JP3339112B2 - Digital cordless telephone equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital cordless telephone device for performing communication between a master unit and a slave unit by transmitting and receiving digital data.

[0002]

2. Description of the Related Art A digital cordless telephone device is configured as shown in FIG. 4, for example. In FIG. 4, reference numeral 1 denotes a base unit serving as a base station. The base unit 1 is connected to a telephone line and has two antennas 1a and 1b for communicating with a slave unit. A plurality (three in this case) of slave units capable of communicating with the master unit 1 are prepared. That is, the slave units 2, 3, and 4 are prepared, and the antennas 2a, 3a, and 4a are attached to the slave units 2, 3, and 4, respectively.
Wireless transmission is performed between the antenna 1a or 1b of the master unit 1 and the antennas 2a, 3a, and 4a of the slave units 2, 3, and 4.

When each of the slave units 2, 3, and 4 talks with the master unit 1 (or the other party connected to the master unit 1 via a telephone line), a connection control signal of a predetermined format is sent to the master unit 1.
Side, and transmits voice data converted into digital data in a time-sharing manner with the base unit 1 to make a call.

In this case, the base unit 1 has two antennas 1
a and 1b are prepared, so that these two antennas 1
By selecting and using an antenna that can communicate well with the slave unit from a and 1b, a so-called space diversity communication is performed and the communication performance can be improved.

In such a digital cordless telephone device, transmission and reception are performed at the same frequency, and a TDD system (time division duplex system) or a TDMA / TDD system (time division multiple access / time division system) for performing so-called ping-pong transmission. Some methods employ a dual method.

That is, in the case of the TDD system, for example, FIG.
As shown in (1), one channel (frequency) is temporally divided into a transmission slot T and a reception slot R, and the slots T and R are alternately repeated. A time (not shown) is provided. In this case, for example, each of the slots T and R is set to 1 ms, and the guard time is set to several tens of microseconds. And
The mobile phone (slave) performs communication to the base station (master) in the transmission slot T, and receives from the base station in the reception slot R.

In the case of the TDMA / TDD system,
As shown in FIG. 5B, in the communication between one slave unit and the master unit, the transmission slot T and the reception slot R in one channel are used.
Is used only once in several cycles, and the other transmission slot T and reception slot R in the same channel are used for communication between the other handset and the base unit, and a plurality of Are multiplexed so that communication between the communication devices can be performed.
Due to such multiplexing, the frequency band prepared for the cordless telephone is used efficiently.

Next, a conventional configuration of a base unit of a digital cordless telephone device for performing such communication will be described with reference to FIG. In FIG. 6, reference numerals 11 and 12 denote antennas for transmitting and receiving.
One and the other fixed contacts 13a of the changeover switch 13 of the
13b. Then, the first changeover switch 1
The third movable contact 13m is connected to the movable contact 14m of the second changeover switch 14, and one fixed contact 14a of the second changeover switch 14 is connected to the receiver 21.

The receiving unit 21 uses the antenna 11,
A predetermined frequency band is received from the received signal supplied from the 12 side, and the processed received signal is supplied to the modulation / demodulation unit 23 to demodulate the received signal. Then, the demodulated signal is supplied to the communication control unit 24. Further, data on the received field strength (RSSI) at the receiving unit 21 is transmitted to the communication control unit 2.
4

A transmission signal output from the communication control unit 24 is modulated for transmission by the modulation / demodulation unit 23, and the modulated transmission signal is transmitted by the transmission unit 22. Then, the processed transmission signal is supplied to the other fixed contact 14 b of the second changeover switch 14, and the transmission signal is supplied to the antennas 11 and 12 via the changeover switches 14 and 13.

The communication control unit 24 performs various communication controls such as setting of a channel for performing communication with each slave unit and control of transmission / reception timing. Control of the changeover switches 13 and 14 so that the first changeover switch 13 selects an antenna to be transmitted and received, and the second changeover switch 14
Is used to switch between transmission and reception.

The communication control unit 24 includes an ADPC
The M codec unit 25 is connected, and the audio data (ADPCM signal) included in the received signal is converted into an analog audio signal by the ADPCM codec unit 25 and supplied to the line interface unit 26 side. Analog audio signal supplied from
The signal is converted into a PCM signal and supplied to the communication control unit 24.

