JPH03183228A - Sound/data multiplexing device - Google Patents

Abstract

PURPOSE:To raise the transmitting efficiency of a data signal and the using efficiency of a communication line by detecting the presence of an inputted sound signal, and doubling the data read-out speed of the speed converting means of a transmitting part during the non-signal period of the sound signal, and sending only the read out data signal as time division multiplexed data. CONSTITUTION:When a sound detector 2 provided at the transmitting part does not detect the sound signal inputted to an input terminal 10, namely, during the non-signal period of the sound signal, the data signal stored in a memory in a speed converting means 3 is read out at twice higher speed than prescribed read-out speed in response to a sound detection signal 14 which the sound detector 2 outputs, and is outputted to a multiplexing means 4. The multiplexing means 4 not recognizing the sound detection signal 14 which the sound detector 2 outputs samples only the data signal 13 inputted at twice higher speed than the prescribed speed at both the leading and the trailing edges of a clock signal, and outputs the same data signal 13 by assigning it to both the areas of the transmission area of the sound data of the time division multiplexed data 20 and the transmission area of the data signal. As mentioned above, one frame is constituted of the prescribed number of bits of the multiplexed data 20.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multiplexing device that time-division multiplexes and transmits digitized audio data and digital data signals.

[Conventional technology]

Audio data obtained by digitizing a conventional analog audio signal and a signal obtained by time-division multiplexing of digital data signals each have independent signal regions, and even if one of them has no signal, the corresponding signal region remains unchanged. was to be transmitted without a signal.

[Problem to be solved by the invention]

During the no-signal period of the audio signal due to the intermittent audio signal, only the data signal is transmitted while the audio data area of the time-division multiplexed data remains in a no-signal state, resulting in poor utilization efficiency of the communication line.

The present invention effectively utilizes the audio data area during the no-signal period of audio signals, thereby increasing the efficiency of using communication lines.

[Means for Solving the Problem] A means for detecting the presence or absence of a human-generated audio signal is provided, and the data reading speed of the speed converting means of the transmitting section is changed during the no-signal period of the audio signal by the audio detection signal outputted by the detection means. 2
The speed is doubled, and only the read data signal is sent as time-division multiplexed data, increasing data signal transmission efficiency and communication line usage efficiency.

[Effect]

An analog audio signal input to an input terminal 10 of the transmitting section is converted into audio data 12 which is digital data by an encoding means 1 such as an adaptive delta modulation method, and is supplied to a multiplexing means 4.

On the other hand, by reading the data signals input to the input terminal 11 of the transmitter, temporarily storing the same data signals in the memory in the order of input, and reading the same data signals in the order of memory at a speed different from the writing speed at the time of storage, it is compatible with the communication line. The data is converted to a predetermined data transmission rate and supplied to the multiplexing means 4.

When the multiplexing means 4 detects the audio signal input to the input terminal 10 via the audio detector 2, the multiplexing means 4 detects the input audio signal by the rising edge of the clock signal, as shown in the time chart shown in FIG. 2(a). The audio data 12 of the signal is sampled by a data signal 13 obtained by converting the speed of the input data signal at the falling edge of the same clock signal, and multiplexed data 20 in which each sampled data is arranged alternately on the time axis is output.

The ○ marks on the state lines representing the states of the audio data 12 and data signal 13 in the figure indicate the sampling time of each signal,
Multiplexed data 20 is constructed by holding the state of each signal at the same sampling point until the next sampling point.

When the audio detector 2 does not detect the audio signal input to the input terminal 10, the audio detection signal 14 output from the audio detector 2 reads out the data signal stored in the memory in the speed converting means 3 at a predetermined reading speed. The data is read out at twice the speed and output to the multiplexing means 4.

The multiplexing means 4, which does not recognize the audio detection signal 14 output from the audio detector 2, converts only the data signal 13 inputted at twice the predetermined transmission rate into a clock signal, as shown in FIG. 2(b). In both the audio data transmission area and the data signal transmission area of the multiplexed data 20 sampled at rising and falling edges and time-divided,
The same data signal 13 is assigned and output.

