JPH0998466A - Mobile communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To continuously monitor a peripheral base station and an original base station even when a reception level is degraded during communication with the base station. SOLUTION: A mobile station B of this mobile object communication equipment provided with a base station A and the mobile station B for taking a TDMA/TDD system for performing communication by time division multiple access and time division bidirectional transmission is provided with a means 15 for storing the frequency and a time slot during the communication with the base station A, the means 14b for monitoring control signals for re- synchronization from the base station A during the communication, the means 14a for monitoring the control signals for synchronization from the peripheral base station, a monitoring part control means 14c for controlling the operations of two monitoring means 14a and 14b and a control means for transmitting the control signals for the sychronization to the base station A and recoverying a communication state at the time of receiving the control signals for the synchronization from one of the base station A during the communication and the peripheral base station.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a mobile communication device,
Particularly, the present invention relates to a base station monitoring technique by a mobile station of a mobile communication device used in a PHS mobile communication device or the like.

[0002]

2. Description of the Related Art Recently, a mobile communication service based on PHS has been started and is becoming widespread. FIG. 5 shows a conventional telephone device for mobile communication (hereinafter referred to as a mobile telephone device).
Is shown. In FIG. 5, A is a public base station or a branch office base station, and B is a schematic block diagram of a mobile station. In base station A, 101 is an antenna,
It is connected to the wireless circuit 102. The wireless circuit 102 is
The wireless controller 103 transmits and receives wireless data while instructing the frequency and the transmission and reception timing. 102
a is a synthesizer built in the wireless circuit 102,
A frequency designated by the radio control unit 103 is generated. The radio control unit 103 measures the reception level from the received radio data to determine the position of the mobile station, and the temporary storage memory 10
4 is written. Reference numeral 105 denotes a call / line control unit, which is a line 106 and a channel codec unit 107.
It is connected to the. Reference numeral 108 denotes a control unit composed of a microcomputer or the like, which issues a line control instruction to the call / line control unit 105. Call / line control unit 105
For voice information, the signal received from the line 106 is digitally converted and transferred to the channel codec unit 107, and the digital voice data received from the channel codec unit 107 is converted into an analog signal.
Send to 6. The channel codec unit 107 assembles and disassembles data transmitted and received on the wireless communication channel and control channel. The data of the communication channel is composed of information such as voice and control information processed by the control unit 108, and user data such as voice is controlled by the control unit 10.
It is processed without going through 8. In the control unit 108 of the base station, 108a stores the frequency and time slot during a call with the mobile station B, and informs the mobile station B when the signal from the mobile station B cannot be received during the call. Reference numeral 108b denotes a call state storage unit for transmitting the control signal for synchronization, and 108b denotes the mobile station B when the control signal for synchronization is received from the mobile station B while transmitting the control signal for synchronization to the mobile station B. And a synchronization control unit for returning to the call state.

Control channel data and communication channel control data are transmitted from an antenna 101 to a radio circuit 102.
If received via the channel codec 107, the channel codec 107 transfers only the data to the temporary storage memory 104, and the control unit 10
8 is notified of reception. The reception timing is instructed from the channel codec unit 107 to the wireless control unit 103 and the wireless circuit 102 each time. The reception frequency is preset in the wireless control unit 103 by the control unit 108 at each reception timing. When transmitting the control data, the control unit 108 controls the wireless control unit 103 and the wireless circuit 102.
To the wireless circuit 102 by instructing the transmission timing in advance. Further, the channel codec unit 107 has a function of generating a transmission timing of control data to be intermittently transmitted at a constant time in the control channel, a function of detecting the presence or absence of an error at the time of data reception, a temporary storage memory 104 together with the received data. It has the function of transferring to.

