JPH1098429A - Digital cordless telephone system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the power consumption in a public base station where a plurality of circuits of local oscillators as a synthesizer are mounted, each output of each local oscillator is assigned individually to each of a plurality of slots for transmission and reception to make time division multiplex communication with each cordless slave set. SOLUTION: A 1st local oscillator 19A in 1st and 2nd local oscillators is provided with a power switch 19F that is set in an operation state at all times and supplies power to the 2nd local oscillator 19B, and a control section 26 turns on the power switch in the case that a plurality of cordless slave sets make radio communication via a base station to set the local oscillator 19F into the operating state. As a result, only when one cordless slave set in the operating state is in use, all local oscillators are not in the operating state and then the power consumption of the base station is reduced.

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 system such as a PHS (Personal Handy Phone System) comprising a base station and a cordless handset wirelessly connected to the base station.

[0002]

2. Description of the Related Art A cordless handset constituting this kind of digital cordless telephone system is wirelessly connected to a public base station when used for public use, and external lines are transmitted / received via the public base station. On the other hand, when the cordless handset is used for private use, it is wirelessly connected to a base unit provided in a home or an office, for example, and outgoing / incoming / outgoing calls are performed via the base unit.

In a public base station wirelessly connected to such a cordless handset, the radio section is divided into four transmission time slots and four reception time slots in order to enable simultaneous communication with a plurality of cordless handset. It divides and performs time division multiplex communication with each cordless handset via each time slot. In this case, two local oscillators are mounted as synthesizers so that channel switching (that is, frequency switching) can be performed for each time slot.

[0004]

In such a public base station, if there is at least one mobile station (that is, a cordless handset) that has entered the service area and is in a standby state, or has a communication state in the service area. In the case where even one cordless handset exists, the local oscillator for two circuits is operated, so that the power consumption of the apparatus increases. Accordingly, the present invention provides a time division multiplex communication with each cordless handset by mounting a plurality of local oscillators as a synthesizer of a radio unit, and allocating each output of each local oscillator to each of a plurality of transmission and reception time slots. It is intended to reduce the power consumption of a public base station that performs the above.

[0005]

SUMMARY OF THE INVENTION In order to solve such a problem, the present invention provides a cordless slave unit which is time-divided into a plurality of time slots as transmission and reception timings. In contrast, each base station has at least a first and a second local oscillator assigned to each output, and comprises a base station that performs digital communication of radio signals with the cordless slave through one of transmission and reception time slots. In a digital cordless telephone system, a base station includes a power supply unit for supplying power to a local oscillator, and a power supply unit for setting all local oscillators to an operation state when a plurality of cordless handsets perform wireless communication via the base station. And control means for controlling the Therefore, when a plurality of cordless handsets perform wireless communication via the base station, all the local oscillators are set to the operating state. In addition, one of the first and second local oscillators is always supplied with power, and a power switch for supplying power to the other of the first and second local oscillators is provided. The controller is provided as the power supply unit, and the control unit turns on a power switch to bring all the local oscillators into operation when a plurality of cordless handsets perform wireless communication via the base station.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a digital cordless telephone system according to the present invention, and in particular, is a block diagram showing a configuration of a public base station (hereinafter, base station) to which a cordless cordless handset used in a PHS or the like is wirelessly connected. In the figure, 11 is an antenna switch, 12 is a low noise amplifier as a receiving amplifier, 13 and 14 are first and second mixers as receiving mixers, and 15 is an intermediate frequency amplifier. Also,
16 is a quadrature modulator for modulating the quadrature signals I and Q, 17 is a transmission mixer, 18 is a transmission amplifier, and 19 is a synthesizer for controlling the frequency of the transmission and reception signals.

The synthesizer section 19 includes a first local oscillator 19A, a second local oscillator 19B, and a second mixer 14
And a third local oscillator 19C that outputs a predetermined frequency signal to the quadrature modulator 16; a first local oscillator 19A;
A switch 19D for switching the local oscillator 19B;
The frequency signal output of either one of the first local oscillator 19A and the second local oscillator 19B is output to the first mixer 1
3 and a switch 19E provided to the transmission mixer 17;
And a power switch 19F for switching power supply / non-power supply to the local oscillator 19. The above-described units constitute the radio unit 1 of the base station.

On the other hand, the modulation / demodulation control unit 2 of the base station includes:
Modem demodulator 21, channel codecs 22, 24,
It comprises a voice codec 23, a modem modulator 25, and a control unit 26 for controlling these. Here, a two-wire / four-wire conversion unit 27 is connected to the audio codec 23,
The base station is connected to a switching network (not shown) via a wired line L connected to the end of the two-wire / four-wire conversion unit 27. A predetermined voltage V is supplied from the power supply unit 30 to each unit of the radio unit 1 of the base station and each unit of the modulation / demodulation control unit 2 (excluding the second local oscillator 19B).

