JPH0799473A - Digital mobile communication equipment - Google Patents

Abstract

PURPOSE:To improve the frequency utilizing efficiency by allowing a master set starting communication with a desired slave set among plural master sets to detect a signal pattern of the master set having already made communication so as to establish the synchronization with the master set thereby eliminating a time not available for the communication. CONSTITUTION:When a master set 100 starts communication, a radio section 11 receives control use burst data communicated between other master set and slave set. The burst data are fed to a MODEM 12, in which the data are converted into a digital signal and it is inputted to a synchronization control section 16 and a unique word detection circuit 17 detects a unique word. Then a synchronization generating circuit 18 establishes the synchronization between the master set 100 and other master set based on a detection timing of the unique word in the unique word detection circuit 17. Furthermore, the synchronization generating circuit 18 detects a reception level from the radio section 11 to detect an idle area through which other master set makes no communication thereby deciding a slot used for the communication.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital mobile communication device such as a cordless telephone device mounted value or a mobile telephone system, and more particularly, it detects a signal pattern of a base unit which is already in communication and based on the signal pattern. The present invention relates to a digital mobile communication device that establishes synchronization with a master device that newly starts communication.

[0002]

2. Description of the Related Art Conventionally, in this type of device, the frequency that can be used for communication is limited, and in order to improve the utilization efficiency per frequency, the TDMA-TDD system is adopted as the communication system.

In this TDMA-TDD system, as shown in FIG. 4, transmission and reception are alternately performed at one frequency, and further, transmission and reception are each divided into four, whereby burst data is multiplexed and transmitted and received. Thereby, the utilization efficiency per frequency is improved.

That is, as shown in FIGS. 4 (a) and 4 (b), the slot configuration of transmission data from the master unit to the slave unit and the slot configuration of transmission data from the slave unit to the master unit are 5 ms, respectively. In this configuration, when the parent device and the child device communicate with each other, for example, the parent device sends a frame to the child device. The burst signal is transmitted using the second transmission slot T2 from the beginning, and the burst signal from the handset is received in the reception slot R2 four slots later. Further, the slave unit receives the burst signal from the master unit using the second reception slot R2 from the beginning of the frame, and the transmission slot T four slots after the burst signal is received.
In 2, the burst signal is transmitted to the master unit.

Here, the burst data transmitted from the master unit to the slave unit and the burst data transmitted from the slave unit to the master unit include control data and communication data, and the control data is as shown in FIG. 4 (c). , 4-bit ramp time (R), 2-bit start symbol (SS), 62-bit preamble (PR), 32-bit unique word (UW), 4-bit channel identification code (C
I), 104-bit data (I), 16-bit error checking bit (CRC), and 16-bit guard time (G) for control, and the communication data is shown in FIG. 4 (d). 4 bit ramp time (R), 2 bit start symbol (SS), 6 bit preamble (PR), 16 bit unique word (UW), 4 bit channel identification code (C
I) 176-bit data (I), 16-bit error check bit (CRC), and 16-bit guard time (G) for communication. Then, the control data and the communication data can be identified by the contents of the burst data.

By the way, as shown in FIG.
-1, 100-2, 100-3 are PBX (exchange) 30
When it is connected to 0, a synchronization signal is sent from the PBX 300 side to the parent devices 100-1, 100-2, 100-3, and the parent devices 100-1, 100-2, 100-3 As shown in FIG.
-1, 100-2, 100-3 are synchronized with each other so that transmission / reception signals do not collide with each other to realize communication.

That is, at the timing shown in FIG. 6 (a), the PBX 300 to the base units 100-1, 100-2, 1
A synchronization signal is transmitted to 00-3, and the master units 100-1 and 10-3
In 0-2 and 100-3, as shown in FIGS. 6B to 6D, each frame, that is, frame 1, frame 2, and frame 3 is configured in synchronization with this synchronization signal. , And realize communication with the slave units 200-1, 200-2, 200-3.

