JP2002374579A - Acoustic communication device and acoustic signal communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the transmission rate of acoustic communication. SOLUTION: A transmission section 1 applies either or both of amplitude modulation and phase modulation based on transmission information and modulation based on a signal representing a window function to a carrier with a prescribed frequency, and transmits the modulated signal in sound. A reception section 2 receives an acoustic signal sent from the transmission section 1 and converts the signal into an electric signal. Then the reception section 2 applies Fourier transform to the converted signal, reads either or both of a phase and an amplitude with the carrier frequency and demodulates the communication information on the basis of the read value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound transmitting apparatus and a sound signal transmitting method for transmitting transmission information as a sound signal. Further, the present invention relates to an audio receiving device and an audio signal receiving method for receiving communication information as an audio signal. Further, the present invention relates to an acoustic communication device and an acoustic signal communication method including such an acoustic transmitting device and an acoustic receiving device.

[0002] The present invention also relates to a program to be executed by a computer provided in an acoustic transmission device.

[0003]

2. Description of the Related Art The amount of gas used in each home (house) is transmitted to a center station for automatic meter reading and collection, the occurrence of gas leakage is notified to the center station, or the center is responsive to the gas leak notification. A remote monitoring / control system for shutting off a gas meter by remote control from a station has been put to practical use.

In such a remote monitoring / control system,
A microcomputer or the like having a communication function is provided in a gas meter installed in each home (house). And
The microcomputer of the gas meter is connected to a terminal network control device by a wire line, and the terminal network control device is further connected to a center station by a telephone line.

[0005] For this reason, in the house, through-hole construction for passing a wired line between the gas meter and the terminal network control device is performed. However, especially in apartment buildings, construction is often difficult, and aesthetic problems may arise.

[0006] On the other hand, a microcomputer of a gas meter is connected to a terminal network controller by radio communication such as radio waves, and the terminal network controller is connected to telephones (fixed telephones) of respective homes. It is also considered to connect to a center station by using the same. However, with the spread of mobile phones and PHS in recent years, many customers who do not have telephones in their homes have increased, and such a method using radio waves cannot be applied to all homes.

There is also a demand for cost reduction of such communication equipment.

[0008]

Therefore, an acoustic signal communication method for transmitting communication information as an acoustic signal to the inside of a gas pipe or the like has been studied. In this method, communication information such as a meter reading value and a notice of gas leak occurrence is transmitted by an acoustic signal from a gas meter installed on one side of the gas pipe to a terminal network control apparatus installed on the other side of the gas pipe.

However, when the inside of a gas pipe or the like is communicated by an acoustic signal, reverberation (delayed wave) due to sound reflection occurs at a bent portion or a branch portion of the pipe, for example. Therefore, when the communication information is continuously transmitted, the reverberation of the previously transmitted acoustic signal disturbs the next transmitted acoustic signal, and the receiving side cannot accurately receive the acoustic signal.

In order to avoid the effect of this reverberation, it is necessary to wait for the reverberation of the previously transmitted acoustic signal to attenuate below a certain level before transmitting the next acoustic signal. Therefore, for acoustic communication using simple pulse signals,
There was a limit to the improvement of transmission speed.

The present invention has been made in view of such a situation, and an object of the present invention is to improve the transmission speed of acoustic communication.

Another object of the present invention is to provide an acoustic communication device and an acoustic signal communication method which are resistant to reverberation.

[0013]

In order to achieve the above-mentioned object, an audio transmitting apparatus according to a first aspect of the present invention provides an audio transmitting apparatus having an amplitude based on transmission information for one or a plurality of carriers having a predetermined frequency. Modulation means for performing modulation and / or phase modulation, and modulation with a signal representing a window function, and sound transmission means for transmitting a signal modulated by the modulation means by sound.

[0014] The program according to the first aspect of the present invention comprises:
A computer provided in an acoustic transmission device for transmitting transmission information as an acoustic signal transmits, to one or more digital data representing a carrier having a predetermined frequency, amplitude modulation and digital modulation based on the digital data representing the transmission information. A procedure for performing phase modulation and / or phase modulation;
And modulating the digital data representing the carrier having the predetermined frequency with a signal representing a window function.

