JP3292613B2 - Single-wave simultaneous transmission / reception radio - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system in which a single wireless transmission channel is used to obtain a communication state as if two-way simultaneous communication has been obtained, that is, a so-called one-wave simultaneous transmission and reception. Related to wireless systems. Here, one wave has the same meaning as one frequency.

[0002]

2. Description of the Related Art As effective use of wireless channels has been strongly called out, a communication system called a one-wave simultaneous transmission / reception system has recently attracted attention.
This one-wave simultaneous transmission / reception system is also called a time-division simultaneous transmission / reception system. The time compression and time expansion of the audio signal creates a vacant time required for alternate time-division transmission. A more specific description will be given below. First, as shown in FIG. 4A, a signal such as a microphone input signal that is continuous in time is sequentially transmitted for a period T. Each time, the time is compressed to a period Tx = Rx ≒ T / 2 by a time axis compression circuit.
An intermittent audio compression signal is generated as shown in FIG. As the period T at this time, a period of, for example, about 400 milliseconds is selected. Therefore, in this case, the period Tx = Rx ≒ 200 milliseconds.

In response to this, the transmission / reception operation of one of the wireless devices, for example, the calling wireless device, is alternately divided into a transmission period Tx and a reception period Rx as shown in FIG. At the same time, the transmission / reception operation of the other radio, that is, the called radio, is alternately divided into a reception period Rx and a transmission period Tx as shown in FIG. The intermittent signal is transmitted from one side to the other side, so that the T / 2 period created within the period T is used as the reception period of the signal from the other party, thereby enabling bidirectional transmission under a single frequency carrier signal. This allows simultaneous transmission and reception.

[0006] As shown in FIG. 4 (e), the intermittent audio compression signal received during the reception period Rx is returned to a continuous signal that is time-expanded by approximately twice as shown in FIG. 4 (f). , And a received audio signal is obtained. Switching of transmission and reception at this time,
As shown in FIG. 4B, the timing of the time compression / time expansion is controlled by a time division synchronization signal added to the intermittent audio compression signal.

[0005] As a conventional technique of this kind of one-wave simultaneous transmission / reception system, the description in International Publication No. WO91 / 02414 can be given.

[0006]

In the above prior art, no consideration was given to operation under radio wave management by the government, and there was a problem of deterioration in usability. That is, for example, according to the Radio Law of Japan, when operating such a communication method using a wireless device, at least at the start and end of a call, it is necessary to identify each wireless device.
For example, transmission of predetermined information such as a call sign is obligatory.

For this reason, in the prior art, the caller needs to call a predetermined call sign, such as the number of each radio, as necessary. Is accompanied by a considerable sense of incongruity and a sense of duty, which is inconvenient and, in some cases, causes problems such as hindering operation.

[0008] The object of the present invention is to comply with laws and regulations,
It is an object of the present invention to provide a single-wave simultaneous transmission / reception radio device which does not require a caller such as a call sign by a caller and can provide the same excellent usability as a normal telephone.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a single-wave simultaneous transmission / reception radio device having a control means for inserting an identification signal of its own station into a transmission signal, and at least a signal transmitted first at the start of a call. This is achieved by inserting the identification signal of the own station into the signal transmitted last at the end of the call.

[0010]

The control means for inserting the identification signal of the own station into the transmission signal operates so that the identification signal of the own station is automatically transmitted at the start and end of the emission of the radio wave.

Therefore, since the caller can make a call in the same manner as a normal telephone without being conscious of any restrictions, there is no possibility that the usability will deteriorate.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A single-wave simultaneous transmission / reception radio according to the present invention will be described below in detail with reference to the illustrated embodiment.

FIG. 1 shows an embodiment of the present invention. In FIG. 1, first, a time axis companding section 2 is adapted to input an audio signal input from an audio signal input terminal 1 as shown in FIG. (Microphone input signal) v is sequentially divided for each period T, and time-compressed to 1/25 (compression ratio) in the transmission period Tx to produce an audio compression intermittent signal as shown in FIG. together serve to create a V _1, as shown in FIG. 4 (e), the reception period Rx, an audio compression intermittent signal input from the FM demodulator 12 (described later), about twice (2.25 ), And returns to a continuous signal to obtain a received voice signal as shown in FIG.

