JPH0715220Y2 - Cordless telephone device - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slave station equipped with a handset and a transmitter / receiver, a connection device connected to a telephone line, capable of wireless communication with the slave station, and equipped with a transmitter / receiver. The present invention relates to a cordless telephone device having a multi-channel access (MCA) system and a low power cordless telephone device.

[0002]

2. Description of the Related Art 89 channels are allocated to this type of MCA type low power cordless telephone apparatus.
Of 89 channels, 87 are call channels and 2
The channel is a control channel. Adjacent channels are 12.5 kHz apart. The MCA low-power cordless telephone device has a slave station and a connection device. The slave station includes a handset and a transceiver. The connection device is connected to a telephone line, can perform wireless communication with a slave station, and includes a transmission / reception device.

In the conventional MCA type low power cordless telephone apparatus, each of the slave station and the connecting apparatus has an antenna connected to the transmitting / receiving apparatus. This antenna has a predetermined gain corresponding to a predetermined communication distance. The antenna gain may change slightly due to the influence of the surroundings.

[0004]

[Problems to be Solved by the Invention] Such a conventional MC
Let's assume that a plurality of A-system low-power cordless telephone devices are simultaneously used in a narrow range. In this case, since the antenna gain is almost constant even if the distance between the connection device and the slave station changes, interference interference such as intermodulation is likely to occur. Only 8 channels can be used. That is, up to 8 conventional MCA
Only small power cordless telephone devices can be used simultaneously in a narrow range. On the other hand, if the antenna gain is set to a small value from the beginning in order to reduce the adverse effect of interference and interference, there is a drawback that the maximum callable distance is shortened.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a cordless telephone device which can reduce the adverse effects of interference without shortening the maximum callable distance.

[0006]

A cordless telephone device to which the present invention is applied is connected to a slave station provided with a handset and a transmitter / receiver and a telephone line, and is capable of wireless communication with the slave station. And a connection device including a transmission / reception device. According to a first aspect of the present invention, each of the slave station and the connection device has a first antenna having a first gain corresponding to a first callable distance, and the first callable distance. A second antenna having a second gain corresponding to a shorter second callable distance, a determination unit that determines a distance between the slave station and the connection device, and the determination unit that determines the distance according to the determination result. Switch means for switching and connecting one of the first antenna and the second antenna to the transmission / reception device. According to a second aspect of the present invention, each of the slave station and the connection device includes an antenna having a predetermined gain, determination means for determining a distance between the slave station and the connection device, Switch means for turning on / off the connection between the antenna and the transmitting / receiving device according to the determination result of the determining means.

[0007]

[Operation] When the distance between the slave station and the connection device is short,
In the cordless telephone device of the first aspect, the second antenna and the transmitting / receiving device are connected, and in the cordless telephone device of the second aspect, the connection between the antenna and the transmitting / receiving device is turned off. Therefore, interference from other cordless telephone devices is less likely to be received, and interference with other cordless telephone devices is also reduced. Therefore, when a large number of cordless telephone devices are installed close to each other, the number of units that can be used simultaneously increases.

[0008]

Embodiments of the present invention will now be described with reference to the drawings. Referring to FIG. 1, a cordless telephone device according to a first embodiment of the present invention includes a connection device 10 and a slave station 20.
Have and. The cordless telephone device of this embodiment is a multi-channel access type low power cordless telephone device.

The connection device 10 is connected to the telephone line 30 and is capable of wireless communication with the slave station 20. The connection device 10 includes a control device 11 connected to the telephone line 30, a transmission / reception device 12 connected to the control device 11, and a transmission / reception device 1.
It has a radio frequency (RF) switch 13 connected to 2, and first and second antennas 16 and 17 connected to the RF switch 13.

The slave station 20 has a handset 40. The slave station 20 includes a control device 21 connected to the handset 40, a transmission / reception device 22 connected to the control device 21, an RF switch 23 connected to the transmission / reception device 22, and an RF switch 2
3 and the first and second antennas 26 and 27 connected to each other.

Each of the first antennas 16 and 26 has a first
Has a first gain corresponding to the callable distance of. on the other hand,
Each of the second antennas 17 and 27 has a second gain corresponding to a second callable distance shorter than the first callable distance. In this embodiment, the first callable distance is 100 m
And the second callable distance is 10 m. Therefore,
The first antennas 16 and 26 are connected to the connection device 10 and the slave station 2.
0 can be used in a range of 10 to 100 m, and the second antennas 17 and 27 can be used in a range of 0 to 10 m between the connection device 10 and the slave station 20. .

Each of the control devices 11 and 21 includes a slave station 20.
It has a determination circuit 50 for determining the distance between the connection device 10 and the connection device 10. In the connection device 10, the RF switch 13 is
According to the determination result signal indicating the determination result of the determination circuit 50,
As will be described later, one of the first antenna 16 and the second antenna 17 is switched and connected to the transmitter / receiver 12. Similarly, in the slave station 20, the RF switch 23
According to the determination result of the determination circuit 50, one of the first antenna 26 and the second antenna 27 is switched and connected to the transmitter / receiver 22 as described later.

