JPH01126836A - Amplitude compressing/expanding single side band communication equipment - Google Patents

Abstract

PURPOSE:To attain low speed data transmission as well as signaling tone signal transmission by selecting the band width of a voice signal as a band width required for low speed data transmission, inserting a reference signal at the outside of the lower side band of the band width and inserting a signaling tone signal at the outside of the upper band of the band width of the voice signal. CONSTITUTION:A required frequency band width for a low speed data signal as an occupied frequency band width of a voice signal is provided. The voice signal subjected to amplitude compression is given to a mixer 20 and a reference signal of the output of a reference signal oscillator 11' is given to the mixer 20, where the voice signal and the reference signal are mixed and the reference signal is inserted at the outside of the lower side band of the frequency band width of the voice signal. Moreover, the upper side band amplitude modulation signal of the output of a narrow band filter 16 and the signaling tone signal of the output of the mixer 24 are given to a synthesizer 25 and the signaling tone signal is inserted at the outside of the upper side band of the voice signal frequency band width of the upper side band amplitude modulation signal. Thus, the low speed data transmission and the signaling tone signal transmission are attained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an amplitude-companded single sideband system for transmitting audio signals through a narrowband transmission path.
Regarding Single Side Band (hereinafter referred to as AC35B) communication equipment, in particular, signaling tones (Signal Side Band) for low speed data transmission and connection to telephone exchanges.
lling tone) signal transmission device.

(Prior art) In recent years, with the development of mobile communications, it has been desired to make effective use of radio frequencies.
It is possible to effectively utilize radio frequencies at frequency intervals of 2.51 fllZ.

On the other hand, in mobile satellite communication systems, the usable radio frequency is approximately 10MI+ in the 1600M1lz band.

Since the frequency is limited within the bandwidth, increasingly narrower bands are required. In order to achieve narrower bandwidth, the use of amplitude modulation, which allows communication in a narrower band than phase modulation or frequency modulation, is being considered in mobile satellite communication systems. Among them, Single Side Band (S S
B) Amplitude companding for modulation and improving signal-to-noise ratio
It has been proposed to use an AC35B modulation scheme with ng) functionality. It is known that when this modulation method is used, communication is possible in a narrow band of about 5 KH2. less than,
A conventional AC35B communication device using the AC35B modulation method will be described with reference to the drawings.

FIG. 4 is a configuration diagram of a conventional AC35B communication device,
1 is a transmitting section, 2 is an antenna section, 3 is a receiving section, 11 is an automatic frequency control in the receiving section 3.
control (hereinafter referred to as AFC) and automatic gain control (hereinafter referred to as AFC) and automatic gain control (hereinafter referred to as AFC).
12 is a local oscillator that generates an intermediate frequency carrier signal, 13 is a compressor that compresses the amplitude of the audio signal, and 14 is the audio signal. and reference signal oscillator 1
15 is a modulator that amplitude modulates the carrier signal output from the local oscillator 12 with an audio signal; 16 is a narrowband filter that outputs an upper sideband modulated signal; 17 18 is a synthesizer that generates a high frequency signal; 18 is a mixer that converts the upper sideband modulated signal output from the narrowband filter 16 into a high frequency signal to produce a wireless communication signal; and 1 is a mixer that amplifies the wireless communication signal. Output transmitting amplifier, 31 is A
32 is a synthesizer that generates a high frequency signal based on AP'C; 33 is a frequency converter for the wireless communication signal output from the receiving amplifier 31 into an intermediate frequency signal; 34 is a narrowband filter that outputs the upper sideband modulated signal, and 35 demodulates the intermediate frequency communication signal, which is the upper sideband modulated signal, by product detection and demodulates the baseband. A demodulator outputs the signal, 36 is a splitter that splits the demodulated signal into two, 37 is an audio band filter that outputs the reproduced audio signal, 38 is an expander that expands the amplitude of the audio signal, and 39 is a splitter. A reference signal filter 40 extracts a reference signal from the demodulated signal output from the reference signal filter 39, and a reference signal filter 40 detects the amplitude value of the reference signal output from the reference signal filter 39, and the amplitude value is always within a predetermined range. An automatic gain controller 41 automatically controls the gain of the reception amplifier 31 so that Synthesizer 3 so that it is below the value
This is an automatic frequency controller that automatically controls the frequency of 2.

FIG. 5 is a diagram showing the spectrum of a signal related to a conventional transmitter, in which FIG. 5(a) is a spectrum of the output signal of the synthesizer 14, and FIG. , FIG. 5(C) is the spectrum of the output signal of the narrowband filter 16, and FIG. 5(d) is the spectrum of the output signal of the mixer 18.

Next, referring to FIGS. 4 and 5, the conventional AC3
The operation of the 5B communication device will be explained.