The line interface unit 26 has a terminal 27 for connecting to a telephone line, and is connected to the telephone office via the terminal 27. Further, a handset 28 and a key input unit 29 are connected to the line interface unit 26, and external and internal calls can be made using a microphone and a speaker in the handset 28, and supplied from the key input unit 29. Control such as a telephone call according to the key operation information performed is performed.

Next, the configuration of a conventional slave unit will be described with reference to FIG. 7, reference numeral 31 denotes an antenna. The antenna 31 is connected to the movable contact 32m of the changeover switch 32. Then, a reception signal obtained at one fixed contact 32a of the changeover switch 32 is supplied to the reception unit 33, and the reception unit 33 performs reception processing of a predetermined frequency band from the reception signal supplied from the antenna 31 side. The modulated reception signal is supplied to the modulation / demodulation unit 35 to demodulate the reception signal. Then, the demodulated signal is supplied to the communication control unit 36.

The transmission signal output from the communication control section 36 is modulated for transmission by the modulation / demodulation section 35, and the modulated transmission signal is transmitted by the transmission section 34. Then, the processed transmission signal is transmitted to the other fixed contact 32b of the changeover switch 14.
And a transmission signal is supplied to the antenna 31 via the changeover switch 32.

The communication control section 36 performs various communication controls such as setting of a communication channel and control of transmission / reception timing, and controls switching of the changeover switch 32 to switch between transmission and reception.

The communication control unit 36 includes an ADPC
An M codec unit 37 is connected, converts audio data (ADPCM signal) included in the received signal into an analog audio signal by the ADPCM codec unit 37, and outputs
And reproduces it, and converts the analog audio signal supplied from the microphone 39 into an ADPCM signal and supplies it to the communication control unit 36.

The ADPCM codec unit 37 has:
The key input unit 41 and the display unit 42 are connected via the man-machine interface unit 40, and the operation information of the key input unit 41 is transmitted to the man-machine interface unit 40, AD.
While being supplied to the communication control unit 36 via the PCM codec unit 37, display information for displaying the communication state and the like on the display unit 42 from the communication control unit 36 is transmitted via the ADPCM codec unit 37 and the man-machine interface unit 40. Supplied.

When making an extension call between the slave unit and the master unit or an outside line call from the slave unit, the slave unit transmits a connection request signal to the master unit to confirm that the master unit has a connection request. After the notification, a process for synchronizing the slave unit and the master unit is performed, and then, using a predetermined slot in the communication channel based on the instruction by the control signal from the master unit, the slave unit and the master unit are connected. Initiate communication for a call between them. When calling a slave from the master, a control signal is transmitted from the master to the slave to cause the slave to be called. For this reason, when each slave unit is in the standby state, only the control signal transmitted from the master unit is intermittently received.

In such a case where communication is performed,
Changeover switch 13 for two antennas 11 and 12 in parent device
Is performed based on the data of the received electric field strength supplied to the communication control unit 24. That is, for example, first, the movable contact 13m of the first change-over switch 13 is connected to the one fixed contact 13a, and the signal received by the antenna 11 is supplied to the receiving unit 21 for receiving processing. And
When the communication control unit 24 determines that the reception electric field strength of the signal transmitted from the slave unit at this time is equal to or higher than a predetermined threshold level sufficient for reception, the transmission and reception by the antenna 11 are executed.

When the communication control unit 24 determines that it is difficult to perform good reception when the reception electric field strength of the signal transmitted from the slave unit is below the threshold level, the first changeover switch 13 is moved. The contact 13m is switched to the other fixed contact 13b, so that the signal received by the antenna 12 is supplied to the receiving unit 21 for receiving processing. When the communication control unit 24 determines that the reception electric field strength of the signal transmitted from the slave unit at this time is equal to or higher than a threshold level sufficient for reception, the antenna 12
To perform transmission and reception.

When the reception electric field intensity at the time of reception using the antenna 12 falls below the threshold level, the antenna 12 is switched to the antenna 11 again.