Each of the transmitter / receivers 12 and 22 has a received signal level detector 61 and a squelch circuit 62. The reception signal level detector 61 detects the level of the reception signal,
A signal meter output signal indicating the received signal level is output. The squelch circuit 62 monitors the speech quality and outputs a squelch signal indicating whether or not there is a received carrier. In this embodiment, when the call quality is good, that is,
When there is a reception carrier, the squelch circuit 62 outputs a squelch signal of logic "0" level. When the speech quality deteriorates, that is, when there is no received carrier, the squelch circuit 62 outputs a squelch signal of logic "1" level.

The decision circuit 50 includes a prescribed signal generator 51,
Comparator 52 and RS flip-flop (F / F) 5
3 and 3. The prescribed signal generator 51 generates a prescribed signal representing a prescribed signal level corresponding to the second callable distance. The specified signal is supplied to the comparator 52. The signal meter output signal is supplied from the reception signal level detector 61 to the comparator 52. The comparator 52 compares the received signal level with a predetermined signal level. When the received signal level becomes higher than the predetermined signal level, the comparator 52 outputs a logical "1" level comparison result signal. The comparison result signal is supplied to the input terminal S of the RS flip-flop 53. When the logic "1" level comparison result signal is supplied to the input terminal S, the RS flip-flop 53 outputs the output terminal Q.
Outputs a logic "1" level determination result signal. This logic "1" level determination result signal is called a first switching control signal. A squelch signal is supplied from the squelch circuit 62 to the input terminal R of the RS flip-flop 53. When a squelch signal of logic “1” level is supplied to the input terminal R, the RS flip-flop 53 outputs a judgment result signal of logic “0” level from its output terminal Q. This logic "0" level determination result signal is the second
Is called a switching control signal.

In the connection device 10, the RF switch 13
The second antenna 1 in response to the first switching control signal.
7 and the transmission / reception device 12 are switched to be connected. Similarly, in the slave station 20, the RF switch 23 switches to connect the second antenna 27 and the transmitting / receiving device 22 in response to the first switching control signal. On the other hand, in the connection device 10, the RF switch 13 is responsive to the second switching control signal and the first antenna 16 and the transmission / reception device 12 are connected.
Switch to connect and. Similarly, in the slave station 20, the RF switch 23 switches to connect the first antenna 26 and the transmission / reception device 22 in response to the second switching control signal.

As described above, the cordless telephone device of the above embodiment has two modes as the callable distance. That is, there are two modes: a mode having a relatively long distance corresponding to the first callable distance and a mode having a relatively short distance corresponding to the second callable distance. The former mode is called the normal mode and the latter mode is called the proximity mode.

Next, the operation of the cordless telephone device of this embodiment will be described. First, as an initial state, it is assumed that the distance between the connection device 10 and the slave station 20 is within the range of the normal mode, that is, within the range of 10 to 100 m. At this time,
The RS flip-flop 53 of the judgment circuit 50 outputs the judgment result signal of the logic "0" level, that is, the second switching control signal from the output terminal Q thereof. Therefore, R
As shown by the solid line in FIG. 1, the F-switches 12 and 23 are switched so as to connect the first antennas 16 and 26 and the transceivers 12 and 22 in response to the second switching control signal, respectively. .

In this state, the connection device 10 and the slave station 2
The distance between 0 and 0 is the range of the proximity mode, that is, 0 to 10 m.
It becomes the range of. At this time, the reception signal level represented by the signal meter output signal outputted from the reception signal level detector 61 of the connection device 10 and the slave station 20 is regulated by the regulation signal outputted from the regulation signal generator 51. Greater than signal level. Therefore, the comparator 52 outputs a comparison result signal of logic "1" level. In response to the comparison result signal of this logic "1" level,
The RS flip-flop 53 enters the set state, and outputs the judgment result signal of the logic "1" level, that is, the first switching control signal from the output terminal Q thereof. In response to this first switching control signal, the RF switches 12 and 23 are
As shown by the dotted line in FIG. 1, switching is performed so as to connect the second antennas 17 and 27 and the transmission / reception devices 12 and 22, respectively.

Further, in this state, the connection device 10
It is assumed that the distance between the slave station 20 and the slave station 20 is within the range of the normal mode. At this time, the call quality deteriorates, so the connection device 1
The squelch circuit 62 of 0 and the slave station 20 outputs a squelch signal of logic “1” level. In response to the squelch signal of the logic "1" level, the RS flip-flop 53
Goes to the reset state, and its output terminal Q outputs a logic "0".
The level determination result signal, that is, the second switching control signal is output. RF in response to the second switching control signal
The switches 12 and 23 are switched so as to connect the first antennas 16 and 26 and the transmission / reception devices 12 and 22, respectively, as shown by the solid line in FIG.