Further, the program according to the first aspect of the present invention provides a computer provided in an audio transmitting apparatus for transmitting transmission information as an audio signal, by transmitting one or a plurality of predetermined frequencies based on the transmission information. If the modulation performed on the carrier has phase shift keying, the transmission information is converted into a phase shift amount of the carrier, and if the modulation is amplitude shift keying, the transmission information is converted into an amplitude value of the carrier. And, if the modulation is QAM, the transmission information is converted to the amplitude value and the phase shift amount of the carrier, and if the modulation is phase shift keying, the phase shift amount of the carrier is , When the modulation is amplitude shift keying, the amplitude value of the carrier is
When the modulation is QAM, the amplitude value and the phase shift amount of the carrier are given as parameters, respectively.
And substituting a value converted from the transmission information into the parameter of a calculation expression obtained by multiplying the expression representing the one or more carrier waves and the expression representing the window function. .

According to the first aspect of the present invention, for one or a plurality of carriers having a predetermined frequency, a signal representing an amplitude function and / or a phase modulation based on transmission information and a window function is provided. Modulation is performed. Then, the modulated signal is transmitted by sound. By performing amplitude modulation and / or phase modulation on a carrier and expressing transmission information having multiple values (for example, a plurality of bits), a plurality of pieces of information are transmitted with one modulation symbol on one carrier. can do.
Therefore, the transmission speed can be improved. Further, the transmission interval of the acoustic signal can be set to such an extent as not to be adversely affected by reverberation, and an acoustic transmission device which is strong in reverberation is provided. Further, since the signal is modulated by a signal representing a window function, even when a plurality of carrier waves are superimposed,
Interference between carriers can be reduced, which can also improve the transmission speed.

In the first aspect of the present invention, preferably, when there are a plurality of carriers having the predetermined frequency, each of the plurality of carriers has a different frequency;
The modulation unit performs the modulation on each of the plurality of carriers based on individual transmission information. Thereby, transmission information by one modulation symbol can be further increased. That is, when modulation is performed on all the carrier waves by the same modulating means, the transmission speed is multiplied by the number of carrier waves as compared with the case where only one carrier wave is used.

An acoustic receiving apparatus according to a second aspect of the present invention is characterized in that, for one or a plurality of carriers having a predetermined frequency, an amplitude modulation and / or a phase modulation based on transmission information and a window function A receiving means for receiving communication information modulated by a signal representing a sound signal as an acoustic signal and converting the signal into an electric signal, a Fourier transform of the signal converted by the acoustic receiving means, and a phase value at a frequency of the carrier wave And / or an amplitude value, and demodulating means for demodulating communication information based on the read value.

According to a second aspect of the present invention, for one or a plurality of carriers having a predetermined frequency, a signal representing an amplitude function and / or a phase modulation based on transmission information and a window function is provided. The communication information that has been subjected to the modulation is received as an acoustic signal and converted into an electric signal. Then, the converted signal is subjected to Fourier transform, and both or one of the phase value and the amplitude value at the frequency of the carrier is read out. Subsequently, the communication information is demodulated based on the read value. Thereby, the receiving device can be simplified.

An acoustic communication device according to a third aspect of the present invention is an acoustic communication device including an acoustic transmitting device and an acoustic receiving device, wherein the acoustic transmitting device transmits one or a plurality of predetermined frequencies. Modulating means for performing amplitude modulation and / or phase modulation based on transmission information and / or modulating with a signal representing a window function on a carrier having the same; Sound transmitting means, wherein the sound receiving apparatus receives the sound signal transmitted by the sound transmitting means and converts the sound signal into an electric signal, and Fourier transforms the signal converted by the sound receiving means. A demodulating means for reading out the phase value and / or the amplitude value at the frequency of the carrier wave and demodulating the communication information based on the read out value. To have.

According to a third aspect of the present invention, the acoustic transmitting apparatus performs one or more of amplitude modulation and / or phase modulation based on transmission information on one or a plurality of carriers having a predetermined frequency. , Modulation by a signal representing a window function, and the modulated signal is transmitted by sound. The sound receiving device receives the sound signal transmitted by the sound transmitting device, converts the sound signal into an electric signal, Fourier-transforms the converted signal, and / or a phase value and / or an amplitude value at a carrier frequency. One of them is read, and the communication information is demodulated based on the read value. This also allows the first and second aspects of the present invention described above.
The function and effect according to the aspect can be obtained.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which an acoustic communication device according to the present invention is applied to a system for performing automatic meter reading of a gas meter, a gas leak alarm, and the like will be described below. This embodiment is merely an example. It does not limit the technical scope of the present invention.

