JP3283813B2 - Wireless base station - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to audio, data, images and the like.
Related to the telephone exchange system that exchanges and connects information
A communication terminal device such as a telephone and a data terminal device;
The transmission path between the switching devices is made wireless and the
Switching equipment with digital transmission lines
You. [0002] Taking the example of a wireless telephone system,
Car phones and wireless phones have been put into practical use. Previous
In the case of wireless communication, the
Thus, phase modulation and frequency modulation are employed. For example,
"New edition mobile communication method" published by Kagaku Shimbun (1979)
Issued on May 10) (hereinafter referred to as “Reference Document 1”) No. 23
A summary can be found in paragraphs 9-260. The latter is generally
Typically, a cable is drawn from the central office to the subscriber's premises.
Wireless within the subscriber's premises.
Numerical modulation is often used. (Reference 1, No. 294
Paragraphs to 301) Also, the uses which are relatively targeted by the present invention
Experimental systems close to the environment have also been tried,
Modulation system is adopted, and the exchange is also a crossbar system.
Therefore, the issues of confidentiality, noise immunity, and interference immunity have been resolved.
Not in. (Ref. 1, 291 to 294)
As a mobile radio system using a digital switching system
Are described, for example, in JP-A-59-58927.
It is. [0003] The above-mentioned prior arts are exchangeable.
The wireless transmission path between the device and the communication terminal
Use, there is a problem with confidentiality, noise resistance, and interference resistance.
Yes, and telephone exchanges that use the digital exchange
Is not very good
Was. An object of the present invention is to provide an analog wireless system as described above.
To solve the problem of the terminal device used,
Specifically, the wireless connection between the telecommunications terminal and the switching equipment
To improve privacy and noise resistance, and
Telephone switching system that uses digital switching
To provide a terminal device with improved suitability for
You. In addition, the speed of the synchronization process with the exchange
To provide a terminal device with enhanced privacy of communication with
You. In addition, when connecting and exchanging a partner communicating with the terminal device,
Flexible system configuration that does not cause restrictions on connection paths etc.
Connection, system installation and setting changes, etc.
A terminal device suitable for wireless communication that is easy to construct with a simple configuration
To provide. [0004] To solve the above problems,
In the switching device of the present invention, the terminal device
Receiving means for receiving a signal to be tuned and transmitted, and said receiving means
Spread code for spread spectrum demodulation of the signal received by
Spreading code generating means for generating a spreading code;
The receiving means receives the signal based on the spread code generated by the stage.
Spread spectrum demodulation for spread spectrum demodulation of the received signal.
Control means for controlling generation of a spread code by the spread code generation means.
And control means for controlling the spread demodulation.
When capturing code synchronization for
This is different from the communication spreading code used for spreading information such as images.
And a code shorter than the communication spread code.
The spread code generator generates a spread code for signal synchronization.
Controlling the sound generation means, such as voice, data or images.
When communicating information, the communication spread code is generated.
The spreading code generating means is controlled in such a manner as to be described above. Also, the sign
The spreading code for synchronization is a fraction of the integer of the spreading code for communication.
That's it. With the above arrangement, the communication terminal device and the exchange device are provided.
Wireless communication between the devices, improving confidentiality and noise resistance.
Phone with digital switching system
It is possible to improve the compatibility with the switching system
Become. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS SUMMARY OF THE INVENTION The present invention provides a communication system between a communication terminal device and a time division multiplexing switching device.
Spread spectrum modulation and demodulation technology
The spread spectrum modulator / demodulator is connected to the central control
Control by means of an economical exchange system.
Systems, especially wireless switching systems
Things. Connection between terminal equipment and switching equipment in the office
When wireless, the terminal device is in use
Can be considered to be stationary, and communicating in mobile radio, etc.
The problem caused by the movement of the terminal device is not considered. Ma
The distance between the terminal device and the antenna on the exchange
Or a leaky coaxial cable on the ceiling, etc.
It can be made almost even by laying or other methods
The terminal device side compensates for the distance difference from the antenna.
Spread spectrum without controlling transmission power for
Communication becomes possible. Further, radio waves transmitted from one antenna
Reach the same room or the same floor,
As it can be limited to a relatively narrow range, weak radio waves can be used
Thus, effective use of radio waves is possible. Spectrum expansion
Pseudo-noise codes for spread demodulation are also considered for offices.
In other words, the number of terminal devices in the same system is too large.
On the other hand, the difficulty of signal decoding
I don't think a high degree of confidentiality is required
Thus, a relatively simple code can be used. That is,
The spread spectrum modulator / demodulator can be simplified. [0008] Based on this premise, the present invention provides a terminal device.
Spread and spread spectrum modulator and demodulator
Set up a transceiver including a similar noise code generator, antenna, etc.
For example, the range of radio waves transmitted from each antenna
Within a certain area determined by
At least, it is given individually for each terminal device. In the case of a call from a terminal device, the terminal device
Is the spreading code (pseudo-noise code) given to the own terminal device
Sends out a calling signal that is spread spectrum modulated by
The demodulator captures this signal and
The noise code or the information transmitted by this code,
Transfers to the central control of the switching equipment, which places the call
Identify the terminal device. The central control unit simulates the calling terminal.
A similar noise code is set in the spread spectrum modulator on the switching equipment side.
And set a downlink channel to the calling terminal device. [0010] In the case of an incoming call to the terminal device, the terminal
Of the called number is sent to the central control unit of
Identifies the called terminal device from the number, and
The spread code of the spread spectrum modulator and demodulator is
Terminal device's pseudo-noise code and the terminal device's control signal
By transmitting on this channel, the called terminal
Call. [0011] Both the outgoing call and the incoming call are explained above.
After setting the channel between the terminal device and the switching device by the method
Is 8 bits of 8000 samples / sec for audio
The companded PCM code is a pseudo-noise code given to the terminal device.
The signal is spread spectrum and transmitted and received. In this way,
A highly confidential and highly anti-jamming communication system can be realized.