On the transmitting side, the audio signal input to this device is input to the compressor 13 of the transmitter 1, and the amplitude of the audio signal is compressed. The compression ratio of the compressor 13 is set to, for example, 2:1 (or 4:1), and is combined with the expander 38 of the receiving section 3 to constitute a compandor, which converts the audio signal into an auditory signal pair. The noise ratio (hereinafter referred to as S/N ratio) is improved by about 20 dB. The audio signal output from the compressor 13 is input to a synthesizer 14, and the reference signal output from the reference signal oscillator 11 is input to the synthesizer 14, where the audio signal and the reference signal are combined.

To ensure that the combined signal is within a narrow bandwidth of 5Ktlz and that the audio signal and reference signal do not interfere with each other,
As shown in Figure 5(a), the bandwidth of the audio signal is 300
Hz to 2600 Hz, and the frequency of the reference signal is selected to be 3100 Hz.

The bandwidth of the audio signal and the frequency of the reference signal are selected to be the best values based on conventional wave technology. The combined signal output from the combiner 14 is input to the modulator 15, and
The carrier wave signal (frequency = f1) output from the local oscillator 12 is input to the modulator 15, where the carrier wave signal is amplitude-modulated with a composite signal, and the carrier wave signal is amplitude-modulated on both sides with the spectrum shown in FIG. 5(b). A waveband modulated signal is output from the modulator 15. The both-sideband modulated signal output from the modulator 15 is input to the narrowband filter 16, and the lower sideband modulated signal is sufficiently attenuated by the bandpass filtering characteristics of the band width 5 [2].
The upper sideband modulated signal shown in Figure (c) is transmitted to the narrowband filter 1.
6 pieces are output.

The upper sideband modulated signal of the output of the narrowband filter 16 is sent to the mixer 1
8, and the high frequency signal (frequency = f2) output from the synthesizer 17 is input to the mixer 18, and the upper sideband modulation signal, which is an intermediate frequency signal, is converted into the high frequency signal shown in FIG. 5(d). The frequency is converted to The wireless communication signal output from the mixer 18 is amplified by a transmission amplifier 19 with good linearity, and the wireless communication signal output from the transmitting section 1 is transmitted through the antenna section 2. On the other hand, on the receiving side, the wireless communication signal received via the antenna section 2 is transmitted to the receiving amplifier 31 of the receiving section 3.
Low noise amplification is achieved. The gain of the receiving amplifier 31 is controlled by an AGC signal from an automatic gain controller 40. The wireless communication signal output from the receiving amplifier 31 is input to the mixer 33, and the high frequency signal output from the synthesizer 32 is input to the mixer 33.The mixer 33 converts the wireless communication signal into an intermediate frequency communication signal. converted. synthesizer 3
2 is frequency controlled by an AFC signal from an automatic frequency controller 41, and as a result, an intermediate frequency communication signal in the same intermediate frequency band as the signal in the intermediate frequency band in the transmitter 1 is output from the mixer 33.

The intermediate frequency communication signal output from the mixer 33 is passed through the narrowband filter 3.
4, and the upper sideband modulated signal is extracted by bandpass filtering characteristics with a bandwidth of 5 KHz.

The upper sideband modulated signal of the output of the narrowband filter 34 is sent to the demodulator 3.
5, and the carrier signal output from the local oscillator 12 is also input to the demodulator 35.

The upper sideband modulated signal is demodulated by product detection in the demodulator 35, and a baseband demodulated signal is output from the demodulator 35. The demodulated signal output from the demodulator 35 is sent to the splitter 3
6, is branched into two, and is output. One output signal of the splitter 36 is input to an audio band filter 37, where the reference signal synthesized with the audio signal is sufficiently attenuated, and a reproduced amplitude-compressed audio signal is output. Audio band filter 3
The amplitude compressed audio signal output from 7 is input to an expander 38,
The amplitude of the amplitude compressed audio signal is expanded.

The expansion ratio of the expander 38 is a value that is inversely compatible with the compression ratio of the compressor 13, and is set to, for example, 1:2 (or 1:4). Due to the companding function of the combination of the compressor 13 of the transmitter 1 and the expander 38 of the receiver 3, the S/N ratio is approximately 2.
The audio signal output from the receiving section 3 is outputted from the apparatus.

