JP3036804B2 - ADPCM transmultiplexer coded bit information transmission system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a coded bit information transmission method of an ADPCM transmultiplexer.

Conventional technology The conventional ADPCM converter uses the algorithm of CCITT recommendation G.721 to fix the coding bits to 4 bits and compress the band, or in the case of variable bits, performs coding using a separate line. Band compression was performed by transmitting bit information.

Problems to be Solved by the Invention In the conventional ADPCM conversion unit described above, in the case of variable bits, since a separate line is used to transmit coded bit information, there is a disadvantage that an extra line is required. For example, if the coded bits are fixed to 4 bits, there is a disadvantage that transmission cannot be performed with the ADPCM code when the audio band data is 9600 bps or more.

The present invention has been made in view of the above-described conventional circumstances, and accordingly, an object of the present invention is to provide a novel coded bit information transmission method for an ADPCM transmultiplexer that can eliminate the above-described disadvantages inherent in the conventional technology. It is to provide a method.

Means for Solving the Problems In order to achieve the above object, the coded bit information transmission method of the ADPCM transmultiplexer according to the present invention employs a method of directly multiplexing a frequency multiplexed signal and a time division multiplexed signal without returning them to an audio signal. Conversion function and PCM
ADP by band compression of two signals (2.048Mbit / s)
A function of mutually converting into one CM signal (2.048 Mbit / s) and a non-sync word (Nonsyncwo
a function of transmitting the ADPCM coded bit information of the own apparatus to the other apparatus using the empty bits of rd.

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

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

In FIG. 1, an A / D converter 1 converts an FDM signal input from a transmission line into a digital signal from an analog signal, and an F / T (FDM / TDM) conversion circuit 2 converts the FDM signal into a PCM signal.
Convert to a signal. First format conversion circuit (FMT1)
In step 3, the PCM-converted signal is converted into a frame configuration based on CCITT recommendation G.704, and the PCM / ADPCM codec (CODEC) 4
Then, the PCM signal is encoded into the ADPCM signal. The second format conversion circuit (FMT2) 5 converts the ADPCM-coded signal into C
The frame is converted into a frame configuration based on CITT recommendation G.761, and the data of the coded bit determination circuit 6 is inserted into a vacant bit of a nonsync word and output to the transmission path.

On the other hand, in the second format conversion circuit 5,
Inputs the ADPCM signal and outputs the result of detecting the coded bit to the PCM
Sends to / ADPCM codec 4. The PCM / ADPCM codec 4 decodes the ADPCM signal into a PCM signal using the detected coded bits. The first format conversion circuit 3 converts the decoded PCM signal into a frame configuration based on CCITT recommendation G.704. The T / F (TDM / FDM) conversion circuit 7 converts a PCM signal into an FDM signal, and the D / A converter 8 converts a digital signal into an analog signal and outputs the signal to a transmission line.

In FIG. 2, the FDM terminal device 9 receives an audio signal and
After conversion into a signal, the signal is output to a transmission path (FDM signal) 10. ADPCM
In the transmultiplexer 11, the signal is input from the transmission path 10.
The FDM signal is converted to the ADPCM signal and the alarm (alar
The information such as m) and coded bits are output to the transmission path 12 on predetermined bits of the ADPCM multiframe. The ADPCM transmultiplexer 13 detects an alarm (alarm) and a coded bit from the ADPCM signal input from the transmission path 12, converts the ADPCM signal into an FDM signal based on the detected coded bit, and outputs the FDM signal to the transmission path 14. The FDM terminal device 15 converts the FDM signal input from the transmission line 14 into a voice signal and outputs the voice signal.

Referring to FIG. 3, reference numeral 18 indicates a multi-frame, and 17 indicates a frame. 16 is the odd frame TSO (N
onsyncword), 3 and 4 bits indicate an alarm signal transmission bit (RMT) 19, 5 and 6 bits indicate an encoded bit transmission bit 20, and 7 and 8 bits indicate an alarm signal transmission bit (AIS) 21. Is entered.

For example, the value of the coded bit 20 is (b ₅ , b ₆ ) = (0, 0)
Is 2-bit encoded, (b ₅ , b ₆ ) = (0, 1) is 3-bit encoded, (b ₅ , b ₆ ) = (1, 0) is 4-bit encoded,
If (b ₅ , b ₆ ) = (1, 1) is divided by 5-bit encoding, four types of encoding can be transmitted to the opposite station.

The non-sync word (Nonsyncword) other than 5 and 6 bits can be applied as it is in the frame configuration of CCITT recommendation G.761.

Effect of the Invention As described above, according to the present invention, in the ADPCM transmultiplexer, the ADPCM line can be used effectively, and the algorithm of the variable bit ADPCM encoding method is used without using another line. The effect that transmission is possible is obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an ADPCM transmultiplexer according to the present invention, FIG. 2 is a block diagram showing an example of a system configuration using the ADPCM transmultiplexer, and FIG.
It is a figure which shows a side frame structure. 1 ... A / D converter, 2 ... F / T conversion circuit, 3 ... first
Format conversion circuit (FMT1), 4 ... PCM / ADPCM codec (CODEC), 5 ... second format conversion circuit (FMT2), 6 ... coded bit determination circuit, 7 ... T / F
Conversion circuit, 8 D / A converter, 9 FDM terminal equipment,
10: Transmission line (FDM signal), 11: ADPCM transmultiplexer, 12: Transmission line (ADPCM signal), 13: ADPCM transmultiplexer, 14: Transmission line (FDM signal), 15
…… FDM terminal equipment, 16 …… Nonsync word (Nonsyncwo
rd) Bit configuration, 17: Frame, 18: Multiframe, 19: Alarm signal transmission bit (RMT A / B), 20
…… Encoding bit transmission bit, 21 …… Alarm signal transmission bit (AIS AB)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-57-118450 (JP, A) JP-A-63-43435 (JP, A) JP-A-64-62040 (JP, A) JP-A-63-118 316530 (JP, A) JP-A-4-253431 (JP, A) JP-A-3-278628 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04J 3/00-3 / 26 H04B 14/00-14/08 H03H 7/38

Claims (1)

(57) [Claims] 1. A function of directly converting a frequency division multiplexed signal and a time division multiplexed signal to each other in a multiplexing step without returning them to a voice band signal, and performing band compression of two PCM signals (2.048 Mbit / s). In an ADPCM conversion function-equipped transmultiplexer (hereinafter abbreviated as ADPCM transmultiplexer) comprising a function of mutually converting one ADPCM signal (2.048 Mbit / s) into one, an empty bit of a non-sync word of the frame of the ADPCM signal is converted. Use AD on partner device
ADPCM for transmitting PCM coded bit information
A method for transmitting encoded bit information of a transmultiplexer.