You. The spread spectrum and direct frequency
Several modulation methods are considered, such as several hopping
However, the present invention does not depend on the modulation method. FIG. 4 shows an example of a communication system in a building.
Then, an external cable 400, for example, an office line comes in.
The main exchange 300 is placed on each floor, and child exchanges are placed on each floor.
The exchange device 200 is installed, and the main exchange device 300 and each child exchange are installed.
The switching device 200 includes a cable 600 such as an optical fiber cable.
-Connected to each other via a node device 610
I have. The main switching device 300 and the child switching device 200
Connected to the antenna 500, for example, a leaky coaxial cable.
You. The terminal device 100 is a combined voice / data terminal device,
Exchange device 2 having an antenna
00 or 300 is connected wirelessly. this
In a communication system, switching devices 200/300 and terminals
Since the device 100 is wireless, installation work
Is the installation of the exchange device 200/300 and the node device 61
0, connection with external cable 400, antenna 5
00 and the exchange device 200/300
No wiring is required between the terminal device 100 and the terminal device 100. further
An optical fiber is used for the cable 600 to perform time division multiplexing.
Eliminates the need to route large amounts of cable,
Things become very easy. FIGS. 1 and 2 show the main replacement device in FIG.
Device 300 or child switching device 200 relating to the present invention.
FIG. 3 shows a first and a second embodiment of a portion, and FIG.
1 shows an embodiment of a terminal device 100. Hereinafter, referring to FIG.
The first embodiment will be described in detail. 2. a. First Embodiment In this embodiment, as shown in FIG.
Depending on the hicks, only the number of simultaneous calls / communications is provided.
Demodulator 210 handles only one line of information, so low speed
There is a feature that works with. The terminal device 100 and the switching device 2 in FIG.
Information between 00 and 300 is integrated.
Service Digital Network (ISDN:
Standardized as Integrated Services Digital Network)
64 kb / s for voice or data
Channel B and 16 kb / s channels for data and signals
Channel D. FIG.
Above and on the transmission path between the switching equipment and the terminal equipment.
9 shows the relationship between channels B and D. FIG.
(A) is a case where voice is mainly used, and the terminal device is B + D information.
When exchanging, FIG. 5 (b) becomes the ISDN standard.
A place to exchange B + B + D information that is considered to be
It is. The frame shown in FIG. 5A is 8000 per second.
Audio is sampled at the rate of sample, one sample
A minute time corresponds to 125 μs. In this frame
n time slots are time-division multiplexed and one
Time slot, for example, TS0 is composed of 8 bits.
ing. When sending to the transmission path to the terminal,
2 bits as a channel are added and expanded in time to obtain 8 bits.
It is sent at a rate of 0 kb / s. Sent from the terminal
On the contrary, after removing 2 bits of D channel,
At the specified time on the highway
Inserted into the memory slot. Further, FIG.
In the case of + B + D, the signal speed with the terminal device is 144 kb
/ S. In the figure, the time slot is set as B + B.
Although TS0 and TS1 have been assigned,
Not limited to im slots, and for different highways
It is possible. In this embodiment, for the sake of simplicity, FIG.
The case will be described. First, when there is no call / communication state, FIG.
In the switching devices 200/300, the central control unit 24
0 is a modulation / demodulation device 210 via a signal reception / distribution device 230.
To prepare for call detection. That is, the central control unit 240
Specifies an empty modem 210, and temporarily
If the modulation / demodulation device 210
Call the noise code generator (hereinafter referred to as PN generator) 213
The spreading code assigned to the terminal device 100 to be detected
Specify preamble code to capture code synchronization of signal
Then, the spread demodulator 212 is driven by this preamble code.
Instruct the user to When detecting calls from multiple terminals
In the central control unit 240, the demodulation unit of the modem 210 is
Call demodulator after enough time to capture signal synchronization
With the preamble code of the terminal device 100 which may be
Next, it switches to drive and detects a call. In this case,
Detects multiple calls at the same time using the modem 210 of
You can also. In the embodiment, the preamble code
Is used as a pseudo-noise code (hereinafter referred to as PN).
You. That is, in a known switching device, a central system is used.
The controller spatially scans the line interface circuit
On the other hand, in the exchange device of the system of the present invention,
The central control unit 240 uses the modem 210
The spreading code (preamble code) of the spread demodulator 212 is sequentially
Switched and scanned, synchronization of spread code was performed
In this case, it is regarded as a call. In the same terminal device
The given PN code is sent upstream (from the terminal
Transmission) and downstream (transmission from the switching equipment to the terminal equipment)
If different, the P set in the spread demodulator 212
The N code is an upstream spreading code. Next, the terminal device 100
Also, in FIG. 3, when there is no call / communication state,
Only the spread demodulator 112 can be
Generated by the downlink preamble code of its own terminal device.
A signal synchronization acquisition operation is performed to prepare for reception. What
As described in the second embodiment, the time until code synchronization acquisition is performed.
Preamble for code synchronization acquisition to shorten
Spreading code is simpler than communication spreading code
That the same code must be repeated
Then, the length of the preamble code for code synchronization acquisition is
It is preferable that the number be a fraction of an integer of the communication spreading code. 2. a. 1 Transmission operation First, the transmission operation of the terminal device is described with reference to the flowcharts of FIGS.
Explanation will be made using a chart. Transmission and reception in the # m1 terminal device 100 of FIG.
When the vessel is raised (FIGS. 6, 601), the control device 1 shown in FIG.
40 detects this (not shown). The control device 140
PN generator 113 via interface circuit 150
Then, the uplink preamble code is supplied to the spread modulator 111.
And the spread modulator 111
Spread modulation is performed with a bull code to generate a preamble signal. Self
Spread spectrum modulation with uplink preamble code of terminal equipment
The adjusted preamble signal is transmitted to the
It is amplified to power and transmitted from the antenna 130 (see FIG.
