JPS5944166A - System for transmitting voice and data signal - Google Patents

Abstract

PURPOSE:To obtain a transmitter/receiver for voice and a data signal with low cost and small size without using any filter, by deleting periodically a sampled voice at a transmission station and superimposing the data signal on the deleted period for transmitting the result. CONSTITUTION:The voice signal is inputted to an amplitude limiting circuit 1 and converted into a band of 4kHz at a frequency band limit circuit 2, the voice is sampled in the period of 125mus at a sampling circuit 3 and inputted to a sampling delete circuit 4. The circuit 4 deletes the sampling signal periodically once for four times and the data signal is superimposed on the deleted part at a voice data synthesis circuit 6 and the result is outputted to a transmission circuit. A data signal recognizing circuit 8 at the receiving side detects the data signal having a large amplitude, a polarity is given at a data output waveform predicting circuit 9 and outputted to an operating circuit 11 in time series. Further, the data signal is deleted at the operating circuit 11 from the receiving signal inputted to a delay circuit 10 and the voice signal is extracted.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a voice and data signal transmission system that simultaneously transmits voice and data signals using an analog transmission path.

(b> Prior art and problems When transmitting audio, it is necessary to limit the amplitude of the audio signal!
or 3.4 guirohertz (KH2) Q) 4 KH2
3) To recognize this voice, the frequency band below 1-5 KH2 is mainly used, and in order to maintain clarity, 3 Kl(
Since it is sufficient to have the frequency band Z and above as a secondary frequency band, the unused part of the voice in the 2 to 2-5KH2 frequency band is removed and this frequency band 4j) is utilized.
A method is generally adopted in which data signals are transmitted using

However, in this conventional method, it takes 2 to 2.5 Pjj to separate the voice signal and data signal from the signal to be transmitted.
KH2O) filters were used, and there were many of these filters.

(C) OBJECT OF THE INVENTION The present invention was created in view of the above-mentioned drawbacks of the prior art, and aims to provide a voice and data signal transmission system that can be miniaturized.

(Reason for the Structure of the Invention) Briefly stated, the present invention includes a sample deletion circuit that periodically deletes sampled audio in a transmitting station, superimposes a data signal on the deleted period, and transmits the data signal to the receiving station. [1
Data signal magazine that knows the issue 1IC, ii & circuit and data signal waveforms 1. (j ↑, d region ('iii, the output of the recognition circuit is used to calculate the waveform and the received signal ↑f, so that 7゛11 voice signals and 11 The goal is to make it cheaper and smaller.
(c) Embodiments of the Invention Embodiments of the present invention will be explained in detail below using figures.

FIG. 1 shows waveform 1 <I
, FIG. 2 shows the audio and data signal transmission system of the present invention.
1 is a block diagram of one embodiment, l is a vibration 'f'j+f limiting circuit, 2 is a frequency band limiting circuit, 3 is a sampling circuit,
4 is a sample deletion circuit, and 5 is a scrambler.

6 is a voice data synthesis circuit, 7 is a band limiting circuit, 8 is an arc signal recognition circuit, 9 is a data output waveform P cough measurement circuit, 1
0 is a delay circuit, 11 is an arithmetic circuit, and 12 is an Okinami circuit.

Figure 1 (~ is a commonly used audio signal)
The audio signals sampled at a period of KH2, that is, 125 x 10-' seconds (μs), are expressed as A, B, C, D, . . . . Of course, this conventional sampling signal faithfully reproduces audio signals up to 4KH2. If the sampled signal in Figure 1 (FL) is periodically deleted at a rate of 1 out of 4, then (b)
It becomes a diagram.