In this way, the antenna is switched to the antenna 11 or 12 that can perform good reception, and communication of the space diversity system for performing transmission and reception is performed. In this case, the TDMA / TDD to which this cordless telephone applies
In the case of the system and the TDD system, transmission and reception are performed at the same frequency, so if the reception at the master unit can be performed well, the transmission from the master unit can be performed under the same conditions. Only by providing two antennas on the master unit side, favorable spatial diversity communication can be performed in both cases of downlink communication from the master unit and uplink communication to the master unit.

[0024]

However, if two antennas are provided in the base unit for performing such diversity communication, the reception unit 21 and the transmission unit 22 of the base unit are required.
Two antenna changeover switches 13 and 14 are inserted in series between the antennas 11 and 12, and there is a disadvantage that a loss of a transmission signal or a reception signal is large. That is, it is necessary to increase the output of the power amplifier in the transmission unit 22 by an amount corresponding to the insertion loss caused by each of the changeover switches 13 and 14, so that the load on the power amplifier is large and the reception signal level supplied to the reception unit 21 Lower that much,
The receiving ability will be reduced.

Further, when two antennas are provided only in the master unit, only one of the antennas is used when only the control signal is transmitted from the master unit to each slave unit. There was an inability to communicate. In this case, if each slave unit is provided with two antennas,
Diversity communication becomes possible even when the control signal is received on the slave unit side. However, similar to the case of the above-described master unit, antenna switching switches are connected in two stages in series, and this switching is performed. The transmission / reception performance is reduced by the insertion loss of the switch.

Furthermore, if two antennas are provided only in the master unit, diversity communication cannot be performed when a slave unit talks between two slave units. There is a disadvantage that the communication performance at the time is reduced as compared with the case where communication with the master unit is performed.

The present invention has been made in view of these points, and in this kind of cordless telephone device, it is an object of the present invention to enable efficient and efficient diversity communication in any case.

[0028]

SUMMARY OF THE INVENTION The present invention relates to a digital cordless telephone apparatus comprising a master unit and a slave unit, and performing a wireless communication of digital data between the master unit and the slave unit to make a telephone call. only set two transmitting and receiving antenna of the base unit, a single transmitting and receiving antenna of the the one reception-only antenna in the slave unit is provided, the line transmission of the connection request signal between the master unit and the slave unit
Transmission of the connection request signal from the base unit
Select an antenna that can be received well among trusted antennas
And use this connection request signal in the slave unit.
Reception is performed with one transmitting / receiving antenna and one receiving-only antenna.
Using only one of the antennas
That's how it works.

[0029]

Further, the present invention comprises a master unit and a slave unit,
Wireless transmission of digital data is performed between the master unit and the slave unit.
In a digital cordless telephone device that makes a telephone call,
Two transmission / reception antennas are provided on the parent device, and one transmission / reception device is provided on the child device.
Provide a receiving antenna and one receiving-only antenna, and
When transmitting call signals between the handset and the handset,
Good transmission and reception between two transmitting and receiving antennas
And selectively use the antenna that can
Transmission and reception using only one transmission / reception antenna.
That's how it works.

Further, the present invention comprises a master unit and a slave unit,
Wireless transmission of digital data is performed between the master unit and the slave unit.
In a digital cordless telephone device that makes a telephone call,
One transmission / reception antenna and one reception antenna on the base unit
And one slave transceiver and one receiver for the slave unit.
A dedicated antenna is provided, and when transmitting a call signal between the master unit and the slave unit, transmission / reception with the master unit is selectively used from among the two transmission / reception antennas that can receive well. In addition, transmission and reception in the slave unit are performed using only one transmission / reception antenna.

[0032]

[0033]

Further, the present invention comprises a master unit and a slave unit,
Wireless transmission of digital data is performed between the master unit and the slave unit.
In a digital cordless telephone device that makes a telephone call,
Two transmission / reception antennas are provided on the parent device, and one transmission / reception device is
A receiving antenna and one receiving-only antenna are provided, and when the slave unit communicates with the public base station, only one transmitting / receiving antenna is used as the sending / receiving antenna of the slave unit. is there.

[0035]

According to the present invention, two transmission / reception antennas are provided in the parent device, and one transmission / reception antenna and one
By providing the reception-only antenna, diversity communication can be performed by switching the reception antenna to a better one even at the time of reception on the handset side.