In mobile station B, 110 is an antenna, which is connected to a radio circuit 111. Wireless circuit 111
Has a built-in synthesizer 111a. Reference numeral 112 is a wireless control unit, 113 is a channel codec unit, 114 is a control unit including a microcomputer, etc., and is a peripheral base station monitoring unit 114a and a communicating base station resynchronization monitoring unit 114.
b and the call state storage unit 114c are built in. The call state storage unit 114c is a memory that stores that a call was in progress during a call with the base station A and the frequency and time slot used during the call. Reference numeral 115 is a temporary storage memory. The above-mentioned parts are basically the base station A
Although the mobile station B does not perform the intermittent transmission function, the channel codec unit 113 does not have the intermittent transmission timing generation function. Instead, in order to suppress the average current consumption of the internal battery of the mobile station, it has a intermittent reception timing generation function for intermittently receiving a signal on the control channel that the base station intermittently transmits during standby. At the same time, it has a function of generating a transmission timing based on the received reception timing from the base station. 116 is a call control unit, 117 is a receiver, 1
18 is a microphone. The call control unit 116 includes a channel codec unit 113, a receiver 117, and a microphone 118.
Performs analog / digital conversion of voice between and. The operation unit 119 and the display unit 120 are connected to the control unit 114, and the control unit 114 detects an input such as communication start from the operation unit 119 and outputs information for display to the display unit 120.

Next, the TDMA / TDD system (a bidirectional transmission system in which a plurality of uplink / downlink transmission paths are secured by using a frequency carrier by time division) will be briefly described. FIG. 6 shows that a certain frequency carrier goes up (direction from the mobile station to the base station or the called side mobile station to the calling side mobile station) and goes down (from the base station to the mobile station or the calling side mobile station to the called side mobile station). Direction 4) and 4 each
It shows the concept of a method of time division and transmission in the information direction. Usually, one time segment divided in time is called a time slot or a slot, and wireless data transmitted in the slot is called a burst. One frequency carrier is temporally divided into four time slots, and an up-and-down pair of each time slot is assigned a bidirectional channel for one communication.

In communication between a base station and a mobile station, a frequency carrier is a carrier for control that transmits control data for connection control and a carrier for communication that transfers voice, user data, etc. Used independently. Usually, a channel on a communication frequency carrier is called a communication channel, and a channel on a control frequency carrier is called a control channel.

FIG. 7 shows a burst structure of a control channel, a burst structure of a communication channel, and a burst structure of a synchronization burst signal. In the case of communication between base stations and mobile stations, in the downlink control channel, after transmitting control data by one shot, a non-transmission period of a certain period is repeatedly set to intermittently transmit the downlink signal. This is called intermittent transmission, and the base station constantly transmits the data necessary for the mobile station flowing into the area to access the base station immediately. Also,
Even when notifying the mobile station of an incoming call, this intermittent transmission is used. The uplink signal of the control channel is a random access because it is used when the mobile station requests to allocate the communication channel to the base station for transmission, etc., but is naturally transmitted at the uplink timing. . Even when the base station allocates the communication channel to the mobile station, the downlink control signal is transmitted by intermittent transmission. Once the communication channel is assigned, the mobile station continuously transmits the synchronization burst signal to the base station. As a result, the mobile station and the base station can recognize that they have secured a one-to-one bidirectional communication channel and can continuously transmit burst signals for communication with each other. The sync burst signal is transmitted continuously after the transfer to the communication channel in order to ensure synchronization,
Like the control burst, it has a long preamble and unique word. Since the communication burst is always transmitted continuously, the preamble and unique word are short.
Instead, it has enough user information fields to store voice and user data.

Next, the standby operation of the mobile station in the conventional example shown in FIG. 5 will be described. First, the standby operation of communication between base stations and mobile stations will be described with reference to the flowchart of FIG. At the time of waiting for the communication between the base stations and the mobile stations, the control unit 114 in the mobile station B is activated by the activation of the power supply or the like.
Instructs the channel codec unit 113 to be in the continuous reception state, and waits for the reception of the control downlink signal intermittently transmitted from the base station A on the control channel (steps 131 and 139). Next, when receiving the control downlink signal from the base station A, the control unit decodes whether the received signal is a signal from a base station that can form a pair with the mobile station, and if the signal is from a base station that can form a pair. , Communication control with the base station is performed so that the incoming signal from the base station is intermittently received at the intermittent transmission timing after communication with the base station for the registration of the position of the mobile station. Part 11
4a instructs the channel codec unit 113 (steps 132, 133, 134, 140, 141, 142,
143). When the incoming data is received, the control unit 114 instructs the channel codec unit 1 to send the control data.
13 and shifts to the operation during communication connection (steps 135, 136, 137, 138, 144, 145, 1
46, 147).

