JP3498282B2 - Connection device for digital cordless telephone equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the digital cordless telephone system that adopts a distribution processing method by obtaining a synchronizing signal from a frame signal of outgoing bus data so as to eliminate the need for a leased line for the synchronizing signal. SOLUTION: The digital cordless telephone system is provided with plurality of connectors connecting to an extension bus from a home telephone set or a key telephone set and plurality of slave sets connecting to the connectors through radio channels adopting the TDMA/TDD system. In this case, each connector for the digital cordless telephone system is provided with a means that generates a reference clock and a reference timing from a frame signal of outgoing bus data and specific data sent for a prescribed period from the master set through the extension buses so that the connectors conduct transmission reception slot synchronization without a phase deviation.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plurality of connecting devices connected to an extension bus from a main unit of a home telephone or a key telephone device, and these connecting devices and TDMA / TDD.
The present invention relates to a connection device in a digital cordless telephone device including a plurality of slave units connected by a wireless line using a system (time division multiple access time division two-way communication system). 2. Description of the Related Art Conventionally, in a digital cordless telephone apparatus, when a plurality of slave units are used at the same time, the following two systems have been used. By controlling the frequency and the transmission / reception slot by the control unit of the main device, centralized control is performed so as not to cause interference in the wireless transmission path of each connection device. Alternatively, there is a method in which transmission / reception slots are asynchronously distributed between connected devices regardless of radio wave interference. [0003] However, in the former centralized control method, the load on the control unit of the main unit is large, and complicated control means is required. For example, when a plurality of connecting devices are connected to the main device, the main device and each connecting device are connected by a dedicated line for synchronization separately from the extension bus. Also, in the latter conventional distributed processing method, radio interference between the connected devices occurs. Therefore, the number of connected devices in one digital cordless telephone device is limited in consideration of the transmission / reception characteristics of the radio unit with respect to the radio interference. It could only accommodate about a unit. An object of the present invention is to obtain a synchronization signal from a multi-frame signal of downlink bus data, thereby eliminating the need for a dedicated line for synchronization, and at the same time, using a distributed cordless digital cordless system controlled by a connection device connected to an extension bus. Telephone equipment. The present invention has the following configuration to achieve the above object. A digital cordless telephone including a plurality of connection devices connected to an extension bus from a main device of a home telephone or a key telephone device, and a plurality of slave units connected to these connection devices via a wireless line using a TDMA / TDD system. In the device, a multi-frame clock from a multi-frame signal of downlink bus data transmitted from the main device through the extension bus, and a means for generating a basic frame signal, reference clock generating means generated by the basic frame signal, After receiving the reference clock generation means receiving the reference clock and generating the reference timing, and receiving the data included in the multi-frame signal of the downlink bus data and activating the slot synchronization between the connection devices transmitted at a constant period, The means for generating the reference timing with the multi-frame clock is Ttoshi connecting device of a digital cordless telephone apparatus and performs no transmission and reception slot synchronization of phase shift in only the connection device side among the connected devices. FIG. 1 is a diagram showing a TDMA / TDD frame composed of transmission / reception slots according to an embodiment of the present invention. FIG. 2 (1) is a diagram showing a basic frame × X coming from a reception line of an extension bus. FIG. 2 (2) is a diagram showing a multi-frame signal composed of N signals, FIG. 2 (2) is a diagram extracting a multi-frame clock MFCK from the multi-frame signal, and FIG. 2 (3) is a basic frame signal extracted from the multi-frame signal. FIG.
FIG. 3 is a configuration diagram of a home telephone using the digital cordless telephone device of the present invention. FIG. 4 is a block diagram of the connection device. FIG. 5 is a configuration diagram of a home telephone using a conventional digital cordless telephone device. 1 is a main device, 2 is a connection device (CS1 to L), 3 is an antenna, and 4 is a slave (PS). 10 is a telephone exchange, 11 is an IS
A DN line or a telephone line, 12 is an extension bus, 14 is a telephone connected to the extension bus, 20 is a digital cordless telephone device composed of a part of the main device 1, a connection device 2 and a group of 4 slave units. 21 is an extension bus connector, 23 is a bus data transmission / reception unit, 24 is a phase corrector, 25 is a baseband LSI, and 26 is an ADPCM in the baseband LSI 25.
