JPS63268325A - Channel check system for dsi/adpcm transmission section - Google Patents

Abstract

PURPOSE:To simply attain the channel path check of a transmission section by using a 1st test signal so as to allocate a channel test signal to a DSI channel, inserting a 2nd test signal to a channel time slot to be tested actually and using said signal so as to apply time check. CONSTITUTION:A 1st test signal inserting means 11 inserts the 1st test signal to a predetermined time slot of a digital voice multiplex signal string. Then the 2nd test signal is inserted to the channel time slot with the 1st test signal inserted thereto when the 1st test signal is at a high level. As the 2nd test signal, a test pattern where the input/output pattern of ADPCM is clarified is prepared and it is stored in a ROM, and the 2nd test signal read from the ROM is used for checking the channel path of the DSI/ADPCM while the 1st test signal is set. Thus, the system can check even up to the ADPCM in comparison with a conventional system which checks only the DSI part.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention targets digital audio multiplexed signals, and uses DSI (digital speech interpolation) in which only significant periods of the audio signal are inserted into empty channels and transmitted. system, and the audio signal is converted into ADPCM (Adaptive Di
fferential PulseCode Modu
ration) in combination with the ADPCM method for encoding,
The present invention relates to a channel check method for a transmitter in a DSI/ADPCM system that realizes more efficient audio transmission.

[Conventional technology]

DSI (Digital 5peech engineering)
The method uses the statistical property that the average activity of voices during one call in a telephone conversation is less than 40% and the crowd effect, and inserts only significant voices into the periods of vacant calls. It is a method that allows normal communication with fewer transmission channels than the number of voice channels, and has been put into practical use in recent years as a typical method for high-efficiency voice transmission.

Especially in the satellite communications field, LN-based SAT and KUTKL
It has been officially adopted as the TDMA/DSI method in SAT. It is said that line usage efficiency can be improved by 6 to 4 times compared to conventional FDMA/FM.

In addition, the ADPCM encoding method uses the correlation of audio signals to predict a new sample value from the past sample value, calculates the difference between this predicted signal and the new sample value, and quantizes and encodes only the error signal. By transmitting it, characteristics equivalent to the conventional 64kt+/S can be obtained at a transmission rate of 32kb/s.

The ADPCM system was also officially recommended by CC engineering (Rzc ()721) and has been actively introduced and used for efficient use of transmission lines.

Recently, 16K, which is intended for more efficient use of communication lines, has been introduced.
Attention is being paid to the adoption of transmission methods below b/s, and this D
The SI/ADPCM method is also a useful method that can achieve transmission equivalent to 16 kb/s.

Devices and equipment for these high-efficiency transmission systems, including the DSI/ADPCM system, generally perform complex processing, so they have a larger hardware scale and are more complex than conventional systems.

Furthermore, in the DSI/ADPCM system, a large number of channels are processed by a common circuit, so when a failure occurs in a device, the communication line is greatly affected.

Therefore, it is necessary to constantly monitor the device, and if there is an abnormality in its internal operation, it must be detected immediately, an alarm must be generated, and appropriate measures must be taken.

Conventionally, in the DSII system, a constant monitoring method called the channel check test method was useful - 65E (Rev.
, 2) The details are described in 8.5.5 Channel Check Procedure 7e.

However, D8 which combines DSI and ADPCM
In the engineering/ADPCM method, from DSI processing to ADPC
I couldn't find a way to centrally and constantly monitor the M part.

[Problem that the invention seeks to solve]

The conventional method targets only DEI■, so A
If DPCM is added, this method cannot be said to be appropriate for checking the functional operation of ADPCM.

In other words, since the process of ADPCM encoding is added,
It is impossible to predict how the test signal inserted for checking the DSI will be encoded, and the conventional test signal is not necessarily suitable for checking the functional operation of the ADPCM.

An object of the present invention is to provide a DS that can easily check the channel path of the transmitter in the D8/ADPCM combined system.
The purpose of this invention is to provide a channel check method for I/ADPCM.

[Means for solving problems]

According to the present invention, a digital audio multiplexed signal is targeted, and the audio detection means (3) detects the presence or absence of audio based on a predetermined threshold value from this multiplexed signal, and the audio detection result is used to detect significant audio. Search for a DSI channel as an empty transmission channel for transmitting the channel, and perform channel assignment.

