JP2000295136A - Transmitter and receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the lack of transmission sound on transmission start time and to dissolve the uneasiness of a call owing to the delay of transmission sound, which occurs in a delay circuit, by shortening delay time after prescribed time passes after a transmitter is started and shortening delay time when the operation of the transmitter stops with respect to the termination of transmission sound. SOLUTION: When first transmission sound data at the time of starting transmission is inputted to RAM 63, CPU 68 writes transmission sound data through a timing control circuit 65 and delays timing when data is read to a second latch circuit 64 by transmission starting time (20ms, for example) on a transmitter 30. When next sound data is inputted to RAM 63, CPU 68 delays reading timing by 18ms and sequentially shortens the delay time of reading timing by 2ms to 16ms, 14ms...0 ms with respect to input sound data. The delay of reading timing is set to be zero against eleventh sound data and below. Thus, uneasiness owing to sound delay can be dissolved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmitting / receiving apparatus,
In particular, the present invention relates to a means for eliminating a sense of incongruity in a call caused by a time delay of an audio signal generated by a delay circuit in a transmitting / receiving apparatus having a VOX function.

[0002]

2. Description of the Related Art A press-talk radio is inexpensive due to its simple structure, and is widely used for business communication and the like because of effective use of frequency. As is well known, in this radio, the user presses the press-talk switch during voice transmission to switch the transmission / reception processing.However, in order to reduce the operation burden on the user, the transmission / reception processing is automatically detected by detecting the input voice. Transmission / reception switching device (Voic
e OperatedTransmitter, hereafter V
OX device) may be used by being incorporated inside the wireless device.

FIG. 2 is a block diagram showing an example of the configuration of a press-talk radio apparatus incorporating a conventional VOX device.
The press-talk wireless device shown in this example has a switch 100
And an antenna 110, a transmitter 120, a receiver 130, a microphone 140, and a transmission voice from the microphone 140, which are connected to each other via the antenna 110, and control the switch 100 to control the transmitter 120 and the receiver 1.
And a VOX device 150 for controlling 30 functions. Here, the VOX device 150 includes a delay circuit 151 for delaying the transmission sound from the microphone 140 and outputting the delay to the transmitter 120, a sound detection circuit 152 for detecting the level of the transmission sound, and a signal based on the output signal. Transmission / reception control circuit 153 for outputting a control signal to the switch 100
It is composed of

[0004] The press-talk radio shown in this example functions as follows. That is, if the transmission sound output from the microphone 140 is equal to or higher than the predetermined level value, the sound detection circuit 152 determines that the state is “transmission state”, and connects the common terminals c1 and c2 of the switch 100 to the terminals 12
By connecting to the antennas 110a and 120b, respectively, the driving power is supplied to the transmitter 120 to start it, and the transmitter 120 is connected to the antenna 110. Therefore, microphone 1
The transmission voice output from 40 is transmitted from antenna 110 via delay circuit 151 and transmitter 120.

On the other hand, the sound detection circuit 152
If the transmission sound output from the switch 100 is equal to or lower than a predetermined level value, it is determined to be in the “reception state”, and the common terminals c1 and c2 of the switch 100 are connected to the terminals 130a
By switching to the 130b side, the supply of driving power is switched from the transmitter 120 to the receiver 130 and the receiver 130 is connected to the antenna 110. As a result, the received signal (the signal arriving at the wireless device) is transmitted to the antenna 11
The signal is guided to the earphone 160 via 0 and the receiver 130.

Here, the function of the above-described delay circuit 151 will be described in detail. In the case where the radio performs transmission processing, after the transmission voice is detected by the voice detection circuit 152, driving power is supplied to the transmitter 120. Starts up,
Thereafter, it is known that it generally takes several tens of milliseconds until it becomes operable (hereinafter, this is referred to as transmission start time). In addition, the operator often starts speaking directly into the microphone immediately after pressing the press-talk switch, except in the case of special training, and therefore, when the state is switched from the reception state to the transmission state considering that there is no delay circuit. The transmission voice input to the transmitter 120 during the transmission start time is lost, which hinders communication (call). This phenomenon is generally called "talking off", but in order to avoid this obstacle, the transmission sound is delayed by the transmission start time by using the delay circuit 151, and the transmitter 120 becomes operable. Later, the transmission voice is input to the transmitter 120 to prevent the head disconnection. The delay circuit 151 generally has a BBD (Packet B
Rigid Devices, charge transfer devices) and the like are often used.