Here, as shown in FIG. 6 (e), in frame 1, communication is performed using the slot of slot number "1", and in frame 2, the slot of slot number "2" is used. Communication is performed, and in frame 3, communication is performed using the slot with the slot number “3”.

However, as shown in FIG.
-1, 100-2, 100-3 are general public lines (stations) 4
If it is connected to 00, the master devices 100-1 and 10
Since 0-2 and 100-3 cannot obtain the synchronization signal as shown in FIG. 6 from the station 400 side, the master unit 100-
1, 100-2 and 100-3 are configured to detect the reception sensitivity between the base unit and the handset that are already in communication, and make sure that the transmission / reception signals do not collide before performing the communication.

That is, as in the frame 1 shown in FIG. 8A, when the master unit 100-1 and the slave unit 200-1 are communicating with each other, the master unit 100-2 has the slave unit 200-2.
When starting communication with the parent device 200-2,
By detecting the reception sensitivities of the transmission 1 and the reception 1 shown in FIG.
As in the frame 2 shown in (b), another base unit, that is, a free area in which the base unit 100-1 is not communicating is searched and the free area is used to search for the base unit 100-2 and the slave unit 20.
Communicate with 0-2.

However, according to such a method of measuring the reception sensitivity, the reception sensitivity, that is, the timing of transmission and reception cannot be measured very accurately due to interference or the like, and therefore, FIG.
As shown in (c), a time Δt that cannot be used for communication occurs between the transmission 1 and the transmission 2 and between the reception 1 and the reception 2.

As a result, four-multiplex communication per frequency becomes impossible, and the number of communicable channels decreases.
There is a problem that the frequency utilization efficiency is reduced.

[0013]

As described above, in the conventional digital mobile communication apparatus, the timing Δt cannot be used for communication because the timing cannot be measured accurately due to interference or the like, and therefore, the frequency Δt per frequency is not available. There is a problem that the 4-multiplex communication becomes impossible, the number of communicable channels decreases, and the frequency utilization efficiency decreases.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a digital mobile communication device capable of eliminating the time during which communication cannot be used and improving the frequency utilization efficiency.

[0015]

To achieve the above object, the present invention provides a digital mobile communication device having a plurality of slaves and a plurality of masters communicating with the slaves in a predetermined communication area. In the above, the master unit that starts communication with a desired slave unit among the plurality of master units detects the signal pattern of the master unit that is already communicating, and synchronizes with the master unit based on the signal pattern. Is established.

[0016]

According to the present invention, when a parent machine starts communication with a desired child machine while another parent machine is communicating with the child machine, this certain parent machine is already communicating. The signal pattern of the other master unit is detected, and the synchronization with the master unit is established based on the detected signal pattern of the other master unit.

Here, as the signal pattern, a unique word which is one of the signal patterns of the master unit can be used.

Further, the master unit which starts the communication detects the reception level of the signal transmitted from the master unit or the slave unit which has already communicated, and determines the slot for communication based on the detected reception level. .

The master unit has two states, master mode and slave mode, and the master unit in master mode transmits and receives signals at its own timing.
The slave unit master unit may be configured to detect a signal pattern transmitted from the master unit master unit and establish synchronization with the master unit master unit based on the detected signal pattern.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a digital mobile communication device according to the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a detailed configuration of a master unit 100 in an embodiment apparatus to which the present invention is applied, and FIG. 2 is a block diagram showing a detailed configuration of a slave unit 200 in the embodiment apparatus. It is shown in.

Note that this embodiment is applied to a configuration in which the base units 100-1, 100-2, 100-3 are connected to a general public line (station) 400 as shown in FIG. The base unit 100 shown in FIG. 1 is the base unit 10 shown in FIG.
It corresponds to 0-1, 100-2, 100-3, and FIG.
The slave unit 200 shown in FIG.
It corresponds to 200-2 and 200-3.

