JP2004221671A - Mobile station apparatus and cell search control method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the power consumption without lowering call origination rate and call reception rate by enabling to perform cell search, immediately and accurately responding to changes in the state of a radio wave. <P>SOLUTION: When the timing of cell search comes, a timer 144 of a control unit 104 actuates a radio unit 102 and a clock control unit 105, and in this case, when a new detecting cell search executing cycle timer is completed, the timer 144 actuates a delay profile calculating unit 133 to perform new detecting cell search. On the contrary, if the timer is not completed, known detecting cell search is performed using a detected diffusion code and a detected diffusion timing which are stored in a storage unit 141. Also, a determining unit 142 determines whether or not the level of line quality of a waiting base station which has been measured by a level measurement unit 136 is equal to or more than a threshold. If the level is equal to or more than the threshold, new detecting cell search execution cycle timer of the timer 144 is set to be long. If the level is lower than the threshold, the new detecting cell search execution cycle timer is set to be short. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a mobile station device used in a mobile communication system, and a cell search control method and a program for searching for an optimal base station for communication in the mobile station device.
[0002]
[Prior art]
2. Description of the Related Art In a mobile communication system using a mobile phone device or the like that is currently widespread, a wireless area for performing wireless communication is divided into a plurality of wireless areas called "cells", and a base station is provided for each cell. The base station communicates with the mobile station that has moved into the cell, so that the mobile station communicates with the nearest base station.
[0003]
Each of the above base stations constantly transmits a signal of the synchronization wireless channel of the mobile station at a fixed transmission power. Since the radio wave of this signal propagates in space while being attenuated, the longer the propagation distance, the greater the amount of attenuation. Therefore, when the mobile station receives radio waves from the base station, a state occurs in which the reception quality of the synchronization radio channel from the near base station is good and the reception quality of the synchronization radio channel from the distant base station is poor. .
[0004]
The waiting mobile station measures and monitors the line quality based on the reception level of the synchronization radio channel transmitted from the base station. Then, by monitoring the line quality, a wireless channel for synchronization of the base station which is optimal for communication is found out, and the base station enters a standby operation to prepare for a call or an incoming call. Finding this synchronization radio channel and measuring the channel quality of the found synchronization radio channel are called "cell search".
[0005]
As the mobile station moves, the radio wave condition of the synchronization radio channel arriving from each of the aforementioned base stations changes. Therefore, it is important for the mobile station to always perform the above cell search, select an optimal base station for communication, and enter a standby operation for the optimal base station in order to maintain the calling rate and the incoming rate.
[0006]
In a CDMA (Code Division Multiple Access) type mobile communication system, a signal of a synchronization radio channel is spread and transmitted with a spreading timing and a spreading code that are different for each base station. For this reason, the mobile station needs to detect a spread timing and a spread code in order to measure or demodulate the reception level of the signal of the synchronization radio channel (for example, see Patent Document 1).
[0007]
By the way, the contents of the above-described cell search process include a process of searching for a new base station by newly detecting a spreading timing and a spreading code of a synchronization radio channel, and measuring a channel quality thereof (hereinafter, this process is referred to as “process”). A process of measuring channel quality again for a base station that has already been detected using a new detection cell search) and a spreading timing and a spreading code that have already been detected (hereinafter, this process is referred to as a “known detection cell search”). Search ”).
[0008]
The mobile station of the mobile communication system repeats the operations of the above-described new detection cell search and known detection cell search. The mobile station holds channel quality information on each of the neighboring base stations and the waiting base station for each of these base stations, and performs ranking. Then, when the order of the line quality is changed, an operation of changing the standby base station to the optimum base station in the held information is performed.
[0009]
Here, since the spreading timing and spreading code of the base station that has been detected in the past are held and known, demodulation and reception level measurement are performed using the already detected spreading timing and spreading code. The known detection cell search to be performed can measure the line quality in a shorter time than the new detection cell search.
[0010]
On the other hand, the mobile station performs an intermittent reception operation to stop power supply and clock supply of the radio unit and the signal processing unit to reduce useless current at a timing when the operation is unnecessary when the operation is unnecessary, thereby extending a battery operation. I have. In particular, the above-described process of the newly detected cell search requires a longer operation time than the known detected cell search for measuring the line quality again for the detected base station. This is effective for reducing power consumption.
