JPH0652890B2 - Multiplexer / Demultiplexer - Google Patents

Description

DETAILED DESCRIPTION [Overview] Multiplexing of carrier signals transmitted in a digital communication system /
Regarding the demultiplexing device, voice telephone signals and dial signals are time-division multiplexed, for the purpose of enabling transmission of 24 channels of voice telephones through a transmission path of 384Kbps.
In a device for separating a voice signal and a dial signal from a multiplexed signal, a pulse code modulation / decoding means for modulating the voice telephone signal into a predetermined pulse code and decoding the modulated pulse code into a voice telephone signal, A time-division multiplexing means for time-division multiplexing the output signals of a plurality of pulse code modulation / decoding means to modulate at a predetermined speed; and a pulse train of a pulse code of a predetermined speed time-division multiplexed by the time-division multiplexing means. Extraction means for dividing into a plurality of sections and extracting a division pulse train of a predetermined unit for each division, accumulating the division pulse train extracted by the extraction means, processing the reading process at a predetermined speed, and dial signal at a predetermined rate. A transmission unit having speed conversion means for inserting and transmitting a dial pulse with
Reading means for accumulating the pulse train transmitted from the transmitting part and having a memory means for separating the inserted dial pulse, and reading the pulse train accumulated in the memory means repeatedly a plurality of times at a predetermined speed; And a receiving unit including a separating unit that separates a pulse train of a pulse code having a predetermined speed.

[Industrial application field]

The present invention relates to a multiplexer / demultiplexer for carrier signals transmitted in a digital communication system.

The transmission line of the digital communication system requires how much information can be efficiently transmitted, and the voice (0.3
Up to 3.4 KHz), there is a direction to transmit at 32 Kbps from the technology transmitting at 64 bps.

As a result, there has been a demand for a multiplexer / demultiplexer arranged in a digital communication system of a telephone dedicated line, which is functionalized so as to further improve the communication transmission efficiency.

[Conventional technology]

FIG. 6 shows a block diagram for explaining a conventional example. FIG. 6 shows a functional block diagram of a multiplexer / demultiplexer in the pulse code modulation system. The configuration is such that a voice telephone signal is encoded into a pulse code modulation (hereinafter referred to as PCM) signal at a predetermined speed (for example, 64 Kbps), A codec unit 1 for decoding, a transmitter 2 for time-division-multiplexing and transmitting a pulse train of a predetermined speed (for example, 1.544 Mbps) to put multiple PCM signals on one transmission medium, and time division. The reception unit 3 separates a multiplexed pulse train of a predetermined speed (for example, 1.544 Mbps) into a plurality of PCM signals.

In addition, the CODEC unit 1 supports channel (CH) (for example, 24CH
In the case of, it is located on the number corresponding to 24CH) and the source signal (4WS) of the voice transmitted from the 4W telephone line is transmitted to the PC.
It consists of a codec 11 that encodes M signals and decodes PCM signals into voice (4WR), and a clock generation circuit 12 that generates a clock that becomes the processing timing of the codec 11. The transmitter 2 uses a channel (CH). Multiplexing circuit (hereinafter referred to as MUX) 21 that time-division multiplexes a considerable number of PCM signals and converts them to a 1.5 Mbps pulse train, and the multiplexed PCM signals to a 1.5 Mbps pulse train and synchronizes the subsequent processing. A sync signal insertion circuit 22 for inserting a sync signal, a parallel / serial conversion circuit (hereinafter referred to as P / S conversion circuit) 24 for sending a 1.5Mbps pulse train as a serial PCM signal, and a DC dial pulse for AC A dial pulse modulating circuit 25 for modulating a pulse and a ringer pulse inserting circuit 26 for inserting a dial pulse into a PCM signal are provided.

On the other hand, the receiver 3 is a serial 1.5 Mbps pulse train PC
S / P converter circuit 31 that converts M signals to parallel signals, separation circuit (hereinafter referred to as DE MUX) 33 that separates a 1.5 Mbps pulse train into multiple PCM signals, and ringer pulse from S / P converter circuit 31 It comprises a ringer pulse register 35 for taking in and storing it, and a dial pulse demodulation circuit 36 for demodulating the ringer pulse stored in the ringer pulse register 35 into a DC dial pulse.

For example, 24CH PCM signal is time-division multiplexed and 1.5Mbps
In the method of transmitting as a pulse train of, the codec section 1 pulse code modulates a 64Kbps PCM signal, and the transmitting section 2 time-division-multiplexes the 64Kbps PCM signal for 24CH into a 1.5Mbps pulse train. Send.

In the receiver 3, this 1.5 Mbps pulse train is 24
It is separated into CH PCM signals, and is further decoded by the codec unit 1 into 24CH audio.

[Problems to be solved by the invention]

As described above, in the method of using one transmission line with 64CHbps of 24CH, for example, when transmitting a 96CH audio signal, four times as many transmission lines are required.

This is 1 to improve the transmission efficiency of the transmission line.
It becomes one neck.

