signal form based on the determination results of the tone presence / absence determination section 15 and the phase inversion presence / absence determination section 13 on its own side.
No. 6 forcibly sets the signal form to "no phase-inversion tone" irrespective of the judgment result of the tone presence / absence judgment unit 15 or the like on its own side.

As is clear from the above, the first embodiment
According to 7, the S / N ratio calculated by the S / N calculation unit 107 of the transmission unit 101 and the S / N calculation unit 10 of the reception unit 102
7, the real part R and the imaginary part Q of the PCM signal obtained by the DFT operation unit 11 on the higher S / N ratio side are selected, and the phase amount calculation unit 12 Since the output is performed, the phase amount calculation unit 12 and the phase inversion presence / absence determination unit 13 can be shared. As a result, the processing amount of the tone signal detection device can be reduced and the configuration can be simplified. It has an effect that can be done.

Embodiment 18 FIG. FIG. 32 is a configuration diagram showing a tone signal detecting apparatus according to Embodiment 18 of the present invention. In the figure, the same reference numerals as those in FIG. 2 denote the same or corresponding parts, and a description thereof will be omitted. 11a is a DFT operation unit (Fourier transform means) having the same function as the DFT operation unit 11.
And the PCM signal of channel 1 is used as an input signal. 1
Reference numeral 1b denotes a DFT operation unit (Fourier transform means) having the same function as the DFT operation unit 11;
Let the signal be the input signal. Reference numeral 11c denotes a DFT operation unit (Fourier transform means) having a function similar to that of the DFT operation unit 11, and uses the PCM signal of channel 3 as an input signal.

Reference numeral 111 denotes a counter (selection means) for specifying a channel for specifying a signal form. Reference numeral 112 denotes a DFT operation unit 11a, 1 based on the output SCH of the counter 111.
A selector (selecting means) 113 for selecting any one of the outputs 1b and 11c outputs a determination result RJ of the phase inversion presence / absence determination unit 13 to the determination result output unit 16 of the corresponding channel based on the output DCH of the counter 111. It is a multiplexer (selection means).

Next, the operation will be described. When the tone signal detecting device specifies the signal form of the PCM signal of a plurality of channels, if the tone signal detecting device is configured as shown in FIG. 32, the processing amount of the tone signal detecting device can be reduced and the configuration is simplified. can do.

That is, the DFT operation unit 11 and the power calculation unit 1
4, the tone presence / absence determination unit 15 and the determination result output unit 16 are provided for each channel, but the phase amount calculation unit 12 and the phase inversion presence / absence determination unit 13 can be shared. Specifically, the DFT calculation units 11a, 11b, and 11c of each channel start the DFT calculation when the outputs CH1, CH2, and CH3 of the counter 111 change from "1" to "0", as shown in FIG. Then, when the outputs CH1, CH2, and CH3 of the counter 111 change from "1" to "0", the DFT operation ends. The outputs CH1, CH2, CH3 of the counter 111 are
As shown in FIG. 33, they do not change at the same time, but change sequentially for each channel.

Then, the selector 112 sets the counter 11
1 based on the output SCH.
b or 11c is selected, but the counter 11
1 is, as shown in FIG.
DFT for which DFT operation has been completed in a certain processing frame
In order to select the output of the arithmetic unit, the SCH indicating the channel to be selected among CH1 to CH3 is output to the selector 112. Specifically, if the output SCH of the counter 111 is “1”, the output of the DFT operation unit 11a is selected and output to the phase amount calculation unit 12, and the output SC of the counter 111 is output.
If H is "2", the output of the DFT operation unit 11b is selected and output to the phase amount calculation unit 12, and if the output SCH of the counter 111 is "3", the output of the DFT operation unit 11c is selected. And outputs it to the phase amount calculator 12.