The other output signal of the splitter 36 is input to three reference signal filters, and a 3100 Hz reference signal is extracted from the demodulated signal. The reference signal output from the reference signal filter 39 is input to an automatic gain controller 40, where the amplitude value of the reference signal is compared with a predetermined value. When the amplitude value of the reference signal is larger than a predetermined value, the gain of the receiving amplifier 31 is reduced, and when the amplitude value of the reference signal is smaller than the predetermined value, the gain of the receiving amplifier 31 is controlled to be increased. The automatic gain controller 40 outputs an AGC signal that automatically controls the gain of the receiving amplifier 31 so that the amplitude value is always within a predetermined range. The reference signal output from the standard signal filter 39 and the reference signal output from the reference signal oscillator 11 are input to the automatic frequency controller 41, and the phases of the two reference signals are compared. The automatic frequency controller 41 outputs an AFC signal that automatically controls the frequency of the synthesizer 32 so that the phase error is less than or equal to a predetermined value.

As described above, the conventional AC35B communication device limits the audio band from 300 H2 to 2600112 and 3100 H2.
By inserting a reference signal of 112 and using a single sideband modulation communication method, it is possible to transmit a communication signal with a wireless bandwidth of 5KII2. Furthermore, AFC and AGC in the receiving section can be performed using the reference signal inserted in the transmitting section, and it is possible to automatically correct frequency fluctuations and amplitude value fluctuations of communication signals generated on the wireless line. Therefore, in a mobile satellite communication system that requires narrowband communication and is likely to experience frequency fluctuations due to frequency fluctuations of satellite equipment and the Doppler effect, as well as frequent amplitude fluctuations due to multipath fading, the above-mentioned Based on the prior art, an AC35B communication device is used.

(Problems to be Solved by the Invention) However, in the above-mentioned conventional AC35B communication device, 3100
A Hz reference signal is inserted, and the upper side of the audio signal bandwidth is set to 2600 Hz to prevent interference between the audio signal and the reference signal.
It is limited to Hz.

For this reason, there is a problem that low-speed data transmission (for example, 4800 bps data transmission) that requires a bandwidth of 3000H2 or more on the upper side cannot be performed.

In addition, in order to connect this AC35B communication device to a telephone exchange used in a normal telephone line network, in addition to voice signals, a signaling tone signal (usually a 3825Hz signal), which is a signal for connecting to a telephone exchange, is required. need to be transmitted. However, in the conventional AC35B communication device, 3
Since the 100 Hz reference signal is inserted outside the upper band of the audio signal, there is a problem that additional 3825+12 signaling tone signals cannot be inserted outside the upper band of the audio signal. With conventional filtering technology, 3100
H2 reference signal and 382511. It is difficult to insert both signaling tone signals outside the upper band of the voice signal without interference. That is, the conventional AC35B communication device has the drawbacks of not being able to transmit low-speed data and not being able to transmit signaling tone signals.

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the conventional technology, it is an object of the present invention to set the bandwidth of an audio signal to a bandwidth necessary for low-speed data transmission, and to set a reference signal outside the lower band of the bandwidth of the audio signal. To provide an AC35B communication device capable of low-speed data transmission and signaling tone signal transmission by inserting the signaling tone signal into the upper band of the voice signal bandwidth. be.

(Means for Solving the Problems) In order to achieve the above object, the present invention has the following membrane configuration. That is, the AC'SSB communication device according to the present invention compresses the amplitude of an audio signal including a low-speed data signal on the transmitting side, and generates a wireless communication signal that is a high-frequency signal that is single-sideband amplitude-modulated with the amplitude-compressed audio signal. is transmitted to the receiving side via the antenna, the receiving side receives the wireless communication signal from the transmitting side via the antenna, demodulates the amplitude compressed audio signal from the wireless communication signal, and expands the amplitude of the amplitude compressed audio signal. AC35
B is a communication device, which includes, on the transmitting side, compression means for compressing the amplitude of an audio signal including a low-speed data signal based on predetermined compression characteristics; and on the receiving side, generating a reference signal for use in AGC and AFC. , and the amplitude-compressed audio signal is frequency-converted by a predetermined frequency toward a higher frequency, and the occupied frequency bandwidth of the audio signal is set as the required frequency bandwidth necessary for the low-speed data signal, and the audio signal is a synthesizing means for generating a synthesized signal by synthesizing the frequency-converted audio signal and the reference signal such that the reference signal exists outside the lower band of the signal frequency bandwidth; a carrier signal of a predetermined intermediate frequency; modulation means for generating a modulation signal that is single sideband amplitude modulated using the composite signal; a mouse signal that is a signal for connecting to a telephone exchange is input, and a predetermined frequency is determined from the mouse signal depending on the presence or absence of the mouse signal; Signaling, which is a signal with or without a signal.
a mouse signal converting means for converting into a tone signal; setting the occupied frequency bandwidth of the audio signal as the required frequency bandwidth necessary for the low-speed data signal, outside the upper band of the frequency bandwidth for the audio signal; A receiving side generates a radio communication signal which is a high frequency signal by combining the modulated signal and the signaling tone signal so that the signaling tone signal exists inside the frequency bandwidth required for narrowband transmission. a transmitting means for transmitting to; and on the receiving side,
A wireless communication signal from the transmitting side is received and amplified under AGC, the received and amplified wireless communication signal is mixed with a high frequency signal generated under AFC, and the wireless communication signal is frequency-converted to a predetermined intermediate frequency. receiving means for generating a communication signal and also extracting a signaling tone signal by a filtrate process that passes the signaling tone signal and blocks the voice signal and the reference signal; a telephone exchange from said extracted signaling tone signal; Ear, which is a connection signal.
) an ear signal converting means for converting into a signal; extracting a single sideband amplitude modulated signal from the intermediate frequency communication signal and demodulating it to generate a demodulated signal, and also passing a reference signal to generate an audio signal and a signaling signal; demodulation means for extracting a reference signal by filtrate processing to block tone signals; automatic gain/demodulation means for generating an AGC signal and an AFC signal for performing AGC and AFC on the receiving means from the extracted reference signal; frequency control means; audio signal reproduction means for converting the frequency of the demodulated signal to a lower frequency by a predetermined frequency and reproducing a baseband amplitude compressed audio signal; An AC35B communication device comprising: expansion means for expanding the amplitude of the reproduced amplitude compressed audio signal based on expansion characteristics; and an AC35B communication device.