[0011]
However, when the mobile station moves, or when the situation of obstacles surrounding the mobile station changes, the distance from all the base stations that have already been detected is significantly large or the line quality deteriorates. In this case, there is a possibility that there is no cell to be awaited and the cell goes out of the service area. At this time, for example, if the power consumption is reduced by always performing only the known detection cell search, the new base station cannot take in. Therefore, the conventional apparatus adopts a method of reducing the frequency of the newly detected cell search and reducing the power consumption by periodically omitting the newly detected cell search during the cell search operation. .
[0012]
However, when there are no obstacles blocking the radio wave between the base station and the mobile station and the mobile station is stationary in the same cell, the radio wave condition of the surrounding lines (hereinafter referred to as line condition) is good. Even if the mobile station periodically performs a new detection cell search and consumes a large amount of power due to the operation of the radio unit and the signal processing unit, no new base station is detected, and only the known detection cell search is performed. The result is the same as if you did. In this case, the mobile station performs a useless operation without finding a new base station, and the power consumption increases due to the newly detected cell search, which results in faster battery consumption of the mobile station.
[0013]
In addition, in order to reduce the frequency of the newly detected cell search, the method of fixedly lengthening the cycle of the newly detected cell search involves changing the radio wave condition of the line surrounding the mobile station and changing the currently detected base station. Even if an optimum base station appears in addition to the above, its detection is delayed by an increase in the cycle of the newly detected cell search. In this case, the base station selection performance deteriorates, and as a result, the calling rate and the incoming call rate decrease.
[0014]
As a cell search control method that solves the above problems, a mobile station measures the reception quality (maximum received power, etc.) of a perch channel (synchronization radio channel) of a base station that is currently being acquired, and performs a new search. It is automatically determined whether the mobile station is located in the periphery of the cell where the necessity of searching for the perch channel is high, or whether the mobile station is located near the base station where the necessity is low. A method has been shown to increase the frequency of searching at high points and, conversely, reduce the frequency of searching at points where the need is low, thereby reducing power consumption while maintaining high accuracy in selecting the best base station ( For example, see Patent Document 2).
[0015]
[Patent Document 1]
JP 2001-78245 A
[Patent Document 2]
JP 2001-28778 A
[0016]
[Problems to be solved by the invention]
As described above, the conventional mobile station apparatus and the cell search control method have a problem in that the power consumption increases in the cell search during standby. Further, when the cell search cycle is lengthened to suppress power consumption, when a new optimal base station appears, it takes a lot of time to detect and select a synchronization radio channel from this base station. It takes time, and as a result, there is a problem that the calling rate and the incoming call rate decrease.
[0017]
In the method disclosed in Patent Document 2, the mobile station measures the reception quality (maximum received power, etc.) of the perch channel (synchronization radio channel) of the base station that is currently being acquired, thereby enabling cell search. Adjusting the frequency is specified. However, in such a system, in a situation where the reception quality of the capturing base station is good and the frequency of cell search is reduced, there is a time zone in which neither new cell search nor known cell search is executed, In some cases, it is difficult to detect an instantaneous cell change, so that an optimal base station cannot be acquired and the incoming call rate is reduced.
[0018]
The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to perform a cell search quickly and accurately in response to a change in line conditions, without reducing a call rate or a call rate. It is an object of the present invention to provide a mobile station device capable of reducing power consumption, a cell search control method, and a program.
[0019]
[Means for Solving the Problems]
A mobile station device according to the present invention detects a synchronization radio channel of a base station arranged for each of a plurality of cells constituting a radio area, and performs a cell search for measuring a channel quality level of the detected synchronization radio channel. A mobile station apparatus comprising a cell search unit for performing a search for a newly detected cell for a new base station and a search for a known cell for an already searched base station. Can be executed, and furthermore, a timer means for counting the execution cycle of the newly detected cell search, and when the timing to execute the cell search has arrived, the execution cycle of the newly detected cell search has not been reached. In this case, the cell search execution system executes the known detection cell search, and executes the new detection cell search when the execution cycle of the new detection cell search has been reached. Means, if the line quality level of the base station to be awaited measured in the known detected cell search or the newly detected cell search is less than a predetermined value, shorten the execution cycle of the newly detected cell search in the clocking means. And an execution cycle control means for setting a long execution cycle of the newly detected cell search in the timing means when the line quality level is equal to or more than a predetermined value.