6, 602). Preamble sent from antenna 130
The signal is received by the antenna 500 of FIG.
The signal is amplified by 220 and spread by all modems 210.
The signal is input to the adjuster 212. Now, No. 1 modem 21
0 spread demodulator 212 is a
Updating of the # m1 calling terminal by the control for exit
If the preamble code is set, the synchronization
The path 214 is activated, and the upstream preamble code
The code synchronization of the spreading code is captured (611 in FIG. 6). In switching devices 200/300, No. One change
From the synchronization circuit 214 of the demodulation device 210,
The signal is transmitted through the signal receiving and distributing device 230 to the central control system.
It is sent to the control device 240. The central control device 240 is no.
The spread demodulator 212 of the first modulator / demodulator 210 is a # m1 terminal device.
Synchronization of spread code with upstream preamble code
And that the # m1 terminal device has originated the call.
(FIGS. 6, 612). The central control device 240 1 modem
For the spread modulator 211 of the device 210, the # m1 terminal device 1
00 to the PN code generator 213
Set (FIG. 6, 613). This allows the spread modulator
211 is spread modulation with a downlink preamble code and
An amble signal is generated, and the transceiver 220 and the antenna 50
Send through 0. In the # m1 calling terminal apparatus 100, this downlink
The preamble signal is transmitted to the antenna 130 and the transceiver 120
Received by the spread demodulator 112 and controlled by the synchronization circuit 114
To capture the spread code synchronously (603 in FIG. 6). to this
Therefore, the code synchronization of the spreading code is acquired for both the uplink and downlink.
The # m1 terminal device 100 can confirm that it has been caught.
The uplink spread spectrum code is used for synchronization acquisition.
Switch from reamble code to PN code for communication.
The synchronization circuit 114 keeps track of the synchronization of the spreading code. To switch
Prior to this, the terminal device 100 spreads the switching signal in the spectrum.
The spread modulation is carried on the preamble signal and the
The signal is sent to the spread demodulator 212 and the spread modulator 11 on the terminal device side is sent.
1 and the spreading demodulator 212 on the switching device side
Preamble code for synchronization acquisition while maintaining the initial state
Is switched to a PN code for communication (FIG. 6, 604,
And FIGS. 6, 615). In the switching device 200, the spread demodulator 212
From preamble code for code synchronization acquisition to PN code for communication
Terminal device 100, the
Check that the reamble signal has been captured, and
A switching instruction signal is sent on the amble signal,
Use the same procedure to set the preamble code for code synchronization acquisition on the downlink.
Switch to a PN code for communication (Figs. 6, 616,
And FIG. 6, 605). With the above operation, the terminal device 100 and
Since the bidirectional line between the switching devices 200 has been set,
The switching device 200 generates a dial tone for the calling terminal device.
Sending out (FIG. 6, 617), and dial monitoring is started. this
The subsequent operation of the exchange device is the same as the operation of the known exchange device.
It is performed. Communication after setting the line is as described in FIG.
For communication and high-speed data, use B channel
And low-speed data are performed using the D channel. The operation after transmission of the dial tone is described with reference to FIGS.
A brief description will be given below. The central control unit 240 1 modem
The spreading code of the spreading modulator 211 of the device 210 is a preamble.
The switch from the code to the PN code is performed by the PN generator 213.
From the signal receiving and distributing device 230,
Sending circuit (not shown) and No. With one modem 210
For example, transmission highway 261, switching net
Free time through the work 250 and the reception highway 260
Select a slot and connect. Switching net here
The work 250 includes a time switch and a space switch.
Alternatively, any of the combination of the two may be used. When the above connection is made, the central control unit 2
No. 40 is passed through the signal receiving and distributing device 230, One reversion
Time in the buffer memory 215 of the adjusting device 210
Reception highway 26 selected for slot memory 215-2
The time slot on 0 is stored. After that time
In the slot, the time slot switch 215-1
Is closed, and the 8-bit encoded dial tone is shifted to the shift register 21.
Receive at 5-3. To shift register 215-3
The entered 8-bit information is immediately transferred to another shift register.
Transferred to the register 215-4,
3 is for receiving the signal of the time slot of the next frame.
Prepare. 8 transferred to the shift register 215-4
After the bit information, a total of 2 bits of data and control bits
Is added under the control of the central controller 240 (see FIG. 1).
The hatched portion of the shift register 215-4), FIG.
As shown in (a), the spread modulator 2 is operated at a speed of 80 kb / s.
11 and the downstream P given to the # m1 terminal device.
Spread spectrum modulation with N codes
The signal is amplified and transmitted from the antenna 500. In the # m1 terminal device 100, this signal is
As shown in FIG.
And input to the spread demodulator 112. In the spread demodulator 112, the own terminal device (#m
Demodulate with the downstream PN code of 1) and control the control device 140
Therefore, through the interface circuit 150, the B channel
Only the signal is extracted and the PCM demodulator 162 outputs the signal at a predetermined speed.
And sent. 800 in the PCM demodulator 162
8-bit code sent at a rate of 0 samples / second
Operate receiver 164 with predetermined power after converting to analog signal
And let the caller hear a dial tone. The dialer 165 sets the connection destination
When the number is dialed, the control device 140
Detecting this through the interface circuit 150,
The spread modulator 111 shown in FIG.
A predetermined code is input to the channel position, and the upstream PN code is input.
, And then amplifies it with the transceiver 120 and
From the computer 130. On the exchange device side, this radio signal is transmitted as shown in FIG.
After being received by the antenna 500 and amplified by the transceiver 220
The signal demodulated by the spread demodulator 212 is transmitted to the shift register 2
16-4. Control signals are hatched in the figure.
Input to the signal receiving and distributing device 2
Via 30, it is read by the central control unit 240. After receiving the predetermined dial, the central control unit
Station 240 identifies the called terminal and performs a paging operation.
