JPS5933937A - System for compressing transmission time of sound signal for radio inter-call system - Google Patents

Abstract

PURPOSE:To attain the compression of transmission time with a small sized device with simple operation, by repeating the operation in which a sound signal is sampled, stored, read out and converted into a continuous signal. CONSTITUTION:The sound signal 101 is sampled at a samping circuit 21 and a PAM (pulse amplitude modulation) signal representing the sampling value is stored in a memory circuit 23 at a write circuit 22. A high speed readout circuit 24 applies its read-out value to an integrating circuit 25, which converts the PAM signal into a sound signal 202 supplied with time compression. The signal 202 via a transmission circuit 6 and a receiving circuit 7 is sampled in the same frequency as the circuit 24 again at a sampling circuit 26 to be the PAM signal and stored in a memory circuit 28 at a high speed write circuit 27. The PAM signal read out in a prescribed frequency at a readout circuit 29 is applied to an integrating circuit 30 to restore a sound signal 203 similar to the sound signal 101.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a voice signal transmission time compression method, and particularly to the same method used in a wireless individual paging method (bazing method).

Conventionally, a method has been proposed to compress the transmission time of audio signals by converting the speed of a tape recorder, but tape recorders require a rotating mechanism, so they are prone to wear and tear, and operation is a chore. It has not been put into practical use. In particular, since there is a strong demand for miniaturization of basic receivers in wireless individual paging systems, tape recorders cannot be used in practice. However, in the so-called tone and voice wireless individual paging system, it is highly necessary to compress the transmission time of voice signals in order to reduce the number of paging receivers that can join one wireless channel.

SUMMARY OF THE INVENTION An object of the present invention is to provide a voice signal transmission time compression method for a wireless individual paging system that is free from wear and tear due to use, is easy to operate, and is compact.

The audio signal transmission time compression method for a wireless individual paging system according to the present invention includes a first circuit that samples an audio signal at a first frequency and stores a signal representing the sampled value, and a second circuit for reading out a signal representing a sample value at a second frequency higher than the first frequency; a third circuit for converting the output of the second circuit into a first continuous signal; a fourth circuit that transmits the first continuous signal on a high-frequency signal; a fifth circuit that receives this high-frequency signal and reproduces the first continuous signal; a sixth circuit that samples at a third frequency higher than the third frequency and stores a signal representing the sampled value; 4, and an eighth circuit that converts the output of the seventh circuit into a second continuous signal.

Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing a first embodiment of the present invention. The audio signal 101 that has entered the A/D (analog-digital) conversion circuit 1 is encoded using one of pulse encoding methods such as ΔM and PCM, and is stored in the memory circuit 3 by the write circuit 2. be done.

When the pulse code stored in the memory circuit 3 is read out by the high-speed reading circuit 4 and restored to analog by the D/A (digital-to-analog) conversion circuit 5, a compressed audio signal 102 whose time is compressed by the writing and reading speed ratio is generated. become. This compressed audio signal 102 is converted to a p radio frequency by the transmitting circuit 6, then reproduced by the receiving circuit 7, and sampled and encoded by the A/D at the same frequency as the high-speed reading circuit frequency (reading speed). It is added to the conversion circuit 8. High speed write circuit 9
stores this encoded signal in the memory circuit 10. By reading out the information stored in the memory circuit 10 at an arbitrary speed by the reading circuit 11 and applying it to the D/A conversion circuit 12, the audio signal 101 and the market price audio information 103 are obtained.

FIG. 2 is a block diagram showing a second embodiment of the invention. The audio signal 101 is sampled by a sampling circuit 21, and a PAM (pulse amplitude modulation) signal representing the sample value is stored by a write circuit 22 into a memory circuit 23 such as a C0D (charge coupled device) that can also store the amplitude amount. be done. The high-speed readout circuit 24 applies the readout value to the integration circuit 25, and the integration circuit 25 converts the PAM signal into a time-compressed audio signal 202. The compressed audio signal 202 that has passed through the transmitter circuit 6 and the receiver circuit 7 is sampled at the same frequency as the read frequency of the high-speed read circuit 24 in the re-sampling link circuit 26, converted into a PAM signal, and stored in the memory in the high-speed write circuit 27. The memory is transferred to the circuit 28. The PAM signal read out at a predetermined frequency by the readout circuit 29 is added to the integration circuit 30, and the audio signal 101 is
and the market price audio signal 203.

Since the above system does not have a rotation mechanism, it can be downsized to a sufficiently practical size by using semiconductors, and is easy to operate. Furthermore, since the method of the present invention has no mechanical wear and tear, it can operate semi-permanently, and the compression rate of the transmission time can be arbitrarily selected by selecting the speed difference between writing and reading.
The received audio signal can be played back at any time and with any consistency (
For example, play the audio as fast as you can understand it, or play it repeatedly if you can't understand the meaning at once)
There are other effects.

[Brief explanation of the drawing]

FIGS. 1 and 2 are block diagrams showing first and second embodiments of the present invention, respectively. 1.8...A/D conversion circuit, 2,22...Writing circuit, 3.10.23.28...Memory circuit, 4,24...High speed reading circuit , 5, 12...
・D/A, conversion circuit, 6...transmission circuit, 7...
...Receiving circuit, 9,27...High speed writing circuit, 1
1.29... One after another circuit, 21.26...
Sampling circuit, 25.30...Integrator circuit.

Claims (1)

Scope of Claims: (1) A first circuit that samples an audio signal at a first frequency and stores a signal representing the sampled value; and a first circuit that samples a signal representing the sampled value from the first circuit; a second circuit for reading at a second frequency higher than the first frequency; a third circuit for converting the output of the second circuit into a first continuous signal; a fourth circuit that carries and transmits;
a fifth circuit that receives the high frequency signal and reproduces the first continuous signal; and a fifth circuit that receives the high frequency signal and reproduces the first continuous signal;
a sixth circuit that samples at a third frequency higher than the third frequency and stores a signal representing the sample value; and a sixth circuit that stores a signal representing the sample value from the sixth circuit at a third frequency lower than the third frequency. A voice transmission time compression system for a wireless individual paging system, which comprises a seventh circuit that reads at a frequency of 4, and an eighth circuit that converts the output of the seventh circuit into a second continuous signal. (A voice signal for a wireless individual paging system according to claim 1, characterized in that the first frequency and the fourth frequency are equal, and the second frequency and the third frequency are equal. Transmission time compression method. (3) The first circuit consists of a circuit that samples the audio signal at a first frequency and converts the sampled value into a digital signal, and a circuit that stores this digital signal, and the circuit samples the reproduced first continuous signal at a third frequency;
Claim 1, characterized in that the third and eighth circuits, each consisting of a circuit for converting the sample value into a digital signal and a circuit for storing this digital signal, are digital-to-analog conversion circuits. An audio signal transmission time compression method for a wireless individual paging method according to item 1 or 2. (4) The first circuit and the sixth circuit are composed of a sampling circuit and a charge-coupled device that stores the sampled value that is the output thereof, and the third and M8 circuits are composed of an integrating circuit. An audio signal transmission time compression method for a wireless individual paging method according to claim 1 or 2.