JP2010219755A - Wireless communication terminal - Google Patents

Abstract

A processing time until a wireless communication terminal in a mobile communication system enters a range mode is reduced.
The position information of the wireless communication terminal is acquired using the received GPS signal, the map information including the installation status of the base station is received and acquired from the base station, and the acquired map information and the position of the wireless communication terminal are received. Based on the information, a base station search process is executed to determine a base station to be connected.
[Selection] Figure 1

Description

  The present invention relates to, for example, a radio communication terminal in a mobile communication system, and more particularly, to a base station search processing technique for a radio communication terminal.

FIG. 5 shows a configuration example of a wireless communication terminal in the prior art.
The wireless communication terminal of this example includes a wireless unit 51, a station search control unit 52, a baseband transmission / reception unit 53, a broadcast information acquisition unit 54, a station list control unit 55, an application data transmission / reception unit 56, and a main control. A portion 57 is provided.

  The wireless unit 51 transmits and receives signals wirelessly communicated between the base station apparatus and the wireless communication terminal (mobile station), and performs band conversion between the wireless frequency band signal and the baseband signal that are wirelessly communicated. . The station search control unit 52 performs base station search processing for searching for connectable base stations. The baseband transmission / reception unit 53 performs baseband reception processing of the signal converted into the baseband band and baseband transmission processing for transmitting data to the base station via the radio unit 51. The broadcast information acquisition unit 54 acquires and analyzes broadcast information transmitted from the base station based on the data subjected to the baseband reception process. The station list control unit 55 creates and updates a peripheral station list used for the base station search process based on the analysis result of the broadcast information transmitted from the base station. The application data transmission / reception unit 56 performs data transmission / reception processing associated with a communication application executed by the wireless communication terminal. The main control unit 57 controls the radio unit 51, the station search control unit 52, the baseband transmission / reception unit 53, the broadcast information acquisition unit 54, the station list control unit 55, and the application data transmission / reception unit 56 as a radio communication terminal. Perform call processing and the like.

Next, the operation of a conventional wireless communication terminal will be described.
It is divided into the operation in the initial state where the in-zone cell does not exist or the wireless communication terminal is started up (hereinafter referred to as out-of-service mode) and the operation in the case where the in-zone cell exists (hereinafter referred to as in-range mode). I will explain. In addition, the state where the serving cell exists means a state where a communicable base station exists, and the state where the serving cell does not exist means a state where no communicable base station exists.

[Operation in out-of-service mode]
In the out-of-service mode, the station search control unit 52 sequentially sets the reception frequency of the radio unit 51 to a plurality of frequencies that are to be used in this system one by one, and starts the base station search process. . When the station search control unit 52 detects a signal received from a certain base station as an effective signal that matches the reception frequency set in the radio unit 51, the base station that has transmitted the signal detects the station search control unit 52. Thus, it is determined as a connection candidate station. Whether or not the detected signal is valid can be determined, for example, based on whether or not a quality measurement result such as carrier level (RSSI) or reception quality (RSCP or Ec / Io) of the detected signal is equal to or higher than a predetermined threshold. Here, Received Signal Strength Indicator (RSSI) represents received signal strength. RSCP (Received Signal Code Power) represents the desired wave received power. Ec / Io represents (pilot received power / all received power).

The baseband transmission / reception unit 53 performs baseband reception processing of the received signal, and the broadcast information obtained by the baseband reception processing is acquired and analyzed by the broadcast information acquisition unit 54. If it is determined that the base station is connectable from the analysis result in the broadcast information acquisition unit 54, the base station is connected to the base station mode. In the broadcast information, there is information such as whether the base station that sent the broadcast information is a construction station or a station of another business operator, and the vicinity of the base station that sent the broadcast information. Information such as the location information of peripheral stations is included.
When the station search control unit 52 cannot detect a valid signal that matches the reception frequency set in the wireless unit 51 and cannot detect a connection candidate station, or from the analysis result in the broadcast information acquisition unit 54, For example, if it is determined that the base station that sent out the broadcast information is a construction station or is a station of another business operator and cannot be connected, the frequency of the wireless unit 51 should be used in this system. Among the plurality of frequencies, the frequency of the next base station is set, and the above operation is repeated until the in-zone mode is entered.

[Operation in coverage mode]
In the peripheral mode, based on the peripheral station information included in the broadcast information received from the base station in the serving cell, that is, the connected base station, the station list control unit 55 uses the peripheral station search processing Create a station list. Using this peripheral station list, a search is made for a peripheral base station of a base station that is periodically connected.