-CODEC, 27 is a TDMA / TDD processing unit, 28 is a π / 4 QPSK modem, 29 is a radio unit, 30 is a bus,
1 is a CPU, 32 is a reference clock generator, 33 is a transmission / reception slot timing and TDMA
A reference timing generator for generating the synchronization timing of the / TDD frame, a construction switch for setting the number of the connection device, a memory, an ID-ROM for storing the CS-ID of the connection device , 37 are power supplies. The TDMA / TDD frame shown in FIG. 1 is 5 mS, and is composed of 4 slots for transmission and 4 slots for reception. In principle, the connection device 2 and the slave unit 4 can use the same carrier wave and simultaneously perform four conversations. I do. 101 is the main device, 10
2 is a connection device (CS11, 12, 13, ...), 10
Reference numeral 3 denotes a dedicated synchronization line, and reference numeral 200 denotes a digital cordless telephone device. The reference clock in claim 1 is a 19.2 MHz clock transmitted from the reference clock generation means (the reference clock generation unit 32 in FIG. 4). The reference timing in claim 1 indicates “transmission / reception slot timing” of 625 μS and “TDMA / TDD frame timing” of 5 mS. First, the configuration of a conventional home telephone is shown in FIG.
It will be described based on. The main device 101 accommodates an ISDN line (or a telephone line, the same applies hereinafter) 11 from the central office exchange 10. The connection device 102 and the telephone 14 are connected to the main device 101 through the extension bus 12. In addition, a two-line dedicated synchronization line 103 for designating an individual transmission / reception slot position for each connection device 102 so that transmission / reception slots of each connection device 102 do not overlap each other is connected to the main device 101.
And each connection device 102 (CS11, 12, 13,
...). Under the control of the main device 101, the slave unit 4 sends a call to the ISDN line via the connection device 102 connected via a wireless line and receives an incoming call from the ISDN line. The conventional main unit 101 is connected to a dedicated line 103 connected to the
The synchronization timing of 5 ms of the A / TDD frame was supplied. Each connecting device 102 synchronizes the TDMA / TDD frame with the transmission / reception slot. Next, the configuration of a home telephone according to the present invention will be described with reference to FIG. Main unit 1 is central office exchange 1
ISDN line from 0 (or telephone line, same hereafter) 11
Is housed. The connection device 2 and the telephone set 14 are connected to the main device 1 via an extension bus 12. Under the control of the main unit 1, the slave unit 4 sends a call to the ISDN line via the connection device 2 connected by a wireless line, and receives an incoming call from the ISDN line. A portion of the connection device 2, the slave 4, and the main device 1, such as control of a wireless line, that is, a portion excluding control of a telephone or the like is defined as a digital cordless telephone device 20. Next, the operation of the connection device 2 of the present invention shown in FIGS. 3 and 4 will be described with reference to various signals shown in FIGS. Various signals are transmitted from the main device 1 to the connection device 2 through the extension bus 12. These signals are configured in a multi-frame format as shown in FIG. The multi-frame is composed of N basic frames each consisting of frame number data, B-channel data corresponding to each connection device, D-channel data for control, and the like. FIG. 2 supplied from the main device 1 to each connection device 2 via the extension bus 12
The multi-frame signal of (1) reaches the bus data transmitting / receiving unit 23 through the bus connector 21. The bus data transmission / reception unit 23 converts the input multi-frame signal
The multi-frame clock MFCK shown in (2) is generated and output to the reference timing generator 33. FIG.
An 8 kHz basic frame signal shown in (3) is generated and output to the reference clock generator 32 and the phase corrector 24. The reference clock generating section 32 is a PLL circuit, and is configured to adjust the 8 kHz used as a PCM synchronization signal between the baseband LSI 25 and the phase corrector 24 to the basic frame signal 8 kHz from the bus data transmitting / receiving section 23. The oscillation of the clock 19.2 MHz is controlled. In the baseband LSI 25, the reference clock 19.2
After receiving the supply of MHz, the frequency is divided to 8 kHz and returned to the reference clock generator 32. Reference timing generator 3
3, the frequency of the reference clock 19.2 MHz input from the reference clock generator 32 is divided, and the frequency is divided by the TDMA / TDD processor 2.
The transmission / reception slot timing of 625 μS, which is the synchronization signal shown in FIG.
5mS TDMA / TDD frame timing by CPU
31. The control data on the multiframe from the extension bus 12 (indicated by D (N-1) in FIG.
Output to the bus 30 toward U31. The CPU 31 performs various controls based on the received control data and also controls transmission of control data transmitted from the own connection device 2 to the main device 1. In addition, the Bch data (voice data or data for data communication) in the multi-frame is sent from the bus data transmitting / receiving unit 23 to the phase corrector 24 in synchronization with the basic frame signal 8 kHz. One connecting device 2 is shown in FIG.