Vacant channel between the calling terminal and the calling terminal
Free time slots on both transmission and reception highways on the equipment side
Vacant on both the transmitting and receiving highways of the called terminal device
Select a time slot and pass it through the signal
Call, the time slot memo of the called terminal device 210
Enter the selected time slot into files 215-2 and 216-2.
Write the unit number. On the other hand, the switching network
250 to control calling time slot and called time
Connect the slots. 2. a. 2. Incoming call operation Next, the call operation of the called terminal device will be described with reference to FIGS.
This will be described with reference to the flowchart of FIG. In FIG. 1, the central control unit 240 is a dial
Upon receiving the (called number) (FIG. 7, 711),
Identify which terminal device it belongs to. Now, the called terminal
Assuming that #mi in FIG.
0 is an empty modem capable of calling the called terminal device #mi.
1, for example, FIG. Select and capture the n-modem 210
(FIG. 7, 712). Subsequently, the central control unit 240 sends a call to the called terminal device.
Code of each of the uplink and downlink assigned to the
Preamble code for period acquisition (communication PN after synchronization acquisition)
No.) through the signal reception and distribution device 230. n
Set to the PN generator 213 of the modem 210 (see FIG.
7, 713). As a result, the spread modulator 211
Start transmitting the amble signal (714 in FIG. 7), the spread demodulator
Reference numeral 212 denotes an uplink preamble signal from the #mi terminal device.
Prepare for reception. The preamble signal is transmitted to the transceiver 220,
#Mi terminal device 100
Then, the signal is received by the antenna 130 of FIG.
0 is input to the spread demodulator. Explain in case of outgoing call
As described above, when the terminal device is empty, the spread demodulator 11
2 is a preamble so that the synchronization of the spreading code can always be captured.
Since the preamble signal is input
Then, the synchronization of the spreading code is controlled by the control of the synchronization circuit 114.
(FIG. 7, 701). Code synchronization acquisition of downlink preamble signal
Immediately, under the control of the control device 140,
From the spread modulator 111 to the transceiver 120,
The data is transmitted through the antenna 130 (702 in FIG. 7). this
The uplink preamble signal is transmitted and received by the antenna 500 of FIG.
The signal is input to the spread demodulator 212 through the transceiver 220. No. Spread demodulator 2 of n modem 210
12, the pre-processing from the #mi terminal device has already been performed as described above.
It is set to receive amble signals, so input
The acquired preamble signal is immediately code-synchronized (see
7, 715). Upon completion of code synchronization acquisition, the spread modulator 21
1, while maintaining code synchronization with the #mi terminal device 100
From the preamble code (PN code) for code synchronization.
Switching to a trusted PN code (FIG. 7, 716). In response to this, the terminal device 100 spreads.
The spreading code of the demodulator 112 is changed to a pre-
Switch from Bull code (PN code) to PN code for communication
(703 in FIG. 7), followed by the spreading code of the spreading modulator 111
Is a preamble code (PN code) for code synchronization acquisition
Is switched to a communication PN code (704 in FIG. 7). On the exchange device side, No. Expansion of n modems
The spreading code of the spread demodulator 212 is synchronized with the terminal device.
Switch from preamble code to PN code for communication while maintaining
No. (717 in FIG. 7, 717). n modems 210 and #
between the up and down radio channels between the mi terminal devices 100
Setting is completed. As described above, the preamble signal
Synchronization of spread codes and switching to communication PN codes
7 and 717,
The central control unit 240 switches both the downlink and the uplink by the signal switching.
You can confirm that the channel has been set. After that, the central control unit 240 returns to the normal replacement equipment.
The ringer is sent to the caller as in
Is controlled to transmit a calling signal (see FIG. 7, 71).
8). In transmitting the calling signal, the central control unit 2
Under the control of 40, an instruction for controlling the transmission of the call signal is issued.
The data is transmitted to the terminal device on the D channel in FIG.
In the terminal device 100, the control device 140 receives the
Dung-166 is driven. As described above, when making or receiving a call
To the terminal device 100 using the idle modem 210.
Wireless communication by spread spectrum communication between the switching devices 200.
By setting channels, the number of simultaneous calls / communications
n wireless communication systems can be realized. With this method
Means that the number of simultaneous calls / communications is n
In the market, it becomes irrelevant to the number of terminal devices.
In application areas where the call volume per terminal device is small,
is there. In the above embodiment, the terminal device shown in FIG.
# M1 and #mi connect the child switching device 200 on the floor.
In the above description, the main exchange 3
00, for example, the # 1 and # 1 terminal devices talk / communicate
The same applies to the case of # m1 terminal device and #nj terminal.
The terminal device communicates / communicates through the #m and #n child switching devices.
Communication, the exchange operation of the exchange
Radio channel between the terminal equipment and the modem in the switching equipment.
Related to the present invention, such as channel setting, call detection, calling, etc.
The same is true for minutes. Therefore, the exchange method is decentralized.
Control, centralized control or configuration of time-division communication path
The present invention can be applied without being affected by this. Signal transmission method between switching equipment and terminal equipment
Is also limited to the format of FIG. 5A in the embodiment.
Instead, B + B + D shown in FIG. 5B may be used.
There is no problem even if the method is very different. Further examples
Call on the dial 165 for telephone calls
Call from the speaker with the ton ringer 166, and send and receive
163 and 164 have been described,
After setting the communication path, the spread modulation / demodulation device 11 in the terminal device 100
1, 112 and the PCM modems 161, 162
If switched to the data terminal device 170, PCM voice
It is possible to perform not only communication but also data communication
Then, instead of the dial 165, the data terminal 170
Enter the destination number / code using the keyboard to establish a connection.
Needless to say, it is possible to do so. In this embodiment, one time slot
8 bit, 8000 frames / sec
As described above, a digital radio
Since one channel is set for the channel, the switching equipment
Even if it is a switching device, there is no problem even if it sends image signals.
There is no. 2. b Second Embodiment In the second embodiment, as shown in FIG.