According to the present invention, the master unit is provided with one transmission / reception antenna and one reception-only antenna, and the slave unit is provided with one transmission / reception antenna and one reception-only antenna. By switching the receiving antenna to a better one even during reception at the slave unit, diversity communication can be performed, and the configuration of the antenna switch of the master unit and the slave unit can be made the same, and the parts can be shared. Can be achieved.

[0037]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A slave according to an embodiment of the present invention will now be described with reference to FIG.
This will be described with reference to FIG. In FIG. 1, the same reference numerals are given to portions corresponding to FIG. 7 shown as a conventional example, and detailed description thereof will be omitted.

In the present embodiment, the TDMA
This is applied to a digital cordless telephone device of the / TDD system, and is configured as shown in FIG. That is, in FIG. 1, 51 indicates a transmitting / receiving antenna, and 52 indicates a receiving-only antenna. Then, the transmission / reception antenna 51 is connected to the movable contact 53m of the transmission / reception changeover switch 53, and one fixed contact 53a of the transmission / reception changeover switch 53 is connected to one fixed contact 54a of the reception antenna changeover switch 54. Then, the reception antenna 52 is connected to the other fixed contact 54b of the reception antenna changeover switch 54. Then, a reception signal obtained at the movable contact 54m of the reception antenna changeover switch 54 is supplied to the reception unit 33. The transmission signal output from the transmission unit 34 is supplied to the other fixed contact 53 b of the transmission / reception switch 53.

The switching between the transmission / reception changeover switch 53 and the reception antenna changeover switch 54 is controlled by the communication control section 36. In this case, the communication control unit 36 of the present example is supplied with data relating to the reception electric field intensity at the reception unit 33. When the reception electric field intensity falls below a predetermined threshold level, the reception antenna switching is performed. The switch 54 is switched. The switching of the transmission / reception changeover switch 53 is performed in conjunction with the switching between transmission and reception by the slave unit.

The other parts are configured in the same manner as the slave unit shown in FIG. 7 as a conventional example.

Next, a description will be given of a communication state using the slave unit configured as described above. Here, it is assumed that communication is performed with the master unit shown in FIG. 6 described in the conventional example. At this time, two transmission / reception antennas 11 and 12 are prepared for the parent device, and one transmission / reception antenna 51 and one reception-only antenna 52 are prepared for the child device.

First, it is assumed that the slave unit is in a standby state for intermittently receiving a control signal transmitted from the master unit. At this time, only one of the two transmitting / receiving antennas 11 and 12 is used as the antenna used for transmitting the control signal from the master unit, and the changeover switch 13 is fixed. Then, the control signal transmitted from the antenna 11 or 12 is intermittently received by the slave unit.
At this time, the communication control unit 36 determines the reception electric field strength of the control signal, and when it is determined that the reception electric field strength is equal to or lower than the predetermined threshold level, the reception antenna changeover switch 54 is switched. Therefore, by using the changeover switch 54, reception using the transmission / reception antenna 51 and reception using the reception-only antenna 52 are selectively performed,
Diversity communication is performed in which a person who can perform good reception is selected. It is to be noted that the transmission / reception changeover switch 53 is always set to the movable contact 53 at the timing of receiving the control signal.
m is connected to one fixed contact 53a.

Next, a case will be described in which a calling operation is performed on the slave unit and a connection request signal is transmitted from the slave unit to the master unit. At this time, under the control of the communication control unit 36, the movable contact 54m of the reception antenna changeover switch 54 of the slave unit is connected to one fixed contact 54a, and the antenna used for reception is fixed to the transmission / reception antenna 51. When the connection control signal is transmitted from the slave unit, the movable contact 53m of the transmission / reception switch 53 is set to the other fixed contact 53b.
Side, and transmits a connection request signal using the transmitting / receiving antenna 51.

Receiving the connection request signal on the master unit side is performed by selectively using the two transmitting / receiving antennas 11 and 12 and using the antenna that can receive signals favorably. Diversity communication is performed by switching the antenna on the side. In this case, the transmission of the control signal including the data for permitting the connection, which is performed subsequent to the reception of the connection request signal by the master unit, is performed by the antenna 1 that has successfully received the connection request signal.
This is performed using 1 or 12, and both communication between the master unit and the slave unit is performed in a diversity manner.