As a result, the phase amount calculating section 12 sets the phase amount P
After calculating H, the phase inversion presence / absence determination unit 13 outputs the determination result RJ to the demultiplexer 113, and the demultiplexer 113 outputs the determination result RJ of the phase inversion presence / absence determination unit 13 based on the output DCH of the counter 111 to the corresponding channel. Output to the judgment result output unit 16,
As shown in FIG. 33, CH1 is used to cause the demultiplexer 113 to output the determination result RJ of the phase inversion presence / absence determination unit 13 to the determination result output unit 16 of the corresponding channel.
Among them, the DCH indicating the channel to be output is output to the demultiplexer 113. Specifically, when the output DCH of the counter 111 is “1”, the determination result RJ of the phase inversion presence / absence determination unit 13 is output to the determination result output unit 16 of the channel 1, and the output DCH of the counter 111 is “2”. Then, the determination result RJ of the phase inversion presence / absence determination unit 13 is output to the determination result output unit 16 of the channel 2 and the counter 111
Is "3", the phase inversion presence / absence determination unit 1
The determination result RJ of No. 3 is output to the determination result output unit 16 of channel 3.

As is clear from the above, the first embodiment
8, according to the output SCH of the counter 111, D
One of the outputs of the FT calculation units 11a, 11b, and 11c is selected, and the determination result RJ of the phase inversion presence / absence determination unit 13 is output to the determination result output unit 16 of the corresponding channel based on the output DCH of the counter 111. Therefore, when the tone signal detection device specifies the signal form of the PCM signals of a plurality of channels, the phase amount calculation unit 12 and the phase inversion presence / absence determination unit 13 can be shared, and as a result, It is possible to reduce the processing amount of the tone signal detection device and to simplify the configuration.

Although the eighteenth embodiment has shown the case where the number of channels is three, the number of channels is two.
The same effects as those of the eighteenth embodiment can be obtained.

Embodiment 19 FIG. FIG. 34 is a configuration diagram showing a tone signal detecting apparatus according to Embodiment 19 of the present invention. In the figure, the same reference numerals as those in FIG. 32 denote the same or corresponding parts, and a description thereof will be omitted. 114a is the channel 1 P
A buffer for holding the CM signal, a buffer for holding the PCM signal of channel 2, and a buffer for holding the PCM signal of channel 2
Buffer 115 holds the PCM signal of
11 based on the output SCH.
A selector (selecting means) for selecting any one of the outputs b and 114c.

Next, the operation will be described. When the tone signal detecting device specifies the signal form of the PCM signal of a plurality of channels, if the tone signal detecting device is configured as shown in FIG. 34, the processing amount of the tone signal detecting device can be reduced and the configuration is simplified. can do.

That is, the power calculation unit 14, the tone presence / absence determination unit 15, and the determination result output unit 16 are provided for each channel, but the DFT operation unit 11, the phase amount calculation unit 12, and the phase inversion presence / absence determination unit 13 are provided. Can be shared. Specifically, the buffer 11 of each channel
4a, 114b, and 114c hold the number of past PCM signals corresponding to the processing frame length. As shown in FIG. Select the signal and DF
The SCH value is sequentially changed (for example, “1” → “2” → “3”) so as to be output to the T calculation unit 11. If the output SCH of the counter 111 is "1", the output of the buffer 114a is selected and D
Output to the FT operation unit 11 and output SCH of the counter 111
Is "2", the output of the buffer 114b is selected and output to the DFT operation unit 11, and the output SC of the counter 111 is output.
If H is “3”, the output of the buffer 114 c is selected and output to the DFT operation unit 11.

As a result, the DFT calculator 11 calculates the real part R and the imaginary part Q of the PCM signal, and
2 calculates the phase amount PH, and then determines whether or not phase inversion exists 1
3 outputs the determination result RJ to the demultiplexer 113, and the demultiplexer 113 outputs
Determination result RJ of phase inversion presence / absence determination unit 13 based on CH
Is output to the determination result output unit 16 of the corresponding channel, and the counter 111 sends the determination result RJ of the phase inversion presence / absence determination unit 13 to the demultiplexer 113 as shown in FIG. In order to output to DCH 16, the value of DCH is changed in synchronization with SCH. Specifically, when the output DCH of the counter 111 is “1”, the determination result RJ of the phase inversion presence / absence determination unit 13 is output to the determination result output unit 16 of the channel 1, and the output DCH of the counter 111 is “2”. Then, the determination result RJ of the phase inversion presence / absence determination unit 13 is output to the determination result output unit 16 of the channel 2. If the output DCH of the counter 111 is “3”, the determination result RJ of the phase inversion presence / absence determination unit 13 is output. Is output to the determination result output unit 16 of the channel 3.