Frame and time slot supplied from the signal generation circuit 270
Synchronization signal generation circuit for spreading the synchronization signal for synchronizing
At 280, spread spectrum modulation is performed and a spread synchronization signal is generated.
Is generated and transmitted to the terminal device, and the switching device and the terminal device are scanned.
Mutually time slots through a spread spectrum communication channel
By operating the units synchronously,
Division multiplexing of the spread spectrum modulation / demodulation device 210 on the installation side
It has been made possible to use it. The switching devices 200 and 300
As in the embodiment, each frame is composed of 8000 frames per second.
Eway 260-1 to 260-r and 261-1 to 26-2
On 61-r, one frame consists of n time slots
Shall consist of These frames, time slots, etc.
Is the synchronization supplied from the synchronization signal generation circuit 270 of FIG.
Synchronization is achieved by signals. Each terminal device 100 has a spectrum
PN code, PNU (for upstream) and PND for ram spreading
(For going down) is given. Terminal device J (not shown in FIG. 4)
Abbreviations) are denoted as PNUj and PNDj.
You. In the present embodiment, furthermore, all operating with the same synchronization signal
Synchronous signal receiving PN code PNC common to terminal devices
Provided. This PNC is used for synchronous acquisition of a spreading code.
Also serves as a preamble code. Therefore, the PNC is
Commonly used as a spreading code for signal synchronization acquisition by all terminals
The Rukoto. The switching device, for example 200, enters the operating state.
And the spread synchronizing signal generation circuit 280 of FIG.
Upon receiving the synchronization signal from the circuit 270, the terminal device synchronization signal
Is spread-spectrum by a spreading code PNC to generate a spread synchronizing signal.
Generate and transmit through transceiver 220 and antenna 500
I do. FIG. 8 illustrates the spread synchronization signal transmitted.
It is. FIG. 8A shows an extension transmitted from the switching device.
The scattered sync signal is shown on the time axis.
Are the synchronization signals SNC1 to SNCn on the upper side of the horizontal axis.
Is spread-modulated by the spreading code PNC. same
The period signals SNC1 to SNCn correspond to time slots.
The receiving side receives this and the time
The slot number can be identified. That is, the frame synchronization signal
Has become. Here, this spread synchronizing signal is a preamble.
Since it also serves as a signal, the time until code synchronization acquisition is shortened
To do this, the spreading code PNC must be a communication spreading code PN.
The code is simpler than U and PND.
Since repetition is required, the spreading code PNC
Is the time slot length (PNU, PND) or
Is preferably a fraction of that integer. That is,
Spreading code PNC must be shorter than PNU and PND
Is preferred. 2. b. 1 Terminal device start-up operation On the terminal device side, power is turned on and the spread synchronization is performed.
Receives the signal and captures the spread code synchronously.
Waiting for incoming call with code synchronization with 200/300
Performs a calling operation. This state is shown in FIGS. 3, 8 and 9.
This will be described with reference to the flowchart. In FIG. 8, when the power of the terminal device J is turned on,
Since it is performed independently of the operation of the switching equipment,
No signal synchronization. When the power of the terminal device J is turned on (FIG. 8)
(B)), the control device 140 of FIG.
The operation is started under the control of 140 (FIGS. 9, 90).
1). First, the PN generator 113 operates to receive the spread synchronization signal.
A PN code PNC is generated (902 in FIG. 9), and a spread demodulator
112 starts the demodulation operation with the PN code PNC (FIG.
9, 903). On the other hand, the synchronization circuit 114 includes the PN generator 1
13 to start the code synchronization acquisition operation (FIGS. 9 and 9).
11). When the power is turned on, as shown in FIG.
And the PN code of the spread demodulator 112 are code synchronized.
Although no output is obtained from the spread demodulator 112,
When the code is synchronized with the received signal under the control of the
An output is obtained from the spread demodulator 112 (904 in FIG. 9),
The code synchronization acquisition is completed (FIG. 9, 912), and the synchronization circuit 11
4 shifts from the synchronization acquisition operation to the synchronization tracking operation (FIGS. 9 and 9).
13). Completion of acquisition of code synchronization of spread codes
The synchronization signal obtained as the output of the spread demodulator 112
The time slot number of the switching equipment can be obtained from the
As a result, the clock and time slot in the terminal device 100 are
Synchronize the slot, frame, etc. with the switching equipment. After that
As shown in FIG. 8B, the synchronization received substantially every frame.
The signal is used to correct a time slot or other synchronization error. The control device 140 controls the code synchronization of the spread code.
When the acquisition is completed, the PN generator 113 is controlled.
PN code to spread demodulator 112 from PNC
Is switched to the downstream PN code PNDj given to the
905), the spread demodulator 112 decodes with a PN code and PNDj.
The adjusting operation is started (FIG. 9, 906). At this time, the terminal device 1
00, which time slot
As shown in FIG. 8 (b),
Demodulation operation by PNDj for all time slots
Now. In order to maintain synchronization, for example, as shown in FIG.
The PN generator 113 is controlled every +1 time slot.
To change the PN code of the spread demodulator 112 to PNC and
Issue. The control device 140 outputs the output of the spread demodulator 112.
Monitor, and if no signal is detected, the next time slot
The demodulation operation is continued (at 907 in FIG. 9), and a signal is detected.
If a call is received using the time slot
That the operation of the spread demodulator 112
Fixed to slot, other times to prevent malfunction
The demodulation operation in the slot stops (908 in FIG. 9). What
The reception of the synchronization signal is also easy
As described above, the time slot immediately before the time slot
Fixed to Of the above operations, the judgment in FIG.
If the terminal device is idle,
Operation. 2. b. 2 Transmission operation Next, the operation when the terminal device transmits a signal will be described with reference to FIGS.
10 and the time relationship diagram of FIG. 10, and the flowchart of FIG.
I will explain using. When the caller raises the handset of the terminal device J,
FIG. 3 shows that the hook switch (not shown) is closed.