Next, when the slave unit receives a control signal in a standby state and talks with the master unit (this call includes a case where the slave unit communicates with an outside line via the master unit), or A description will be given of a case where a call is made based on the control of the master unit after the connection request signal is transmitted from the base unit. When a call is made with the master unit, the movable contact 54m of the reception antenna changeover switch 54 of the slave unit is kept connected to one fixed contact 54a, and transmission and reception are performed using only the transmission / reception antenna 51. Is performed in a time-division manner, and transmission and reception on the communication channel are performed alternately. Then, as in the related art, the two antennas 11 and 12 are switched based on the received electric field strength, and diversity communication for performing transmission and reception is performed using the antenna 11 or 12 that can receive signals satisfactorily.

Next, a case in which a call is made between two slave units will be described. In this case, first, connection control is performed between the calling handset and the called handset, and then communication between the handset units is started by transmission / reception using a communication channel. In each state from the time to the time when a call is made, at the timing of receiving by each slave unit, the receiving antenna changeover switch 54 is switched to the one capable of good reception based on the received electric field strength, and the antenna used for reception is set to the antenna. Diversity communication for switching between 51 and 52 is performed. However, the transmission and reception antenna 5
Since only one can be used, the antenna 5
Use 1.

As described above, by using the slave unit of this embodiment,
In any case, good diversity communication is performed.
That is, when receiving a signal from the master unit or the like, the antenna used for reception can be switched by switching the reception antenna changeover switch 54, and the reception of the diversity system for selecting the reception antenna in good condition can be performed. In particular, diversity communication is performed even during standby when intermittently receiving a control signal transmitted from the master unit or when performing a call between slave units, and good transmission with reduced reception errors and the like due to fading can be performed. Become like

Since the reception-only antenna 52 is connected to the reception section 33 through only one antenna changeover switch 54, the antenna changeover switch is used at least when receiving using this antenna 52. , The reception loss can be reduced, and good reception characteristics can be ensured compared to a case where two transmitting / receiving antennas are provided in the slave unit. Can be reduced.

Next, the configuration of the base unit of the cordless telephone of this embodiment will be described with reference to FIG. In FIG. 2, portions corresponding to FIG. 6 shown as a conventional example are denoted by the same reference numerals, and detailed description thereof will be omitted.

In this embodiment, the configuration of the antenna switch is the same as that of the above-mentioned slave unit, and is configured as shown in FIG. That is, in FIG. 2, 61 indicates a transmitting / receiving antenna, and 62 indicates a receiving-only antenna. And
The transmission / reception antenna 61 is connected to the movable contact 63m of the transmission / reception changeover switch 63, and one fixed contact 63a of the transmission / reception changeover switch 63 is connected to the reception antenna changeover switch 6
4 is connected to one of the fixed contacts 64a. Then, the reception antenna 62 is connected to the other fixed contact 64 b of the reception antenna changeover switch 64. Then, a reception signal obtained at the movable contact 64 m of the reception antenna switch 64 is supplied to the reception unit 21. The transmission signal output from the transmission unit 22 is supplied to the other fixed contact 63 b of the transmission / reception switch 63.

The switching between the transmission / reception changeover switch 63 and the reception antenna changeover switch 64 is controlled by the communication control section 24. In this case, the communication control unit 24 of the present example is supplied with data relating to the reception electric field intensity at the reception unit 21. When the reception electric field intensity falls below a predetermined threshold level, the reception antenna switching is performed. The switch 64 is switched. The switching of the transmission / reception changeover switch 63 is performed in conjunction with the switching between transmission and reception at the master unit.

Other parts are configured in the same manner as the parent machine shown in FIG. 6 as a conventional example.

Next, a description will be given of a communication state of a cordless telephone using the master unit of the example shown in FIG. 2 and the slave unit shown in FIG. At this time, one transmission / reception antenna 61 and one reception-only antenna 62 are prepared for the parent device, and one transmission / reception antenna 51 and one reception-only antenna 52 are prepared for the child device. Will be.