A predetermined number of bits of the multiplexed data 20 as described above constitutes one frame, and a predetermined number of frames constitutes a group, and the beginning of the data group is indicated at the beginning of the data of the - group. Header part 2 composed of specific code
1 and output it to the communication line.

An example of the format of data output by the multiplexing means 4 is shown in FIG.

Bits 22 to 23 are arranged as the start bit of each frame to identify the content of the data in the same frame, and the audio data and data signal are arranged alternately according to the contents of the identification bits 22 to 23, or multiple data or data signal. Separate the water.

Time division multiplexed data 2 output from the multiplexing means 4 of the transmitting section
0 is sent to the receiving section via a digital communication line which is a transmission line, and the separating means 5 of the receiving section separates the audio data 1.
5 and data signal 16.

The separating means 5 of the receiving section detects the header part 21 of the input multiplexed data 20, detects the start of a group of data and the division position of each frame, and detects the identification bits 22 to 22 which are the start bits of each frame. Check 23.

The separating means 5 alternately distributes the data in the same frame to the audio data decoding means 6 and the data signal speed converting means 7 every 1 bit, depending on the contents of the identification bits 22 to 23 of each frame. It is supplied to the speed conversion means 7 together with the high speed data identification signal 17.

The audio data 15 input to the decoding means 6 is converted into an analog audio signal and output from the audio output terminal 18, and the data signal 16 input to the speed converting means 7 can be specified by a control signal included in the data. Convert to a certain transmission speed,
It is output from the data output terminal 19.

〔Example〕

The input terminal 10 of the transmitting section is supplied with a human-powered audio signal to the audio encoder 1 which is a means for encoding the same signal, and
The signal is also supplied to an audio detector 2 that detects the presence or absence of the same audio signal.

The audio encoder l converts the input analog audio signal into digital audio data 12, and converts the input analog audio signal into digital audio data 12.
2 is supplied to the multiplexing means 4.

On the other hand, the audio detector 2 detects the presence or absence of an input audio signal and outputs an audio detection signal 14, which is supplied to the multiplexing means 4 and the speed converting means 3 for converting the transmission speed of the data signal, which will be described next. .

The audio detection signal 14 outputted by the audio detector 2 is a signal indicating that the audio is being sent together with the audio signal supplied to the input terminal 10, for example, a transmission/reception switching signal in a simplex communication system. Press-to
- It may be a talk signal.

Speed conversion that reads the data signal input to the input terminal 11 that is multiplied and transmitted together with the audio signal input to the input terminal 10, and converts the speed of input/output data by temporarily storing the same data signal in a memory and reading it out. It is supplied via means 3 to said multiplexing means 4.

The speed converting means for converting the speed of such human output data is a multi-board memory or F I F O (F
This can be easily realized using a memory (first in - first out).

The audio data 12 outputted by the audio encoder 1, the audio detection signal 14 outputted from the audio detector 3, and the speed-converted data signal 13 outputted from the speed converter 3 are manually multiplexed by the multiplexing means 4, which detects the same audio data. When there is an audio signal by signal 14, audio data I2 and data signal 1
3 are alternately sampled to form multiplexed data.

The above-mentioned sampling data are arranged alternately on the time axis to form multiplexed data, and frames are constructed for each predetermined data length, and at the beginning of each frame, the data in the same frame is combined with the audio data 12 and data signal 13. Identification bits 22 to 23 indicating that the data is multiplexed data are added.

The speed converting means 3, which does not recognize the voice detection signal 14 outputted by the voice detector 2, converts the data signal already stored from the memory in the speed converting means 3 into two signals at a predetermined successive speed.
It is read out at twice the speed and output to the multiplexing means 4.

Only the data signal 13 input from the speed conversion means 3 to the multiplexing means 4 at twice the predetermined speed is sampled, and the identification bits 22 to 23 of each frame are changed to a code indicating that the data signal is a high-speed data signal. and output it.