As is apparent from the above, the first embodiment
According to No. 9, any one of the buffers 114a, 114b, and 114c is selected based on the output SCH of the counter 111, and the determination result RJ of the phase inversion presence / absence determination unit 13 is determined based on the output DCH of the counter 111. Is output to the determination result output unit 16 of
When the tone signal detection device specifies the signal form of the PCM signal of a plurality of channels, the DFT operation unit 11, the phase amount calculation unit 12, and the phase inversion presence / absence determination unit 13 can be shared. As a result, the processing amount of the tone signal detection device can be reduced, and the configuration can be simplified.

Although the nineteenth embodiment has been described for the case where the number of channels is three, the number of channels is two.
The same effect as that of the nineteenth embodiment can be obtained as long as the above is satisfied.

[0174]

As described above, according to the first aspect of the present invention, the change of the phase amount calculated by the phase amount calculating means is compared with a predetermined value to determine whether or not the input signal is inverted. With such a configuration, when a tone signal is included in the input signal, it is possible to determine the presence or absence of phase inversion of the tone signal.

According to the second aspect of the present invention, the signal form of the input signal is specified based on the results of the determination by the tone signal presence / absence determination means and the phase inversion presence / absence determination means. This has the effect of being able to detect the tone signal that is present and to determine the presence or absence of phase inversion of the tone signal.

According to the third aspect of the present invention, as a method of performing an inverse trigonometric function operation on a division result output from a divider, a method of reading a value of a table created in a storage medium in advance is used. Since the range of the value of the division result is limited, there is an effect that the capacity of the table can be reduced.

According to the fourth aspect of the present invention, as a method of performing an inverse trigonometric function operation on a division result output from a divider, a method of reading a value of a table created in a storage medium in advance is used. Since the range of the value of the division result is limited, there is an effect that the capacity of the table can be reduced.

According to the present invention, the real part is divided by the imaginary part or the imaginary part is divided by the real part based on the comparison result of the absolute value comparing part, and the result of the division is compared with a predetermined value. Since the inverse trigonometric function is configured to be linearly approximated based on the operation formula selected based on the comparison result,
There is an effect that the inverse trigonometric function operation can be easily calculated.

According to the invention of claim 6, the real part or the imaginary part is divided by the square root of the sum of squares based on the comparison result of the absolute value comparing section, and the division result is compared with a predetermined value. Since the inverse trigonometric function is configured to be linearly approximated based on the arithmetic expression selected based on the comparison result, there is an effect that the inverse trigonometric function operation can be easily calculated.

According to the present invention, the difference value between the current phase amount calculated by the phase amount calculating means and the past phase amount delayed by a plurality of frames by the delay unit is compared with a predetermined value. Since the configuration is such that the presence or absence of the phase inversion of the input signal is determined, there is an effect that the influence of noise or the like is reduced and the presence or absence of the phase inversion can be accurately determined.

According to the present invention, the difference between the current phase calculated by the phase calculator and the past phase delayed by the delay unit is smoothed, and the smoothed difference is calculated. Is added to the past phase amount, so that the presence / absence of phase inversion can be accurately determined even when the phase amount increases or decreases at a constant rate despite no phase inversion. There is.

According to the ninth aspect of the present invention, the difference between the phase amount delayed by the first delay circuit and the phase amount delayed by the second delay circuit is smoothed, and the smoothed value is obtained. The difference value is multiplied by a predetermined coefficient, and the multiplication result is added to the phase amount delayed by the delay unit, so that the phase amount increases or decreases at a constant rate despite no phase inversion. Even in the case of performing, there is an effect that the presence or absence of phase inversion can be accurately determined.

According to the tenth aspect of the present invention, a plurality of phase amount compensators for compensating for past phase amounts having different numbers of delay frames from each other, and a phase of an input signal based on outputs of the plurality of phase amount compensators, respectively. Since there are provided a plurality of difference value comparison units for determining the presence or absence of inversion and a final determination unit for finally determining the presence or absence of phase inversion of the input signal based on the determination results of the plurality of difference value comparison units. There is an effect that the presence or absence of the phase inversion can be determined more reliably without being affected by noise or the like.