FIG. 1 is a block diagram showing the overall configuration of the acoustic communication device according to the present embodiment. This acoustic communication device includes a transmitting unit 1 and a receiving unit 2. As a communication path between the transmission unit 1 and the reception unit 2, a space in the gas pipe 3 is used.

The transmitting section 1 includes a serial / parallel converter 11, a modulator 12, a digital / analog converter (hereinafter referred to as a "D / A converter") 13, an amplifier 14, and a speaker 1.
5 The receiving unit 2 includes a parallel / serial converter 21, a demodulation processor 27, a fast Fourier transformer (hereinafter referred to as "FFT") 22, and an analog / digital converter (hereinafter referred to as "A /
D converter ". ) 23, bandpass filter (BPF) 2
4, an amplifier 25, and a microphone 26.

In the transmitting section 1, the serial / parallel converter 11
The transmission / reception and processing are performed by electric signals from transmission data input to the input device to the speaker 15 through the serial / parallel converter 11, the modulator 12, the D / A converter 13, and the amplifier 14. . From the output data of the speaker 15 to the input data of the microphone 26 via the gas pipe 3, transmission and reception are performed by an acoustic signal. In the receiving unit 2, the amplifier 2
5, A / D converter 23, FFT 22, demodulation processor 27,
The transmission / reception and processing are performed by electric signals until the data reaches the reception data output from the parallel / serial converter 21 via the parallel / serial converter 21.

In this acoustic communication device, for example, gas
Shows meter readings (gas consumption), gas leak alarms, etc.
Digital M-bit transmission data d = ｛d₁, D_Two,
…, D _M｝ (M is a positive integer, d₁~ D_MAre 1 bit each
Data) is input to the transmission unit 1. The transmission data d is
The signal is converted into an acoustic signal x (t) (t: time) by the transmission unit 2.
And transmitted to the receiving unit 2 via the gas pipe 3.

The receiver 2 receives the received acoustic signal x
(T) is demodulated and converted to digital reception data having the same value as the transmission data d. The received data is sent to a terminal network controller,
It is transmitted to a center station or the like.

In the present embodiment, the acoustic signal x (t) is

[0029]

(Equation 1)

Is represented by

Here, N is a positive integer, and a carrier (carrier) signal u _i (t) = sin (2πf _i ) used for transmission.
(T−t _Pi )). In the present embodiment, one or more arbitrary number of carrier waves can be used. F _i is a carrier frequency, t _Pi is a phase offset time [sec], and φ _i is a phase modulation parameter. exp (-
B ² (t−t _C ) ² ) is a modulation signal (hereinafter referred to as “gas window signal”) representing a Gaussian window function (or Gaussian window) as an example of “window function”, and B is the Gaussian window signal. The band parameter [Hz] and t _C are the window center time [sec] of the Gaussian window signal.

A specific example of the acoustic signal x (t) will be described below.

1. First Example of Acoustic Signal Multi-level phase shift keying (PSK) is performed based on transmission data d by carrier signal u _i (t).
To generate an acoustic signal x (t). In this case, the acoustic signal x expressed by the above equation (1)
The amplitude parameter (amplitude value) a _i and the phase offset time t _Pi of (t) are each set to a constant value (hereinafter, as an example, a = 1 [V] and t _Pi = 0 [second]).
Then, the phase of each carrier signal u _i (t) is shifted (shifted) by a phase modulation parameter φ _i whose value is determined based on the transmission data d.

FIG. 2A is a block diagram showing a detailed configuration of the serial / parallel converter 11 and the modulator 12 when performing PSK. FIG. 2B is a block diagram showing the PSK included in the modulator 12. FIG. 3 is a block diagram illustrating a detailed configuration of a modulator 12a _i (i = 1 to N). The M-bit transmission data d = {d ₁ , d ₂ ,..., D _M } input to the transmission unit 1 is first input to the serial / parallel converter 11.

The serial / parallel converter 11 divides the input M-bit transmission data d into M / N bits in order from the first bit, and N groups (parallel data) each having M / N bits. Divide into p _{1 to} p _N. series/
Parallel converter 11 has N output terminals O ₁ ~ O _N, and outputs the respective parallel data p ₁ ~p _N which is divided into the output terminal O ₁ ~ O _N.