[0020]
With the above configuration, for example, when the mobile station device is stationary and the line condition is good and the line quality level of the base station to be awaited is equal to or higher than a predetermined value, the execution cycle of the newly detected cell search is extended. However, by lowering the frequency of executing the newly detected cell search, it is possible to reduce the power consumption without lowering the calling rate or the incoming call rate. Also, at the cell search execution timing, the newly detected cell search is executed only when the execution cycle of the newly detected cell search has been reached, and the known detection cell search is executed when the execution cycle has not been reached. It is possible to execute an appropriate cell search at an appropriate timing in response to a change or the like, and to wait for an optimal base station while reducing power consumption.
[0021]
Further, the cell search execution control means activates a radio unit and a signal processing unit when the timing to execute the cell search arrives, executes the known detected cell search or the newly detected cell search, and After the measurement of the channel quality level of the synchronization radio channel from the station is completed, the operation of the radio unit is stopped.
[0022]
With the above configuration, when the line quality level of the base station to be awaited is equal to or higher than a predetermined value, power consumption due to the operations of the radio unit and the signal processing unit can be reduced by extending the execution cycle of the newly detected cell search. Power consumption can be reduced.
[0023]
A cell search control method according to the present invention is a cell search for detecting a synchronization radio channel of a base station arranged for each of a plurality of cells constituting a radio area and measuring a line quality level of the detected synchronization radio channel. A cell search control method in a mobile station device that performs a time search step of timing the execution cycle of a newly detected cell search to search for a new base station as the cell search; and When it arrives, if the execution cycle of the newly detected cell search has not been reached, the cell search is executed as a known detected cell search for a base station that has already been searched, and the newly detected cell search is executed. A cell search execution control step of executing the newly detected cell search when the cycle has been reached; and If the line quality level of the target base station measured in the newly detected cell search is less than a predetermined value, the execution cycle of the newly detected cell search in the timing step is set short, and the line quality level is equal to or more than a predetermined value. , An execution cycle control step of setting a longer execution cycle of the newly detected cell search in the clocking step.
[0024]
According to the above procedure, for example, when the mobile station apparatus is in a stationary state, the line condition is good, and the line quality level of the base station to be awaited is equal to or higher than a predetermined value, the execution cycle of the newly detected cell search is extended. However, by lowering the frequency of executing the newly detected cell search, it becomes possible to reduce the power consumption of the mobile station apparatus without lowering the call rate or the call rate. Also, at the cell search execution timing, the newly detected cell search is executed only when the execution cycle of the newly detected cell search has been reached, and the known detection cell search is executed when the execution cycle has not been reached. An appropriate cell search can be executed at an appropriate timing in response to a change or the like, and the mobile station apparatus can wait for an optimal base station while reducing power consumption.
[0025]
In the cell search execution control step, when a timing to execute the cell search comes, a radio unit and a signal processing unit are started to execute the known detection cell search or the new detection cell search, and After the measurement of the channel quality level of the synchronization radio channel from the station is completed, the operation of the radio unit is stopped.
[0026]
According to the above procedure, when the line quality level of the base station to be awaited is equal to or higher than a predetermined value, power consumption due to the operations of the radio unit and the signal processing unit can be reduced by extending the execution cycle of the newly detected cell search, The power consumption of the station device can be reduced.
[0027]
Further, the present invention provides a cell search control program for executing each step of any one of the above cell search control methods using a computer.
[0028]
According to the above-described program, for example, when the mobile station device is stationary and the line condition is good and the line quality level of the base station to be awaited is equal to or higher than a predetermined value, the execution cycle of the newly detected cell search is extended. However, by lowering the frequency of executing the newly detected cell search, it is possible to realize a cell search control capable of reducing the power consumption of the mobile station apparatus without lowering the call rate or the call reception rate.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, an outline of the present invention will be described. The present invention performs a cell search for detecting a signal transmitted from a detected base station apparatus, and when the line quality of a standby base station is equal to or higher than a predetermined level, the stationary state continues, or Note that the radio wave condition (line condition) of the line is good, it can be determined that there is no need to switch the target base station (standby cell), and there is no need to perform a cell search to detect a new base station device. It was done. Here, a mobile station apparatus in a mobile communication system using spread spectrum communication of the CDMA system will be described as an example, and a cell search control method for detecting a spread timing and a spread code of a signal transmitted from a base station will be described.