[0007]

However, the press-talk radio apparatus incorporating the above-mentioned conventional VOX device has the following problems. That is, when the sender (user of the wireless device) ends the transmission and returns to the receiving state, the VOX is performed despite the end of the transmission.
Since the transmission state continues for the delay time of the delay circuit in the device, the transmitting party responds after listening to it, and the time delay causes a break in the conversation. The sender felt uncomfortable and there was a problem that the call could not be made smoothly. SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem relating to the conventional VOX device, and it is intended to prevent a loss of transmission voice related to a transmission start time and to reduce a sense of incongruity in a call due to a delay of transmission voice generated in a delay circuit. It is an object of the present invention to provide a transmission / reception device provided with the eliminated VOX device.

[0008]

In order to achieve the above object, a transmitting / receiving apparatus according to the present invention detects a transmission voice and automatically activates a transmitter, and simultaneously transmits the transmission voice. A transmission / reception device which detects the interruption of a predetermined time and stops the operation of the transmitter, comprising a variable delay means for delaying the input transmission sound for an arbitrary time, and the delay time when the transmission sound is input is such that the transmitter is normal. In addition to the time required for the operation, the delay time is shortened after the elapse of a predetermined time after the activation of the transmitter, so that the delay time when the operation of the transmitter is stopped with respect to the end of the transmission voice is reduced. According to a second aspect of the present invention, there is provided a transmission / reception apparatus which detects a transmission voice and automatically activates a transmitter, detects that transmission voice is interrupted for a predetermined time, and stops the operation of the transmitter. The apparatus further comprises: an analog-to-digital converter for converting the transmission sound into a digital signal; and a storage unit for storing the digital signal, wherein a digital signal is output from the storage unit after a lapse of a predetermined delay time after the input of the sound. The signal reading is started, and thereafter, the timing of the reading is sequentially advanced to control so as to eliminate the delay time. According to a third aspect of the transmitting and receiving apparatus according to the present invention, in the transmitting and receiving apparatus according to the second aspect, after reading of the digital signal from the storage means is started, the digital signal is thinned to eliminate the delay time. did. According to a fourth aspect of the transmitting / receiving apparatus according to the present invention, in the transmitting / receiving apparatus according to the second or third aspect, the storage means is controlled via a CPU, and the CPU is configured to control the storage means based on the level of the transmission sound. The transmission / reception state is grasped and required transmission / reception processing is performed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on illustrated embodiments. FIG. 1 is a block diagram showing an embodiment of a press-talk radio apparatus to which a VOX device according to the present invention is added. The press-talk radio apparatus shown in this example has a transmitter 30 and a receiver 40 connected to the antenna 20 via the switch 10 and a transmission sound from the microphone 50, and delays this sound signal by a required time. The switch 10 is supplied to the transmitter 30 and
And a VOX device 60 for controlling the same.

On the other hand, the VOX device 60, which characterizes the present invention, is provided with an analog-to-digital converter (A) for converting voice (analog signal) transmitted from the microphone 50 into a digital signal.
/ D converter) 61, a first latch circuit 62 for parallel-converting the converted digital signal into a predetermined number of bits,
RAM (RandomA) for storing the latched signal
access memory) 63 and a second latch circuit 64 for reading the parallel signal stored in the RAM 63
A timing control circuit 65 for adjusting the read timing; and a digital / analog converter (D / A converter) for converting a digital signal output from the second latch circuit 64 into an analog signal and supplying the analog signal to the transmitter 30. Vessel) 66
A Schmitt trigger circuit 67 for determining whether or not the transmission sound from the microphone 50 is higher than a required level, and a central processing unit (CP) for controlling the switch 10, the RAM 63, and the timing control circuit 65 based on the output signal.
U) 68.