An object of the present invention is to enable transmission of 24CH of a voice telephone on a transmission path of 384Kbps.

[Means for solving problems]

 FIG. 1 shows a block diagram illustrating the principle of the present invention.

The block diagram of the principle of the present invention shown in FIG. 1 shows a functional block of a demultiplexing / demultiplexing device when transmitting 24CH of a voice telephone at 384Kbps. The configuration is such that a voice telephone signal is modulated into a predetermined pulse code. , Pulse code modulation / decoding means 10 for decoding the modulated pulse code into a voice telephone signal, and time division multiplexing means for multiplexing the output signals of a plurality of pulse code modulation / decoding means 10 in a time division manner to modulate at a predetermined speed 20a
An extraction unit 20b that divides a pulse train of a pulse code of a predetermined speed that has been time-division-multiplexed by the time-division multiplexing unit 20a into a plurality and extracts a divided pulse train of a predetermined unit for each division. The extracted segmented pulse train is accumulated, the reading process is performed at a predetermined speed, and the dial signal is transmitted from the transmission unit 200 including the speed conversion unit 20c for inserting and transmitting the dial pulse at a predetermined rate, and the transmission unit 200. The storage means 30a for accumulating the received pulse train and separating the inserted dial pulse.
And a receiving section 300 having a reading means 30b for repeatedly reading the pulse train accumulated in the storage means 30a a plurality of times at a predetermined speed, and a separating means 30c for separating the pulse train having a pulse code having a predetermined speed. Is configured.

[Work]

The voice telephone signal is modulated into a PCM signal by the pulse code modulation / decoding means 10, and a plurality of PCM signals are further time-division multiplexed means 20a.
360 ms from 1.544 Mbps pulse train time-division multiplexed at
A 90 ms pulse train is extracted for each time by the extraction means 20b, accumulated in the speed conversion means 20b, and read out by 384 Kbps.
Convert to and send.

On the other hand, in the receiving section 300, the digital signal string received at 384 Kbps is accumulated in the storage means 30a and the read means 30b stores it.
By reading 4 times at a rate of 5 Mbps, separating by the separating means 30c and decoding each into a voice telephone signal by the pulse code modulating / decoding means 10, a more multiplexed voice signal can be transmitted efficiently. It becomes possible to do.

〔Example〕

Hereinafter, the gist of the present invention will be specifically described with reference to the embodiments shown in FIGS.

FIG. 2 is a block diagram illustrating an embodiment of the present invention, FIG. 3 is a diagram illustrating processing conditions in the embodiment of the present invention, and FIG.
FIG. 5 is a diagram for explaining an outline of the system configuration in the embodiment of the present invention, and FIG. 5 is a diagram for explaining a voice situation. The same reference numerals denote the same objects throughout the drawings.

The embodiment of the present invention shown in FIG. 2 has a codec 11 described in FIG. 6 as the pulse code modulation / decoding means 10 described in FIG. 1, a codec section 1 including a clock generation circuit 12, and a transmission section 200. The functional blocks 21, 22, described in FIG.
An interface circuit 210 that forms an interface between 25 and 26 and a digital pulse train time-division multiplexed by the MUX21.
And a pulse train extraction circuit 220 that extracts a 90 ms pulse train every 360 ms from a 1.5 Mbps pulse train, and a pulse train extraction circuit
Memory 230 for storing the pulse train extracted by 220 and 384K
P / S converter circuit 240 that reads out memory 230 at bps rate and sends it out as 384Kbps PCM signal, and pulse train extraction circuit 2
A transmitting unit 200a and a receiving unit 300 each including an extraction pulse generation circuit 250 that generates a pulse for extracting a 90 ms pulse train at 20 and a memory 230 and a synchronization signal insertion circuit 260 that outputs the processing timing of the extraction pulse generation circuit 250. As shown in FIG. 6, the functional blocks 31, 33,
35,36 and the PC of 384Kbps sent from the transmitter 200a
Memory 310 for storing M signal, read circuit 320 for reading 384Kbps PCM signal stored in memory 310 four times and converting to PCM pulse train of 1.5Mbps, interface circuit 330 for adjusting PCM pulse train of 1.5Mbps, and interface circuit This is an example of a configuration including a reception unit 300a including a synchronization signal insertion circuit 340 that generates and inserts the synchronization signal of 330.

In normal conversation, it is common to speak two to three notes per second.

That is, as shown in FIG. 5, a voice call sound when transmitting a conversation through a telephone line has a waveform of a certain sound repeated when viewed on a predetermined time axis t, and therefore a part of this waveform is extracted. It is possible to bring the sound closer to the original sound by repeatedly reproducing the data on the receiving side.

The shaded waveform in FIG. 5 is the waveform sound extracted and transmitted by the pulse train extraction circuit 220 shown in FIG. 2, and FIG. 5 (A) shows “A”, “A”, and “U”. FIG. 5B shows an example of transmitting a PCM signal sequence, and transmitting a PCM signal sequence of "a", "b", and "c".