Taking into account the processing time required for the audio detection and the channel allocation, the digital audio multiplexed signal is delayed for a certain period of time by a time adjusting means (6), and the significant audio channel is connected to the DSI channel according to the channel allocation information. (7), and converts this DSI channel into a DSI channel signal sequence by further ADPCM encoding means (8).
), the channel assignment information and the ADP (!M encoded digital audio signal) are multiplexed and transmitted from the transmitting section, and the receiving side receives the received DSI/A
ADPCM decoding is performed from the DPCM multiplexed signal sequence,
In the DSI/ADPCM method, the DSI channel signal string is returned to the original digital audio multiplexed signal string based on the transmitted channel assignment information, and channel connection conversion is performed. 2. The height of the high-level signal that causes the voice detecting means to determine that there is a voice and the low-level signal that causes the voice detecting means to determine that there is no voice at a certain period.
a first test signal generating means (1o) for generating a first test signal of a certain level;
a first test signal inserting means (11) for inserting a test signal into a predetermined channel time slot of the input digital audio multiplexed signal stream; and generating a test signal for checking the operation of the ADPCM encoding means. and a second test signal generating means (12) for generating a second test signal at a stage before the time adjustment means, in the same channel time slot in which the @1 test signal was inserted in the digital audio multiplexed signal train. The output of the second test signal insertion means (13) and the ADP(!M encoding means) is monitored, and the first test signal is inserted into the DEI channel within the period allocated to the DEI channel.

A test signal inspection means (15) for inspecting whether the ADPCM encoded output pattern in a specific period of a specific channel matches a predetermined expected value is added to the transmitter, and the channel test signal is assigned to a DSI channel. is performed using the first test signal, but a second test signal is inserted into the channel time slot that is actually to be tested.

A channel check method for the transmitting section of DI9/ADPCM is obtained, which is characterized in that the second test signal is used to check the channel from the channel connection means to the ADPCM encoding means [Embodiment] FIG. FIG. 1 is a block diagram of an embodiment of the present invention. Terminal 1
The digital audio multiplexed signal sequence added to the first test signal insertion means 11 and the second test signal insertion means 16
join. The first test signal insertion means 11 is supplied with a first test signal and a first control signal from the first test signal generation means 10 . This first test signal insertion means 11 is responsive to a first control signal.

After inserting the first test signal into a predetermined time slot of the digital audio multiplexed signal train, it is output and applied to the audio detector 3. The audio detector 3 detects the presence or absence of audio for each channel time slot of the audio multiplexed signal sequence using a predetermined threshold, and sends the result to the channel allocation processing means 4 as an allocation request signal. do.

In the channel allocation processing means 4, based on the 9 allocation request signal,
Check the currently allocated and used 9 channels and the unused empty channels. 9 Input audio POM channel number for which allocation was requested (hereinafter).

A Ds channel number (hereinafter referred to as a DC-H number) for transmitting this is assigned to the PCH number.

This pair of PCH number and DCH number is called an allocation information signal and is sent to the allocation control means 5, the second time adjustment means 14, and the multiplexing means 9.

On the other hand, in the second test signal insertion means 13, the second
receiving the second test signal from the test signal generating means 12, and receiving the second test signal from the first test signal generating means 10;
In response to the N signal, the first test signal is at a high level (
A second test signal is inserted when the test signal is active).

After the second test signal has been inserted, the audio multiplexed signal sequence is applied to the first time adjustment means 6.

Here, the signal train is delayed by a predetermined time and is applied to the channel connection means 7.

In the channel connection means 7, according to the write address signal from the 2 allocation control means 5, the PC that requested 2 allocation!
Hfr:DC! To connect to H.

Writes the contents of PCH to the specified D61 channel address.

The reading of the channel connection means 7 is the same.

In response to a read address signal from the allocation control means 5, data is read out in order according to a fixed DCH number, and the ADP
It is sent to the CM encoding means 8.

ADPf:! In the M encoding means 8, the 64 kb/s P CN signal is converted into a 32 kb/s ADP CN signal by the ADPCM encoding means 8 (or common encoding means) provided individually for each channel, and the code is converted into a 32 kb/s ADP CN signal. ADPCM encoded test pattern detection means (
That is, it is sent to the test signal inspection means) 15 and the multiplexing means 9.

The ADPCM encoded test pattern detection means (i.e., test signal inspection means) 15 responds to the control signal from the second time adjustment means 14 and detects the second test signal assigned to the DSI channel multiplexed signal train. The pattern after ADPCM encoding is verified, and if it matches a predetermined reference test pattern, it is determined that the channel path from DSI assignment to ADPCM encoding is normal. On the other hand, if the ADPCM encoded test pattern is not correctly detected despite the DSI channel assignment being made, the channel path is determined to be abnormal and an alarm signal is output from the terminal 16. The multiplexing means 9 multiplexes the ADPCM encoded DSI channel signal sequence and the allocation information and sends the multiplexed information via the terminal 2.

Send to the receiving section.

In the above explanation, the first test signal is.

The sound detection means can reliably determine the presence or absence of the signal.2For example, as specified in IN SAT SpθC, a 1 kHz square wave signal that is ON for 1 second and OFF for 9 seconds (alt when ON) ``1''.

