JPH02209033A - Transmission system for highly efficient digital multiplexer - Google Patents

Abstract

PURPOSE:To attain the decoding of voice without occurring synchronizing step- out at the reception side by dividing the transmission frame of a voice signal into plural frames, giving identification information ID to each divided frame and designating silence to the identification information ID to a silence division frame. CONSTITUTION:A frame conversion section 3 divides a voice frame into N sets of frames, 10msec long each and an identification ID code is given to each frame. A code designating whether the voice of the frame is a sound frame or a silence frame is set to the identification code ID based on a silence detection signal (b) from a silence detection section 1. A converted frame (d) is inputted to a packet data insertion section 4, where a packet data (f) is inserted to a frame in which the identification code ID designates the silence. Thus, a voice data forming one frame by NX10msec and a packet data forming one frame by 10msec are transmitted while being multiplexed at the silence and sure frame synchronization for voice decoding is taken at the reception side.

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] This invention relates to a transmission method for a high-efficiency digital multiplexing device that improves transmission efficiency by inserting packet data during voice silence when transmitting an audio signal.

Even if the frame length when encoding audio is an integral multiple of the frame of the digital multiplexer, it is possible to insert packet data during audio silence and transmit the audio without causing synchronization on the receiving side. The purpose is to decrypt the code.

On the transmitting side, N of frames in a high efficiency digital multiplexer
The transmission frame of the audio signal, which is formed twice, is divided into multiple frames, and identification information that specifies whether the audio is active or silent is added to these divided frames and transmitted to the receiving side. The audio signal is configured to separate the audio signal and the packet data based on the identification information.

(Field of Industrial Application) The present invention relates to a transmission system for a high-efficiency digital multiplexer that improves transmission efficiency by inserting and transmitting packet data during voice silence when transmitting an audio signal.

In recent years, the construction of corporate networks has become popular.

The scale of the network is also expanding from a domestic network to an international network. Along with this, there is a need to improve the transmission efficiency of one line. For this reason, when transmitting an audio signal, a highly efficient digital multiplexer is provided which inserts and transmits packet data when there is no audio information and there is no audio.

(Prior Art) In the conventional transmission system of a high-efficiency digital multiplexer for audio signals, the frame of the digital multiplexer is, for example, 10m5.
If one frame is formed using EC, in order to synchronize each audio frame to be transmitted, the audio frame must also be 10
It was necessary to set the frame length to m5ec. On the other hand, the encoding frame length when encoding an audio signal depends on the encoding method.

In some cases, the unit is not 1Qmsec but 9, for example, NxlQmsec. Here, N is an integer of 2 or more.

[Problem to be solved by the invention]

For example, the encoding frame length when encoding an audio signal is N
In the case of XIQmsec, if the transmission frame length for sending the audio signal to the line is 10 m5ec as described above, even though the frame length when decoding the received frame on the receiving side needs to be NxlQmsec. , the frame length of the received frame is 10m5ec
Because it is.

Frame synchronization for decoding cannot be achieved.

There is a problem that the audio signal cannot be decoded.

Therefore, an object of the present invention is to insert packet data during voice silence even when the frame length during voice encoding is an integral multiple of the frame length of a high-efficiency digital multiplexer, as described above. The object of the present invention is to enable decoding of audio without causing synchronization on the receiving side while transmitting it.

[Means to solve the problem]

FIG. 1 is a diagram for explaining the present invention in detail.

In order to solve the above-mentioned problems, the high-efficiency multiplex transmission system according to the present invention is a high-efficiency multiplex transmission system that improves transmission efficiency by inserting and transmitting packet data PD during voice silence when transmitting audio signals. In the multiplex transmission system, on the transmitting side, the transmission frame of the audio signal, which is formed by N times the frame of the high-efficiency digital multiplexer, is divided into a plurality of frames 1G, ~1G+s, and these divided frames 101~l□ + is added with identification information ID specifying whether the audio is active or silent, and transmitted to the receiving side, and the receiving side is configured to separate the audio signal VD and the packet data PD based on this identification information ID. Ru.