The press-talk radio according to the present invention shown in this example functions as follows. That is, the VOX device 6
0 indicates the transmission voice (analog signal) from the microphone 50 as A /
The signal is converted into a digital signal by the D converter 61 and a parallel signal (for example, 8
(A bit signal) and stored in the RAM 63. After the transmission voice is stored in the RAM 63 for the required time, the second
The transmission timing is adjusted through the latch circuit 64 and the signal is guided to the D / A converter 66, where the digital signal is converted again into an analog signal and output to the transmitter 30.

In parallel with the above operation, the Schmitt trigger circuit 67 compares the transmission voice level from the microphone 50 with a predetermined threshold value and outputs a trigger pulse signal to the CPU 68 if the level is equal to or higher than the threshold value. The operation of the Schmitt trigger circuit 67 is described in, for example, “Sakuraba et al.
211-214, Morikita Publishing, 1987 ", and a description thereof will be omitted.

The CPU 68 includes a Schmitt trigger circuit 67
When the pulse signal is supplied from the switch 10, it is determined that the wireless device should be in the “transmission state”, and the common terminal c1 of the switch 10
c2 is connected to terminals 30a and 30b, respectively, to supply driving power to the transmitter 30 to start the transmitter 30 and
Is connected to the antenna 20. That is, the transmission sound output from the microphone 50 is supplied as a modulation signal of the transmitter 30 after being delayed for a required time in the above-described VOX device 60, and is superimposed on a carrier wave and transmitted from the antenna 20. At this time, the audio delay time by the VOX device 60 is set to be substantially equal to the time required for the transmitter to be turned on and to reach normal operation. As a result, the voice is transmitted to the other party without disconnecting the head. On the other hand, the CPU 68
If the transmission audio level continues for a predetermined time and is equal to or less than the required value, it is determined that the radio should be set to the “reception state”, and the common terminals c1 and c2 of the switch 10 are switched to the terminals 40a and 40b, respectively. The driving power is supplied to the receiver 40 and the antenna 20 is connected to the receiver 40. As a result, the received signal (the signal arriving at the wireless device) is transmitted to the earphone 7 via the antenna 20 and the receiver 40.
It is led to 0.

The above operation is almost the same as that of the conventional transceiver.
This is under the control of the timing control circuit 65 in the X device 60.
That is, when the CPU 68 determines that the state is “transmission state” as described above, the sound transmitted from the microphone 50 is transmitted to the VOX device 6.
0 is transmitted from the antenna 20 via the transmitter 30. At this time, when the transmission voice temporarily stored in the RAM 63 is output to the transmitter 30 with a required delay (time) added thereto,
As will be described in detail below, by controlling the delay time, the actual end of the voice and the end of the operation of the transmitter are matched.

First, when the first transmission voice data at the start of transmission is input to the RAM 63, the CPU 68 writes the transmission voice data via the timing control circuit 65 and then reads the data to the second latch circuit 64 as described above. For the transmission start time related to the transmitter 30 (for example, 20 ms)
Just delay. That is, the first transmission audio data is stored in RAM
The signal is input to the transmitter 30 with a delay of 20 ms according to 63.
When the next audio data is input to the RAM 63, the CPU 6
8 delays the readout timing by 18 ms, and then sequentially reduces the readout timing delay for input audio data by 16 ms, 14 ms,. In this case, the read timing delay is set to zero. If the next audio signal is read before all the (digital) audio signals whose output has been started are converted to analog signals, the end of the previously output audio is deleted. However, the call is not affected because it is only slightly removed.

In short, the VOX device according to the present invention delays the transmission sound at the start of transmission (sending) and outputs it to the transmitter.
After a second, the transmitted voice is output to the transmitter without delay for the transmission. Therefore, send (speak)
It is possible to prevent the transmission voice from being lost during the transmission start time at the time of starting, and it is also possible to eliminate the uncomfortable feeling of the call (conversation) due to the voice delay.