For example, B0 assigned to itself is fetched from Bch of the multi-frame of (1). The phase corrector 24 replaces (synchronizes) this with the PCM synchronization signal 8 kHz of the baseband LSI 25 supplied from the baseband LSI 25 and synchronizes the ADPCM in the baseband LSI 25.
-Sending to CODEC 26. Further TDMA /
In the TDD processing unit 27, the ADPCM-CODEC 26
Is converted into a burst signal of 384 kbps, and is assigned to one of the transmission slots indicated by CS1 in FIG. 1 generated at the transmission / reception slot timing of 625 μS generated by the reference timing generation unit 33. Send to 4QPSK modem 28. The π / 4 QPSK modem 28 modulates the input signal and sends it to the radio unit 29. The radio unit 29 converts this signal into a transmission frequency and emits it from the antenna 3 as a radio wave. On the other hand, the radio unit 29, which has received the radio wave emitted from the slave unit through the antenna of the connection device 20, converts the frequency and then outputs the π / 4 QPS in the baseband LSI 25.
Send it to the K modem 28. The signal demodulated by the π / 4 QPSK modem 28 is arranged at a reception slot position corresponding to a transmission slot position as shown in FIG. TDMA
In the / TDD processing section 27, 384 kb
The speed is converted from ps to 32 kbps, the reception data at the unique reception slot position is detected, and the ADPCM-C
The ODEC 26 converts the data into 64 kbps data and sends the converted data to the phase corrector 24. Phase corrector 2
In step 4, the data received from the baseband LSI 25 is transmitted to the bus data transmission / reception unit 23 with the timing of the basic frame signal 8 KHz on the bus data transmission / reception unit 23 side. The CPU 31 sends the received data from the phase corrector 24 to the bus
At the position of the channel, control data from the CPU 31 is inserted into the Dch to create a transmission multiframe (not shown) synchronized with the reception multiframe of FIG.
(Transmission line). In this manner, in the digital cordless telephone device 20, each connection device 2 performs transmission and reception with the slave unit 4 connected by a wireless line. However, in the above-described apparatus, when a new home telephone is installed or when a power outage is restored, the transmission / reception between the connected apparatuses is performed in the same manner as in the conventional distributed processing type connected apparatus only by supplying power to each apparatus. The slots are not synchronized, and control to avoid radio wave interference between connected devices cannot be performed. Therefore, the present invention is as follows.
The main device 1 inserts data for activating slot synchronization between the connected devices once every 30 seconds into the reception timing RT in the basic frame of the frame number F0 in FIG. The CPUs 31 of all the connection devices 2
When the data at the reception timing RT is detected as data relating to control input from the extension bus through the bus data transmission / reception unit 23, the data is transmitted from the extension bus 12 to the TDMA / TDD processing unit 27 in the baseband LSI 25 via the bus 30. Instructs to enter a waiting state for an incoming frame signal. Next, the frame number “F”, which is the head of the next multiframe following the multiframe in which the data was inserted in the reception timing RT,
A multi-frame clock MFCK responding at the beginning of B0, which is Bch data following “0”, is output from the bus data transmission / reception unit 23 to the reference timing generation unit 33. When reset by this multi-frame clock MFCK, the reference timing generator 33 starts transmitting and receiving 625 μS slot timing and 5 mS shown in FIG.
Output of the TDMA / TDD frame timing is newly started. In the baseband LSI 25, the input 625
The counting of the μS signal (pulse) is started by a counter (not shown). 5 ms signal (pulse) input by the CPU 31
Sends a reset signal of the counter to the baseband LSI 25 every time is input. Then, baseband LSI25
Counter receives the signal of 625 μS eight times, the CPU 3
It is cleared by the reset signal of 5 ms from 1. Then, this operation is repeated. TDMA / T
The DD processing unit 27 synchronizes transmission / reception slots based on the reference timing shown in FIG. That is, by this synchronization timing, 5mS TDMA / T composed of four transmission slots and four reception slots of 625 μS.
