JPS6119246A - Voice communication method - Google Patents

Abstract

PURPOSE:To attain miniaturization and light weight of a communication equipment for voice communication by retarding remarkably the transmission speed at transmission and reception so as to decrease the power per bit at digital communication. CONSTITUTION:A microphone 1 of the voice communication system converts a voice into a voice signal, a voice synthesis circuit 2 analyzes the inputted voice signal and converts it into a digital signal of 2.4kBPS. The signal is stored once in a transmission voice memory 3 and when a voice data of 1 message is stored in the memory 3, the voice signal digitized from the memory 3 is read in the transmission speed of 80BPS, 1/30 at input and the signal is transmitted to a satellite via a modulator 4, a transmitter 5, a branching device 6 and an antenna 7. Further, a radio wave from the satellite is demodulated into a digital signal in 80BPS by a demodulator 9 and stored in a reception voice memory 10. The voice data is read in the speed of 2.4kBPS, converted into the voice signal by a voice synthesis circuit 11 and outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to communication equipment for transmitting and receiving audio, and particularly relates to a communication system for transmitting digitized audio by satellite communication.

[Background of the invention]

Conventionally, earth stations for satellite communications have had to install very large systems compared to the bit rate of the data to be transmitted, because the transmission power of the satellite is low and the distance between the satellite and the earth is long and attenuation is large. For example, the specifications of an earth station that transmits 64KBPS data in the 2nd band via the O8 satellite are that the antenna has a diameter of about 277L, the transmitter output is about 2W, and the receiver noise temperature is about 800℃. In order to transmit data for at most one channel of a telephone line, it was necessary to install extremely large and expensive transmitting and receiving equipment.

[Purpose of the invention]

The purpose of the present invention is to make a satellite communication earth station that transmits and receives one channel of telephone line smaller and lighter than conventional ones.
The objective is to make the equipment easy to move and economical.

[Summary of the invention]

The transmitting side device of the earth station of the present invention stores the digitized audio signal in a single audio signal memory, reads it out at a speed lower than the speed of the original digital audio signal, and transmits the digital signal to the transmitter. ; and transmits it to the other party's station via the antenna, and the receiving device similarly stores the low-speed digital signal received via the antenna and receiver in the audio signal memory, reads it out at normal speed, and converts it into a digital signal. The system is characterized in that by obtaining converted audio signals, audio data can be transmitted between earth stations at low speeds.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to a block diagram of a satellite communication earth station shown in FIG.

At the time of transmitting a voice, when a voice is emitted by pressing a voice valve button switch (not shown), the voice is converted into a voice signal by the microphone 1 and input to the voice analysis circuit 2. The voice analysis circuit 2 is P A It COR.

Performed audio analysis of the method and reduced the input audio signal to 29.4KB.
Convert to PS digital signal. The digital signal is stored in the transmission audio memory 3. When the voice data of one message has been stored in the transmission voice memory 6, the transmitter releases the transmitting valve button switch (not shown).
The digitized audio signal is sent from the transmission audio memory 3.
808 PS, which is 1/30th the transmission rate of input, and the modulator 4. Transmission@51 Via the duplexer 6 and the antenna 7, the signal is transmitted to the satellite on a carrier wave.

When receiving a call, the radio waves from the satellite are received by the antenna Z splitter 6 receiver 8, and the demodulator 9 sends them to 8o B P
It is demodulated into a digital signal of S and stored in reception audio memory 0. When the voice data of 1 message and sage is accumulated and the reception voice memory 0 identifies the end of 1 message, the voice data is read from the reception voice memory 0 at a speed of 2.4KBPS, and the voice synthesis circuit W611 converts it into υ analog voice. The signal is converted into a signal and output as audio from the speaker 2.

The above operation will be explained using the time chart shown in FIG.

At the sending station, when the transmitting valve button switch (not shown) is pressed, a voice is emitted for 10 seconds to send one message, and the transmitting valve button switch (not shown) is released.
The voice data stored in the transmission voice memory 3 is transmitted to the other station over a period of 300 seconds. The receiving earth station transmits audio data for 300 seconds and stores it in the reception audio memory 10. When one message is stored, the audio data is read out at a speed of 2.4KBP8, and the audio data is output from the speaker 12 for 10 seconds. is output.

Note that a method may also be considered in which, on the transmitting side, the accumulation of audio signals in the transmission audio memory and the start of low-speed reading are performed simultaneously.

In addition, by providing multiple reception voice memories and using them in order to store voice data, it is possible to read voice data from the reception voice memory in which voice data has been stored first, and to store voice data in another reception voice memory. This can be done as many times as you like, making it possible to repeat the audio output.

In this embodiment, the conventional method, which could only transmit voice data at a speed of 2.4KBP8, is
PS can be sent at 1/30th the speed of conventional systems.As a result, it is possible to reduce the bit power in satellite communication to 1/30th of that of conventional systems. Specifically, this means increasing the transmitter's transmitting output or the receiver's receiving sensitivity by 1.
/30, or make the antenna smaller and increase the transmitting sensitivity and receiving sensitivity of the antenna to 1/5.5 respectively.
can be reduced to

Especially in the case of an antenna, the diameter is 1/26.

In this example, since the PAROOI (method) audio analysis is used, the transmission speed of the digitized audio is S2, 4K.
There is an option B, which is 1/2 the transmission speed of 64KBPS of digitized audio without band compression such as PAROOR method.
It is 7.

Therefore, when this embodiment is applied to band communication via the O8 satellite, the earth station equipment has an antenna diameter of 40 cI when one of the stations is an earth station with the same specifications as the conventional one.
n1 transmitter output is 0.1 W.

The noise temperature of the receiver is about 100 K, making it small and lightweight.

〔Effect of the invention〕

As described above, according to the present invention, by significantly lowering the transmission speed during transmission and reception compared to conventional methods, it is possible to reduce the bit stress in digital communication.
Satellite communication earth stations can be configured with antennas and transceivers that are smaller and lighter than before, making it possible to install easily mobile earth stations and even portable earth station equipment1. This has the effect of making it possible to perform satellite communications even in places where there is no satellite communication.

The present invention is particularly effective for calls where no response is expected, such as sending messages, but it can also be applied to conversations.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a satellite communication earth station showing an embodiment of the present invention, and FIG. 2 is a time chart showing the temporal flow of transmission and reception at the satellite communication earth station. 1... Microphone 2... Audio analysis circuit 6... Transmission audio memory 4... Modulator 5... Transmitter 6... ...Dunplexer 7...Antenna 8...Receiver 9...Demodulator 10...Received audio memory 11...Kanae Synthesis circuit 12...Speaker

Claims (1)

[Claims] 1. In a device that transmits and receives audio signals, the transmitting and receiving devices each include a transmitting audio memory and a receiving audio memory that store audio data, and the transmitting device stores the digitized audio signals in the audio signal memory. The readout speed is lower than that of the original digital audio signal, and the low-speed digital audio signal is sent to the receiving device. An audio communication system characterized by transmitting audio data between a transmitting device and a receiving device at a low transmission speed by storing the data in an audio memory and reading it at a normal speed to obtain a digital audio signal.