  Specifically, the station search control unit 52 sets the frequency of the station included in the peripheral station list in the wireless unit 51, and performs base station search processing. If a valid signal having the same frequency as the frequency set in the wireless unit 51 is detected, the station search control unit 52 determines that it is a peripheral station candidate. Thereafter, the baseband transmission / reception unit 53 performs baseband reception processing of the received signal, and the broadcast information acquisition unit 54 acquires and analyzes the broadcast information subjected to the baseband reception process. If it is determined from the analysis result in the broadcast information acquisition unit 54 that the base station is connectable, it is stored as a detected station in the peripheral station list.

The base station search process in the zone mode is also performed during communication of application data by the application data transmission / reception unit 56, for example. As a result of such base station search processing, it is possible to perform processing for switching base stations such as handover processing during communication and movement of a serving cell during standby (cells change as the wireless communication terminal moves) It becomes. Along with the movement of the serving cell, a new peripheral station list is generated based on the peripheral station information included in the newly received broadcast information, and the base station search process in the coverage mode is continuously executed.
In Japanese Patent Application Laid-Open No. 2008-118420, information on a base station existing around the other station is acquired by a signal from another station other than the connected base station, and the candidate station list generation unit 27 is based on the information. And generating a list of other stations in the vicinity.

JP 2008-118420 A

  However, in the base station search process in the out-of-service mode of the conventional wireless communication terminal as described above, for example, a plurality of frequencies that are to be used in this system are set in the wireless unit 51 one by one. Therefore, if there is a station with a frequency that matches the valid cell (base station) at the beginning of the search order, it is possible to shift to the coverage mode in a short time. When there is a station having a frequency that matches the valid cell at the end of the search order, there is a problem that it takes time to shift to the in-zone mode. In addition, there is a valid cell at the beginning of the search order, but if the cell cannot be detected accidentally due to deterioration of the radio environment due to fading, etc., the mode shifts to the coverage mode. It took a long time before.

  The present invention was made in order to solve such a conventional problem, specifies the position of the wireless communication terminal, based on the specified position information and map information including base station installation information, An object of the present invention is to provide a wireless communication terminal that efficiently performs a base station search process.

In order to achieve the above object, in the first invention of the present application, the wireless communication terminal is configured as follows. That is,
A wireless communication terminal in a mobile communication system, a first wireless unit that receives a GPS (Global Positioning System) signal in a radio frequency band, and position information that acquires position information of the wireless communication terminal based on the received GPS signal An acquisition unit, a second radio unit that transmits and receives a signal wirelessly communicated between the base station and the radio communication terminal, and map information including a base station installation status is acquired based on the signal received by the second radio unit. Based on the map information acquisition unit, the acquired map information and the acquired location information of the wireless communication terminal, a base station search process for searching for a connectable base station and determining a base station to be connected is performed. A wireless communication terminal comprising: a control unit;

  According to the first invention, based on the map information (base station installation status) and the position information of the wireless communication terminal, for example, the base station search process can be performed first from the base station with a short distance. Processing time can be shortened compared to the conventional method.

  In the first invention, the position information of the wireless communication terminal is acquired by using the received GPS signal. However, the position information of the wireless communication terminal may be acquired by position information acquisition means other than GPS. Good.

  Further, the map information including the base station installation status can be handled as map information as long as the information includes at least data on the distance between each base station and the wireless communication terminal.

Next, in the second invention of the present application, the wireless communication terminal is configured as follows.
That is, the wireless communication terminal according to the first aspect of the present invention further includes a broadcast information acquisition unit that acquires broadcast information including a transmission power value transmitted from a base station, and the station search control unit includes the acquisition A base station search process is executed based on the obtained map information, the acquired location information, and the acquired broadcast information to determine a base station to be connected.

  According to the second invention, based on the map information (base station installation status), the position information of the wireless communication terminal, and the broadcast information including the transmission power value, for example, the short distance and effective broadcast information Since the base station search process can be performed first from the base station that issues (such as high transmission power), the base station search process time can be further shortened and performed efficiently.

In the third invention of the present application, the wireless communication terminal is configured as follows.
That is, the wireless communication terminal according to the first invention or the second invention,
Furthermore, based on the map information including the base station installation status, comprising a station list control unit for creating a station list of the base station included in the map information, when the wireless communication terminal moves in the serving cell, Receive and acquire new map information from the base station of the destination cell, create a station list based on the acquired new map information, the station search control unit based on the map information and the position information A radio communication terminal that selects a target base station to check a received signal from the created station list.

  According to the third invention, when the wireless communication terminal moves in the serving cell, a station list is created based on the new map information, and the station search control unit checks the received signal from the created station list. Since the stations can be selected, it is effective to shorten the processing time for entering the in-service mode and the processing time at start-up by using the station list.