FIG. 9 is a timing chart showing the operation of the mobile station during intermittent reception. In FIG. 9, T
Reference symbol a is a carrier reception cycle that matches the timing of intermittent transmission from the base station, and intermittent reception is performed at this timing. In this intermittent reception, it is desirable that the time during which the reception is turned on is as close as possible to the actual data reception time.However, considering the rise time of the wireless circuit, etc., the reception on time may be earlier than the actual data reception time. It is common to

Next, the operation of the mobile station when the reception level deteriorates during communication between the mobile station and the base station will be described. During communication with the base station, the mobile station detects, via the radio control section 112, that the control section 114 has deteriorated the reception level itself or that the number of frame error rates of communication bursts within a certain period exceeds a certain value. At this time, if it is determined that the distance between the base station and the mobile station is long and it is being used as a cordless phone for public mode or business, another base station is installed around the base station. Therefore, the communication with the communication base station is temporarily interrupted, and the peripheral base station monitoring unit 114a of the control unit 114 in the mobile station B instructs the channel codec unit 113 to perform the continuous reception state. The reception of the control downlink signal intermittently transmitted on the control channel from the other base station is performed for a certain period of time. Then, when receiving a control downlink signal from another base station in the vicinity, the control unit decodes whether the received signal is a signal from a base station that can form a pair with the mobile station, and a signal from a base station that can form a pair. In that case, in synchronization with the downlink signal from the base station, the uplink control signal is transmitted toward the base station, and after moving to the communication carrier, the mobile station sends an uplink signal indicating that the connection is reconnection. By transmitting to the base station,
Communication can be continued by reconnecting to the base station.
When the control downlink signal from other base stations in the vicinity cannot be received even after waiting for reception of the control downlink signal for a certain period of time, the control unit 114 determines that there is no other base station in the vicinity, The communication base station resynchronization monitoring unit 114a is operated to continuously use the communication carrier communicating with the channel codec unit 107 so as to continuously receive the downlink synchronization burst signal from the communicating base station. Indicate the reception status.

[0011]

However, in the above conventional mobile telephone device, when the reception level deteriorates during communication between the mobile station and the base station, the communication with the communication base station is temporarily interrupted. , If it cannot wait to receive control downlink signals from other neighboring base stations for a certain period of time and cannot connect to other neighboring base stations, it will stop trying to connect to these neighboring base stations and the base station that was originally communicating It was operating to resynchronize with the station. However, the deterioration of the reception level during communication as described above means that the mobile station is near the boundary of the coverage area of the base station during communication, and the mobile station is from one place to another. Often in the process of moving to. Therefore, as described above, while the mobile station continues to move while the connection attempt to the peripheral base station is stopped and the operation of resynchronizing with the base station that was originally in communication is being performed, other peripheral base stations are It often happens that the reachable range is reached. Even in such a case, in the past, once the connection attempt to the neighboring base station is stopped, only the operation of resynchronizing with the base station which was originally in communication is executed, so that the neighboring neighborhood is approached. There is a problem in that the communication with the base station is no longer connected and the communication restart operation when moving between communication areas is not performed smoothly.

The present invention solves such a conventional problem and continuously and repeatedly monitors the surrounding base stations and the original base station even when the reception level deteriorates during communication with the base station. It is an object of the present invention to provide an excellent mobile telephone device that can be used.

[0013]

In order to achieve the above object, the present invention provides a mobile station that temporarily suspends communication with a communication base station and waits for reception of a control downlink signal from another base station in the vicinity. When the mobile station monitors the resynchronization signal from the original base station, and then reconnects to the original base station after a certain period of time, the mobile station monitors the resynchronization signal from the original base station, and reports from other peripheral base stations at a constant cycle. The gist is that a control means capable of monitoring a signal is provided.

Further, according to the present invention, in the same case as described above, when the mobile station monitors a resynchronization signal from the original base station, and further monitors a broadcast signal from another peripheral base station, The control means for alternately monitoring the notification signal from the base station and the notification signal from other peripheral base stations.