First, it is assumed that the slave unit is in a standby state for intermittently receiving a control signal transmitted from the master unit. At this time, the transmitting / receiving antenna 61 is the only antenna used for transmitting the control signal from the master unit. Then, the control signal transmitted from the antenna 61 is intermittently received by the slave unit.
Determine the received signal strength of the control signal in the, when it is determined that the received signal strength is below a predetermined threshold level,
The receiving antenna switch 54 is switched. Therefore, by switching the changeover switch 54, reception using the transmission / reception antenna 51 and reception using the reception-only antenna 52 are selectively performed, and diversity communication is performed in which the one that can perform good reception is selected.

Next, a case will be described in which a calling operation is performed on the slave unit side and a connection request signal is transmitted from the slave unit to the master unit. At this time, under the control of the communication control unit 36, the movable contact 54m of the reception antenna changeover switch 54 of the slave unit is connected to one fixed contact 54a, and the antenna used for reception is fixed to the transmission / reception antenna 51. When the connection control signal is transmitted from the slave unit, the movable contact 53m of the transmission / reception switch 53 is set to the other fixed contact 53b.
Side, and transmits a connection request signal using the transmitting / receiving antenna 51.

By receiving the connection request signal on the master unit side, the reception antenna changeover switch 64 is switched so that the transmission / reception antenna 61 and the reception-only antenna 62 can be selectively used to receive the connection request signal well. The diversity communication is performed by switching the antenna on the master unit side using the other antenna. However, the transmission of the control signal including the data permitting the connection to be performed subsequent to the reception of the connection request signal by the master unit uses the transmission / reception antenna 61 regardless of which antenna receives the connection request signal. Do.

Next, when the slave unit receives a control signal in a standby state and performs a call with the master unit (this call includes a case where the slave unit communicates with an outside line via the master unit), or A description will be given of a case where a call is made based on the control of the master unit after the connection request signal is transmitted from the base unit. When a call is made with the master unit, the reception antenna changeover switch 54 of the slave unit is switched to selectively use the transmission / reception antenna 51 and the reception-only antenna 52, and use the antenna that can receive signals satisfactorily. To perform diversity communication by switching the receiving antenna. And on the parent machine side,
The transmission / reception antenna 61 and the reception-only antenna 62 are selectively used to perform the diversity communication by switching the reception antennas, using the antenna that can receive signals favorably.

In this way, at the time of a telephone call, the processing for switching the receiving antennas of both the master unit and the slave unit to the one that can receive signals satisfactorily is performed, thereby realizing bidirectional diversity communication.

As described above, even when the master unit and the slave unit of the present embodiment are used in combination, good diversity communication is performed in any case, and good transmission in which reception errors and the like due to fading are reduced is enabled. Become. In this case, the configuration of the parent device's antenna switching device (switches 63 and 64) and the configuration of the child device's antenna switching device (switches 53 and 54) are the same. The switch can be shared, and the manufacturing cost of the cordless telephone can be reduced.

Further, in this example, since the receiving-only antenna 62 is connected to the receiving section 21 via only one antenna change-over switch 64 on the master unit side, reception is performed using at least this antenna 62. In this case, reception can be performed in a state where the insertion loss of the received signal by the antenna changeover switch is small, and good reception characteristics are ensured as compared with the case where two transmitting / receiving antennas are provided in the master unit, and the received signal is accordingly reduced. Can reduce the burden on the power amplifier that processes

The above-described antenna switching state during communication is based on the use of a base unit and a child unit combined as a cordless telephone, and a large number of public base stations installed outdoors or the like are used as base units. When used as a so-called personal handy phone that performs communication between this public base station and a slave unit, it is assumed that diversity communication is performed using a plurality of antennas on the base station side. You. For this reason, when the personal handy phone is used, the mobile unit maintains the state in which the movable contact 54m of the receiving antenna changeover switch 54 is connected to one fixed contact 54a, and uses only the transmitting / receiving antenna 51. Good communication can be performed by receiving a control signal or performing communication on a communication channel.