  As described above, according to the wireless communication terminal according to the present invention, for example, in the base station search process in the out-of-service mode, compared with a method in which all the frequency ranges that can be set in the wireless unit 51 are searched in order. In addition, the base station search time can be shortened and the variation thereof can be improved, and the problem that it takes a long time to shift to the in-zone mode in some cases can be improved.

It is a figure which shows the structural example of the radio | wireless communication terminal which concerns on one Example of this invention. It is a figure which shows an example of the control flow of the radio | wireless communication terminal of this invention. It is a figure which shows an example of the control flow of the radio | wireless communication terminal of this invention. It is a figure which shows an example of a station list. It is a figure which shows the structural example of the conventional radio | wireless communication terminal.

FIG. 1 is a configuration example of a wireless communication terminal according to an embodiment of the present invention.
The radio communication terminal of this example is a radio communication terminal in a mobile communication system, and includes a first radio unit 1, an LCS measurement unit 2, a position information acquisition unit 3, a second radio unit 6, and a baseband. Transmission / reception unit 7, map information acquisition unit 10, map information storage unit 5, station search control unit 4, broadcast information acquisition unit 8, station list control unit 9, application data transmission / reception unit 11, main control unit 12.

  The first radio unit 1 receives a GPS signal in a radio frequency band and performs band conversion to a baseband signal. The LCS measurement unit 2 measures the position of the wireless communication terminal using the received GPS signal. Here, LCS (LoCation Service) is a position information acquisition method proposed by 3GPP (3rd Generation Partnership Project). The position information acquisition unit 3 acquires position information based on the measurement result measured by the LCS measurement unit 2. The second wireless unit 6 transmits and receives signals wirelessly communicated between the base station and the wireless communication terminal, and performs band conversion between a radio frequency band signal and a baseband signal. The baseband transmitting / receiving unit 7 is a baseband receiving process for the signal converted into the baseband by the second radio unit 6, and a base for transmitting data to the base station via the second radio unit 6. Perform band transmission processing.

  The broadcast information acquisition unit 8 acquires broadcast information including the transmission power value transmitted from the base station based on the data subjected to the baseband reception process. The map information acquisition unit 10 acquires map information including the base station installation status based on the data subjected to the baseband reception process. The map information storage unit 5 stores and stores the acquired map information. The station search control unit 4 executes a base station search process based on the acquired map information, the acquired position information, and the acquired broadcast information, and determines a base station to be connected.

  The station list control unit 9 creates a station list of all the base stations included in the map information based on the map information including the base station installation status and the broadcast information. The application data transmission / reception unit 11 performs data transmission / reception processing associated with a communication application executed by the wireless communication terminal. The main control unit 12 includes a first radio unit 1, an LCS measurement unit 2, a position information acquisition unit 3, a second radio unit 6, a baseband transmission / reception unit 7, a broadcast information acquisition unit 8, a map information acquisition unit 10, a map While centrally controlling the information storage unit 5, the station search control unit 4, the station list control unit 9, and the application data transmission / reception unit 11, call processing as a wireless communication terminal is executed.

  Next, the operation of the wireless communication terminal of the present invention and the control method thereof will be described using the flowchart of FIG. 2 for the out-of-service mode and the flowchart of FIG. 3 for the in-service mode.

[Operation in out-of-service mode]
The operation in the out-of-service mode will be described using the flowchart of FIG.
The first radio unit 1 receives a GPS signal in the radio frequency band, performs band conversion on the baseband signal, and then uses the GPS signal converted into the baseband band to perform radio transmission in the LCS measurement unit 2. The position of the communication terminal is measured (step ST-A1).
Based on the measurement result of the LCS measurement unit 2, the location information acquisition unit 3 creates location information data and acquires location information (step ST-A2). Further, based on the reception information received by the baseband transmission / reception unit 7, the map information acquisition unit 10 acquires map information including the base station installation status. The map information storage unit 5 stores and stores the acquired map information. The station search control unit 4 acquires location information from the location information acquisition unit 3 and map information from the map information acquisition unit 10 or the map information storage unit 5 (step ST-A3). The map information includes the installation status of base stations existing in the area drawn on the map. The base station installation status includes, for example, base station installation position information (latitude, longitude, coordinate position on the map, etc.), use frequency, and base station code number (for example, W-CDMA (Wideband-Code Division Multiple Access)). In the case of).