For example, when M = 24 and N = 8, the transmission data d = {d ₁ , d ₂ ,..., D ₂₄ } is parallel data p ₁ = {d _1, consisting of eight 3 bits each. , D ₂ , d ₃ }, p
₂ = {d ₄ , d ₅ , d ₆ },..., P ₈ = {d ₂₂ , d ₂₃ ,
d ₂₄ }. Then, the parallel data p ₁ output terminals O _1, parallel data p ₂ to the output terminal O _2, ..., parallel data p ₈ to the output terminal O _8, are output.

As described above, it is preferable that the values of the integers M and N are set so that each of the N pieces of parallel data has the same number of bits. That is, the integer M is preferably set to an integral multiple of the integer N.

The modulator 12 includes N PSK modulators 12a.
_{1 to} 12a _N , an adder 12b, a multiplier 12c, and a Gaussian window signal generator 12d. N parallel data p ₁
~p _N are input to the N PSK modulators 12a ₁ ~12a _N.

Each of the PSK modulators 12a _i (i = 1 to N, the same applies hereinafter) has the same configuration, and includes a sine wave signal generator 121 _i for generating a sine wave carrier signal u _i (t) and a carrier. It has a phase shifter 122 _i for shifting the phase of the signal u _i (t).

However, different frequencies are assigned to the frequencies f _i of the sine wave signal generators 121 _i of the respective PSK modulators 12 a _i . For example, f ₁ = 2000
[Hz], f ₂ = 2250 [Hz], f ₃ = 2500 [H
z],... 2,000 from f ₁ to f _N
250 [Hz] interval starting from [Hz] (constant interval)
May be assigned, or a frequency in which the interval between two adjacent frequencies is not constant may be assigned.

By providing N carrier signals to be transmitted, the transmission speed can be increased by N times.

The carrier wave (signal representing the carrier wave) generated by each sine wave signal generator 121 _i is input to the phase shifter 122 _i . On the other hand, the parallel data p _i is also input to the phase shifter 122 _i .

[0043] The phase shifter 122 _i, the phase shift amount corresponding to the parallel data p _i (phase shift amount) phi _i is set in advance. As the phase shift amount φ _i , for example, an angle of 2π ÷ 2 ^{M / N} interval by 2 ^{M / N} phase PSK is assigned. For example, in the 8-phase PSK in the case where M = 24 and N = 8, the phase shift amount as shown in FIG. 3 can be assigned to each of the 3-bit parallel data. In FIG.
A constellation is made between the amount of phase shift and the parallel data of 3 bits so that the inter-code distance between adjacent phases is minimized.

The phase shifter 122 _i outputs the carrier signal u _i (t) by the phase shift amount φ _i corresponding to the input parallel data p _i.
Is shifted. Thereby, the carrier signal u _i
(T) is the modulated signal is shown in the following equation (2) v _i (t)
Is converted to

[0045]

(Equation 2)

However, as described above, since the phase offset time t _{Pi is set} to 0, this time t _Pi is _calculated by the equation (2).
Are omitted.

The N modulated signals v ₁ (t) to v _N (t) output from each phase shifter 122 _i are provided to an adder 12 b and added. As a result, an addition signal w (t) represented by the following equation (3) is generated.

[0048]

(Equation 3)

The addition signal w (t) is multiplied by the multiplier 12 with the Gaussian window signal g (t) = exp (−B ² (t−t _C ) ² ) input from the Gaussian window signal generator 12d. Is done.

FIG. 4 is a graph showing the waveform of the Gaussian window signal g (t) generated by the Gaussian window signal generator 12d. FIG. 4A shows a time waveform, and FIG. 4B shows a power spectrum. (Frequency spectrum) are shown.

As shown in FIG. 4, the Gaussian window signal g (t)
In the time domain, the amplitude rapidly approaches 0 in a time domain other than the limited time domain T, and the power spectrum is localized in the limited frequency domain F in the frequency domain. Have.

Therefore, the signal v _i (t) · g obtained by multiplying the modulated signal v _i (t) by the Gaussian window signal g (t)
In (t) as well, the amplitude rapidly approaches 0 outside of a certain limited time domain, and the power spectrum is localized in a certain limited frequency domain. FIG.
(A) shows eight signals v when N = 8.
Examples of time waveforms of ₁ (t) · g (t) to v ₈ (t) · g (t) are shown, and FIG. 2B shows their power spectra. FIG. 4C shows eight signals v
_{1 (t) · g (t} ) ~v 8 (t) · g (t) to indicate the time waveform but the sum, FIG. (D) shows the power spectrum although the sum. Thus, the signal v
_{Since i} (t) · g (t) also has a certain range in the time domain and the frequency domain, a plurality of added signals w
Even when (t) · g (t) is created, each signal v
The interference between _i (t) and g (t) can be reduced.