Therefore, according to the present invention, since it is possible to continuously monitor any of the base stations capable of communication connection between the original base station and other peripheral base stations, it is possible to quickly switch the communication base station. Therefore, the function as a communication means can be improved. Furthermore, according to the present invention, since the notification signal from the base station is monitored in the same manner as in the area outside the base station, the notification signal from the base station immediately when moving from the area outside the base station to the area Can be received.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention comprises a base station and a mobile station, and performs communication by time division multiple access and time division bidirectional transmission.
In a mobile communication device adopting the DD system, a mobile station monitors for resynchronization with the base station currently in communication during communication between mobile station base stations, and monitors for synchronization with neighboring base stations. The operation to do is repeated.

According to a second aspect of the present invention, there is provided a mobile communication device of a TDMA / TDD system, which comprises a base station and a mobile station and performs communication by time division multiple access and time division bidirectional transmission, The mobile station stores the frequency and time slot during communication with the base station, monitors resynchronization control signals from the base station in communication, and controls synchronization from peripheral base stations. Means for monitoring a signal, monitoring section control means for controlling the operation of the two monitoring means, and an uplink synchronization burst signal for the base station when a downlink synchronization burst signal is received from the base station in communication. To return to the call state while receiving a synchronization control signal from a peripheral base station, sends a synchronization control signal to the base station and shifts to the call state. A mobile communication device that includes a stage.

According to a third aspect of the present invention, in the mobile communication device according to the second aspect, the monitoring unit control means is
During the operation of the means for monitoring the resynchronization control signal from the base station in communication, the operation of the means for monitoring the synchronization control signal from the peripheral base station is executed by the interrupt operation.

According to a fourth aspect of the present invention, in the mobile communication device according to the second aspect, the monitoring unit control means is
The means for monitoring the resynchronization control signal from the base station in communication and the means for monitoring the synchronization control signal from the peripheral base station are alternately operated.

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 shows a configuration of a first embodiment of the present invention. In FIG. 1, A is a base station and B is a mobile station. In the base station A, 1 is an antenna and 2 is a radio circuit. The wireless circuit 2 transmits and receives wireless data while being instructed by the wireless controller 3 about the frequency and the transmission / reception timing. Reference numeral 2a is a synthesizer built in the wireless circuit 2 and generates a frequency designated by the wireless control unit 3. The radio control unit 3 measures the reception level from the received radio data, determines the position of the mobile station, and writes it in the temporary storage memory 4.
A call / line control unit 5 is connected to the line 6 and the channel codec unit 7. Reference numeral 8 denotes a control unit composed of a microcomputer or the like, which issues a line control instruction to the call / line control unit 5. Call / line control unit 5
For the voice information, the digital signal of the signal received from the line 6 is transferred to the channel codec unit 7, and the digital voice data received from the channel codec unit 7 is converted into an analog signal and transmitted to the line 6. The channel codec unit 7 assembles and disassembles data transmitted and received on the wireless communication channel and control channel. The data of the communication channel includes information such as voice and control information processed by the control unit 8, and user data such as voice is processed without the control unit 8. In the communication control unit 8 of the base station, 8a stores the frequency and time slot during the call with the mobile station B, and when the signal from the mobile station B cannot be received during the call, Reference numeral 8b denotes a call state storage unit for transmitting a synchronization control signal to the mobile station B when the synchronization control signal is received from the mobile station B while transmitting the synchronization control signal to the mobile station B. It is a synchronization control unit for returning to a talking state with B.

In the mobile station B, 10 is an antenna, which is connected to the radio circuit 11. The wireless circuit 11 has a synthesizer 11a built therein. 12 is a wireless control unit,
Reference numeral 13 is a channel codec unit, 14 is a control unit including a microcomputer, etc., and is a peripheral base station monitoring unit 1.
4a, a base station resynchronization monitoring unit 14b during communication, and a monitoring unit operation control unit 14c are incorporated. Reference numeral 15 is a temporary storage memory. Each of the above-mentioned units basically has the same function as the base station A, but the mobile station B does not perform the intermittent transmission function, so the channel codec unit 13 does not have the intermittent transmission timing generation function. Instead, in order to suppress the average current consumption of the built-in battery of the mobile station B, it has an intermittent reception timing generation function for intermittently receiving a signal on the control channel that the base station intermittently transmits during standby. .
Reference numeral 16 is a call control unit, 17 is a receiver, and 18 is a microphone. The call control unit 16 includes the channel codec unit 1
Analog / digital conversion of voice is performed between the receiver 3 and the receiver 17 and the microphone 18. The operation unit 19 and the display unit 20 are connected to the control unit 14, and the control unit 14 detects an input such as communication start from the operation unit 19 and outputs information for display to the display unit 20.