(Function) Hereinafter, the function of the amplitude companding single sideband communication device of the present invention having the above means configuration will be explained.

On the transmitting side, the audio signal including the low-speed data signal input to the apparatus is input to a compression means, and the amplitude of the audio signal is compressed based on predetermined compression characteristics. The amplitude-compressed audio signal is input to a synthesizing means and frequency-converted by a predetermined frequency in the direction of higher frequencies. Next, the frequency-converted audio signal and the reference signal are combined. The reference signal is a signal used for AGC and AFC on the receiving side, and is inserted outside the lower frequency band of the audio signal and synthesized. The composite signal obtained by combining the audio signal and the reference signal has a required frequency bandwidth necessary for the low-speed data signal as the occupied frequency bandwidth of the audio signal. The composite signal is input to a modulation means, and a modulated signal is generated by single sideband amplitude modulating a carrier signal of a predetermined intermediate frequency with the composite signal.

The modulated signal is input to the transmitting means. On the other hand, the mouse signal, which is a telephone exchange connection signal input to this device, is input to the mouse signal conversion means, and a signaling tone signal, which is a signal in which a signal of a predetermined frequency is present or absent depending on the presence or absence of the mouse signal, is input to the mouse signal conversion means. is converted to The signaling tone signal is input to the transmitting means. The transmitting means generates a radio communication signal, which is a high frequency signal in which the modulation signal and the signaling tone signal are combined. The wireless communication signal has the required frequency bandwidth necessary for the low-speed data signal as the frequency bandwidth occupied by the voice signal, and has a frequency bandwidth outside the upper band of the frequency bandwidth for the voice signal for persistent, narrowband transmission. This is a signal in which a signaling tone signal is inserted inside the required frequency bandwidth. Wireless communication signals are transmitted to a receiving end via an antenna. On the receiving side, the wireless communication signal received from the transmitting side via the antenna is input to the receiving means and is received and amplified under AGC.

Next, the received and amplified radio communication signal and the high frequency signal generated under AFC are mixed, and the radio communication signal is frequency-converted to a lower frequency direction to generate a predetermined intermediate frequency communication signal. Also, in the receiving means, the signaling tone signal is extracted by a filtrate treatment that passes the signaling tone signal and blocks the audio signal and the reference signal.

The extracted signaling tone signal is input to the ear signal converting means, where it is converted into an ear signal which is a signal for connection to a telephone exchange, and the ear signal is output from the device. The intermediate frequency communication signal is input to the demodulation means, and the single sideband amplitude modulated intermediate frequency communication signal is demodulated to generate a demodulated signal. Further, in the demodulation means, the reference signal is extracted by filtrate processing that passes the reference signal and blocks the audio signal and the signaling signals. The extracted reference signal is input to the automatic gain/frequency control means, and an AGC signal and an AFC signal for performing AGC and AFC on the receiving means are generated.

The demodulated signal is input to the audio signal reproducing means, frequency-converted by a predetermined frequency in the direction of lower frequencies, and a baseband amplitude-compressed audio signal is reproduced. The reproduced amplitude-compressed audio signal is input to the expansion means, and the amplitude of the amplitude-compressed audio signal is expanded based on a predetermined expansion characteristic that matches the compression characteristics of the compression means. The device outputs an audio signal whose signal-to-noise ratio has been improved by the companding function.