The time axis compander 2 generates a time-division synchronization signal S and generates a transmission switching signal SW. Thus, during the transmission period Tx, first, the high-frequency transmitter 8 Is operated, the antenna switch 9 is tilted to the transmitting side, the high-frequency receiving unit 11 is stopped, and
In the reception period Rx, the high-frequency transmission unit 8 is stopped,
Flip the antenna switch 9 to the receiving side, and
So that the control to operate is obtained.

The control unit 5 is configured to take four types of operation modes by operating the call switch 14. That is, even when the call switch 14 is pressed in the call stop state, the call mode is not set immediately, but first the call start processing mode is set, and then the mode is shifted to the normal call mode. . Also, when the call switch 14 is pressed while in the call mode,
Therefore, instead of immediately terminating the call, the system is configured to temporarily enter the call termination processing mode and then to stop the call.

First, the operation when the control unit 5 enters the talking mode will be described. In the talking mode, the operation described with reference to FIG. 4, that is, the one-wave simultaneous transmission / reception operation is performed. In the transmission period Tx,
The intermittent audio compression signal V ₁ is output from the time axis compander 2 to the MSK modulator 6 and the FM modulator 7, FM-modulated and output to the high-frequency transmitter 8, amplified, and then transmitted through the antenna switch 9. is transmitted from the antenna 10, then the reception period Rx, signals received by the antenna 10 is inputted from the high-frequency receiving unit 11 to the FM demodulator 12, demodulated received voice compression intermittent signal V ₁ is the time scale modification The received audio signal is supplied to the section 2, whereby the received audio signal that has been extended in time and returned to a continuous state is supplied to the received audio signal output terminal 16 via the received audio mute circuit 15. Therefore, the operation in the call mode is the same as the simultaneous transmission / reception operation in the conventional one-wave simultaneous transmission / reception radio.

Next, the operation when the control unit 5 enters the call start processing mode will be described. The call start processing mode is, as described above, a mode in which only the first transmission period Tx is set after the call switch 14 is pressed in the call stop state, and thereafter, the mode automatically shifts to the normal call mode. This is one of the features of the present invention together with a call termination processing mode described later.

[0018] When this call initiation processing mode, the control unit 5, the transmission start timing signal of the audio compressing intermittent signal V ₁ supplied from the time scale modification section 2, a timing signal indicating the end of transmission of the clogging time division synchronization signal In the first transmission period Tx after the high-frequency transmission unit 8 is activated,
Instead of part or all of the audio compression intermittent signal, a bit synchronization signal (bit synchronization signal of the identification signal) B, a frame synchronization signal (frame synchronization signal of the identification signal) F, and an identification code signal (self) The ID is read from the identification code storage device 4, and these are sequentially read from the M code.
Output to the SK modulator / demodulator 6. Accordingly, the identification signal in this embodiment is composed of the bit synchronization signal B, the frame synchronization signal F, and the identification code signal ID. Hereinafter, the entire identification signal is also represented by ID.

The identification signal input to the MSK modulator / demodulator 6 is modulated into an MSK signal, and then FM-modulated by the FM modulator 7.
After being modulated, the signal is amplified by the high-frequency transmitting unit 8 and transmitted from the antenna 10. The reason why the MSK modulation / demodulation unit 6 is provided in this embodiment is that the identification signal is a digital signal.

When the transmission of the identification signal is completed, the control unit 5 automatically switches to the communication mode, and controls the operation of the MSK modulation / demodulation unit 6 by changing the voice compression intermittent signal V ₁ from the time axis companding unit 2 to F
The operation is switched to the operation to be output to the M modulation unit 7, and the operation shifts to the operation in the above-described communication mode, and the simultaneous one-wave simultaneous communication operation is started.

Next, the operation when the control unit 5 enters the call stop processing mode will be described. In the call stop processing mode, the call switch 14
Is a mode in which only the last transmission period Tx is taken after the key is pressed, and thereafter, the mode automatically shifts to a call stop. It is one.