According to the eleventh aspect, when the determination result of the tone signal presence / absence determination means changes from no tone signal to presence and the first set time has elapsed, the phase amount calculated by the phase amount calculation means is obtained. And a phase amount calculated by the phase amount calculation means when the determination result of the tone signal presence / absence determination means changes from no tone signal to presence and a second set time elapses. A second storage unit, wherein the phase amount stored by the first storage unit and the second
Calculate the difference value with the phase amount stored by the storage unit of
Since the difference value is compared with a predetermined value to determine the presence or absence of the phase inversion of the input signal, if the first and second set times are set to appropriate values, the phase instability before and after the phase inversion may be reduced. Phase inversion can be determined based on the phase amount when the phase is stable instead of the amount of phase inversion. As a result, the phase inversion does not occur instantaneously, and the phase is gradually inverted over a certain period of time. Even in this case, there is an effect that the presence or absence of phase inversion can be accurately determined.

According to the twelfth aspect of the present invention, it is finally determined whether or not the phase of the input signal is inverted based on the current determination result by the difference value comparison unit and the past determination result held in the result holding unit. With this configuration, it is possible to accurately determine the presence / absence of phase inversion without causing erroneous determination due to the influence of noise or the like.

According to the thirteenth aspect of the present invention, the signal form of the input signal is specified to be either a phase-inverted tone signal, a non-phase-inverted tone signal, or a non-tone signal. There is an effect that can be.

According to the fourteenth aspect of the present invention, when the determination result of the tone signal presence / absence determination means changes from no tone signal to presence, the phase inversion presence / absence input within a certain period after the change indicates the presence of phase inversion. Since the determination result of the determination means is configured to be invalid, the determination result indicating the presence of the phase inversion is usually given as noise or the like in a period in which phase inversion cannot normally occur, that is, in a period immediately after the tone signal is detected. Can be regarded as an erroneous determination due to the effect of the above, and as a result, there is an effect that the presence / absence of the phase inversion can be more accurately determined.

According to the fifteenth aspect, when the signal form is specified with the determination result of the phase inversion presence / absence determination means as valid, the phase inversion input within a certain period after the determination result is input. Since the determination result of the phase inversion presence / absence determination means indicating presence is configured to be invalid, the period in which phase inversion cannot normally occur, that is, in the period immediately after phase inversion is detected, the presence of phase inversion is determined. The determination result shown can be regarded as an erroneous determination due to the influence of noise or the like, and as a result, there is an effect that the presence or absence of phase inversion can be determined more accurately.

According to the sixteenth aspect of the present invention, the signal form is identified as having phase inversion only when the determination result of the phase inversion presence / absence determining means indicating that phase inversion is present is input at least twice or more. Therefore, there is an effect that erroneous determination due to the influence of noise or the like can be effectively prevented.

According to the seventeenth aspect, the power calculated by the power calculating means on the transmitting side is compared with the power calculated by the power calculating means on the receiving side, and the output of the Fourier transforming means on the higher power side is compared. When the tone signal detection device inputs the transmission side signal and the reception side signal and specifies the signal form of the input signal for both of them, the phase amount calculation means and the presence or absence of the phase inversion are selected. The determination means can be shared, and as a result, the processing amount of the tone signal detection device can be reduced and the configuration can be simplified.

According to the eighteenth aspect of the present invention, the whole band power on the transmitting side and the whole band power on the receiving side calculated by the whole band power calculating means are compared with each other. Since we have configured to select the output,
When the tone signal detection device inputs the transmission side signal and the reception side signal and specifies the signal form of the input signal for both of them, the phase amount calculation means and the phase inversion presence / absence determination means may be shared. As a result, the processing amount of the tone signal detection device can be reduced, and the configuration can be simplified.