[0062]

According to the present invention, by providing two transmission / reception antennas in the master unit and providing one transmission / reception antenna and one reception-only antenna in the slave unit, the handset side can be provided. Even at the time of reception, diversity communication in which the receiving antenna is switched to the better one for reception can be performed, and good reception performance is ensured.

[0063]

In this case, when transmitting the connection request signal between the parent device and the child device, the transmission of the connection request signal from the parent device is satisfactorily received by the two transmitting / receiving antennas. In addition to selectively using antennas that can be used, the slave unit can receive the connection request signal by using only one of the one transmitting and receiving antenna and the one receiving-only antenna. By performing the connection, it is possible to transmit the connection request signal by the excellent diversity communication only by controlling the switching of the antenna on the parent device side.

In this case, when transmitting a call signal between the master unit and the slave unit, transmission / reception at the master unit is selectively performed by selecting an antenna which can be satisfactorily received from two transmission / reception antennas. In addition to the use of the transmission and reception in the slave unit, by using only one transmission and reception antenna,
In the two-way transmission of a call signal, diversity communication can be favorably performed only by controlling the antenna switching on the master unit side.

[0066]

According to the present invention, the master unit is provided with one transmission / reception antenna and one reception-only antenna, and the slave unit is provided with one transmission / reception antenna and one reception-only antenna. By switching the receiving antenna to a better one even during reception at the slave unit, diversity communication can be performed, and the configuration of the antenna switch of the master unit and the slave unit can be made the same, and the parts can be shared. The digital cordless telephone can be configured at low cost.

In these cases, when the slave unit is made to communicate with the public base station, only one transmission / reception antenna is used as the transmission / reception antenna of the slave unit. Diversity communication can be performed stably by switching antennas on the station side.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a child device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a parent device according to one embodiment.

FIG. 3 is an explanatory diagram showing a control signal according to one embodiment.

FIG. 4 is a configuration diagram illustrating a system configuration of the cordless telephone device.

FIG. 5 is a configuration diagram showing a communication system.

FIG. 6 is a configuration diagram of a base unit of a conventional digital cordless telephone.

FIG. 7 is a configuration diagram of a slave unit of a conventional digital cordless telephone.

[Explanation of symbols]

 51, 61 transmit / receive antenna 52, 62 receive-only antenna 53, 63 transmit / receive switch 54, 64 receive antenna switch

Claims (4)

(57) [Claims] 1. A digital cordless telephone device comprising a master unit and a slave unit, and performing a wireless communication of digital data between the master unit and the slave unit to make a telephone call. only set the use antenna, only <br/> set and one transmitting and receiving antenna and one receive-only antenna to said child machine, when performing the transmission of the connection request signal between the master unit and the slave unit, The transmission of the connection request signal from the master unit is for two
Of the antennas, select the antenna that can receive well
And the reception of the connection request signal by the slave unit is performed by one transmission / reception address.
Any one of antenna and one receiving only antenna
Digital code using only antennas
Dress phone equipment. 2. The apparatus according to claim 1, wherein said master unit and said child unit are comprised.
Wireless communication of digital data between the
In the digital cordless telephone device, the base unit is provided with two transmitting / receiving antennas, and
One transmit / receive antenna and one receive-only antenna
When transmitting a call signal between the master unit and the slave unit, transmission and reception by the master unit are performed by two of the two transmitting / receiving antennas.
Selective use of antennas that can receive
, The transmission and reception of the child machine, using only one transmitting and receiving antenna of
A digital cordless telephone device designed to be used. 3. A mobile telephone comprising a master unit and a slave unit.
Wireless communication of digital data between the
In the digital cordless telephone device, the base unit is provided with two transmitting / receiving antennas, and
One transmit / receive antenna and one receive-only antenna
To communicate with the base station for public use,
Only one transmitting and receiving antenna is used as a trust antenna.
Digital cordless telephone device for use. 4. A base unit and a child unit.
Wireless communication of digital data between the
In the digital cordless telephone device, one transmitting / receiving antenna and one receiving-only
Antenna and one transceiver antenna for the slave unit.
When a single reception-only antenna is provided to allow a slave unit to communicate with a public base station, transmission and reception of the slave unit
Only one transmitting and receiving antenna is used as a trust antenna.
Digital cordless telephone device for use.