The operation in the call stop processing mode is almost the same as the above-described call start processing mode. When an input is made from the call switch 14, the control unit 5 enters the call stop processing mode, and the time axis compression and expansion is performed. The processing starts from the transmission start timing signal of the audio compression intermittent signal V ₁ , that is, the timing signal indicating the end of transmission of the time-division synchronization signal, from the unit 2. In the last transmission period Tx by the high-frequency transmission unit 8, the bit synchronization is started. The identification signal including the signal B, the frame synchronization signal F, and the identification code signal ID is read out from the identification code storage device 4, and the MSK modulation / demodulation unit 6 is sequentially replaced with part or all of the audio compression intermittent signal during this period. Output to

The identification signal input to the MSK modulator / demodulator 6 is modulated into an MSK signal, and then FM-modulated by the FM modulator 7.
After being modulated, the signal is amplified by the high-frequency transmitting unit 8 and transmitted from the antenna 10. And the control unit 5
When the transmission of the identification signal ends, the time axis compander 2 and M
The SK modulation / demodulation unit 6 is stopped, and the call is stopped.

Therefore, according to this embodiment, the identification signal is automatically transmitted from both the calling side and the called side at the beginning and end of the emission of the radio wave, so that the caller can talk. In this case, it is possible to identify and monitor the wireless device without specially calling the call sign, thereby always providing good usability.

Next, the operation of the remaining part of the embodiment of FIG. 1 will be described. In this embodiment, as described above, the identification signal is transmitted at the start and end of the call. However, if this is reproduced as an audio signal, it is annoying. However, according to this embodiment, as described below, the generation of noise due to the identification signal is automatically suppressed.

That is, this embodiment utilizes the fact that the time axis companding unit 2 delays the voice signal and the identification signal in order to prevent the transmission of the identification signal from affecting the other wireless device. It is. In other words, the transmission start timing of the identification signal to be transmitted at the end of the emission of the radio wave to the other wireless device having means for cutting off the sound for a certain period of time by the bit synchronization signal and the frame synchronization signal is determined by the time division synchronization signal. Is transmitted, the time of the bit synchronization signal and the frame synchronization signal constituting a part of the identification signal is set to 1.
This is after the time when the time divided by 25 (a value obtained by subtracting 1 from the elongation ratio, 1 or more) has elapsed. Here, the expansion ratio is a value obtained by dividing the time length of the output signal after expansion in the case of expanding the time axis by the time axis compander 2 by the time length of the input signal before expansion. .

First, as described above, the reception period R
At x, the signal transmitted from the wireless device of the communication partner is
Antenna 10, antenna switch 9, and high frequency receiver 1
1 and demodulated by the FM demodulation unit 12, and then supplied to the time axis companding unit 2. At this time, the squelch circuit 1
3 and the MSK modulator / demodulator 6.

First, the squelch circuit 13 detects a noise component of the demodulated signal, and when the noise component exceeds a threshold value, generates a squelch signal SQ for cutting off the audio signal and expands the time axis. Output to section 2. Then, the time axis companding unit 2 time-expands the squelch signal SQ together with the demodulated audio signal, and the time-expanded squelch signal S
The Q controls the reception audio mute circuit 15.

As a result, the time-extended audio signal is switched by the reception audio mute circuit 15 and when the noise component exceeds the threshold value, the path of the reception output terminal 16 is cut off from the time-extended audio signal. Then, a muting operation can be obtained.

On the other hand, the MSK modulator / demodulator 6 demodulates the MSK signal and outputs this to the controller 5. Therefore, the control unit 5
Detects the frame synchronization signal of the identification signal, controls the received audio mute circuit 15 from the detection of this signal until the end of the time-expanded identification code signal, and controls the reception audio mute circuit 15 from the time-expanded audio signal. The path to the reception output terminal 16 is disconnected.

Here, when the emission of the radio wave is started and the identification signal transmitted first is received, the radio wave is not sensed before the identification signal is received. The level of the noise component input to the circuit 13 is considerably high.

Therefore, in this embodiment, the squelch circuit 1
The squelch signal SQ output from the squelch circuit 3 is input to the time axis companding unit 2, whereby the time from when the identification signal is received to when the noise component input to the squelch circuit 13 decreases to a certain value or less is set to 2 .25 times, until the connection path of the audio signal disconnected by the reception audio mute circuit 15 is closed (squelch response time, usually 30 to 100 m
s) is made longer than the duration of the bit synchronization signal and the frame synchronization signal (about 23 ms at 2400 BPS). Therefore, according to this embodiment, when the emission of the radio wave is started, The identification signal is not output as an audio signal.