(Example) Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an AC35B communication device (transmission section 1) according to an embodiment of the present invention. 11' is a reference signal oscillator, 12
is a local oscillator, 13 is a compressor, 14' is a combiner, 15 is a modulator, 16 is a narrow band filter, 17 is a synthesizer, 1
8 is a mixer, 1 is a transmission amplifier, and 20 is a mixer that mixes the audio signal output from the compressor 13 and the reference signal output from the reference signal oscillator 11' to increase the frequency of the audio signal by the frequency of the reference signal. a mixer that converts the frequency in a higher direction; 21 is a narrowband filter that has a frequency bandwidth necessary for the low-speed data signal and has a characteristic of passing the frequency-converted audio signal;
22 receives a mouse signal which is a signal for connecting to a telephone exchange,
A mouse signal converter converts a mouse signal into a control signal that controls the generation of a signaling tone signal, and 23 is a signal that indicates the presence or absence of a signal of a predetermined frequency depending on the presence or absence of a mouse signal based on the control signal. - a signaling tone signal generator that generates a tone signal; 2;
4 is a mixer that mixes the carrier signal output from the local oscillator 12 and the signaling tone signal, and converts the frequency of the signaling tone signal to a higher frequency by the frequency of the carrier signal; 25 is a narrow band filter; 16 output upper sideband amplitude modulated signal and the output of mixer 24.
This is a synthesizer that synthesizes the tone signal. Furthermore, 26 is a synthesis means composed of a reference signal oscillator 11', a synthesizer 14', a mixer 20 and a narrowband filter 21, and 27 is composed of a local oscillator 12, a modulator 15 and a narrowband filter 16. 28 is a mouse signal converting means composed of a mouse signal converter 22 and a signaling tone signal generator 23, two of which are a synthesizer 17, a mixer 18,
It is a transmitting means composed of a transmitting amplifier 19, a mixer 24, and a combiner 25.

Note that components having the same numbers and the same numbers with dashes as the component numbers shown in FIG. 4 are the same as the components of the conventional AC35B communication device shown in FIG. Also shown are the antenna section 2, the receiving section 3, and the demodulator 35, automatic frequency controller 41, and mixer 45, which are components of the receiving section 3, as related equipment although they are not components of the transmitting section 1. .

FIG. 2 is a configuration diagram of an AC, SSB communication device (receiving section 3) according to an embodiment of the present invention. 31 is a receiving amplifier, 32 is a synthesizer, 33 is a mixer, 34 is a narrowband filter, 35
is a demodulator, 36 is a splitter, 37 is a voice band filter, 38
39' is an expander, 39' is a reference signal filter, 40 is an automatic gain controller, 41 is an automatic frequency controller, 42 is a splitter that splits the output signal of the mixer 33 into two, and 43 is one of the splitters 42. A signaling tone signal filter 44 extracts a signaling tone signal from the output signal, and a signal filter 44 converts the signaling tone signal output from the signaling tone signal filter 43 into an ear signal which is a signal for connection to a telephone exchange. A signal converter 45 mixes the demodulated signal of one output of the splitter 36 and the reference signal of the output of the reference signal oscillator 11' of the transmitter 1, and increases the frequency of the demodulated signal by the frequency of the reference signal. It is a mixer that converts the frequency in the lower direction. Furthermore, 46 is a reception amplifier 31, a synthesizer 3
2, receiving means consisting of a mixer 33, a splitter 42 and a signaling tone signal filter 43; 47 is a narrow band filter 34, a demodulator 35, a splitter 36 and a reference signal filter 39'; 48 is an automatic gain/frequency control means consisting of an automatic gain controller 40 and an automatic frequency controller 41; 49 is an audio signal reproducing means consisting of an audio band filter 37 and a mixer 45; It is.

Note that components having the same numbers and the same numbers with dashes as the component numbers shown in FIG. 4 are the same as the components of the conventional AC35B communication device shown in FIG. Also shown are the antenna section 2, the transmitter 1, and the reference signal oscillator 11' and local oscillator 12, which are components of the transmitter 1, as related equipment although they are not components of the receiver 3.

FIG. 3 is a diagram showing the spectrum of a signal related to the transmitting section of the embodiment of the present invention, and FIG. 3(a) shows the narrowband filter 21.
3(b) shows the spectrum of the output signal of the synthesizer 14.
3(c) is the spectrum of the output signal of the narrowband filter 16, FIG. 3(d) is the spectrum of the output signal of the combiner 22, and FIG.
) is the spectrum of the output signal of the mixer 18.

Hereinafter, the operation of the AC35B communication device according to the embodiment of the present invention will be explained with reference to FIGS. 1, 2, and 3. It should be noted that detailed explanations of the functions of components similar to those of the conventional AC35B communication device shown in FIG. 4 will be omitted.

On the transmitting side, the audio signal including the low-speed data signal input to this device is input to the compressor 13 of the transmitter 1, and the amplitude of the audio signal is compressed.