According to the nineteenth aspect of the present invention, the signal-to-noise ratio on the transmitting side and the signal-to-noise ratio on the receiving side calculated by the noise ratio calculating means are compared, and the Fourier transform on the higher signal-to-noise ratio is performed. Since the output of the means is selected, the transmission side signal and the reception side signal are input, and when the signal form of the input signal is specified for both of them, the phase amount calculation means and the phase inversion presence / absence determination means Can be shared, and as a result, the processing amount of the tone signal detecting device can be reduced and the configuration can be simplified.

According to the twentieth aspect of the present invention, each channel includes a Fourier transforming means, a power calculating means, a tone signal presence / absence determining means, and a signal form specifying means, while selecting means for selecting a channel for specifying a signal form. When the tone signal detection device specifies the signal form of the input signals of a plurality of channels, the phase amount calculation means and the phase inversion presence / absence determination means can be shared, As a result, there is an effect that the processing amount of the tone signal detection device can be reduced and the configuration can be simplified.

According to the twenty-first aspect of the present invention, each channel is provided with a power calculating means, a tone signal presence / absence determining means, and a signal form specifying means, and is provided with a selecting means for selecting a channel for specifying a signal form. With this configuration, when the tone signal detection device specifies the signal forms of the input signals of the plurality of channels, the Fourier transform means, the phase amount calculation means, and the phase inversion presence / absence determination means can be shared, As a result, there is an effect that the processing amount of the tone signal detection device can be reduced and the configuration can be simplified.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a tone signal detection device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a tone signal detection device according to a second embodiment of the present invention.

FIG. 3 is an explanatory diagram illustrating a determination result of a determination result output unit.

FIG. 4 is a configuration diagram illustrating a phase amount calculation unit of a tone signal detection device according to a third embodiment of the present invention.

FIG. 5 is an explanatory diagram illustrating an operation of a calculation result output unit.

FIG. 6 is an explanatory diagram illustrating an operation of a calculation result output unit.

FIG. 7 is an explanatory diagram illustrating an operation of a calculation result output unit.

FIG. 8 is an explanatory diagram illustrating an operation of a calculation result output unit.

FIG. 9 is a configuration diagram illustrating a phase amount calculation unit of a tone signal detection device according to a fourth embodiment of the present invention.

FIG. 10 is a configuration diagram illustrating an inverse trigonometric function operation unit of a tone signal detection device according to a fifth embodiment of the present invention.

FIG. 11 is an explanatory diagram illustrating linear approximation.

FIG. 12 is a configuration diagram illustrating a phase inversion presence / absence determination unit of a tone signal detection device according to a sixth embodiment of the present invention.

FIG. 13 is an explanatory diagram illustrating an operation of a phase inversion presence / absence determination unit.

FIG. 14 is an explanatory diagram illustrating an operation of a phase inversion presence / absence determination unit.

FIG. 15 is a configuration diagram illustrating a phase inversion presence / absence determination unit of a tone signal detection device according to a seventh embodiment of the present invention.

FIG. 16 is a configuration diagram illustrating a phase inversion presence / absence determination unit of a tone signal detection device according to an eighth embodiment of the present invention.

FIG. 17 is a configuration diagram showing a phase inversion presence / absence determination unit of a tone signal detection device according to Embodiment 9 of the present invention.

FIG. 18 is a configuration diagram showing a tone signal detection device according to a tenth embodiment of the present invention.

FIG. 19 is a configuration diagram illustrating a phase inversion presence / absence determination unit of the tone signal detection device according to the tenth embodiment of the present invention.

FIG. 20 is an explanatory diagram illustrating an operation of a phase inversion presence / absence determination unit.

FIG. 21 is a configuration diagram showing a phase inversion presence / absence determination unit of a tone signal detection device according to Embodiment 11 of the present invention.

FIG. 22 is an explanatory diagram illustrating a determination result of a determination result output unit.

FIG. 23 is a configuration diagram illustrating a determination result output unit of the tone signal detection device according to Embodiment 13 of the present invention;

FIG. 24 is an explanatory diagram illustrating an operation of a determination result output unit.

FIG. 25 is an explanatory diagram illustrating a determination result of a determination result output unit.

FIG. 26 is a configuration diagram illustrating a determination result output unit of the tone signal detection device according to Embodiment 14 of the present invention;

FIG. 27 is an explanatory diagram illustrating an operation of a determination result output unit.