Next, the operation of suppressing the identification signal at the end of the emission of the radio wave in this embodiment will be described. As is clear from FIG. 1, in this embodiment, the delay circuit 3 is provided on the path of the timing signal indicating the start of transmission of the audio compression intermittent signal, that is, the timing signal indicating the end of transmission of the time-division synchronization signal. The timing signal indicating the end of transmission of the time-division synchronization signal is supplied to the control unit 5 after being delayed by 50 ms.

FIG. 3 shows the relationship between the decompression operation of the bit synchronization signal and the frame synchronization signal and the delay time. Here, S is a time division synchronization signal, V ₁ is an intermittent audio compression signal before decompression, and V ₁ ′
Is an intermittent audio compression signal after expansion, B is a bit synchronization signal before expansion, B 'is a bit synchronization signal after expansion, F is a frame synchronization signal before expansion, F' is a frame synchronization signal after expansion, I
D is an identification signal before expansion, and ID ′ is an identification signal after expansion.

Now, the time-base companding unit 2
When the time axis is extended, the delay time until the input signal is output is zero immediately after the time-division synchronization signal S is received, and thereafter increases linearly with time. This is 1.25 times the time elapsed since the signal S was received.

For example, if the extension ratio is 2.25 times and 200 m
If an input signal having a time length of s is extended to 450 ms, 200 ms from the generation timing of the time-division synchronization signal S
The signal input at the time of elapse is 1.25 times 250m
The output is delayed by s. The output timing is 450 ms from the time when the time division synchronization signal S is generated.
This is the time that has passed.

Here, since the delay circuit 3 is provided, the bit synchronization signal B starts to be received when 50 ms has elapsed since the time point when the time division synchronization signal S was generated, and when 112.5 ms has elapsed since the time division synchronization signal S. It is assumed that the reception of the frame synchronization signal F of the same identification signal has been completed, and the audio signal (identification signal) has been cut off upon detection of the completion of the reception (bit synchronization signal B + frame synchronization signal F ≦ 62.5 ms).

Then, the timing at which the bit synchronization signal B whose time axis has been expanded by the time axis companding unit 2 starts to be output is the time when the signal starts to be received 50 ms after the time division synchronization signal S. From, then 50ms
After the lapse of time, that is, 62.
112.5 ms (5 ms) delayed by 5 ms (50 ms × 1.25)
0 ms × 2.25).

Therefore, when the frame synchronizing signal F is detected and the decompressed audio signal is cut off, the decompressed identification signal becomes the bit synchronizing signal and the reception end point of the frame synchronizing signal.
Since the delay more than (at the time of audio signal disconnection) is given, the identification signal is supplied after disconnection, and there is no fear that this is generated from the speaker.

Here, assuming that the expansion ratio is n, as shown in FIG. 3, the lengths of the bit synchronization signal B and the frame synchronization signal F (B
+ F) is K, x is the start time of reception of the bit synchronization signal B, X _{1 is} the start time of output of the decompressed signal B ', X is the frame synchronization signal F
When the receiving end of the _{X 2, X 1 = nx,} X 2 = x +
It becomes K.

Then, in this case, in order to prevent the expanded identification signal (B + F + ID) from being output, it is sufficient that X ₁ > X ₂ → nx> x + K → x> K / (n−1) holds. .

Therefore, in order to prevent the time-expanded identification signal from being output, the transmission of the identification signal to be transmitted when the emission of the radio wave is terminated must be changed from the termination of the transmission of the time-division synchronization signal to the component of the identification signal. It is sufficient to start from the point where the time is longer than the time obtained by dividing the time of the bit synchronization signal and the frame synchronization signal by the value obtained by subtracting 1 from the expansion ratio of the compressed signal of the time-division simultaneous transmission / reception radio. In the description of the above embodiment, numerically, X ₁ = X ₂ .