The amplitude-compressed audio signal is input to the mixer 20, and the reference signal output from the reference signal oscillator 11' is also input to the mixer 20.
is input. The audio signal and the reference signal are mixed in the mixer 20, and the audio signal is frequency-converted to a higher frequency by the frequency of the reference signal. The audio signal output from the mixer 20 is input to a narrowband filter 21, where the audio signal is filtered using a bandpass filter characteristic whose passband width is the frequency bandwidth required for the low-speed data signal.

For example, if the frequency of the reference signal is selected as 300 Hz and the frequency bandwidth required for the low-speed data signal is 300112 to 3000 Hz, the audio signal output from the narrowband filter 21 will be as shown in FIG. 3(a). As shown, its bandwidth is 3
00+300 (-600)Hz 300 + 30
00 (=3300) Hz signal.

Audio signal output from narrowband filter 21 and reference signal oscillator 1
The reference signal output from the signal generator 1' is input to a synthesizer 14', where the audio signal and the reference signal are synthesized. Since the audio signal is frequency-converted to a higher frequency by the frequency of the reference signal, a composite signal is generated in which the reference signal is inserted outside the lower band of the frequency bandwidth of the audio signal. In other words, Fig. 3 (
A composite signal in which the audio signal and the reference signal are combined as shown in b) is output from the synthesizer 14'. The composite signal is input to the modulator 15, which amplitude modulates the carrier signal (frequency=f+) output from the local oscillator 12 to generate a double-sided band amplitude modulated signal.

The double sideband amplitude modulated signal is input to a narrowband filter 16;
The upper sideband amplitude modulation signal shown in FIG. 3(c) is output. On the other hand, a mouse signal, which is a telephone exchange connection signal input to this device, is input to a mouse signal converter 22.
A control signal is generated that controls the signaling tone signal generator 23. Based on the control signal, the signaling tone signal generator 23 outputs a signaling tone signal, which is a signal in which a signal of a predetermined frequency is present or absent depending on the presence or absence of a mouse signal.

For example, if the predetermined frequency is selected as 3825Hz,
Generates a 382'5Hz continuous signal, switches the continuous signal according to the control signal, turns on the switching when there is a mouse signal, turns off the switching when there is no mouse signal, and connects/disconnects the continuous signal. Possibly 38
251 (Z signaling tone signal is generated.

The signaling tone signal and the carrier signal at the output of local oscillator 12 are mixed in mixer 24 to
The tone signal is frequency-converted to a higher frequency by the frequency (=ft) of the carrier wave signal.

The upper sideband amplitude modulated signal output from the narrowband filter 16 and the signaling tone signal output from the mixer 24 are combined into a combiner 25.
A signaling tone signal is inserted outside the upper band of the audio signal frequency bandwidth of the upper sideband amplitude modulated signal, and the signaling tone signal is inputted into the upper sideband amplitude modulated signal as shown in FIG. 3(d). A composite signal obtained by combining the tone signal and the tone signal is output from the synthesizer 25. The composite signal is a high frequency signal (frequency = f2) output from the synthesizer 17 and the mixer 1
8, and the composite signal is mixed by the frequency of the high frequency signal (
The frequency is converted to a higher frequency by = f 2), and a wireless communication signal as shown in FIG. 3(e) is generated. The wireless communication signal is amplified by a transmission amplifier 19 with good linearity and transmitted to the receiving side via the antenna section 2.

On the receiving side, the wireless communication signal transmitted from the transmitting side is input to the receiving amplifier 31 via the antenna section 2. The reception amplifier 31 amplifies the wireless communication signal with low noise after performing AGC using the AGC signal from the automatic gain controller 40 . The low-noise amplified wireless communication signal is input to the mixer 33, and the high-frequency signal (frequency = f
2), and an intermediate frequency communication signal having an intermediate frequency is output from the mixer 33. The synthesizer 32 is controlled by the AFC signal from the automatic frequency controller 41.
Generates high frequency signals. The intermediate frequency communication signal is sent to the brancher 42
The signal is input into the system, split into two, and output. The intermediate frequency communication signal at one output of the splitter 42 is input to a signaling tone signal filter 43, where the signaling tone signal is passed through, the voice signal and the reference signal are blocked, and only the signaling tone signal is extracted. be done. The extracted signaling tone signal is input to an ear signal converter 44 and converted into an ear signal which is a signal for connection to a telephone exchange.

The ear signal output from the ear signal converter 44 is output from the device. Further, the intermediate frequency communication signal output from the other output of the splitter 42 is input to the narrowband filter 34, and an upper sideband amplitude modulation signal is extracted. The upper sideband amplitude modulated signal is sent to the demodulator 35.
The carrier signal output from the local oscillator 12 of the transmitter 1 is also input to the demodulator 35, where it is demodulated by product detection and a demodulated signal is generated.