FIG. 28 is an explanatory diagram illustrating a state transition of a determination result output unit.

FIG. 29 is a configuration diagram showing a tone signal detection device according to Embodiment 15 of the present invention.

FIG. 30 is a configuration diagram showing a tone signal detection device according to Embodiment 16 of the present invention.

FIG. 31 is a configuration diagram showing a tone signal detection device according to a seventeenth embodiment of the present invention.

FIG. 32 is a configuration diagram showing a tone signal detection device according to Embodiment 18 of the present invention.

FIG. 33 is an explanatory diagram illustrating an operation of a selector and the like.

FIG. 34 is a configuration diagram showing a tone signal detection device according to a nineteenth embodiment of the present invention.

FIG. 35 is an explanatory diagram illustrating an operation of a selector and the like.

FIG. 36 is a configuration diagram showing a conventional tone signal detection device.

FIG. 37 is a waveform diagram showing a power spectrum of a PCM signal.

[Explanation of symbols]

11, 11a, 11b, 11c DFT calculation unit (Fourier transform means), 12 phase amount calculation unit (phase amount calculation means),
13, 81 Phase inversion presence / absence determination section (phase inversion presence / absence determination means), 14 power calculation section (power calculation means), 15 tone presence / absence determination section (tone signal presence / absence determination means), 16 determination result output section (signal form identification means) , 21, 22 Absolute value calculation unit, 23 comparator (absolute value comparison unit), 24, 25
Polarity determination section, 26, 33 Phase amount calculation section, 32 sum of squares calculation section, 51, 52, 61, 62, 63, 71 Delay memory (delay section), 53, 59, 74, 86 Differentiator (difference value comparison) , 54, 75, 87 Comparator (difference value comparison unit), 55 phase amount compensation unit, 64 delay memory (first delay circuit), 65 delay memory (second delay circuit), 66 phase amount compensation circuit , 76, 90 determination circuit (final determination section), 83 data holding circuit (first storage section), 85 data holding circuit (second storage section), 8
8,89 delay memory (result holding unit), 103,10
6,108 comparators (selection means), 104,112,11
5 selector (selection means), 105 all-band power calculation section (all-band power calculation means), 107 S / N calculation section (noise ratio calculation means), 111 counter (selection means), 11
3 Demultiplexer (selection means).

Claims (21)