[0009] In the base station configured as described above,
Frequency from each cordless handset via antenna AT
When a wireless signal in the 9 GHz band is input to the wireless unit 1, the wireless unit 1 amplifies the wireless signal with the low-frequency amplifier 12, and further amplifies the amplified signal with the first mixer 13 using the first local oscillator 19A.
The signal is mixed with, for example, a 1.6 GHz band signal from any of the second local oscillators 19 B and output to the second mixer 14 as a 240 MHz band signal. In the second mixer 14, this input signal is mixed with, for example, a 230 MHz frequency signal from the third local oscillator 19C and output to the intermediate frequency amplifier 15 as a 10.8 MHz frequency signal. Vessel 21
Output to The signal in the frequency band of 10.8 MHz is demodulated by the modem demodulator 21, and the demodulated signal of the designated slot is extracted by the channel codec 22. The data is sent to the exchange via the wired line L via the unit 27.

On the other hand, the audio signal from the wired line L passing through the two-wire / four-wire converter 27 is converted into a digital signal by the audio codec 23, and the signal of the designated slot is extracted by the channel codec 24. Modem modulator 2
5 and is sent to the quadrature modulator 16 as quadrature signals I and Q. In the quadrature modulator 16, this frequency 10.8M
The input signals I and Q in the Hz band are modulated based on the signal in the 230 MHz band from the third local oscillator 19C, and the frequency
The signal is output to the transmission mixer 17 as a signal in the 0 MHz band. The transmission mixer 17 mixes this signal with a 1.6 GHz-band signal from any one of the first local oscillator 19A and the second local oscillator 19B to obtain a frequency of 1.9.
The signal is output to the transmission amplifier 18 as a signal in the GHz band, amplified, and further transmitted as a radio signal to the cordless slave via the antenna switch 11 and the antenna AT.

In such a base station, in order to enable simultaneous multiplex communication with a plurality of cordless handsets, the radio unit 1 is divided into four transmission time slots and four reception time slots, and And time division multiplex communication. For this reason, since it is necessary to switch the frequency for each time slot, a first local oscillator 19A and a second local oscillator 19B are provided in the radio unit 1, and as shown in FIG. First local oscillator 19A
The control unit 26 controls the switches 19D and 19E so as to assign any one of the first local oscillator 19B and the second local oscillator 19B.

That is, as shown in FIG.
The frame is divided into four transmission time slots T1 to T4, 4
In the case where the reception time slot is divided into four reception time slots R1 to R4 and an outside line call is simultaneously performed by four cordless handsets, the slot T
1, R1 is, for example, a transmission / reception slot for cordless handset A,
Slots T2 and R2 are, for example, transmission / reception slots for cordless handset B, slots T3, R3 are transmission / reception slots for cordless handset C, for example, and slots T4, R4 are transmission / reception slots for cordless handset C, for example. Here, when allocating each output of the first local oscillator 19A and the second local oscillator 19B to each time slot, the control unit 26 operates as shown in FIG.
As shown in (b), slots T1, T3, R1, R3
, The output of the first local oscillator 19A is allocated, and the slots T2, T4, R2, and R4 are allocated the output of the second local oscillator 19B.

Then, the first local oscillator 19A is always supplied with power from the power supply unit 30 so that the first local oscillator 19A operates.
The second local oscillator 19B is configured such that the power switch 19F is turned on as needed under the control of the control unit 26 to supply power from the power supply unit 30 and operate. That is, when the first cordless handset first enters the area of the base station and an external call is made, slots T1 and R1 are allocated as time slots, and a voice signal or the like is output by the output of the first local oscillator 19A. Is transmitted. Under these circumstances,
When the second cordless handset enters the area within the base station and performs external line communication or the like, the control unit 26 allocates slots T3 and R3 as time slots and outputs audio signals and the like by the output of the first local oscillator 19A. Perform transmission.

At this time, in order to detect whether or not the third cordless handset comes within the range of the base station,
The control unit 26 turns on the power switch 19F and
The power from 0 is supplied to the second local oscillator 19B to be in an operating state, and the output of the second local oscillator 19B detects the movement of the third cordless handset into the service area via the slots T2 and R2.

In this way, when the first and second cordless handsets are in external line communication, respectively, slots T1, T3, R
When it is detected that the third cordless handset has entered the area of the base station while the R1, R3 is being used, and the cordless handset performs an outside call, the control unit 26
Transmits the audio signal and the like relating to the third cordless handset by the output of the second local oscillator 19B via the slots T2 and R2. Thereafter, when the fourth cordless handset enters the area within the base station and an external call is performed, the control unit 26 controls the second local oscillator 19 via the slots T4 and R4.
With the output of B, the audio signal and the like relating to the fourth cordless handset are transmitted.