The demodulated signal is input to a splitter 36, where it is split into two and output. The demodulated signal at one output of the splitter 36 is input to a reference signal filter 39', where the reference signal is passed, the voice signal and the signaling tone signal are blocked, and only the reference signal is extracted.

The extracted reference signal is input to an automatic gain controller 40 and an automatic frequency controller 41. Based on the reference signal, an automatic gain controller 40 generates an AGC signal, and an automatic frequency controller 41 generates an AFC signal. The generation operation of the AGC signal and AFC signal is similar to that in the conventional example. The demodulated signal output from the other output of the splitter 36 is input to the mixer 45, and the reference signal output from the reference signal oscillator 11' of the transmitter 1 is input to the mixer 45. The demodulated signal and the reference signal are mixed in a mixer 45,
The demodulated signal is frequency-converted down by the frequency of the reference signal to generate a baseband signal. The output signal of the mixer 45 is input to the audio bandpass filter 37,
Signals other than the audio signal are blocked by the filtering characteristic whose passband width is the frequency bandwidth required for the low-speed data signal, and only the baseband amplitude-compressed audio signal is extracted.

The extracted and reproduced amplitude compressed audio signal is input to the expander 38, and the amplitude of the amplitude compressed audio signal is expanded. Stretcher 38
The output audio signal is output from this device.

In the above embodiment, in order to frequency-convert the amplitude-compressed audio signal to a higher frequency by a predetermined frequency, the reference signal oscillator 1 is sent to the mixer 20 of the transmitter 1.
Although the reference signal output from the output signal 1' is input and the frequency is converted in a direction higher by the frequency of the reference signal, the frequency conversion is not necessarily limited to using the reference signal. A reference signal is inserted outside the lower band of the frequency bandwidth of the audio signal, and the audio signal is frequency-modulated by a predetermined frequency in the mixer 20 so that the audio signal and the reference signal can be synthesized and modulated in the upper sideband amplitude. It is only necessary to convert the frequency in the direction of higher frequency, and it is necessary to have an oscillator that generates a signal of a predetermined frequency, input the output signal of this oscillator to the mixer 20 instead of the reference signal, and increase the audio signal by the predetermined frequency. An embodiment that performs frequency conversion is also conceivable. In this case, the receiving section 3
The output signal of the oscillator is input to the mixer 45 instead of the reference signal output from the reference signal oscillator 11' of the transmitter 1, which is input to the mixer 45.

Further, in the transmitter 1, the mixer 24 outputs the signaling tone signal (frequency -3825) 1z) output from the signaling tone signal generator 23 to the local oscillator 12.
An example has been described in which the frequency is converted to a higher frequency by the frequency (-ft) of the carrier signal output from the signal tone signal generator 23, but instead of the continuous signal of 3825112 generated in the signaling tone signal generator 23, a continuous signal of f l + 382511z is generated. Then, this ft+3825Hz continuous signal is switched to generate a signaling tone signal, and the synthesizer 25
It is also possible to consider an embodiment in which the information is input to In this case, mixer 2
4 becomes unnecessary.

Furthermore, the upper sideband modulated signal and the signaling tone signal are combined in an intermediate frequency band to generate a wireless communication signal that is a combination of the upper sideband modulated signal and the signaling tone signal, and then the combined signal is Although we have described an example in which a wireless communication signal, which is a high-frequency signal, is generated by frequency conversion, the intermediate frequency upper sideband modulation signal is first frequency-converted to a high-frequency signal, and the signaling tone signal is also frequency-converted to a high-frequency signal. Embodiments are also contemplated in which the upper sideband modulated signal and the signaling tone signal are then combined to generate the wireless communication signal. Also, signaling
The continuous signal generated within the tone signal generator 23 is f 2+
f '1 + 3825 Hz continuous signal, this continuous signal is switched to generate a signaling tone signal, and the upper sideband modulated signal of the high frequency signal and this signaling tone signal are combined to generate a wireless communication signal. Embodiments in which the data is generated are also conceivable.

(Effects of the Invention) As explained above, in the AC35B communication device of the present invention, by once converting the frequency of the audio signal in the direction of higher frequencies by the required frequency, the lower band of the frequency bandwidth of the audio signal is converted. The audio signal and the reference signal can be synthesized by inserting a reference signal outside. Thereby, the signaling tone signal can be inserted outside the upper band of the frequency bandwidth of the audio signal to synthesize the audio signal, the reference signal, and the signaling tone signal.