  The station search control unit 4 collates the acquired position information and map information, and selects a base station in the vicinity where the wireless communication terminal is currently located as a connection candidate base station (step ST-A4). As a method for selecting a connection candidate base station, for example, a station within a predetermined distance from a point where the wireless communication terminal is currently located can be set as a connection candidate base station. Next, the station search control unit 4 performs a cell search for selecting a base station to be connected to the selected connection candidate station. In the cell search, the use frequency of the base station in the area included in the map information is set in the second radio unit 6, and the received signal is checked. When a signal from a base station is detected by cell search, quality measurement such as carrier level (RSSI) and reception quality (RSCP and Ec / Io) of the signal is performed to obtain quality information of the base station ( Step ST-A5). Also, based on the reception information received and processed by the baseband transmission / reception unit 7, the broadcast information acquisition unit 8 analyzes and acquires broadcast information including transmission power value data transmitted from the base station.

  The station list control unit 9 designates from the station search control unit 4 among the base stations included in the map information, based on the broadcast information including transmission power value data and the quality information of the base station. The station list is updated and created for the base station that has been made (step ST-A6). When the station list does not exist yet, such as when the wireless communication terminal is started up, the station list control unit 9 creates a new station list for the base station designated by the station search control unit 4. If the station list already exists, the station list control unit 9 updates the station list for the base station designated by the station search control unit 4. The station search control unit 4 specifies, for example, a station within a predetermined distance from a point where the wireless communication terminal is currently located.

  An example of the station list is shown in FIG. In the example of FIG. 4, the base station unique code and the base station specific code for all base stations included in the map information stored in the map information storage unit 5 in advance in the area mode are determined based on the information in the map information. A station list containing frequency values has been created. Based on this station list, the station search control unit 4 sets the use frequency of the base station designated by the station search control unit 4 to the second radio unit 6, and examines the received signal from the base station. The station search control unit 4 specifies, for example, a station within a predetermined distance from a point where the wireless communication terminal is currently located. For a base station that detects a received signal and receives broadcast information, based on broadcast information including transmission power value data and quality information of the base station, a transmission power value (base station transmission power), a reception level , Propagation loss (= base station transmission power−reception level), frequency, base station timing, station identification flag for identifying whether or not already detected base station is added as detected, and the station list is updated and created .

In the wireless communication terminal of this example, the station search control unit 4 determines a base station (connection station) to be connected using the updated and created station list (step ST-A7). As a method for determining the connection station, for example, among the several base stations whose station identification flags in the station list have already been detected, for example, a connection with a station with the smallest propagation loss is made. Can do.
Thus, in this example, based on the information in the map information, update and create a station list containing the base station specific code and the frequency value for several base stations close to the wireless communication terminal, Check the received signals from these several base stations and identify the transmission power value, reception level, propagation loss, frequency, base station timing, and whether it is a detected base station based on the acquired quality information and broadcast information. A station identification flag is added to update and create the station list, and the connected station is determined based on the created station list.
In this example, as described above, the station list is updated and created, and the connected station is determined using the created station list. However, the connected station can also be determined without using the station list. In this case, steps ST-A1 to ST-A5 are executed, broadcast information including transmission power value data is acquired, and, for example, a base station with the smallest propagation loss is connected from the connectable base stations. What should I do?

  Through the connection station determined as described above, the main control unit 12 receives the first radio unit 1, the LCS measurement unit 2, the position information acquisition unit 3, the second radio unit 6, the baseband transmission / reception unit 7, and the broadcast information acquisition. Unit 8, map information acquisition unit 10, map information storage unit 5, station search control unit 4, station list control unit 9, and application data transmission / reception unit 11. The application data transmission / reception unit 11 performs communication processing (data transmission / reception) and the like using the terminal application function. The transmission data subjected to the communication process is converted into a radio signal by the second radio unit 6 and the baseband transmission / reception unit 7 and transmitted, and the received radio signal is transmitted by the second radio unit 6 and the baseband transmission / reception unit 7. It is converted into received data and the communication state is maintained.

[Operation in coverage mode]
In a mobile communication system, a cell in a serving area is frequently moved with the movement of a wireless communication terminal. There are various cases of moving the serving cell, such as moving through a handover state during communication or moving the serving cell in a so-called standby state.
Since the operation in the case of not involving the movement of the serving cell is the same as that of the prior art, the present invention relates to the present invention particularly when the serving cell is moved in the coverage mode, which is a feature of the present invention. The operation of the wireless communication terminal will be described using the flowchart of FIG.
In the area mode, the station list control unit 9 creates a station list for all base stations included in the map information stored in the map information storage unit 5.