In this way, when a plurality of cordless handsets are simultaneously performing an outside call or the like, all cordless handsets are terminated, or only one cordless handset continues talking and all other When the cordless cordless handset is terminated, the control unit 26 turns off the power switch 19F and stops the power supply to the second local oscillator 19B. Here, when the other cordless handset terminates the call, if one cordless handset is continuing the call by the output of the second local oscillator 19B via, for example, the slots T2 and R4, the slot is set to the slots T1 and R1. Then, the power supply to the second local oscillator 19B is stopped after using the output of the first local oscillator 19A.

In this case, a switch for controlling the power supply to the first local oscillator 19A is separately provided, and the control unit 26 turns off this switch, thereby making the first local oscillator 19A inoperative and causing the second local oscillator 19A to operate. The communication may be continued by the output of the oscillator 19B. in this way,
When a plurality of local oscillators are mounted as a synthesizer of the radio unit 1 and time-division multiplex communication is performed with each cordless slave unit by allocating the output of each local oscillator to each of the plurality of transmission and reception time slots and allocating the outputs to the respective units. Power is supplied to each local oscillator only when the cordless cordless handset performs a call or the like at the same time, so that only one cordless cordless handset in a communication state exists within the range of the base station. In such a case, all the local oscillators are not in the operating state, so that the power consumption of the base station can be reduced.

FIG. 2 is a diagram showing a configuration of a cordless handset that performs radio communication with the base station shown in FIG. The configuration of the cordless handset is substantially the same as the configuration of the base station, except that one of the transmission slots T1 to T4 has one transmission slot,
Since communication with the base station is performed using one of the reception slots R1 to R4, the configuration of the radio unit 1 includes, for example, the second local oscillator 19B among the first and second local oscillators 19A and 19B. Becomes unnecessary. In addition, a receiver 31 and a microphone 32 are connected to the audio codec 23, and a keyboard 33 such as a dial key is connected to the control unit 28.

In this embodiment, the base station has four transmission slots T1 to T4 as transmission timings and four reception slots R1 as reception timings.
To R4, and the first and second local oscillators 19A,
Although an example has been described in which each output of 19B is assigned to each slot to perform time-division multiplexing wireless communication with each cordless handset, the present invention is not limited to this, and has an arbitrary number of time slots, and The present invention is also applicable to a system in which a plurality of local oscillators are allocated to each slot.

[0020]

As described above, according to the present invention, the power supply means for the local oscillator is provided to the base station, and all the local oscillators are provided when a plurality of cordless handsets perform radio communication via the base station. And control means for controlling the power supply means so as to bring the local oscillator into an operating state, and all the local oscillators are brought into the operating state only when a plurality of cordless handsets perform wireless communication via the base station. If, for example, there is only one cordless handset in the communication state, not all the local oscillators will be in the operating state, so that the power consumption of the base station can be reduced. In addition, a power switch that constantly supplies power to one of the first and second local oscillators and supplies power to the other of the first and second local oscillators Is provided as the power supply means, and the control means turns on the power switch to activate all the local oscillators when a plurality of cordless handsets perform wireless communication via the base station. When the power supply of the oscillator is controlled, the power supply can be controlled by one power switch, so that the apparatus can be configured at low cost.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a digital cordless telephone system according to the present invention.

FIG. 2 is a block diagram showing a configuration of a cordless handset constituting the system.

FIG. 3 is a diagram showing a state of allocation of first and second local oscillators to each time slot in a base station constituting the system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Radio | wireless part, 2 ... Modulation / demodulation control part, 12 ... Low noise amplifier,
13 ... first mixer, 14 ... second mixer, 15 ... intermediate frequency amplifier, 16 ... quadrature modulator, 17 ... transmission mixer, 18 ...
Transmission amplifier, 19: synthesizer section, 19A: first local oscillator, 19B: second local oscillator, 19C: third local oscillator, 19D, 19E: switch, 19F: power switch, 21: modem demodulator, 25: modem modulation Vessel, 26,
28: control unit, 30: power supply unit, AT: antenna, L: wired line.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takanori Horiguchi 2-3-2 Shimomeguro, Meguro-ku, Tokyo Inside Tamura Electric Works, Ltd.

Claims (2)

[Claims] 1. A cordless slave unit, each of which is time-divided into a plurality of time slots as respective transmission and reception timings, and has respective outputs for transmitting a radio signal. In a digital cordless telephone system comprising at least a first and a second local oscillator assigned to each of the cordless handsets and a base station performing digital communication of radio signals with the cordless cordless handset via any of the transmission and reception time slots. The base station, a power supply unit to a local oscillator, and the power supply unit to control all the local oscillators to an operating state when a plurality of cordless handsets perform wireless communication via the base station. A digital cordless telephone system, comprising: 2. The local oscillator according to claim 1, wherein one of the first and second local oscillators is always supplied with power and the other one of the first and second local oscillators is provided. A power switch that supplies power to the power supply unit, the control unit turns on the power switch when a plurality of cordless handsets perform wireless communication via the base station, and turns on all local oscillators. A digital cordless telephone system characterized by being put into an operating state.