JPH04108232A - Coding bit information transmission system for adpcm transmultiplexer - Google Patents

Abstract

PURPOSE:To avoid disable transmission of an ADPCM code by using an idle bit of non SYN word of a frame of an ADPCM signal and sending an ADPCM coding bit information to an opposite equipment. CONSTITUTION:An A/D converter 1 converts an FDM signal inputted through a transmission line into a digital signal and an F/T transformation circuit 2 transforms the FDM signal into a PCM signal. A 1st format conversion circuit 3 converts the PCM processed signal into a signal of frame structure based on the CCITT recommendations G.704 and a PCM/ADPCM CODEC 4 codes the PCM signal into an ADPCM signal. A 2nd format conversion circuit 5 converts a signal subjected to ADPCM coding into a signal of frame structure based on the CCITT recommendations G.761 and inserts a data of a coding bit decision circuit 6 into an idle bit of a non SYNC word and outputs the result to the transmission line. Thus, the transmission employing the variable bit ADPCM coding system algorithm is attained without use other line.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a coded bit information transmission scheme for an ADPCM transmultiplexer.

Prior Art A conventional ADPCM converter is based on CCITT Recommendation G, 721.
Bandwidth compression was performed by fixing the encoded bits to 4 bits using the above algorithm, or by transmitting the encoded bit information using a side line in the case of variable bits.

Problems to be Solved by the Invention In the conventional ADPCM converter described above, in the case of variable bits, a side line is used to transmit encoded bit information, which has the disadvantage of requiring an extra line. For example, if the encoding bits are fixed to 4 bits, ADP
The CM code has the disadvantage that it cannot be transmitted.

The present invention has been made in view of the above-mentioned conventional situation,
SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a new coded bit information transmission system for an ADPCM transmultiplexer, which makes it possible to eliminate the above-mentioned drawbacks inherent in the prior art.

Means for Solving the Problems In order to achieve the above object, the encoded bit information transmission method of the ADPCM transmultiplexer according to the present invention directly multiplexes frequency multiplexed signals and time division multiplexed signals without converting them back into audio signals. The function of mutual conversion in the conversion stage and the P
CM signal (2,048 Mbit/s) ADPCM signal (2,048 Mbit/s) by band compression of two signals.
s) A function to mutually convert into one signal, and a non-sync word of the frame of the ADPC14 signal.
The ADP of the own device is sent to the other device using the empty bit of rd.
It is configured with a function of transmitting CM encoded bit information.

Embodiment Next, a preferred embodiment of the present invention will be specifically explained with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of an encoded bit information transmission system of an ADPCM transmultiplexer according to the present invention. Figure 2 shows the system configuration, and Figure 3 shows the system configuration.
The figure is a diagram showing a frame configuration.

In FIG. 1, an A/D converter 1 converts a PCM signal input from a transmission line into a digital signal from an analog signal, and an F/T (FDM/TDM) conversion circuit H2 converts the PCM signal into a PCM signal. . The first format conversion circuit (FMTI) 3 converts the PCM signal into a frame structure based on CCITT Recommendation G, 704, and converts it into a PCM/ADPCM codec (CODEC).
4 encodes the PCM signal into an ADPCM signal. Second format conversion circuit (FMT2) 5 is ADP
The CM encoded signal is converted into a frame structure based on CCITT Recommendation G.761, and the data in the encoded bit determination circuit 6 is converted into a non-sync word (Nonsyn
cword) and output it to the transmission path.

Conversely, in the second format conversion circuit 5, A
, D P CM signals are input, and the result of detecting encoded bits is sent to the PCM/ADPCM codec 4 .

The PCM/ADPCM codec 4 decodes the ADPCM signal into a PCM signal using the detected encoded bits.

The first format conversion circuit 3 decodes the PCM
The signal is converted into a frame structure based on CCITT Recommendation G,704. T/F (TDM/FDM) conversion circuit 7
Then, the PCM signal is converted into a PCM signal, and the D/A converter 8 converts the digital signal into an analog signal and outputs it to the transmission line.

In FIG. 2, an FDM terminal device 9 receives an audio signal, converts it into an FD4 signal, and outputs it to a transmission line (PCM signal) 10. The ADPCM transmultiplexer 11 converts the PCM signal input from the transmission path 10 into an ADPCM signal, and at the same time outputs information such as alarms and encoded bits onto predetermined bits of the ADPCM multiframe to the transmission path 12. do.

ADPCM trans multiplexer 13 is connected to transmission line 12
An alarm (afar) is generated from the ADPCM signal input from
layer) and encoded bits, converts the ADPCM signal into a PCM signal using the detected encoded bits, and outputs the signal to the transmission line 14. The FDM terminal device 15 is connected to the transmission line 14
The input PCM signal is changed into an audio signal and output.

Referring to FIG. 3, reference number 18 indicates a multiframe, 17 indicates a frame, and 16 indicates an odd frame TS.
3.4 bits are alarm signal transmission bits (RMT) 19, 5.6 bits are encoded bits transmission bits 20, and 7.8 bits are alarm signal transmission bits (RMT). AIS)
21 is input.

For example, the value of encoded bit 20 is (bs, b6)・(0'
, 0) to 2 pips, (bs, b6)・(0,1)
3-bit encoding, (b5.b6)/(1,0) 4-bit encoding, (bs, b6) = (1, 1>) 5-bit encoding, there are 4 types of encoding. can be sent to the opposing station.

Nonsyncword > No. 5
．． For bits other than 6 bits, the frame structure of CCITT Recommendation G, 761 can be applied as is.

As described in detail, according to the present invention, in an ADPCM transmultiplexer, an ADPCM line can be used effectively, and a variable bit ADPCM encoding algorithm can be used without using a separate line. The effect of being able to transmit data can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of an ADPCM transmultiplexer according to the present invention, and FIG.
FIG. 3 is a block diagram showing an example of a system configuration using a CM transmultiplexer. FIG. 3 is a diagram showing a frame structure on the ADPCM side of the ADPCM transmultiplexer. 1... A/D converter, 2... F/T conversion circuit,
3...first format conversion circuit (FMTI),
4...PC+II/ADPCM codec (CODE
C>, 5...Second format conversion circuit (FMT
2), 6... Encoding bit determination circuit, 7... T/F
Conversion circuit, 8...D/A converter, 9...FDM
Terminal equipment, 10... Transmission path (FDM signal), 11...
- ADPCM transformer multiplexer, 12... transmission line (ADPCM signal), 13... ADPCM transformer multiplexer, 14... transmission line (FDM signal),
15...FDM terminal equipment, 16-=Nonsyncword bit configuration, 17...
Frame, 18...Multi frame, 19...Alarm signal transmission bit (R) 4T A-B), 20...
・Encoded bit transmission bit, 21...Alarm signal transmission bit (^Is ^・B)

Claims (1)

[Claims] A function to mutually convert frequency division multiplexed signals and time division multiplexed signals directly at the multiplexing stage without converting them back to voice band signals, and to compress the band of two PCM signals (2.048 Mbit/s) to generate ADPCM signals (2.048 Mbit/s). .048Mb
A consisting of a function to mutually convert into one
Transformer multiplexer with DPCM conversion function (hereinafter referred to as AD
(abbreviated as PCM trans multiplexer),
A coded bit information transmission method for an ADPCM transmultiplexer, characterized in that the ADPCM coded bit information is transmitted to a partner device using empty bits of a non-sync word of a frame of the ADPCM signal.