As described above, when the distance between the slave station 20 and the connection device 10 is relatively short, the gain of the antenna system is set to be low, so that it is difficult to receive interference and interference from other cordless telephone devices. Also, interference with the cordless telephone device is reduced. Therefore, with a simple configuration, it is possible to effectively reduce interference and interference when the cordless telephone device is installed close to each other. As a result, when a large number of cordless telephone devices are installed close to each other, the number of units that can be used simultaneously increases. A large number of cordless telephones without changing the characteristics (for example, transmission output, reception sensitivity, intermodulation characteristics) of the transmission / reception devices 12 and 22 themselves of the connection device 10 and the slave station 20 and without sacrificing the maximum callable distance. Only the characteristics when the devices are installed close to each other can be improved.

Referring to FIG. 2, the cordless telephone device according to the second embodiment of the present invention comprises a connection device 10 and a slave station 2.
0 has no second antennas 17 and 27, respectively, and has the same configuration as that shown in FIG. 1, except that the RF switches 13 and 23 are ON / OFF type switches. . That is, the second antennas 17 and 27
Since the gain is small, in the second embodiment, instead of providing the second antennas 17 and 27, they are deleted.

[0022]

As described above, in the present invention, when the distance between the slave station and the connection device is short, the gain of the antenna system is set low, so that interference from other cordless telephone devices is not received. Difficulty and less interference with other cordless telephone devices. Therefore, when a large number of cordless telephone devices are installed close to each other, the number of units that can be used simultaneously increases. There is also an advantage that the possibility of wiretapping a call from a remote place is reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing a cordless telephone device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a cordless telephone device according to a second embodiment of the present invention.

[Explanation of symbols]

 10 Connection Device 11 Control Device 12 Transceiver Device 13 Radio Frequency (RF) Switch 16 First Antenna 17 Second Antenna 20 Slave Station 21 Control Device 22 Transceiver Device 23 Radio Frequency (RF) Switch 26 First Antenna 27 Second Antenna 30 telephone line 40 handset 50 determination circuit 51 prescribed signal generator 52 comparator 53 RS flip-flop (F / F) 61 received signal level detector 62 squelch circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location H04Q 7/38

Claims (8)

[Scope of utility model registration request] 1. A cordless telephone device having a slave station equipped with a handset and a transmitter / receiver, and a connection device connected to a telephone line, capable of wireless communication with the slave station, and provided with a transmitter / receiver. In each of the slave station and the connection device, a first antenna having a first gain corresponding to a first callable distance and a second callable distance shorter than the first callable distance. A second antenna having a second gain corresponding to, a determining unit that determines the distance between the slave station and the connection device, and the first antenna and the second antenna according to the determination result of the determining unit. A cordless telephone device having switch means for switching and connecting one of the antennas to the transmitting / receiving device. 2. The cordless telephone device according to claim 1, wherein the cordless telephone device is a multi-channel access type low power type. 3. The transmission / reception device of each of the slave station and the connection device outputs a signal meter output signal indicating a reception signal level, and the determination means is a predetermined signal corresponding to the second callable distance. A prescribed signal generating means for generating a prescribed signal representing a level, receiving the signal meter output signal and the prescribed signal, comparing the received signal level with the prescribed signal level, and the received signal level is the prescribed signal level. Comparing means for outputting a first switching control signal as the determination result when it becomes larger, the switching means in response to the first switching control signal, the second antenna and the transceiver device. The cordless telephone device according to claim 1, wherein the cordless telephone device is switched so as to be connected. 4. The transmission / reception device of each of the slave station and the connection device outputs a squelch signal indicating whether or not there is a reception carrier, and the determining means determines that the squelch signal does not include the reception carrier. The switch means has a means for outputting a second switching control signal as the determination result at the time of indicating, and the switch means connects the first antenna and the transceiver device in response to the second switching control signal. The cordless telephone device according to claim 1, wherein the cordless telephone device is switched so as to switch. 5. A cordless telephone device having a slave station equipped with a handset and a transmitter / receiver, and a connection device connected to a telephone line, capable of wireless communication with the slave station, and having a transmitter / receiver. In each of the slave station and the connection device, an antenna having a predetermined gain, a determination unit that determines a distance between the slave station and the connection device, and the antenna according to a determination result of the determination unit. And a switch means for turning on / off the connection with the transmission / reception device. 6. The cordless telephone device according to claim 5, wherein the cordless telephone device is a multi-channel access type low power type. 7. The transmission / reception device of each of the slave station and the connection device outputs a signal meter output signal indicating a reception signal level, and the determination means generates a regulation signal indicating a predetermined signal level. Generating means, receiving the signal meter output signal and the specified signal, comparing the received signal level with the predetermined signal level, and when the received signal level becomes higher than the predetermined signal level, the determination result is 6. The cordless telephone according to claim 5, further comprising: a comparison unit that outputs a switching control signal of 1, wherein the switching unit turns off the connection between the antenna and the transceiver in response to the first switching control signal. apparatus. 8. The transmission / reception device of each of the slave station and the connection device outputs a squelch signal indicating whether there is a reception carrier or not, and the determining means determines that the squelch signal does not have the reception carrier. The switch means turns on the connection between the antenna and the transmission / reception device in response to the second switching control signal when outputting the second switching control signal as the determination result. The cordless telephone device according to claim 5.