A DD frame is generated. Since all the connecting devices perform the same operation at the same timing as described above, each connecting device is in a synchronized state as shown in FIG. Regarding the difference between the device of the present invention and the conventional device,
Each conventional connecting device 102 synchronizes the TDMA / TDD frame timing between the connecting devices by using a 5 ms synchronous dedicated line separately connected to the main device 101, in addition to the extension bus 12. On the other hand, in this embodiment, the baseband LSI in each connection device is obtained by the data of the reception timing RT inserted in the multiframe signal coming from the extension bus and the multiframe clock MFCK extracted from the multiframe. By supplying the TDMA / TDD frame timing and the transmission / reception slot timing synchronized between the connection devices to the TDMA / TDD processing unit 27, the transmission / reception slots of the connection devices 2 are synchronized. In the above embodiment, the control timing and the communication timing are not separately described. However, the operation is the same except that the control timing is a superframe interval. In this embodiment, the case where the above-described synchronization is started only once when the digital cordless telephone device is energized, such as at the time of setting, is described. However, it is also possible to re-synchronize at regular time intervals. In this embodiment, each connection device 2 has a function of performing communication using one channel, that is, one transmission slot and one reception slot. When 22 synchronously connected devices are transmitting and receiving at one specific transmission / reception slot timing of a TDMA / TDD frame, a third connected device that is synchronized with the two connected devices is connected to the third connected device. When transmission is attempted to start at a specific transmission / reception slot timing, there are a plurality of transmission / reception frequencies that can be used. Therefore, the radio unit 29 detects whether or not another connection device is emitting a radio wave (carrier sense). When a radio wave of another connection device is detected, transmission / reception may be performed after changing the use frequency. As an application of the present invention, since a TDMA / TDD frame has four pairs of slots for transmission and reception, in principle four connection devices can be used at the same time. Is possible. As a result, a digital cordless telephone device free from radio interference can be configured. 4 slots for transmission and reception
If more than one, that is, four or more connecting devices are connected to the main device and used, if the other connecting devices have already used the same frequency after the carrier sense described above, change the used frequency and then Just do it. According to the present invention, a plurality of connecting devices of the digital cordless telephone device of the present invention use a distributed processing system, and synchronize the multi-frame signals and the like in the down bus data from the main device to each connecting device. In order to eliminate radio interference between the connected devices, it is possible to omit the dedicated line for synchronization between the main device and each connected device, and to control the connected devices connected to the extension bus. Can be done with Therefore, by adopting this synchronization, which simplifies the configuration of the device and facilitates installation work, it is possible to implement applied means for preventing various types of radio interference between connected devices.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a TDMA / TDD frame constituted by transmission / reception slots according to an embodiment of the present invention. FIG. 2 is a diagram showing a multiframe coming from a reception line of an extension bus. (2) A diagram for extracting a multi-frame clock from a multi-frame (3) A diagram for extracting a basic frame signal from a multi-frame [FIG. 3] A configuration diagram of a home telephone using the digital cordless telephone device of the present invention [FIG. 4] FIG. 5 is a configuration diagram of a home telephone using a conventional digital cordless telephone device. [Description of References] 1 Main device 2 Connection device (CS1 to L) 3 Antenna 4 Remote unit (PS) 10 Telephone exchange 11 ISDN Line 12 Extension bus 14 Telephone 20 Digital cordless telephone device 21 Extension bus connector 23 Bus data transmission / reception unit 24 Phase corrector 25 Baseband LSI 26 ADPCM-CODEC 27 TDMA / TDD processor 28 π / 4 QPSK modem 29 Radio unit 30 Bus 31 CPU 32 Reference clock generator 33 Reference timing generator 34 Work switch 35 Memory 36 ID-ROM 37 Power

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-10-126871 (JP, A) JP-A-8-9460 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04B 7/24-7/26 H04Q 7/00-7/38

Claims (1)

(57) [Claim 1] A plurality of connecting devices connected to an extension bus from a main device of a home telephone or a key telephone device;
In a digital cordless telephone device having a plurality of slave units connected to these connection units and a wireless line using the TDMA / TDD system, a multi-frame signal of downlink bus data sent from the main unit through the extension bus is used. A multi-frame clock, a means for generating a basic frame signal, a reference clock generating means generated by the basic frame signal, a means for receiving a reference clock from the reference clock generating means to generate a reference timing, After receiving the data included in the multi-frame signal and starting the slot synchronization between the connected devices transmitted at a constant period, the means for generating the reference timing with the multi-frame clock is reset, and the phase shift between the connected devices is performed. Transmission / reception slot synchronization without connection Connection device of a digital cordless telephone apparatus according to symptoms.