Next, the standby operation in the communication between the base station and the mobile station in the above-mentioned first embodiment is the same as that by the control unit 114 in the above-mentioned conventional example, and therefore its explanation is omitted here.

Next, the operation of the mobile station when the reception level deteriorates during the communication between the mobile station B and the base station A will be described with reference to the flow chart of FIG. In the mobile station, during communication with the base station, the control unit 14 detects via the radio control unit 12 that the reception level itself has deteriorated or that the number of frame error rates of communication bursts within a certain period exceeds a certain value. At some times, it is determined that the base station and the mobile station are far apart.
And when using it as a public mode or a cordless telephone for offices, it is common to have another base station installed around the base station, so once communication with the communication base station is performed. The operation is interrupted and a resynchronization operation with another peripheral base station in the vicinity or a resynchronization operation with the original base station (the base station which has been in communication connection until then, hereinafter referred to as "in-communication base station") is started. This operation will be described with reference to the flowchart of FIG.

When this operation is started, the monitor controller 14c of the controller 14 of the mobile station B first activates the peripheral base station monitor 14a (step 20). The peripheral base station monitoring unit 14a instructs the channel codec unit 13 to be in a continuous reception state, and waits for reception of a control downlink signal intermittently transmitted on a control channel from another peripheral base station for a certain period of time. . For this purpose, the peripheral base station monitoring unit 14a instructs the channel codec unit 13 to set the frequency of the control carrier for base station communication in the wireless control unit 12 (step 21), and the wireless circuit 1
1 is continuously received. When the radio circuit 11 receives a control downlink signal from a peripheral base station, it decodes whether or not the received signal is a signal from a base station that can be paired with a mobile station, and the received signal from the paired base station is used. If it is determined that the uplink control signal is transmitted to the peripheral base station, the uplink control signal is transmitted in synchronization with the downlink signal from the peripheral base station. That is,
The peripheral base station monitoring unit 14a instructs the channel codec unit 13 to perform control for reception at the timing of intermittent transmission from the peripheral base station, and waits for a control signal from the peripheral base station (step 22). When the control signal from the peripheral base station is received through the channel codec unit 13 (step 23), the control unit 14 decodes the data, and the peripheral base station monitoring unit 14a instructs the channel codec unit 13 to transmit the control data. After that (step 24), in response to a control signal from a peripheral base station, a process for communication connection between mobile station base stations is started (step 25). This means that the peripheral base station monitoring unit 14a has acquired another base station in the vicinity, and the communication can be continued by connecting to the peripheral base station.

When a certain period of time elapses while waiting for a control signal from a peripheral base station (step 26), the control unit 14 judges that there is no other base station in the vicinity, and then the control unit 14 The monitoring unit control unit 14c alternately operates the peripheral base station monitoring unit 14a and the communicating base station resynchronization monitoring unit 14b. As a result, the peripheral base station monitoring unit 14a and the communicating base station resynchronization monitoring unit 14b inform the channel codec unit 13 of the downlink synchronization burst signal from the communicating base station and the peripheral base station that has previously failed to receive. Then, the control signal from is received alternately and continuously (step 27), and each carrier enters a waiting state for synchronization with one of the base stations for a certain period of time. And
When either the control signal from the peripheral base station or the control signal from the communicating base station is received through the channel codec unit 13 (step 28), the data is decoded and then the peripheral base station monitoring unit 14a and the communication unit Of the middle base station resynchronization monitoring unit 14b, the monitoring unit on the side receiving the control signal transmits the uplink synchronization burst to the channel codec unit 13 with respect to the downlink synchronization burst signal from the in-communication base station monitoring unit 14a. A signal transmission is instructed, and in response to a control signal from a peripheral base station, an instruction to transmit control data of a carrier for controlling a base station is transmitted (step 29). , The process for establishing a communication connection between the base stations is started (step 30). When a certain period of time elapses while waiting for a control signal from any of the peripheral base stations or a downlink synchronization burst signal from the communicating base station, the monitoring unit control unit 14c returns to step 27, and again the peripheral base station. The monitoring unit 14a and the communicating base station resynchronization monitoring unit 14b are alternately operated.