The device 140 detects (FIG. 11, 1101), and
From the PN generator 113 via the source circuit 150
A code (PNUj) is generated by the spread modulator 111.
Call signal using the PN code using all time slots.
Spread-modulates the signal through the transceiver 120 and the antenna 130.
And transmits (FIGS. 11 and 1102). Where the spread modulation
The signal to be output is, for example, as shown in FIG.
Is a signal having a configuration such as B + B + D.
Explanation is given assuming the format. That is, on the horizontal axis of FIG.
TS1, TS2, etc. of the section represent time slot numbers,
The hatched part is the D signal, and the unhatched part is the B signal.
Symbol. 10 (a), (b), (e) and (f)
Note that each frame does not start with TS1
This is because the highway of the switching device is used as a reference. The calling signal may be a signal of a specific pattern or
Shall send the caller and calling conditions (telephone, data, etc.)
And it depends on the system. Also, in the time relationship
Is an exchange device shown in FIGS. 8 (b) and 10 (f).
Switching device based on the synchronization signals SNC ~ sent from
And synchronize the frame, time slot, etc.
You. In switching devices 200/300, FIG.
The central control unit 240 of each of the modems 210 (the same server)
If there are multiple modems in the service area
Is the free time for at least one of them)
Using the slot, the uplink PN signal (P
NU)) to drive the sequential spreading demodulator 212 and all available terminals
The device is scanned for a call (see FIGS. 11 and 11).
11). Now, FIG. 10B will be described. Correspondence
The modem 210 on the switching device side to be switched to No. One device
Then, the central control unit 240 transmits the time slot of the frame q.
Outgoing call detection of terminal device m
No. A terminal device is connected to the PN generator 213 of one device.
m, and generates an upstream PN code PNUm of m.
2 was activated, but no signal was obtained and no outgoing call was detected.
Indicates that the The following time slot 2 (highway
The upper part) is already used for communication with the terminal device i. Time slot 3 of frame q (highway
In (b) above, the time slot is detected to detect the call from the terminal device J.
With the same control as in the case of bit 1, the PN code PNUj
The spread demodulator 212 is driven (FIGS. 11 and 1112). end
In the terminal device J, as shown in FIG.
Is spread-modulated with the PN code PNUj and transmitted.
Then, the calling signal is demodulated by the spread demodulator 212 and controlled.
It is detected by the device 217. And the signal reception and distribution device 23
0 to the central control unit 240 (FIG. 11, 1).
113). The central controller 240 controls the spread demodulator 212
Since the calling signal was detected with the PN code PNUj, the terminal
It is identified that the device J has made a call (FIG. 11, 111).
4). The central control unit 240 transmits a dial tone connection (call
Sound, or connection to a pushbutton signal receiver)
The upstream (highway transmission) time slot and the downstream
(Receiving highway) Select a time slot. this
When the uplink time slot is the time used for call detection
Slot or a different time slot (see FIG. 1).
1, 1115). Next, select the down time slot
For example, TSn (time slot on highway
In No. 1), No. Spreading modulator of one modem 210
Receive signal to operate 211 with PN code PNDj
When instructing the control device 217 via the distribution device 230,
In addition, the uplink time slot is also, for example, TS2 (highway
Finger to assign time slot 3) above to terminal device J
Show. The control device 217 controls the PN generator 213
Then, the spread modulator 211 operates in the time slot TSn.
It operates with the PN code PNDj and the spread demodulator 212
Operate with PN code PNUj in slot TS2
(FIGS. 11 and 1116). Buffer memo at the same time
Via uplink 215, the uplink time slot number TS2
A signal is input to the spread modulator 211 and transmitted to the terminal device J.
(FIG. 10 (e), FIG. 11, 1117). At this point, the modem 210 and the modem
There is no need to connect the e-ways 260- / 261-. Ma
In addition, the uplink time slot is the time
For systems that vary from lot to lot, the uptime
After sending the slot number to the terminal device, the terminal device
While maintaining code synchronization with the controller 111, the switching device side
It is preferable to switch the time slot. Of FIG.
The synchronization circuit 214 synchronizes the spread code of the spread demodulator 212.
Perform tracking. In the terminal device J, FIG.
As shown in FIG. 10F, the spread demodulator 112 (FIG. 3)
Operate with PN code PNDj in all time slots
Time slot TSn.
Receives the lot number TS2 (FIGS. 11 and 1103) and exchanges
Call detection performed in device 200/300
Is confirmed, the control device 140 controls the PN generator 113.
The operation of the spread modulator 111 is fixed to TS2.
Further, the operation of the spread demodulator 112 is fixed to TSn (see FIG. 1).
0 (a), (f), FIGS. 11, 1104). Receiving synchronization signal in terminal device 100
Is no more than 1
N + 1 time slot so that signal can be detected with frame delay
Although it is assumed that the data is received at every point (Fig. 8 (b)),
After the time slot is fixed, the time to receive the synchronization signal
Also fix the im slot. This is an n + 1 time slot
Communication is performed once every n frames if the synchronization signal is continuously received for each eye.
To receive the synchronization signal in the time slot for
In the example of FIG. 10, the communication time slot immediately before the communication time slot is used.
A synchronization signal is being received in the time slot. On the exchange device side, the terminal device 100
After sending the time slot number, (from the terminal device 100)
Signal to confirm that uplink time slot number is received
May be sent after receiving it)
Select and capture a button signal receiver (not shown) and call
With the time slot on the highway selected for the end
Set up channels between
The buffer memory shown in FIG.
And 216 are operated. 1 modem and 210
Iway 260-1 and 261-1 are connected (FIG. 1
1, 1118). A dial tone is transmitted from the push button signal receiver,
When dialing with the device, the multi-frequency signal
The signal is sent to the pushbutton signal receiver. It should be noted that multi-frequency signals within the terminal device 100
Although the details of the signal transmission operation are omitted, the control device 140
PCM-encoded corresponding to the dial signal received
Multi-frequency signals are sequentially input to the spread modulator 111.