For example, the transmission rate of the encoded audio signal 12 is 16 kbit/
s, and the transmission speed of the speed-converted data signal 13 is 1
If the transmission speed of the multiplexed data is 6kbit/s and the transmission speed of the multiplexed data is 32kbit/s, the transmission speed of the data signal when there is no audio signal is the same as the transmission speed of the multiplexed data, 32kbit/s. High-speed transmission is possible.

A block is made up of a predetermined number of frames added with the identification bits, and a header portion 21 representing the start of a group of data is placed at the beginning of the block and output to the communication line.

The communication line for transmitting the multiplexed data 20 is not limited to a wired line, but may be a wireless line as long as it has the performance to transmit the multiplexed data 20.

The multiplexed data inputted to the receiving unit via the digital communication line is detected by the separating means 5, which detects the header part 21 of the multiplexed data, determines the frame classification based on the header part 21, and determines the start bit of each frame. Identification bit 22
.about.23 identifies whether the data is multiplexed data of an audio signal and a data signal.

When the identification bits 22 to 23 are codes indicating multiplexed data of audio data and data signals, the separating means 5 separates the audio data 15 and the data signal 1.
6 and supplied to an audio decoder 6 and a speed conversion means 7, respectively.

The audio data 15 input to the audio decoder 6 is converted into an analog audio signal and output from the output terminal I8.

Further, the data signal 16 input to the speed conversion means 7 is converted to the transmission speed at which the data signal was input to the input terminal 11 according to a control code (not shown) in the data signal 16, and the data signal is output. Output from terminal 19.

When the identification bits 22 to 23 are codes indicating high-speed data, the separating means 5 outputs the high-speed data identification signal 17 and only transmits the data signal 16 at twice the predetermined transmission speed. and the speed converting means 7
After converting to the specified transmission speed, output terminal 19
Output from

〔Effect of the invention〕

A communication system that multiplexes and transmits voice signals and data signals.By transmitting data signals even in the voice signal transmission area during pauses due to intermittent voice signals, the actual transmission speed of data signals is increased, and data The aim is to improve the transmission efficiency of communication lines and the efficiency of use of communication lines.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2(a) is a sampling time chart of audio data and data signals when an audio signal is detected, and FIG. 3(b) is a sampling time chart of audio data and data signals when an audio signal is not detected. FIG. 2 is a diagram showing a data format of multiplexed data. In the figure, l is an audio encoder, 2 is an audio detector, 3 and 7 are speed conversion means, 4 is a multiplexing means, 5 is a multiplexed data separation means, 6 is an audio decoder, speed conversion means, and 10 is an audio signal Input terminals, 11 is a data signal input terminal, 12 and 15 are audio data, 13 and 16 are speed-converted data signals, 14 is an audio signal detection signal, 17 is a high-speed data identification signal, 18 is an audio signal output terminal , 19 is a data signal output terminal, 2° is multiplexed data, 21 is a part of a header, and 22 to 23 are identification bits for high-speed data.

Claims (1)

[Claims] An encoding means for converting an input audio signal into digital audio data; a transmission speed conversion means for temporarily storing the input data signal in a memory and reading it out at a different speed than when it was stored; A transmitting section including a multiplexing means for alternately sampling into one time-division multiplexed data, and a separating means for alternately distributing the time-division multiplexed data into audio data and data signals bit by bit; A receiving section is equipped with a decoding means for converting data into an analog audio signal and a separate transmission speed converting means for the same data signal, and the transmitting section and the receiving section are connected via a digital communication line to multiplex the audio signal and the data signal. In the audio/data multiplexing device, when there is no input audio signal, the data signal stored in the memory of the speed converting means of the transmitting unit is converted to a predetermined value by the output of the audio signal detecting means provided in the transmitting unit. An audio/data multiplexing device that reads at twice the speed and transmits only the same data signal.