The Gaussian window signal is multiplied by the multiplier 12c, and as a result, an electric signal (y (t)) having the same waveform as the acoustic signal x (t) as shown in the following equation (4). Is generated.

[0054]

(Equation 4)

The order of processing by the modulator 12 is merely an example. For example, the carrier signal u _i (t) is multiplied by the Gaussian window signal g (t) first, and then the multiplied signal is included. The phase of the carrier signal u _i (t) can be shifted by the phase shifter 122 _i .

The processing of the modulator 12 can be performed by digital data (digital signal) or by analog data (analog signal). When the processing is performed by digital data, as shown in FIG. 1, a D / A converter 13 is provided at the subsequent stage of the modulator 12, and the digital signal y (t) is converted into an analog signal. , Amplifier 14. On the other hand, when the processing is performed using analog data, the D / A converter 13 shown in FIG. 1 is omitted, and the analog signal y (t) is directly supplied to the amplifier 14.

The analog signal y applied to the amplifier 14
(T) is provided to the speaker 15 after being amplified.
The speaker 15 converts the analog electric signal y (t) given from the amplifier 14 into an acoustic signal, and converts the signal into a sound as a sound.
Output (send) within.

The acoustic signal x (t) transmitted in the gas pipe 3
Is received by the microphone 26 of the receiving unit 2 and the electric signal y
After being converted to (t), it is given to the amplifier 25. The microphone 26 may include a preamplifier, and the electric signal y pre-amplified by the preamplifier may be included.
(T) may be provided to the amplifier 25.

Signal y (t) amplified by amplifier 25
Is supplied to the A / D converter 23 after only a signal in a predetermined band is selected by the BPF 24, and is supplied to the A / D converter 2
3 is converted into a digital signal (digital data). This digital data is provided to the FFT 22 and subjected to Fourier transform.

In the FFT 22, N phase values corresponding to the frequency f _i (ie, the frequency of the carrier) of the sine wave signal generator 121 _i of the transmitting section 1 are read out based on the digital data after the Fourier transform. . The read phase value corresponds to the phase shift amount by the phase shifter 122 _i.

As in the phase shifter 122 _i , M / N-bit digital data corresponding to the read phase value is set in the demodulation processor 27 in advance. Thus, the demodulator 27 obtains N digital data of M / N bits corresponding to the read phase value, and the obtained digital data is supplied to the parallel / serial converter 21. .

As described above, the phase value is obtained by the FFT 2, and the phase value is converted into bit information by the demodulation processor 27 based on the same setting as that of the phase shifter 122 _i of the transmission unit 2, thereby obtaining complicated information. The receiving unit 2 that does not require a simple circuit configuration can be configured.

The parallel / serial converter 21 uses these N M
/ N-bit digital data is converted into M-bit serial digital data and output. The M-bit digital data output from the parallel / serial converter 21 is transmitted to a terminal network control device, a center station, or the like via a wired line (for example, a telephone line), a wireless line, or the like.

The transmission interval of the audio signal x (t) is set to an interval at which the influence of the reverberation of the previously transmitted audio signal is small and the receiving unit 2 can discriminate each audio signal. Thereby, transmission data can be transmitted without being affected by reverberation in the gas pipe 3 (particularly, a bent portion, a branch portion, or the like of the gas pipe 3). Further, since a plurality of bits of information can be transmitted by one acoustic signal, the transmission speed can be improved.

Note that it is also possible to set N = 1. In this case, the serial / parallel converter 11 and the adder 12b become unnecessary in the transmitting unit 1, and the parallel /
The serial converter 21 becomes unnecessary. The Gaussian window signal is an example of a signal representing a window function, and other window functions can be used. Further, the above-described processing by the FFT 22
Discrete Fourier Transformer (DFT)
form).

2. Second example of acoustic signal QAM (Quadrative Amplitud) that applies both phase modulation (particularly PSK) and amplitude modulation (particularly Amplitude Shift Keying (ASK)) to a carrier signal.
e Modulation), the transmission data d can be transmitted.