[Effect]

Transmission frames of the audio signal VD are divided into a plurality of frames 101 to 101.
Divide into 10m, each divided frame 101 to 10
Add identification information ID to m. For divided frames in which the audio signal VD is silent, identification information il! A frame for transmission is constructed while LD is designated as silent and packet data PD is inserted. A transmission frame synchronization signal MP is attached to the leading dot of this transmission frame. This transmission frame is then sent to the receiving side.

The receiving side monitors the identification information ID in the received frame, and if this specifies silence, it determines that the data of the divided frame is packet data, and separates and outputs it. For voices designated as voiced, the identification information @ID is removed, the audio frame is reproduced, and this is decoded to obtain an audio signal.

This allows audio data and packet data to be multiplexed and transmitted in a transmission frame, and also allows the receiving side to decode the audio signal in units of the frame length of the audio frame.

〔Example〕

The present invention will be described in detail below with reference to one drawing.

FIG. 2 shows a high rate digital multiplexing apparatus using a transmission method as an embodiment of the present invention. In FIG. 2, audio data (1) is a continuous A/D conversion of an audio signal, and is input to a silence detector 1 and an encoder 2. The silence detector 1 is a circuit that detects a silent portion in the audio data (II), and sends a detection signal (b) to the frame converter 3 when detecting silence.

The encoding unit 2 encodes the input audio data (a) with high efficiency and converts it into N X I Q m5ec as shown in FIG.
(80XNb1t) audio frame (c
) is a circuit that is assembled and output. Here, N is an integer of 2 or more.

The audio frame IC) is further manually inputted to the frame conversion section 3. The frame converter 3 converts the input audio frame (C)
This circuit divides the data into frames of 1Qmsec (80 bits), adds an identification code ID to the beginning of each frame, and outputs the result. As shown in FIG. 4, the frame format of this converted frame (d) is a frame synchronization signal F attached to the beginning of the first divided audio frame, and including this, an identification code ID is sent in approximately IQmsec units. The format is a series of N frames each consisting of voice data. Here, the identification code ID is a code for specifying whether the audio data of the frame is voiced or silent, and is set based on the silence detection signal (bl) from the silence detection section l.

This converted frame td) is then transferred to the packet data insertion unit 4
will be sent to. Packet data (f) is also input to the packet data insertion section 4. Packet data insertion section 4
monitors the identification code 10 of the input conversion frame ld), and if this identification code ID specifies silence, packet data (f) is sent to the frame corresponding to the silence identification code ld instead of audio data. Insert the fifth
Assemble a frame (e) as shown in the figure, and use multiplexer 9 to assemble the frame (e) from other channels.
This is multiplexed to create a transmission frame (■) and sent to the line.

The transmission frame (n) received from the line is separated into frames + 1) for each channel by the demultiplexer 11,
This separated frame (11) is input to the packet data separation unit 5. The packet data separation unit 5 monitors the identification code ID of the input frame +1+, and if this identification code ID is designated as silent, separates and outputs the corresponding frame part as packet data (l,
If there is a sound, it is sent to the frame inverse conversion section 6 as output frame 01.

This output frame 0) is an identification code! The packet data (-) is removed from the area where D specifies silence and remains blank.

The frame inverse converter 6 deletes the identification code ID from the input frame U) and inversely converts it into N
This is the circuit that sends the signal to the Out-of-sync detection section 8 is NX10m
This circuit detects the frame synchronization signal F at 5ec intervals, and when the frame synchronization signal F is not detected when the synchronization is out, the out-of-synchronization is detected and an alarm is generated.

The decoding unit 7 is a circuit that decodes the audio data (illustratively the audio frame color which has been highly efficiently encoded into 10×N m5ec) and outputs it.

The operation of the embodiment device will be explained below.

First, to explain the operation of the transmitting circuit, audio data (a)
is input to the silence detector 1 and the encoder 2.

The encoder 2 encodes the audio data with high efficiency, assembles it into an audio frame (C1) with a frame length of Nx10m5ec, and sends it to the frame converter 3.The silence detector l converts the audio data (
The silent portion of a) is detected, and a silent detection signal (b) is sent to the frame converter 3.