  When there is a movement of the serving cell, the station list control unit 9 updates the map information stored in the map information storage unit 5 with a new map to the network via the base station of the destination cell. The information is requested, the map information is received via the second radio unit 6 and the baseband transmission / reception unit 7, and the map information acquisition unit 10 acquires the map information including the installation status of the base station. Further, the map information including the base station installation status is updated and stored in the map information storage unit 5, and the station list control unit 9 performs the station list based on the base station installation status included in the updated map information. Create a new.

  The wireless communication terminal receives the broadcast information transmitted from the base station of the destination cell via the second wireless unit 6 and the baseband transmission / reception unit 7, acquires the broadcast information by the broadcast information acquisition unit 8, and analyzes it. (Step ST-B1). Next, the base station listed in the station list stored in the station list control unit 9 is collated with the base station that has transmitted the acquired broadcast information (step ST-B2). As a result of the collation, if the station is present in the station list (Yes in step ST-B3), even if the station is not detected (station identification flag is not detected), the detected state The station list is updated with the station identification flag already detected (step ST-B4).

  As a result of the collation, if the station does not exist in the station list (No in step ST-B3), the base station is a station that does not exist in the map information stored in the map information storage unit 5. Become. That is, the place where the wireless communication terminal is currently located is outside the range of the map information stored in the map information storage unit 5. Accordingly, the station list control unit 9 requests new map information from the network via the base station of the destination cell in order to update the map information stored in the map information storage unit 5, and The map information is received via the radio unit 6 and the baseband transmission / reception unit 7, and the map information acquisition unit 10 acquires the map information including the installation status of the base station (step ST-B5). Further, the map information including the base station installation status is updated and stored in the map information storage unit 5, and the station list control unit 9 performs the station list based on the base station installation status included in the updated map information. Create a new.

  As described above, the map information is newly acquired by the movement of the serving cell. While moving the serving cell, the main control unit 12 includes the first radio unit 1, the LCS measurement unit 2, the position information acquisition unit 3, the second radio unit 6, the baseband transmission / reception unit 7, and the broadcast information acquisition unit. 8. While controlling the respective parts of the map information acquisition unit 10, the map information storage unit 5, the station search control unit 4, the station list control unit 9 and the application data transmission / reception unit 11 while performing call processing with the network side, The application data transmission / reception unit 11 performs communication processing (data transmission / reception) by the terminal application function. The transmission data subjected to the communication process is converted into a radio signal by the second radio unit 6 and the baseband transmission / reception unit 7 and transmitted, and the received radio signal is transmitted by the second radio unit 6 and the baseband transmission / reception unit 7. It is converted into received data and the communication state is maintained.

As described above, according to the wireless communication terminal of the present invention, the location information of the wireless communication terminal is acquired, the map information including the base station installation status stored in the wireless communication terminal, and the acquired wireless communication terminal The number of base stations to be subjected to base station search processing can be narrowed down and limited based on the position information.
In addition, when the cell in the area moves, the base station for which the base station search process is performed when the base station search process in the out-of-service mode becomes necessary after the map information is newly acquired and updated. It becomes possible to narrow down and limit the number of.

The present invention is not limited to a device that executes the process according to the present invention, but also as a method and system for executing the process according to the present invention, or a program for realizing the method and system according to the present invention, and the program. Can be grasped as a recording medium or the like.
The present invention may be configured such that the CPU performs control by executing a control program stored in a memory, or may be configured as a hardware circuit.

  1 ··· 1st radio unit 2 ··· LCS measurement unit 3 ·· Location information acquisition unit 4 · · Station search control unit 5 · · Map information storage unit 6 · · 2nd radio unit 7・ ・ Baseband transmission / reception unit, 8 ・ ・ Broadcast information acquisition unit, 9 ・ ・ Station list control unit, 10 ・ ・ Map information acquisition unit, 11 ・ ・ Application data transmission / reception unit, 12 ・ ・ Main control unit, 51 ・ ・ Wireless , 52 ·· Station search control unit, 53 ·· Baseband transmission / reception unit, 54 ·· Broadcast information acquisition unit, 55 ·· Station list control unit, 56 ·· Application data transmission / reception unit, 57 ·· Main control unit.

Claims (1)

A wireless communication terminal in a mobile communication system,
A first radio unit that receives a GPS signal in a radio frequency band;
A position information acquisition unit that acquires position information of the wireless communication terminal based on the received GPS signal;
A second wireless unit that transmits and receives signals wirelessly communicated between the base station and the wireless communication terminal;
A map information acquisition unit for acquiring map information including a base station installation status based on a signal received by the second radio unit;
A station search control unit that executes a base station search process for searching for a connectable base station based on the acquired map information and the acquired position information of the wireless communication terminal, and determines a base station to be connected. A wireless communication terminal characterized by that.

Images