The overall configuration of the acoustic communication device is the same as that shown in FIG. On the other hand, the modulator 12 has a configuration different from that shown in FIG. 2 so as to perform QAM. FIG.
2A is a block diagram showing a detailed configuration of the serial / parallel converter and the modulator 12 when performing QAM, and FIG. 2B is a block diagram showing a QAM modulator 12g _i (i included in the modulator 12. = 1 to N) is a block diagram showing a detailed configuration. The same components as those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof will be omitted.

The serial / parallel converter 11 performs the same processing as in the first example described above, and obtains the divided parallel data p _{1 to} p _N.
And outputs to the output terminal O ₁ ~ O _N a.

The modulator 12 includes N QAM modulators 12g.
_{1 to} 12g _N , an adder 12h, a multiplier 12k, and a Gaussian window signal generator 12d. N parallel data p ₁
~p _N are input to the N QAM modulator 12 g ₁ to 12 g _N.

Each of the QAM modulators 12g _i (i = 1 to N, the same applies hereinafter) has the same configuration, and includes a sine wave signal generator 121 _i for generating a sine wave carrier signal u _i (t) and a carrier. Phase shifter 12 for shifting the phase of signal u _i (t)
2 _i , phase shift / amplitude value setting device 123 _i , and multiplier 12
4 _i .

The parallel data p _i is input to the phase shift amount / amplitude value setting unit 123 _i . Phase shift amount / amplitude value setting device 123 _i
, Corresponding to the value of the parallel data p _i that is input, the phase shift amount for shifting the phase of the carrier signal u _i (t), the amplitude amount of changing the amplitude of the carrier signal u _i (t) is previously Is set. Accordingly, the phase shift amount / amplitude value setting unit 123 _i outputs the phase shift amount corresponding to the value of the parallel data p _i to the phase shifter 122 _i and the amplitude value to the multiplier 124 _i .

The phase shifter 122 _i outputs the carrier signal u _i (t)
Is shifted by the phase shift amount given from the phase shift amount / amplitude value setting unit 123 _i, and the carrier signal u _i (t) whose phase has been shifted is provided to the multiplier 124 _i .

[0073] The multiplier 124 _i is the carrier signal inputted from the phase shifter 122 _i, the phase shift / amplitude value setting unit 123 _i
, And outputs the result to the adder 12b. In the adder 12b and the multiplier 12c, the same processing as in the first example is performed.

As described above, the transmitting section 1 performs QAM on the carrier signal based on the transmission data d, and transmits the modulated signal as an acoustic signal.

On the other hand, the receiving unit 2 performs FFT (or DF
T) 22 (see FIG. 1), the frequency f _i of the sine wave signal generator 121 _i of the transmission unit 1 (ie, the frequency of the carrier wave)
Is read out. And
M / N-bit parallel data corresponding to the read phase value and amplitude value is obtained. The obtained N pieces of parallel data are converted into M by the parallel / serial converter 21 (see FIG. 1).
One bit of digital data is output.

By using such QAM, it is possible to obtain the same operation and effect as those of the first example.

The QAM modulator 12g _i may have the configuration shown in FIG. In this QAM modulator 12g _i ,
First carrier signal u _i1 from sine wave signal generator 125 _i
(T) =-sin2πf _i (tt _Pi ) is output, and the second carrier signal u _i2 (t) is output from the cosine signal generator 127 _i .
= Cos2πf _i (tt _Pi ) is output.

The amplitude value setting unit 126_iContains the average
Column data p_iCorresponding to the first carrier signal u_i1
(T) amplitude value b_i, And the second carrier signal u_i2
(T) amplitude value c_iIs set in advance. amplitude
Value setter 126_iIs the input parallel data p_iAgainst the value of
Corresponding amplitude value b_iAnd c_iTo the multiplier 129_iAnd 13
0 _iRespectively.

The multipliers 129 _i and 130 _{i provide} the first carrier signal u _i1 (t) and the second carrier signal u
_i2 (t) is multiplied by the amplitude values b _i and c _i , respectively, and the multiplication result is output to the adder 131 _i . The adder 131 adds the input signals and provides the addition result to the adder 12b.

With such processing, the acoustic signal x (t)
Is a signal represented by the following equation (5).

[0081]

(Equation 5)

It should be noted that the above-described QAM modulator 12
The processing of g _i can be performed with a digital signal (digital data) or an analog signal (analog data), like the PSK modulator 12 a _i in the first example. Also, as in the first example, N =
1 in this case, and in this case,
The serial / parallel converter 11 and the adder 12b become unnecessary, and the parallel / serial converter 21 becomes unnecessary in the receiving unit 2. In addition, other window functions can be used.