The frame converter 3 converts the input audio frame (C) into
It is converted into a converted frame (d) having the format shown in FIG. In other words, the audio frame (C1) is divided into N frames of 10m5ec length, and each frame is given an identification code.
Add a D. #a A code specifying whether the audio of the frame is voiced or silent is set in the separate code ID based on the silence detection signal from the silence detection section 1.

This converted frame (d) is input to the packet data insertion section 4, where the packet data (f) is inserted into the frame whose identification code ID specifies silence.

Frames whose identification code ID is audible remain audio data. Therefore, the format of the frame created by the packet data insertion section 4 is as shown in FIG. Audio data or packet data is inserted into each divided frame depending on the presence or absence of sound in D.

This frame (1) is multiplexed with frames (1) from other channels and assembled into a transmission frame, as shown in FIG. In this transmission frame), l
Qmsec time length, multiple audio channels CHI
~ CH4 of 10m5ec (80bit) unit “
;-The speed is converted so that the frames are multiplexed.

Further, a multi-frame synchronization signal MF is added to the beginning.

Next, when a transmission frame (n) in the format shown in FIG. 6 is input from line 0, which explains the operation of the receiving side circuit, to the demultiplexer 11, the demultiplexer 11 converts it into frames (1) for each channel. This frame (1) is input to the packet data separation unit 5. The packet data separation unit 5 identifies the identification code ID in the received frame (1).

Identifying code! If D is designated as silent, the data of the divided frame to which it belongs is separated and output as packet data (N). After separating the packet data, the divided frame is sent to the frame inverse conversion unit 6 with blank parts as is. If the code ID specifies the presence of sound, the audio data is sent as is to the frame inverse conversion section 6.

In the frame inverse conversion unit 6, the identification code ID attached to the beginning of each divided frame in the input frame ('')
is deleted, converted into an NX 10m5ec audio frame), and sent to the decoding unit 7. The decoding unit 7 decodes and outputs the audio data (Nx 10 m5ec) as a frame unit.The out-of-synchronization detection unit 8 converts the audio frame into a frame synchronization signal F every N x 10 m5ec.
The occurrence of frame synchronization is monitored by detecting whether or not a frame is received.

As described above, the audio data forming one frame at Nx 10m5ec and the packet data forming one frame at lQmsec are multiplexed and transmitted during voice silence, and frame synchronization for audio decoding is performed on the receiving side. It is possible to take it with certainty.

〔Effect of the invention〕

According to the present invention, even when the frame length when encoding audio is an integral multiple of the frame of a high-efficiency digital multiplexer, packet data can be inserted and transmitted during audio silence, and reception can be performed. On the side, it becomes possible to decode the audio without causing synchronization loss.

[Brief explanation of the drawing]

FIG. 1 is a diagram explaining the principle of the present invention. FIG. 2 is a block diagram showing a high-efficiency digital multiplexing device using a transmission method as an embodiment of the present invention. FIG. 3 is a diagram showing the frame format of the audio frame (C) in the embodiment device. FIG. 4 is a diagram showing the frame format of the converted frame ld) in the embodiment apparatus. FIG. 5 is a diagram showing the frame format of frame (e) in the embodiment device, and FIG. 6 is a diagram showing the frame format of the transmission frame in the embodiment device. In fig. l-- Silence detection section 2...- Encoding section 3-- Frame converting section 4-- Packet data inserting section 5-- Packet data separating section 6-- Frame inverse converting section 7-- Decoding section 8-- Out-of-synchronization detection unit 9--Multiplexer 11--Demultiplexer

Claims (1)

[Claims] In a transmission system for a high-efficiency digital multiplexer that improves transmission efficiency by inserting and transmitting packet data during voice silence when transmitting an audio signal, on the transmitting side, a high-efficiency digital multiplexer is used. N of the frame of
Divide the transmission frame of the audio signal, which is formed twice, into multiple frames (10_1 to 10_N), and add identification information (ID) to the divided frames (10_1 to 10_N) to specify whether the audio is active or silent. The high-efficiency digital multiplexing system is characterized in that it is configured to separate the voice signal (VD) and packet data (PD) based on this identification information (ID) on the receiving side. Device transmission method.