In FIG. 1, the base unit 100 is an antenna 1
0, radio unit (RF) 11, modulator / demodulator (MODEM) 1
2, TDMA circuit 13, code decoder (CODEC) 1
4, a line interface (line I / F) 15, and a synchronization control circuit 16 are provided. Here, the line interface (line I / F) 15 is connected via the public line as shown in FIG.
It is connected to the general public line (station) 400 shown in FIG.

The synchronization control circuit 16 comprises a UW detection circuit 17 and a synchronization generation circuit 18.

In FIG. 1, when the master unit 100 tries to start the communication, the master unit 100 is already in communication between the other master unit and the slave unit, and is used for control as shown in FIG. 4 (c). The burst data is received by the radio unit (RF) 11 via the antenna 10. The received burst data for control is added to a modulator / demodulator (MODEM) 12 and converted from an analog signal to a digital signal.

On the other hand, the burst data converted into a digital signal by the modulator / demodulator (MODEM) 12 is input to the synchronization controller 16.

In the UW detection circuit 17, the synchronization control unit 16 detects the 32-bit unique word (UW) contained in the burst data from the input burst data.
To detect. Then, the synchronization generation circuit 18 establishes synchronization between the master device 100 and another master device that is already in communication, based on the detection timing of the unique word (UW) in the UW detection circuit 17.

That is, the synchronization generation circuit 18 establishes synchronization with another master unit from the detection timing of the unique word (UW) of the other master unit in communication detected by the UW detection circuit 17, and Synchronization generation circuit 18 of synchronization control unit 16
Detects the reception level from the radio unit (RF) 11 and detects an empty area in which another master device is not communicating to determine a slot to be used for communication.

Next, the UW detection circuit 17 of the synchronization control unit 16
Detects a unique word included in the burst data from the slave unit in order to establish synchronization with the slave unit communicating with the master unit 100. Then, based on the detection of this unique word, determine the transmission and reception timing of communication,
Radio unit (RF) 1 based on this transmission and reception timing
1, a modem (MODEM) 12 and a TDMA circuit 13 are controlled.

Thereafter, the burst data converted into a digital signal by the modulator / demodulator (MODEM) 12 is input to the TDMA circuit 13, and after the necessary data is taken out, the voice data is added to the code decoder (CODEC) 14. ,
Here, this voice signal is encoded and output to the public line through the line interface (line I / F) 15.

In FIG. 2, the slave unit 200 includes an antenna 20, a radio section (RF) 21, a modulator / demodulator (MODE).
M) 22, TDMA circuit 23, code decoder (CODE)
C) 24, a speaker 25, a microphone 26, and a synchronization control circuit 27. Here, the synchronization control circuit 27 includes a UW detection circuit 28 and a synchronization generation circuit 29.

In FIG. 2, the slave unit 200 includes a wireless unit (R
F) The burst data received from the master unit 100 at F) 21 is applied to the modulator / demodulator (MODEM) 22, and the burst data is converted from an analog signal to a digital signal here.

On the other hand, the burst data converted by the modulator / demodulator (MODEM) 22 is input to the synchronization control unit 27, and the synchronization control unit 27 detects the unique word included in the burst data by the UW detection circuit 28.
The synchronization generation circuit 29 establishes synchronization with the master device 100 based on the detection timing of the unique word detected by the UW detection circuit 28.

That is, the slave unit 200 detects the unique word included in the burst data from the master unit 100,
Based on the detection of this unique word, the transmission and reception timing of the communication to the master device 100 is determined, and the radio unit (RF) 21, the modulator / demodulator (MODEM) 22, and the TDMA circuit 23 are controlled based on this transmission and reception timing.

Thereafter, the burst data converted into a digital signal by the modulator / demodulator (MODEM) 22 is input to the TDMA circuit 23, and after the necessary data is taken out, the voice data passes through a code decoder (CODEC) 24, The sound is output from the speaker 25.

The voice input from the microphone is decoded by the code decoder (CODEC) 24, and TD
The signal is transmitted from the antenna 20 to the parent device 100 as a radio wave via the MA circuit 23, the modulator / demodulator (MODEM) 22, and the wireless unit (RF) 21.