If the processing of the QAM modulator 12g _i is performed by digital data by a computer or the like,
The AM modulator 12 g _i can be configured as shown in FIG. That is, the amount of phase shift / amplitude value setting unit 51 ₁ to 51 _N
In, the amount of phase shift and the amplitude value corresponding to the parallel data p _{1 to} p _N are obtained and given to the calculation unit 52. The operation unit 52 performs an operation by substituting the given phase shift amount and amplitude value into the equation (1), and outputs the operation result.

The phase shift amount / amplitude value setting units 51 _{1 to} 51 _N are used to control the amplitude value b _{i of} the first carrier signal u _i1 (t) and the amplitude value c of the second carrier signal u _i2 (t). _i , can be replaced with a setting device for setting, and the calculation unit 52 can be replaced with a device that calculates Expression (5).

Also, when the PSK described in the first example is used, a similar configuration can be adopted.

3. Other examples of sound signals Amplitude Shift Keying (ASK)
ng) alone can produce an acoustic signal. In addition, frequency shift keying (FSK)
t Keying) can also create an acoustic signal.

4. Other Embodiments A transmitting unit 1 is provided in, for example, a terminal network controller, a center station or the like, and a receiving unit 2 is provided in a gas meter or the like, so that a command to close a gas tap transmitted from the center station is given to the gas meter or the like. For example, the operation of closing the gas stopper can be performed.

The processing performed by the computer or the like can be described by a program, and this program includes a floppy disk, a memory card, a CD-RO.
M and the like, and can be provided.

[0089]

According to the present invention, the transmission speed of acoustic communication can be improved. Further, an acoustic communication device and an acoustic signal communication method that are resistant to reverberation are provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall configuration of an acoustic communication device according to an embodiment.

FIG. 2A is a block diagram showing a detailed configuration of a serial / parallel converter and a modulator when performing PSK; FIG. 2B is a detailed configuration of a PSK modulator included in the modulator; FIG.

FIG. 3 shows correspondence (constellation) between 3-bit parallel data and phases in 8-phase PSK.

FIG. 4 is a graph showing a waveform of a Gaussian window signal generated by a Gaussian window signal generator.
(B) shows the power spectrum.

FIG. 5A shows an example of a time waveform of eight signals v ₁ (t) · g (t) to v ₈ (t) · g (t) when N = 8, and FIG. ) Shows their power spectra as
(C) shows eight signals v ₁ (t) · g (t) to v ₈ (t)
The time waveform of the sum of g (t) is shown, and the power spectrum of the sum is shown in (D).

FIG. 6A is a block diagram showing a detailed configuration of a serial / parallel converter and a modulator when performing QAM, and FIG. 6B is a detailed configuration of a QAM modulator included in the modulator. FIG.

FIG. 7 is a block diagram illustrating another configuration example of the QAM modulator.

FIG. 8 is a block diagram illustrating another configuration example of the QAM modulator.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 transmission unit 2 reception unit 3 gas pipe 11 serial / parallel converter 12 modulator 15 speaker 21 parallel / serial converter 22 FFT 25 microphone 27 demodulator 12a _{1 to} 12a _N PSK modulator 12b adder 12c multiplier 12d Gauss Window signal generator 121 _i Sine wave signal generator 122 _i phase shifter

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) H04L 27/18 H04L 27/18 Z 27/34 27/00 EF term (reference) 5K004 AA03 AA05 AA08 DA11 DF02 FA09 FG02 JA05 JG01 5K022 AA02 AA04 AA26 5K048 BA01 DB05

Claims (12)