FIG. 3 is a timing chart showing carrier reception by alternate operation of the peripheral base station monitoring unit 14a and the communicating base station resynchronization monitoring unit 14b. The timing chart of FIG. 3 shows the reception timing of each carrier when neither the control signal from the peripheral base station nor the downlink synchronization burst signal from the communicating base station can be received. In FIG. 3, after the communicating base station downlink synchronization burst signal receiving step 41, the receiving base station carrier receiving step 42, the communicating base station downlink synchronizing burst signal receiving step 43, the receiving base carrier carrier receiving step The operation of returning to the first base station in-communication base station downlink synchronization burst signal receiving step 41 after repeating the order of 44 with a constant carrier reception period Ta is repeated.

The operation at the time of resynchronization (communication restoration) with respect to the base station during communication is performed as follows. In the control unit 14, 14d is a call state storage unit for storing the fact that the call was in progress during the call with the base station A and the frequency and the time slot used during the call. Next, the resynchronization operation of the above embodiment will be described with reference to FIG. FIG. 4 shows the base station A and the mobile station B when the reception level deteriorates during a call between the base station A and the mobile station B.
The signal sequence between and is shown. During a call between the base station A and the mobile station B, the call state storage unit 14d of the control unit 14 of the mobile station B stores the fact that the call is in progress, the frequency during the call, and the time slot. When the control unit 14 detects that the reception level has deteriorated during the call, the call state storage unit 14d of the control unit 14 stores the fact.

On the other hand, the base station A stores the frequency and the time slot when the communication state storage unit 8a of the control unit 8 was in communication with the mobile station B during the communication with the mobile station B. When the base station cannot communicate with the mobile station because the reception level deteriorates during a call, the base station uses the time slot stored in the call state storage unit 8a to temporarily store the synchronization control signal in the memory 4 and the channel codec unit. 7, wireless circuit 2
The antenna 1 continues to transmit to the mobile station B at fixed intervals of 5 ms.

On the other hand, when the reception level of the mobile station B returns to normal, the control unit 14 confirms whether or not the call was in progress when the communication was interrupted due to the deterioration of the state, and then the frequency and time slot when the reception level deteriorated. Is set in the temporary storage memory 15 and then the continuous reception is instructed to the channel codec unit 13 to monitor the downlink synchronization burst signal from the base station A. The mobile station B receives the downlink synchronization burst signal from the base station A within a fixed time period by using the antenna 10, the radio circuit 11, the channel codec unit 13, and the temporary storage memory 1.
5, the in-communication base station resynchronization monitoring unit 14b of the control unit 14 instructs the temporary storage memory 15 and the channel codec unit 13 to transmit the uplink synchronization burst signal to the base station A, and then the call. Return to the state. When the downlink synchronization burst signal is not received within a certain time,
It becomes a standby state. On the other hand, when the base station A receives the uplink synchronization burst signal from the mobile station B, it returns to the call state under the control of the synchronization control unit 8b of the control unit 8 and can resume the call.

Thus, when the reception level deteriorates during a call with the base station A, the call state storage section 8a and the synchronization control section 8b in the control section 8 of the base station A and the call in the control section 14 of the mobile station B. Since the state storage unit 14d and the synchronization control unit 14c store and synchronize the frequency and time slot during the call, the call can be resumed immediately.

[0032]

As described above, according to the present invention,
When the mobile station temporarily interrupts communication with the communication base station, waits for reception of a control downlink signal from other base stations in the vicinity for a certain period of time, and then reconnects to the original base station,
The mobile station monitors the resynchronization signal from the original base station, and in monitoring the broadcast signal from the other peripheral base stations, the downlink synchronization burst signal from the original base station and the other peripheral base stations. Since the control means for alternately monitoring the control signal from the base station is provided, it is possible to continuously monitor any base station that can be connected to any of the original base station and other peripheral base stations. The communication base station can be switched and the function as a communication means can be improved.