That is, the occupied frequency bandwidth of the audio signal has the required frequency bandwidth necessary for the low-speed data signal, the reference signal is inserted outside the lower band of the audio signal frequency bandwidth, and the reference signal is inserted outside the upper band of the audio signal frequency bandwidth. , it becomes possible to communicate using wireless communication signals in which signaling tone signals are inserted inside the frequency bandwidth required for persistent narrowband transmission, and low-speed data transmission and signaling tone signal transmission are possible. There is.

[Brief explanation of the drawing]

FIG. 1 shows an AC35B communication device (transmission section 1) according to an embodiment of the present invention.
), FIG. 2 is a configuration diagram of an AC35B communication device (receiving section 3) according to an embodiment of the present invention, FIG. 3 is a spectrum of a signal related to a transmitting section according to an embodiment of the present invention, and FIG. 4 is a diagram showing a conventional AC35B communication device (receiving section 3).
FIG. 5, which is a block diagram of a 5B communication device, shows a spectrum of a signal related to a conventional transmitter. 1... Transmitter section, 2... Antenna section,
3... Receiving unit, 11. 11'... Reference signal oscillator, 12... Local oscillator, 13.
...Compressor, 14.14'...Synthesizer,
15...Modulator, 16...Narrowband filter, 17...Synthesizer, 18...
...Mixer, 19...Transmission amplifier, 20...
...Mixer, 21...Narrowband filter, 2
2... Mouse signal converter, 23...
Signaling tone signal generator, 24...
Mixer, 25...Synthesizer, 26...
Synthesizing means, 27...Modulation means, 28...
... Mouse signal exchange means, 29 ... Transmission means, 31 ... Reception amplifier, 32 ... Synthesizer, 33 ... Mixer, 34 ...・
... Narrowband filter, 35 ... Demodulator, 36.
...brancher, 37...audio band filter, 38...expander, 39.39'...
・Reference signal filter, 40... automatic gain controller, 41... automatic frequency controller, 42...
... Brancher, 43 ... Signaling tone signal filter, 44 ... Ear signal converter,
45... Mixer, 46... Receiving means, 47... Demodulating means, 48... Automatic gain/frequency control means, 49... - Audio signal reproduction means. Agent Patent Attorney Yoshihiro Hachiman

Claims (1)

[Claims] On the transmitting side, an audio signal including a low-speed data signal is amplitude-compressed, and a wireless communication signal, which is a high-frequency signal that is single-sideband amplitude-modulated with the amplitude-compressed audio signal, is received via an antenna. On the receiving side, the wireless communication signal from the transmitting side is received via an antenna, the amplitude compressed audio signal is demodulated from the wireless communication signal, and the amplitude of the amplitude compressed audio signal is expanded. In the wireless communication device, on the transmitting side, compression means compresses the amplitude of the audio signal including the low-speed data signal based on predetermined compression characteristics; and on the receiving side, automatic gain control (AGC)
and automatic frequency control (AFC), and also converts the amplitude-compressed audio signal to a higher frequency by a predetermined frequency,
The audio signal is frequency-converted such that the occupied frequency bandwidth of the audio signal is the required frequency bandwidth necessary for the low-speed data signal, and the reference signal exists outside the lower band of the frequency bandwidth for the audio signal. and the reference signal; a modulation means that generates a modulation signal by single sideband amplitude modulating a carrier signal of a predetermined intermediate frequency with the composite signal; a telephone exchange connection signal; A signaling tone (Sig-nall) is a signal in which a signal of a predetermined frequency is present or absent depending on the presence or absence of a mouse signal.
ingTone) signal; , generating and receiving a wireless communication signal that is a high frequency signal that is a combination of the modulated signal and the signaling tone signal such that the signaling tone signal exists inside the frequency bandwidth required for narrowband transmission; On the receiving side, the receiving side receives and amplifies the wireless communication signal from the transmitting side under AGC, and the received and amplified wireless communication signal and AFC are provided.
The radio communication signal is mixed with a high frequency signal generated under receiving means for extracting the signaling tone signal by wave processing; ear signal converting means for converting the extracted signaling tone signal into an ear signal which is a signal for connecting to a telephone exchange; and the intermediate frequency communication signal. demodulating means for extracting and demodulating a single sideband amplitude modulated signal from a signal to generate a demodulated signal, and also extracting the reference signal by filtering to pass the reference signal and reject the voice signal and the signaling tone signal; and; an AGC signal and A for performing AGC and AFC on the receiving means from the extracted reference signal;
automatic gain/frequency control means for generating an FC signal; audio signal reproduction means for converting the frequency of the demodulated signal to a lower frequency by a predetermined frequency and reproducing a baseband amplitude compressed audio signal; and the compression means. An amplitude companding single sideband communication device comprising: expansion means for expanding the amplitude of the reproduced amplitude compressed audio signal based on a predetermined expansion characteristic that matches the compression characteristic of the signal.