Done by With the above operation, the terminal device 100 and the exchange device
Since the wireless channel between 200/300 has been set,
The subsequent operation of the switching devices 200/300 is the same as that of the known one.
It is done in the same way. In the above description, for example, FIG.
Send uplink time slot number from switching equipment to terminal equipment
In this case, it is written to send within one frame, but D channel
Even if it is sent over multiple frames using
It is clear that there is no obstacle, and it is not limited to the figure
There is no. Although the description is omitted, the addition of the D channel and the like are described in FIG.
And the buffer memory 2 in the same manner as in the first embodiment.
15, 216. 2. b. 3 Incoming call operation Time relationship diagrams in FIGS. 2, 3, and 12, and FIG.
The operation in the case of an incoming call will be described with reference to a flowchart. In FIG. 2, central control unit 240 receives a call.
When the number is received (FIGS. 13 and 1311), the called number
Identifies that the called terminal is, for example, "J" from the
(FIGS. 13 and 1312). Subsequently, the central control unit 240
Is a modem 2 capable of calling the called terminal device J
Select 10. Modulation / demodulation device 2 capable of calling terminal device J
If 10 is only one, it is determined uniquely, but multiple
Vacant channel between the calling terminal and the incoming line
The modulation and demodulation device having the function is selected (FIGS. 13 and 1313). At the same time, the calling terminal device or the incoming
The modulation / demodulation device 210 selected as the line, for example, No. n devices
Send and receive highways with empty time slots between
Select on 260-r, 261-r. This embodiment
The highway time slot and radio channel
No. No. n modem
Time between the terminal 210 and the called terminal device J.
This means that the slot has been selected (FIG. 13, 1314).
Here, TSn as the up time slot, down time
It is assumed that TS2 is selected as a slot (FIG. 12). As described above, the modem 210 and the terminal
No. 100, the uplink and downlink time slots are No.
n, No. J, TSn, TS2 decided, so central system
The control device 240 is connected to the N
o. An instruction is given to the control device 217 of the n-modem 210.
The spread modulator 211 is controlled by the control device 217.
In the time slot TS2, the spread modulation is performed with the PN code PNDj.
Tuning operation (Figs. 13 and 1315) and spread demodulation
The device 212 receives the PN code PN in the time slot TSn.
To perform the spread demodulation operation at Uj (FIG. 13, 1316)
Set. Further, the control device 217
The incoming signal is stored in the downlink buffer memory 215 in TS2.
Required information and the uplink time slot number to be used
Signal TSn is input, and spread modulator 211 expands the signal with PNDj.
Spread modulated and transmitted through the transceiver 220 and the antenna 500
(FIG. 12B, FIGS. 13 and 1317). No. In the J terminal device 100,
This signal is received by the tenor 130 and amplified by the transceiver 120
Then, the signal is input to the spread modulator 112. No. J terminal device 1
In the case of 00, as shown in FIG.
12 is a PN code PNDj and in all time slots,
Since the spread demodulation operation is performed,
The input signal is demodulated immediately, the incoming signal,
The slot number TSn is detected as a signal (FIG. 12).
(C), FIG. 13, 1301). In the terminal device 100, the control device 140
This is received through the interface circuit 150 and the incoming call is processed.
While controlling the PN generator 113 to perform spread demodulation.
The operation of the device 112 is fixed to the time slot TS2,
On the other hand, the reception of the synchronization signal is fixed to the previous time slot.
You. That is, at the position of the time slot TS1, the PN code PNC
Demodulation operation to receive the synchronization signal SNC2 (FIG. 1
2 (c), FIGS. 13, 1303). Similarly, for the spread modulator 111,
In order to operate in the received time slot TSn, P
The N generator 113 is controlled (FIG. 12D, FIG.
302). Control device 140 arrives at spread modulator 111
Input a confirmation signal to confirm that the signal has been
The switching device 200 /
300 (FIGS. 13 and 1304). By the above operation, switching apparatus 200/3
The channel between 00 and the terminal device 100 has been set.
And the control device 140 passes through the interface circuit 150
To ring the ringer 166 and send out a calling signal
(FIGS. 13 and 1305). On the other hand, on the exchange device side, already No. n change
The spread demodulator 212 of the demodulator 210
Since TSn operates with the PN code PNUj,
The confirmation signal sent from the terminal device 100 is immediately restored.
(FIGS. 13 and 1318), and a signal from the controller 217 is output.
The data is transferred to the central control unit 240 via the reception distribution unit 230.
It is. The central control unit 240 is a channel to the terminal device.
After confirming the settings, perform incoming connection processing such as ringing tone transmission.
(FIGS. 13 and 1319). As described above, according to the present invention, the switching device
It is possible to make wireless between terminal devices. Note that the states shown in FIGS. 12B and 12E are referred to.
First, (b) shows the time slot T
Sn is the terminal device K, time slot TS1 is the terminal device
I and time slot TS2 is frame q
From the terminal device J. FIG. 12E shows the time slot of frame q.
TSn (TS1 on the highway), the terminal device M
Call detection was performed, but call detection was not performed.
From frame q + 1 to time slot T
Sn indicates that the terminal device J has been used. Follow
The subsequent call detection uses other available time slots.
Will be done. Also, the time slot TS1 is
Time slot TS2 is used for terminal device I and terminal device K is used for terminal device I.
Is used. The second embodiment has been briefly described above.
However, after the wireless line is set, the time
Same as digital switching system with slot memory
It is clear that the known communication system
All of the functions can be introduced. In the present embodiment, the highway of the switching device is
To the wireless channel between the switching equipment and the terminal equipment.
Was described, the buffer memory 215 of FIG.
A time switch function 216, ie, time slot input
With the function of replacement, the time on the wireless channel
Lot assignment is completely independent of the switching equipment highway
And the number of time slots, ie transmission
The speed can also be independent. For example, wireless
The time slot of the channel is tied to each terminal device.