[Claims] 1. A Fourier transform means for performing a Fourier transform on an input signal to obtain a signal in a frequency domain, and a phase amount of the input signal based on a real part and an imaginary part of the signal in the frequency domain obtained by the Fourier transform means. And a phase inversion presence / absence determination means for comparing the change in the phase amount calculated by the phase amount operation means with a predetermined value to determine whether or not the input signal is inverted. Signal detection device. 2. A power calculating means for calculating the power of the input signal from a real part and an imaginary part of the signal in the frequency domain obtained by the Fourier transform means, and the power of the input signal calculated by the power calculating means being a predetermined value. A tone signal presence / absence determining means for determining the presence / absence of a tone signal; and a signal form identification means for identifying the signal form of the input signal based on the determination results of the tone signal presence / absence determination means and the phase inversion presence / absence determination means. The tone signal detecting device according to claim 1, further comprising: 3. A phase amount calculating means for determining a polarity of a real part and an imaginary part of a signal in a frequency domain obtained by a Fourier transform means, and a polarity determining part for determining a polarity of a real part and an imaginary part of the signal in the frequency domain. An absolute value calculator for calculating an absolute value;
An absolute value comparison unit that compares the absolute value of the real part and the absolute value of the imaginary part calculated by the absolute value calculation unit, and an arithmetic expression corresponding to the determination result of the polarity determination unit and the comparison result of the absolute value comparison unit And a phase amount calculating unit that calculates the phase amount of the input signal by substituting the absolute values of the real part and the imaginary part calculated by the absolute value calculating unit into the arithmetic expression. 3. The tone signal detecting device according to claim 1, wherein 4. A phase amount calculating means for determining a polarity of a real part and an imaginary part of a frequency domain signal obtained by a Fourier transform means, and a real part and an imaginary part of the frequency domain signal. A sum-of-squares calculator for calculating the square root of the sum of squares, an absolute-value calculator for calculating the absolute values of the real part and the imaginary part of the signal in the frequency domain, and a real-number part calculated by the absolute value calculator. An absolute value comparing unit that compares the absolute value and the absolute value of the imaginary part, and an arithmetic expression according to the determination result of the polarity determining unit and the comparison result of the absolute value comparing unit are selected and calculated by the absolute value calculating unit. The absolute value of the real part or the imaginary part obtained by the calculation and the 2
3. The tone signal detection device according to claim 1, further comprising: a phase amount calculation unit that calculates a phase amount of the input signal by substituting the square root of the sum of squares into the calculation expression. 5. The phase amount calculating section divides a real part by an imaginary part or divides an imaginary part by a real part based on a comparison result of the absolute value comparing section, and compares the division result with a predetermined value. 4. The tone signal detecting device according to claim 3, wherein the inverse trigonometric function is linearly approximated based on an arithmetic expression selected based on the comparison result. 6. A phase amount calculating unit for dividing a real part or an imaginary part by a square root of a sum of squares based on a comparison result of an absolute value comparing unit, comparing the division result with a predetermined value, and comparing the comparison result. 5. The tone signal detecting device according to claim 4, wherein the inverse trigonometric function is linearly approximated based on an arithmetic expression selected on the basis of: 7. A phase inversion presence / absence determination means, comprising: a delay unit for delaying the phase amount calculated by the phase amount calculation unit by a plurality of frames, a current phase amount calculated by the phase amount calculation unit, and the delay unit. 3. The apparatus according to claim 1, further comprising: a difference value comparison unit that compares a difference value with the delayed past phase amount with a predetermined value to determine whether or not the input signal is inverted. Tone signal detection device. 8. A phase inversion determining means for delaying a phase amount calculated by the phase amount calculating means, a current phase amount calculated by the phase amount calculating means, and a delay by the delay part. A phase amount compensator for smoothing a difference value with respect to a past phase amount and adding the smoothed difference value to a past phase amount; a current phase amount calculated by the phase amount calculating means and the phase amount compensation; And a difference value comparison unit that calculates a difference value with respect to the past phase amount to which the difference value is added by the unit, and compares the difference value with a predetermined value to determine whether or not the input signal is inverted. The tone signal detection device according to claim 1 or 2, wherein 9. A first delay circuit for delaying a phase amount delayed by the delay unit, and a second delay unit for delaying the phase amount delayed by the first delay circuit by one frame. A delay circuit that smoothes a difference value between the phase amount delayed by the first delay circuit and the phase amount delayed by the second delay circuit, and adds a predetermined coefficient to the smoothed difference value. 9. The tone signal detecting device according to claim 8, further comprising: a phase amount compensating circuit for multiplying and multiplying a result of the multiplication to a phase amount delayed by the delay unit. 10. A phase inversion presence / absence judging means, comprising: a plurality of phase amount compensators for compensating past phase amounts by means different from each other; and a phase inversion of an input signal based on outputs of the plurality of phase amount compensators, respectively. A plurality of difference value comparing units for determining the presence / absence of the input signal, and a final determining unit for finally determining the presence / absence of phase inversion of the input signal based on the determination results of the plurality of difference value comparing units. The tone signal detecting device according to claim 8, wherein 11. A phase inversion presence / absence determination means, wherein when the determination result of the tone signal presence / absence determination means changes from no tone signal to presence and a first set time elapses, the phase amount calculated by the phase amount calculation means is obtained. A first storage unit for storing, and when the determination result of the tone signal presence / absence determination means changes from no tone signal to presence, and a second set time has elapsed, the phase amount calculated by the phase amount calculation means is stored. A second storage unit that calculates a difference value between the phase amount stored by the first storage unit and the phase amount stored by the second storage unit, and compares the difference value with a predetermined value. 