[Claims] 1. Modulation means for performing, on one or a plurality of carriers having a predetermined frequency, amplitude modulation and / or phase modulation based on transmission information and modulation with a signal representing a window function. Sound transmitting means for transmitting a signal modulated by the modulating means by sound. 2. The method according to claim 1, wherein when a plurality of carriers have the predetermined frequency, each of the plurality of carriers has a different frequency, and the modulating means controls each of the plurality of carriers. A sound transmission device for performing the modulation based on individual transmission information. 3. The method according to claim 2, wherein the modulating means comprises:
An acoustic transmission device, comprising: a dividing unit that divides one piece of transmission information into the same number of pieces of partial information as the number of carrier waves to create the individual transmission information. 4. The sound transmitting apparatus according to claim 1, wherein the signal representing the window function is a Gaussian window signal. 5. The modulation according to claim 1, wherein the modulation based on the transmission information by the modulation means is performed by:
One of phase shift keying, amplitude shift keying, and QAM, wherein the modulating means converts the transmission information into a phase shift amount of the carrier in the case of the phase shift keying, and converts the transmission information in the case of the amplitude shift keying. Converts the transmission information to an amplitude value of the carrier,
In the case of M, an acoustic transmission device comprising a conversion unit for converting the transmission information into an amplitude value and a phase shift amount of the carrier. 6. An acoustic signal transmission method performed by an acoustic transmission device for transmitting transmission information as an acoustic signal, wherein an amplitude modulation and a phase of one or a plurality of carriers having a predetermined frequency are performed based on the transmission information. An acoustic signal transmission method, which performs both or one of modulation and modulation by a signal representing a window function, and transmits the modulated signal by sound. 7. A computer provided in an acoustic transmission device for transmitting transmission information as an acoustic signal, wherein one or more digital data representing a carrier having a predetermined frequency are converted into digital data representing the transmission information. A procedure of performing amplitude modulation and / or phase modulation on the basis of the above, and a procedure of performing modulation by a signal representing a window function on digital data representing a carrier having the predetermined frequency. Program for. 8. A computer provided in an acoustic transmission device for transmitting transmission information as an audio signal, wherein a modulation performed on one or a plurality of carriers having a predetermined frequency is performed by phase shift keying based on the transmission information. If the modulation is amplitude shift keying, the transmission information is converted to an amplitude value of the carrier, and if the modulation is QAM. A step of converting the transmission information into an amplitude value and an amount of phase shift of the carrier; and a step of converting the amount of phase shift of the carrier when the modulation is phase shift keying, and the step of The amplitude value of the carrier wave, and the amplitude value of the carrier wave and the phase shift amount given as parameters when the modulation is QAM. Substituting a value converted from the transmission information into the parameter of a calculation expression obtained by multiplying an expression representing a plurality of carrier waves and an expression representing a window function. 9. Communication in which one or a plurality of carriers having a predetermined frequency are subjected to amplitude modulation and / or phase modulation based on transmission information and modulation by a signal representing a window function. An acoustic receiving means for receiving information as an acoustic signal and converting the signal into an electric signal; a Fourier transform of the signal converted by the acoustic receiving means to read out a phase value and / or an amplitude value at the frequency of the carrier wave; And a demodulating means for demodulating the communication information based on the read value. 10. An acoustic signal receiving method performed by an acoustic receiving apparatus for receiving communication information as an acoustic signal, wherein amplitude modulation and phase modulation based on transmission information are performed on one or a plurality of carriers having a predetermined frequency. Receiving communication information obtained by performing modulation by a signal representing a window function as both or one of them and converting it into an electric signal,
An acoustic signal receiving method, comprising: performing a Fourier transform on the converted signal; reading out a phase value and / or an amplitude value at the frequency of the carrier; and demodulating communication information based on the read value. 11. An acoustic communication device comprising an acoustic transmitting device and an acoustic receiving device, wherein the acoustic transmitting device comprises:
Or for a plurality of carriers having a given frequency,
Modulation means for performing amplitude modulation and / or phase modulation based on transmission information, and modulation with a signal representing a window function, and sound transmission means for transmitting a signal modulated by the modulation means by sound. A sound receiving device for receiving the sound signal transmitted by the sound transmitting device and converting the signal into an electric signal; Fourier transforming the signal converted by the sound receiving device; And / or demodulating means for reading out both or one of the phase value and the amplitude value in (1) and demodulating communication information based on the read out value. 12. An audio signal communication method performed by an audio communication device including an audio transmission device and an audio reception device,
The acoustic transmission device performs, on one or a plurality of carrier waves having a predetermined frequency, amplitude modulation and / or phase modulation based on transmission information and / or modulation using a signal representing a window function. Transmitting the modulated signal by sound, the sound receiving device receiving the sound signal transmitted by the sound transmitting device, converting the sound signal into an electric signal,
An acoustic signal communication method, comprising: performing a Fourier transform on the converted signal; reading out a phase value and / or an amplitude value at a frequency of the carrier; and demodulating communication information based on the read value.