Further, according to the present invention, the control signal or the downlink synchronization burst signal from the base station is monitored outside the range of the base station as well as within the range of the base station. Can immediately receive the notification signal from the base station.

Further, according to the present invention, the base station stores the frequency and the time slot during the call with the mobile station, and when the signal from the mobile station cannot be received during the call, the mobile station To the mobile station and a means for returning to a communication state with the mobile station when an uplink synchronization burst signal is received from the mobile station while transmitting the downlink synchronization burst signal to the mobile station. Prepare,
The mobile station, means for storing the frequency and time slot during the call with the base station, means for monitoring the downlink synchronization burst signal from the base station when the communication is temporarily interrupted during communication with the base station, When the downlink synchronization burst signal from the base station is received, it is provided with means for transmitting the uplink synchronization burst signal to the base station and returning to the call state,
Even if the reception level deteriorates during a call with the base station, the call can be immediately resumed with the original base station, and if this is not possible, the communication can be resumed by connecting to the peripheral base station. As a result, the convenience can be improved.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of a mobile telephone device according to an embodiment of the present invention.

FIG. 2 is a flow chart of a control unit at the time of a base station resynchronization monitoring operation of the mobile telephone device in the embodiment.

FIG. 3 is a timing chart showing a carrier receiving operation by an alternate operation of a peripheral base station monitoring unit and a communicating base station resynchronization monitoring unit.

FIG. 4 is a signal sequence diagram showing a resynchronization monitoring processing operation at the time of communication interruption between the base station and the mobile station of the mobile telephone device in the embodiment.

FIG. 5 is a schematic block diagram of a mobile telephone device in a conventional example.

FIG. 6 is a conceptual diagram of a TDMA / TDD transmission method.

FIG. 7 is a block diagram of a burst signal transferred wirelessly in the TDMA / TDD system.

FIG. 8 is a flow chart during a communication standby operation between base stations and mobile stations of a mobile station of a mobile telephone device in a conventional example.

FIG. 9 is a timing chart at the time of a standby operation for communication between base stations and mobile stations of a mobile station of a mobile telephone device in a conventional example.

[Explanation of symbols]

 A base station 1 antenna 2 radio circuit 2a synthesizer 3 radio control unit 4 temporary storage memory 5 call / line control unit 6 line 7 channel codec unit 8 control unit 8a call state storage unit 8b synchronization control unit B mobile station 10 antenna 11 radio circuit 11a synthesizer 12 wireless control unit 13 channel codec unit 14 control unit 14a peripheral base station monitoring unit 14b communicating base station resynchronization monitoring unit 14c monitoring unit control unit 14d call state storage unit 15 temporary storage memory 16 call control unit 17 receiver 18 microphone 19 Operation section 20 Display section

Claims (4)

[Claims] 1. A T which is composed of a base station and a mobile station and performs communication by time division multiple access and time division bidirectional transmission.
In a mobile communication device adopting the DMA / TDD system, a mobile station, during a communication operation between mobile station base stations, performs an operation of monitoring for resynchronization with the base station currently in communication and a synchronization with a peripheral base station. A mobile communication device characterized by repeating the operation of monitoring appropriately. 2. A T which is composed of a base station and a mobile station and performs communication by time division multiple access and time division bidirectional transmission.
In a mobile communication device adopting a DMA / TDD system, the mobile station monitors means for storing its frequency and time slot during communication with the base station, and a downlink synchronization burst signal from the base station in communication. Means, means for monitoring a control signal for synchronization from a peripheral base station, and monitoring section control means for controlling the operation of the two monitoring means,
When a downlink synchronization burst signal from the base station in communication is received, an uplink synchronization burst signal is transmitted to the base station to return to the call state, while a synchronization control signal from a peripheral base station is received. Is a mobile communication device having a control means for transmitting a synchronization control signal to the base station and returning to a call state. 3. The monitoring unit control means of the means for monitoring the control signal for synchronization from the peripheral base station by an interrupt operation during the operation of the means for monitoring the control signal for resynchronization from the base station in communication. The mobile communication device according to claim 2, wherein the mobile communication device executes an operation. 4. The monitoring unit control means alternately executes the means for monitoring the resynchronization control signal from the base station in communication and the means for monitoring the synchronization control signal from the peripheral base station. The mobile communication device according to claim 2, wherein