FIG. 3 is a timing chart showing the transmission / reception operation in this embodiment.

Here, the frame 1 shown in FIG.
FIG. 3B shows a state in which the master unit and the slave unit communicate with each other using the slot with the slot number “1”. The frame 2 shown in FIG. FIG. 3C shows a state in which the master unit and the slave unit communicate with each other using the “2” slot, and the frame 3 shown in FIG.
Indicates that the parent device and the child device communicate with each other using the slot with the slot number “3” adjacent to the slot with the slot number “2”. Here, no time during which communication cannot be used does not occur between each transmission / reception slot.

As described above, in this embodiment, in this embodiment, the master unit 100 receives the burst data for control transmitted from another master unit that is already in communication, and Since the UW included in the burst data received by the UW detection circuit 17 is detected and synchronized with the other base unit, the area that cannot be used for communication is eliminated and the frequency can be effectively used. .

The master unit has two states, master mode and slave mode. The master unit in master mode transmits / receives signals at its own timing, and the master unit in slave mode is the master mode master. The signal pattern of the machine may be detected, and the synchronization may be established with the master machine in the master mode based on the detected signal pattern.

[0041]

As described above, according to the present invention,
When a master unit starts communication with a desired slave unit while another master unit is communicating with the slave unit, this master unit is a signal pattern of another master unit that is already communicating. Is detected and synchronization is established with the parent device based on the detected signal pattern of the other parent device. Therefore, the time during which communication cannot be used is eliminated and the frequency can be effectively used.

Further, since the reception level is detected and the slot for communication is determined based on the detected reception level,
The influence of interference can be avoided.

[Brief description of drawings]

FIG. 1 is a block diagram showing a circuit configuration of a master unit according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a circuit configuration of a slave unit according to an embodiment of the present invention.

FIG. 3 is a timing chart showing transmission / reception operation timing in this embodiment.

FIG. 4 is a slot configuration diagram in the TDMA-TDD system.

FIG. 5 is a configuration diagram of a conventional digital mobile communication device configured by connecting a base unit to a PBX (exchange).

6 is a timing chart showing transmission / reception operation timing in the configuration shown in FIG.

FIG. 7 is a block diagram of a digital mobile communication device when the master unit is connected to a general public line (station).

8 is a timing chart showing conventional transmission / reception operation timing in the configuration shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 antenna 11 radio part (RF) 12 modem (MODEM) 13 TDMA circuit 14 code decoder (CODEC) 15 line interface (line I / F) 16 synchronization control circuit 17 UW detection circuit 18 synchronization generation circuit 20 antenna 21 radio part (RF) 22 Modulator-demodulator (MODEM) 23 TDMA circuit 24 Code decoder (CODEC) 25 Speaker 26 Microphone 27 Sync control circuit 28 UW detection circuit 29 Sync generation circuit 100, 100-1 to 100-3 Master unit 200, 200- 1 to 200-3 cordless handset 300 general public line (station) 400 PBX (exchange)

Claims (4)

[Claims] 1. A digital mobile communication apparatus having a plurality of slaves and a plurality of masters communicating with the slaves in a predetermined communication area, wherein a desired slave among the plurality of masters is provided. The digital mobile communication device, wherein the master unit that starts communication detects a signal pattern of the master unit that is already communicating and establishes synchronization with the master unit based on the signal pattern. 2. The digital mobile communication device according to claim 1, wherein the signal pattern is a unique word which is one of the signal patterns of the master unit. 3. The base unit which initiates communication detects a reception level of a signal transmitted from a base unit or a slave unit which is already in communication, and determines a slot for communication based on the detected reception level. The digital mobile communication device according to claim 1, characterized in that: 4. The master unit has two states, a master mode and a slave mode,
The master unit in master mode transmits / receives signals at its own timing, and the master unit in slave mode detects the reception level of the signal transmitted from the master unit in master mode and uses the detected reception level as the basis. The digital mobile communication device according to claim 1, wherein a slot for communicating with the mobile communication device is determined.