As described above, the method in which the CPU 68 controls the timing based on the reference time as a method of changing the data read timing from the RAM 63 has been described. However, various other methods are conceivable. For example, with respect to the voice data input to the RAM 63 for 200 ms from the start of transmission (transmission), the voice data is reduced by 10% every 20 ms.
(I.e., data for 2 ms) is thinned out and read out, so that the delay of 2 ms is cancelled, so that the delay of 20 ms is canceled after the lapse of 200 ms. That is, even if a delay of 20 ms is given at the start of transmission (sending), a transmission voice with zero delay is input to the transmitter 30 after a lapse of 200 ms. Note that the audio is at most 2ms
It is known that even if the data is thinned out sequentially, intermittently, or discretely, the intelligibility of speech is not significantly affected.

As another timing control method, D /
The operation clock of the A converter 66 may be made variable. That is, if the memory read clock and the latch circuit drive clock frequency are controlled as necessary, the audio frequency is shifted to a slightly higher direction so that the same effect as in the above-described embodiment can be obtained, but the communication is significantly affected. There will not be.

The reason for changing the data read timing from the RAM 63 little by little as described above is that if the modulation signal (transmission signal) changes abruptly with time, the delay time of 20 ms in this example is instantaneously changed. This is because if the delay is set to zero, an unnecessary modulated signal is generated, and a phenomenon in which the sound demodulated on the receiving side becomes unnatural is avoided.

In the above-described embodiment of the present invention, the case where the analog modulator is used in the transmitter 30 has been described. However, when the digital modulator is used in the transmitter 30, the D / A is used. There is no need to particularly explain that the converter 66 is not required and the digital signal output from the second latch circuit 64 may be directly input to the transmitter 30.

[0021]

As described above, according to the present invention, the transmission sound is converted into a digital signal and stored in the RAM, and at the same time, the transmission sound is delayed only within a required time by changing the timing of reading from the RAM. With this configuration, it is possible to prevent a loss of an audio signal at the start of transmission (transmission) and to realize a transmission / reception device to which a VOX device is added, which can eliminate a sense of discomfort in a call (conversation) related to an audio delay. It works.

[Brief description of the drawings]

FIG. 1 is a block diagram when a VOX device according to the present invention is used in a press-talk radio

FIG. 2 is a block diagram in a case where a conventional VOX device is used for a press-talk wireless device.

[Explanation of symbols]

 Reference Signs List 10 switch 20 antenna 30 transmitter 40 receiver 50 microphone 60 transmission / reception switching device (VOX device) 61 A / D converter 62 first latch circuit 63 RAM 64 second latch circuit 65 timing control circuit 66 D / A converter 67 Schmitt trigger circuit 68 CPU (central processing unit) 70 earphone

Claims (4)

[Claims] 1. A transmitting / receiving apparatus which automatically starts a transmitter upon detecting a transmission voice and detects that the transmission voice has been interrupted for a predetermined time and stops the operation of the transmitter. A variable delay means for delaying an arbitrary time is provided, and the delay time at the time of inputting the transmission voice is set to a time necessary for the transmitter to operate normally, and the delay time is reduced after a predetermined time has elapsed after the transmitter is activated. A transmission / reception apparatus characterized in that a delay time when the operation of the transmitter is stopped with respect to the end of transmission voice is reduced. 2. A transmission / reception device which detects a transmission voice and automatically activates a transmitter, detects that the transmission voice has been interrupted for a predetermined time and stops the operation of the transmitter, and converts the transmission voice into a digital signal. Analog-to-digital conversion means for converting, and storage means for storing the digital signal, starting reading of a digital signal from the storage means after a predetermined delay time has elapsed since the input of the audio,
A transmission / reception apparatus which controls so as to eliminate the delay time by sequentially advancing the timing of the reading. 3. The transmission / reception apparatus according to claim 2, wherein after starting reading of the digital signal from said storage means, the digital signal is thinned to eliminate the delay time. 4. The communication device according to claim 2, wherein said storage means is controlled via a CPU, and said CPU recognizes a transmission / reception state based on a level of said transmission voice and performs a required transmission / reception process. Or the transmitting / receiving device according to claim 3.