3. The tone signal detecting device according to claim 2, further comprising: a difference value comparing unit that determines whether or not the input signal is inverted. 12. A phase inversion presence / absence determination unit, comprising: a result holding unit for holding a determination result of a difference value comparison unit; a current determination result by the difference value comparison unit; and a past determination held by the result holding unit. The tone signal detecting device according to any one of claims 7 to 11, further comprising a final determining unit that finally determines the presence or absence of phase inversion of the input signal based on the result. 13. The tone signal detecting device according to claim 2, wherein the signal form specifying means specifies the signal form of the input signal as one of a phase-inverted tone signal, a non-phase-inverted tone signal, and a non-tone signal. apparatus. 14. The signal form identifying means, when the tone signal presence / absence determination means changes from no tone signal to presence, indicates that phase inversion is present within a certain period after the change. 3. The tone signal detection device according to claim 2, wherein the determination result is invalidated. 15. When the signal form is specified with the determination result of the phase inversion presence / absence determination means as valid, the signal form identification means determines that phase inversion is input within a certain period after the input of the determination result. 3. The tone signal detection device according to claim 2, wherein the determination result of said phase inversion presence / absence determination means is invalidated. 16. The signal form specifying unit specifies a signal form as having phase inversion only when a determination result of the phase inversion existence determining unit indicating that phase inversion is present is input at least twice or more. The tone signal detection device according to claim 15. 17. When a transmission side signal and a reception side signal are input and the signal form of the input signal is specified for both of them,
A transmitting side dedicated Fourier transforming means, power calculating means, tone signal presence / absence determining means and signal form specifying means, and a receiving side dedicated Fourier transforming means, power calculating means, tone signal presence / absence determining means and signal form specifying means; Selecting means for comparing the power calculated by the power calculating means on the transmitting side with the power calculated by the power calculating means on the receiving side, and selecting the output of the Fourier transforming means on the side with the larger power; 3. The tone signal detecting device according to claim 2, wherein the calculating means is executed based on an output of the Fourier transform means on the side selected by the selecting means. 18. A transmitter-side signal and a receiver-side signal are input, and when the signal form of the input signal is specified for both of them, a Fourier transform unit dedicated to the transmitter, a power calculator, a tone signal presence / absence determiner, A signal form specifying unit, a Fourier transform unit dedicated to the receiving side, a power calculating unit, a tone signal presence / absence determining unit, and a signal form specifying unit, and calculate the entire band power of the pulse code modulation signal on the transmitting side and the receiving side A selection unit that compares the total band power on the transmitting side and the total band power on the receiving side calculated by the full band power calculating unit with the whole band power calculating unit, and selects the output of the Fourier transform unit on the side with the larger total band power; 3. The apparatus according to claim 2, further comprising means for executing the phase amount calculation means based on an output of the Fourier transform means on the side selected by the selection means.
The tone signal detection device according to any one of the preceding claims. 19. When a transmission side signal and a reception side signal are input and the signal form of the input signal is specified for both of them,
A transmitting side dedicated Fourier transforming means, power calculating means, tone signal presence / absence determining means and signal form specifying means, and a receiving side dedicated Fourier transforming means, power calculating means, tone signal presence / absence determining means and signal form specifying means; A noise ratio calculating means for calculating a signal-to-noise ratio of the pulse code modulation signal on the transmitting side and the receiving side; and a signal-to-noise ratio on the transmitting side and a signal-to-noise ratio on the receiving side calculated by the noise ratio calculating means. Comparing means for selecting an output of the Fourier transform means having a higher signal-to-noise ratio, wherein the phase amount calculating means executes based on an output of the Fourier transform means on the side selected by the select means. 3. The tone signal detecting device according to claim 2, wherein: 20. When specifying the signal forms of input signals of a plurality of channels, each of the channels is provided with a Fourier transforming means, a power calculating means, a tone signal presence / absence determining means and a signal form specifying means, while specifying a signal form. 3. The tone signal detecting device according to claim 2, further comprising a selecting unit for selecting a channel, wherein the phase amount calculating unit executes the phase amount calculating unit based on an output of the Fourier transform unit of the channel selected by the selecting unit. 21. When specifying the signal forms of input signals of a plurality of channels, each of the channels includes a power calculating means, a tone signal presence / absence determining means, and a signal form specifying means.
3. The tone signal detecting device according to claim 2, further comprising a selecting unit for selecting a channel for specifying a signal form, wherein the Fourier transforming unit executes based on an input signal of the channel selected by the selecting unit.