If the sampled signal in Fig. 1(b) is band-limited to 4KH2, it can be used for normal telephone calls, and it can transmit not only the voice band below 2KH2, but also the band above 3KHz. There is. A data signal (not shown in FIG. 1C) is superimposed on the period deleted as described above. Note that this data signal has an amplitude sufficiently larger than the maximum value of the audio signal, that is, the amplitude limit value of the audio signal, so that it can be easily distinguished and separated from the audio signal. When a data signal is superimposed on an audio signal, the sampled transmission signal shown in FIG. 1(a) is obtained. This sampled transmission signal contains the data signal (FIG. 1(c)), which is comparable to noise when viewed from the audio signal side, and must be removed. On the other hand, the waveform obtained by adding the 4KH2 band limit to the data signal shown in FIG. 1(c) is 1.1' as shown in FIG. 1(e). 4
The present invention is based on the fact that by subtracting this waveform (e) from the received signal No. 48, /11 [original voice without sound (t? In other words, when a boot-tuff signal is detected, the stored value is subtracted from the received signal depending on its polarity, and the output signal is +1x./!7J Logic detection timing Immediate beat t calculation timing IJ reception 1j4 It is necessary to synchronize with the signal 4.The lines in the second diagram will be explained below.1, 20(2) is the transmitting station, 20(b) is the receiving station 1. Audio signals are 4 jump width limiting circuits 1 and 1 frequency band limiting circuit II': 4 Kl (
This becomes the Z band and is manually input to the sampling circuit 3. The borrowed i-book conversion circuit 3 is as described above, and 2 J'15/ls round''(I'' is 1
? The voice is input to Keyakimoto 1hi 4:'i'' main rule 1τ circuit 441..

The sample deletion circuit 1 performs sampling 1. -1 is periodically deleted once every four times. On the other hand, the data signal is manually inputted to the audio/data synthesis circuit via the scrap signal 15. The voice data synthesis circuit 6 receives a received signal inputted through the voice sampling signal deletion section transmission circuit and branches it into a data signal recognition circuit 8 and a delay circuit 1t1 shown in FIG. 2(b). The data signal recognition circuit 8 detects a data signal with a large amplitude and outputs it as a data signal, and also inputs the polarity of the data signal and the presence of the data signal to the data output waveform prediction circuit 9.Data output waveform prediction circuit 9 is a single node (corresponding to FIG. 1(e) in which a single node (
A memory circuit 9-1 that stores the pulse waveform, a polarity conversion circuit 9-2 that assigns the polarity of the data signal, for example, 4 negative if positive, and positive if negative, converts the polarity to a single buffless wave. It is composed of a batzer circuit 9-3 that stores data output waveforms. That is, the data output waveform prediction circuit 9 detects a data signal of a single pulse waveform with a polarity and inputs it to the arithmetic circuit 11 in time series. On the other hand, the received signal input to delay circuit 1 (l in this example is 12
57zs
Output via. Of course, even if it is used in a transmission circuit using a modulation/demodulation device, the same effect can be obtained without any problem.

(f) Effects of the Invention As explained in detail above, the voice and data signal transmission system of the present invention does not require the use of an Oki waver to separate the voice and data signals, and therefore can be made inexpensive and compact. It has many advantages when applied to data transmission systems. .

[Brief explanation of the drawing]

FIG. 1 is a waveform diagram for explaining the transmission method of the present invention, and FIG. 2 is a diagram of an embodiment of the voice and data signal transmission method of the present invention. In the figure, 1 is the amplitude limiting circuit t''I'L, 2 is the frequency band limiting circuit, 3 is the sample north circuit Il'+i+, 4 is the sample deletion circuit, -4 is the data signal recognition circuit, and 9 is the data output waveform prediction circuit. Shown respectively.

Claims (1)

[Claims] In a transmission system that transmits voice and data signals by subjecting the audio signal to amplitude limitation and band limitation, the transmitting station is equipped with a sample deletion circuit that periodically deletes the sampled audio, and A data signal recognition circuit that superimposes and transmits the data signal and detects the data signal to a receiving station, and a storage area that stores the waveform of the data signal (
iff, the waveform and the received signal are calculated based on the output of the recognition circuit to separate the audio signal.