The highway from buffer memories 215 and 216
Also, a configuration such as concentrating at the point where the connection is made becomes possible. In the second embodiment, as shown in FIG.
Both the main exchange and the child exchange have exchange functions.
In other words, the connection between the terminal devices accommodated in the same child exchange device.
The following is a case where processing is performed in the child exchange device.
Time switches are stored in buffer memories 215 and 216.
Highway 260-1 to 260-r, 2
61-1 to 261-r are cables 600 (for example, optical fiber
High-speed digital highway by Iva)
Exchange with the central control unit 240 provided in the main exchange.
Communication with the control device 217 in the modem 210 is high.
Some of the time slots on the way are used as signal channels
If used, the child switching device of FIG.
The position 210 itself is good. In this case, the same
All communications between terminal devices in the modem are node devices.
610, via the main exchange 300 via the cable 600
Will be performed. In other words, the modem 21
Configure a switching system using 0 as a remote concentrator
It is also possible. The above embodiment is based on 64 kb / s audio.
I explained about ISDN based on the standard.
If the slot is enlarged, the message slot method
It can also be used for packet communication. Further, the switching system according to the present invention comprises a terminal device
Terminals have separate access channels from
It has a star-shaped wiring for the function
And therefore contention control switching equipment
In other words, after the terminal device sends out a calling signal,
Start communication by receiving communication start permission signal from device
If a packet is transmitted, a star-shaped local area
The same function as the network (LAN) can be realized. One of the features of spread spectrum modulation is
If noise immunity is used, the amount of attenuation is high in the high frequency range.
Wired transmission using existing voice communication local cable
Can also be used as a subscriber line transmission method in ISDN.
Can be used. Time-division multiplexing as shown in the second embodiment
In the case of performing spread spectrum modulation on the converted signal,
Twisted pair as a transmission path between the terminal equipment and the switching equipment
A, or use a wired transmission path such as a coaxial cable
Also connects multiple terminal devices on the same cable,
Connection type or multi-drop type
Multiple terminals can be connected with a single cable without using magnetic waves.
It will also be possible to provide communication between the local and switching equipment. This method can be used along a railway, along a road, or
Communicates using the cable installed along the power line
In such a case, a single cable can
It is very economical because it can provide a communication channel. According to the present invention, synchronization can be acquired at high speed.
High confidentiality and noise immunity, and digital
Compatibility with telephone switching systems that use switching methods
A good wireless telephone exchange system can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a system configuration diagram of an exchange device showing a first embodiment of the present invention. FIG. 2 is a system configuration diagram of a switching device according to a second embodiment of the present invention. FIG. 3 is a system configuration diagram showing one embodiment of a terminal device side according to the present invention. FIG. 4 is a configuration diagram of a distributed switching system showing an example of a switching system according to the present invention. FIG. 5 is a time relationship diagram showing a relationship between a signal on a highway and a signal on a wireless transmission path to a terminal device according to the first embodiment of the present invention. FIG. 6 is a flowchart showing a calling operation according to the first embodiment of the present invention. FIG. 7 is a flowchart showing an incoming call operation according to the first embodiment of the present invention. FIG. 8 is a time relationship diagram showing a state of a synchronization signal and a signal of a demodulation operation from a power-on of a terminal device to a standby for synchronization acquisition reception according to a second embodiment of the present invention. FIG. 9 is a flowchart showing an operation from power-on of a terminal device according to a second embodiment of the present invention to standby for an incoming call; FIG. 10 is a time relationship diagram showing a signal relationship during a calling operation according to the second embodiment of the present invention. FIG. 11 is a flowchart showing a calling operation according to the second embodiment of the present invention. FIG. 12 is a time relationship diagram showing a signal relationship at the time of an incoming call operation according to the second embodiment of the present invention. FIG. 13 is a flowchart showing an incoming call operation according to the second embodiment of the present invention. [Explanation of Codes] 100: terminal device, 111: spread modulator, 112
... Spread demodulator, 113 ... PN generator, 114 ... Synchronous circuit, 120 ... Transceiver, 130 ... Antenna, 1
40: control device, 150: interface circuit,
161, PCM modulator, 162, PCM demodulator, 163, transmitter, 164, receiver, 165 ...
Dial 166 ringer 170 data terminal device 200 switching device 210 modem device
211 ... spread modulator, 212 ... spread demodulator, 213 ...
PN generator, 214: synchronization circuit, 215, 216: buffer memory, 217: control device, 220
... Transceiver, 230 ... Signal reception and distribution device, 240 ...
Central control unit, 250 ... switching network, 3
00: exchange device, 400: external cable, 500:
Antenna, 600 ... cable, 610 ... node device.

────────────────────────────────────────────────── ─── Continuing on the front page (51) Int.Cl. ⁷ Identification symbol FI H04Q 7/38 (72) Inventor Tadahiko Akiyama 94, Kanayama-shi, Fukushima, Nippon Telecom Technology Co., Ltd. (56) References Special Sho-59-49033 (JP, A) JP-B-58-56290 (JP, B2)

Claims (1)

(57) [the claims] 1. In a switching device connected to a plurality of terminal devices via a wireless line, a receiving means for receiving a signal transmitted by the terminal device by spread spectrum modulation, and a spread code for performing spread spectrum demodulation of the signal received by the receiving means. A spread code generating means for generating a spread code; a spread spectrum demodulating means for performing spread spectrum demodulation of a signal received by the receiving means based on the spread code generated by the spread code generating means; Control means for controlling generation, wherein the control means, when capturing code synchronization for spread demodulation, uses a spread code different from a communication spread code used for spreading information such as voice, data or image. Controlling the spreading code generation means so that a spreading code for code synchronization shorter than the communication spreading code is generated.
An exchange apparatus for controlling the spread code generating means so as to generate the communication spread code when communicating information such as data or images. 2. In the exchange device according to claim 1,
The switching device according to claim 1, wherein the spread code for code synchronization has a length that is a fraction of an integer of the spread code for communication.