When OFF, all "0") is appropriate.

However, the second test signal, namely ADPCM
This test signal is not necessarily suitable for checking the encoding operation of .

Therefore, for the second test No. 13, prepare a test pattern in which the input/output pattern of the ADPCM is clear, store it in the ROM, and perform the test pattern read out from the ROM while the first test signal is ON. DS test signal of 2
This is used to check the I/ADPCM channel path.

FIG. 2 is a diagram for explaining the test signal pattern of the present invention. 101 represents a digital audio multiplexed signal train, and represents a POH time slot. Here, PCHn means a time slot for channel check test. POH
A LL'''0'' pattern is inserted in advance in n.

1001-1 and 1001-2 mean the first control signal, which is the timer output 100 of the first test signal generating means.
2: 1 second ON, 9 seconds OFF signal.

This is a control signal that is at H level only during a 1 second ON period.

This first control signal causes a first test signal 100
3 is inserted into POHn by the first test signal insertion means 11, and the second test signal 1201 is inserted into the POHn by the first test signal insertion means 11.
The test signal insertion means 13 inserts the signal into PCHn and uses it for DSI/ADPCM channel path check.

1006 generates a positive/negative signal level with a 1000 Hz rectangular wave as a signal when ON, and becomes zero level when OFF. Further, 1201 is an ADPCM encoding test pattern, which generates an initial setting pattern for initializing the ADPCM encoder for a predetermined time after a certain period of time has passed since the timer is turned on, and then generates an initial setting pattern for initializing the ADPCM encoder for a predetermined period.
A CM encoded test pattern is generated and used as a second test signal for DSI/ADPCM channel path check.

〔Effect of the invention〕

As explained above, according to the present invention, by using the first test signal and the second test signal.

The channel time slot to be tested is assigned to the DSI channel using the first test signal, and the actual Da
Engineering/ADP C! Checking the M channel paths can be performed centrally using the second test signal.

For this reason, it is now possible to check up to ADP (!M), whereas previously only the DSI part could be checked.

Particularly when a large number of individual ADPCM encoders are used, this constant checking of channel paths is an extremely effective means for improving the operating rate of the device.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a channel check test method for DSI/ADPCM transmission ml according to an embodiment of the present invention, and FIG. 2 is a diagram for explaining the pattern of a test signal. 1...Digital audio multiplexed signal input terminal. 2...DEI/ADP (!M signal output terminal, 6...
- Voice detection means, 4... Allocation processing means, 5... Allocation control means. 6... First time adjustment means, 7... Channel connection means, 8... ADPCM encoding means, 9... Multiplexing means. 10... first test signal generating means, 11... first
12... second test signal generating means, 16... second test signal inserting means. 14... Second time adjustment means, 15... ADPcM
Encoded test pattern detection means (test signal inspection means)
, 16... Alarm output terminal. Figure 2 7 Stobano

Claims (1)

[Claims] 1. An empty transmission channel that targets digital audio multiplexed signals, uses audio detection means to detect the presence or absence of audio based on a predetermined threshold value from this multiplexed signal, and transmits a significant audio channel based on the audio detection result. The digital audio multiplexed signal is delayed for a certain period of time by a time adjusting means in consideration of the processing time required for the audio detection and the channel allocation, and the DSI channel is searched for and allocated to the DSI channel. connecting the channel to the DSI channel by a channel connection means;
In a transmitting unit of the DSI/ADPCM method, the DSI channel signal sequence is further ADPCM encoded by an ADPCM encoding means, and the channel allocation information and the ADPCM encoded digital audio signal are multiplexed and transmitted. a first test signal generating means that generates a first test signal of two levels, high and low, at a predetermined period, a high level signal that causes the voice detecting means to determine that there is a voice, and a low level signal that causes the voice detecting means to determine that there is no voice; , a first test signal inserting means for inserting a first test signal into a predetermined channel time slot of the input digital audio multiplexed signal stream, upstream of the audio detecting means;
a second test signal generating means for generating a second test signal for checking the operation of the DPCM encoding means; and a second test signal generating means for generating a second test signal for checking the operation of the DPCM encoding means; A second test signal is inserted into the same channel time slot in which the first test signal is inserted.
The outputs of the test signal insertion means and the ADPCM encoding means are monitored, and the ADPCM encoded output pattern of the particular channel in the particular period within the period in which the first test signal is allocated to the DSI channel is determined in advance. A test signal inspection means for inspecting whether or not it matches a predetermined expected value is added to the transmitting section, and the channel test signal is assigned to the DSI channel using the first test signal, but the channel test signal is actually assigned to the DSI channel. A DSI/ADPCM characterized in that a second test signal is inserted into a time slot, and a channel check from the channel connecting means to the ADPCM encoding means is performed using the second test signal.
Transmitter channel check method.