That is, the voice as shown in FIG. 5 is coded into a PCM signal by the codec unit 1 and made into a PCM pulse train of 1.5 Mbps (frame length is 3 ms) by the MUX21.

Based on the extraction pulse generated from the extraction pulse generation circuit 250, a pulse train of 90 ms, which is ¼, is extracted every 360 ms (this corresponds to one sound when three sounds are spoken in one second).

In the example of FIG. 5 (A), this is, for example, four "A".
Corresponds to 360 ms, and one of them, the "A" in the shaded area, corresponds to 90 ms.

In addition, 90 ms of extraction time is equivalent to 30 times as much as 1.5 Mbps PCM pulse train (frame length is 3 ms). This is 2 waves at 500 Hz (31 sampling) and 3 at 800 Hz as shown in Fig. 3 (A).
Waves (30 sampling), 3.7 waves at 1000Hz (30 samplings), 6 waves at 1600Hz (30 samplings) will be obtained.

This 90ms pulse train is stored in the memory 230 for 384Kbps.
It is transmitted as a PCM signal.

The receiving unit 300a temporarily stores the 384 Kbps PCM signal in the memory 31.
It is stored in 0 and read by the read circuit 320 four times at a speed of 1.5 Mbps.

That is, the 90 ms pulse train in Fig. 3 (A) is read four times, and these are connected as shown in Fig. 3 (B) to connect to a 1.5 Mbps PC.
Set to M pulse train.

Although it becomes discontinuous at the portion where 500 Hz and 1000 Hz are connected, there is a filter (not shown) when converting from a pulse train to an audio signal, and processing is performed so that discontinuity does not occur.

The 1.5 Mbps PCM pulse train processed by the receiving unit 300a is decoded by the codec unit 1 into voice as shown in FIG. 5, so that a normal conversation is performed.

Since 24CH of voice telephone can be transmitted from the rate of 1.5Mbps to the rate of 384Kbps on the above transmission path, as shown in Fig. 4, the multiplexer / demultiplexers 1 (1) to 1 (4 ) And then MUX41 to 1.5 Mbps to enable transmission of 96CH voice telephone over one transmission line, further improving the efficiency of the transmission line.

〔The invention's effect〕

According to the present invention as described above, it is possible to further improve the transmission efficiency.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating the principle of the present invention, FIG. 2 is a block diagram illustrating an embodiment of the present invention, FIG. 3 is a diagram illustrating a processing situation in the embodiment of the present invention, and FIG. FIG. 5 is a diagram for explaining an outline of a system configuration in an embodiment of the present invention, FIG. 5 is a diagram for explaining a voice situation, and FIG. 6 is a block diagram for explaining a conventional example. In the figure, 1 (1) to 1 (4) are demultiplexing / demultiplexing devices, 1 is a codec unit, 2,200,200a is a transmitting unit, 3,300,300a is a receiving unit, 10 is pulse code modulation / decoding means, 11 is a codec, 12 Is a clock generation circuit, 20a is a time division multiplexing means, 20b is an extraction means, 20c is a speed conversion means, 21 is a MUX, 22,260,340 is a sync signal insertion circuit, 24,240 is a P / S conversion circuit, 25 is a dial pulse modulation circuit, 26 is a ringer pulse insertion circuit, 30a is a storage means, 30b is a read means, 30c is a separation means, 31 is a S / P conversion circuit, 33 is a DE MUX, 35 is a ringer pulse register, 36 is a dial pulse demodulation circuit, 210 and 330 are Reference numeral 220 denotes a pulse extraction circuit, 230 and 310 denote memories, 250 denotes an extracted pulse generation circuit, and 320 denotes a read circuit.

Claims (1)

[Claims] 1. A device for time-division multiplexing a voice telephone signal and a dial signal, or for separating the multiplexed signal into the voice telephone signal and the dial signal, wherein the voice telephone signal is modulated to a predetermined pulse code, and The pulse code modulation / decoding means (10) for decoding the modulated pulse code into a voice telephone signal and the output signals of the plurality of pulse code modulation / decoding means (10) are time-division multiplexed and modulated at a predetermined speed. The time-division multiplexing means (20a) and the time-division-multiplexing means (20a) time-division-multiplexing divides the pulse train of the pulse code of a predetermined speed into a plurality, and extracts a division pulse train of a predetermined unit for each division. The extraction means (20b) for storing the divided pulse train extracted by the extraction means (20b) is accumulated, the reading process is performed at a predetermined speed, and the dial signal is transmitted by inserting a dial pulse at a predetermined rate. A transmission unit (200) including a speed conversion unit (20c) for transmitting, a storage unit (30a) for accumulating the pulse train transmitted from the transmission unit (200) and separating the inserted dial pulse. And a reading means (3) for repeatedly reading the pulse train accumulated in the storage means (30a) a plurality of times at a predetermined speed.
0b) and a receiving unit (300) including a demultiplexing unit (30c) for demultiplexing into a pulse train of a pulse code having a predetermined speed, the multiplexing / demultiplexing device.