Therefore, according to this embodiment, it is possible to reliably suppress the possibility of unnecessary noise generation due to insertion of the identification signal. In particular, if the voice signal level of the call is lower than the identification signal, if the identification signal is output, there is a possibility that the sound due to the identification signal may impact the ear. Such a fear can be reliably eliminated.

According to this embodiment, the identification signal is
In the first cycle of the audio compression intermittent signal after the timing signal indicating the end of transmission, the audio compression intermittent signal is transmitted instead of the intermittent audio compression signal. Therefore, according to this embodiment, it is possible to prevent a problem such that phase distortion occurs in the identification signal due to phase distortion caused by compression and decompression.

Next, FIG. 2 shows another embodiment of the present invention.
This embodiment differs from the embodiment of FIG. 1 in that the delay circuit 3 provided in the path of the timing signal indicating the start of transmission of the intermittent audio compression signal in the embodiment of FIG. The same function is provided inside the unit 2 and, therefore, its operation and effect are the same as those of the embodiment of FIG.

[0046]

According to the present invention, the identification signal of the transmitting station is inserted at the beginning and end of transmission in a one-wave simultaneous transmission / reception type radio apparatus by time-division time compression / expansion. The wireless device can be operated with the same feeling as a normal telephone without being conscious of regulations, and the usability can be sufficiently improved with the observance of laws and regulations.

Further, according to the present invention, the transmission is performed when the emission of the radio wave is completed by utilizing the fact that the receiving-side radio has a function of receiving the frame synchronization and cutting off the reception output signal for a certain period of time. By simply controlling the transmission timing of the identification signal to be transmitted, the identification signal can be made inaudible on the receiving side, and as a result, there is a possibility that the identification signal may be generated when the voice signal level of the call is lower than the identification signal. The danger of a shock to the ear due to the signal can be reliably eliminated.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a one-wave simultaneous transmission / reception radio device according to the present invention.

FIG. 2 is a block diagram showing another embodiment of the one-wave simultaneous transmission / reception radio device according to the present invention.

FIG. 3 is a timing chart showing a relationship between an expansion operation of an identification signal, a bit synchronization signal, and a frame synchronization signal and a delay time in one embodiment of the present invention.

FIG. 4 is a timing chart for explaining the operation of the one-wave simultaneous transmission / reception communication system to which the present invention is applied;

[Explanation of symbols]

 Reference Signs List 1 audio input terminal 2 time axis companding unit 3 delay circuit 4 identification code storage device 5 control unit 6 MSK modulation / demodulation unit 7 FM modulation unit 8 high frequency transmission unit 9 antenna switch 10 antenna 11 high frequency reception unit 12 FM demodulation unit 13 squelch circuit 14 Call switch 15 Receive audio mute circuit 16 Receive output terminal 17 Time axis compander

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-58-204631 (JP, A) JP-A-61-7147 (JP, U) International Publication No. 91/2414 (WO, A1) (58) Fields surveyed (Int.Cl. ⁷ , DB name) H04B 1/54 H04B 1/66 H04B 14/00 H04L 5/14

Claims (3)

(57) [Claims] 1. A continuous input signal is sequentially divided for each predetermined period, and the time required for transmission is shortened by time compression for each of the divided sections. In a single-wave simultaneous transmission / reception radio that enables simultaneous transmission / reception by a carrier wave of the same frequency by alternately transmitting and receiving, a control means for inserting an identification signal of the own station into a transmission signal is provided. Wherein the identification signal of the own station is inserted into the signal transmitted last at a predetermined time delay from the time division synchronization signal added to the head of the transmission signal. Receiving radio. 2. The invention according to claim 1, wherein the wireless device has means for cutting off audio for a predetermined time by a bit synchronization signal and a frame synchronization signal, wherein the identification signal is a bit synchronization signal, a frame synchronization signal, and an identification following them. From the point of time that is longer than the time obtained by dividing the time of the bit synchronization signal and the frame synchronization signal, which are the components of the identification signal, by the value obtained by subtracting 1 from the expansion ratio of the time-compressed transmission signal. Characterized in that it is configured to start insertion into the transmission signal. 3. The invention according to claim 1, wherein the identification signal is inserted so as to replace at least a part of the intermittent audio compression signal included in the transmission signal. Wave simultaneous transmission and reception radio.