[0030]
In the present invention, every time a known detected cell search for detecting a detected base station device or a new detected cell search for detecting a new base station device is performed, the line quality of a waiting base station is measured. If the line quality is less than the predetermined level, the execution cycle of the newly detected cell search is shortened, and if the line quality is equal to or more than the predetermined level, the execution cycle of the newly detected cell search is lengthened. As a result, the new base station is detected by executing the new detection cell search only when the line condition surrounding the mobile station changes, so that the selection switching of the base station to be awaited is quickly performed, and the call rate and We try not to reduce the incoming call rate. Also, there is no base station newly detected by performing a new detection cell search that requires processing time even though the state of the surrounding base stations in standby is not changed and the radio wave state is good. The useless operation is reduced.
[0031]
Further, in the present invention, when the cell search timing is to be executed, if the cell search timing is within the execution cycle of the newly detected cell search, the newly detected cell search is not executed, and only the known detection cell search is executed. To finish. Accordingly, even when the cell search is required, if the new detection cell search execution time is not reached, the processing time is shortened without executing the new detection cell search requiring the processing time. Only the known detection cell search that has been completed is executed.
[0032]
FIG. 1 is a block diagram illustrating a configuration of a mobile station device according to an embodiment of the present invention.
The mobile station device 100 according to the present embodiment includes an antenna 101, a radio unit 102, a signal processing unit 103, a control unit 104, and a clock control unit 105 as main components.
[0033]
The signal processing section 103 includes, as main components, an AD section (analog / digital conversion section) 131, a reception data processing section 132, a delay profile calculation section 133, a spreading code detection section 134, and a spreading timing detection section 135. , A level measuring unit 136, a spreading code generating unit 137, and a spreading timing control unit 138. Further, the control unit 104 includes a storage unit 141, a determination unit 142, and a timer 144 as main components.
[0034]
Hereinafter, the function of the mobile station device of the present embodiment will be described for each component.
The antenna 101 receives a radio signal from a base station (not shown). Radio section 102 converts the radio signal received by antenna 101 to a baseband frequency and outputs the obtained baseband signal to AD section 131. The wireless unit 102 stops and starts the power supply under the control of the timer 144.
[0035]
AD section 131 converts the baseband signal from an analog signal to a digital signal, and outputs the signal to reception data processing section 132 and delay profile calculation section 133. The reception data processing unit 132 converts the baseband signal into reception data that can be processed by the control unit 104 and outputs the reception data to the control unit 104.
[0036]
The delay profile calculation unit 133 starts activation in response to an instruction from the timer 144, and based on the spread code generated by the spread code generation unit 137 and the information on the despread start timing from the spread timing control unit 138, the AD unit 131. Despreading the baseband signal that has been digitally converted in step (1) to create a delay profile. Further, delay profile calculation section 133 outputs this delay profile to spreading code detecting section 134, spreading timing detecting section 135, and level measuring section 136.
[0037]
Spreading code detecting section 134 detects a spreading code of a signal transmitted from the base station based on the delay profile output from delay profile calculating section 133 and outputs it to storage section 141. Spread timing detector 135 detects the spread timing of the signal transmitted from the base station based on the delay profile output from delay profile calculator 133, and outputs the detected signal to storage 141. The level measuring section 136 measures the level of the received signal from the delay profile and outputs the measured level to the storage section 141 and the determination section 142.
[0038]
Spreading code generation section 137 reads out the spreading code stored in storage section 141 and outputs it to delay profile calculation section 133. The spread timing control unit 138 reads the spread timing stored in the storage unit 141 and outputs the read spread timing to the delay profile calculation unit 133.
[0039]
The storage unit 141 stores, for each base station, the spreading code output from the spreading code detecting unit 134, the spreading timing output from the spreading timing detecting unit 135, and the measurement level information output from the level measuring unit 136. Attach and remember. The storage unit 141 compares the channel quality levels of the base stations measured by the level measurement unit 136, and ranks these base stations. Further, when the determination unit 142 determines that the level of the line quality is lower than the predetermined threshold value and the determination unit 142 notifies the storage unit 141 of the fact, the data of the designated base station is received. Do not remember.
[0040]
The determining unit 142 determines whether or not it is possible to communicate with the base station whose spread code and spread timing have been detected from the received signal. Specifically, the determination unit 142 determines, based on the measurement level information output from the level measurement unit 136, that if the measurement level of the received signal (that is, the level of the channel quality of the corresponding base station) is equal to or higher than a predetermined threshold value , It is determined that communication with the base station is possible, and if the measured level of the received signal is less than a predetermined threshold, it is determined that communication with the base station is impossible. Further, based on the measurement level information output from the level measurement unit 136, when the level of the received signal is equal to or higher than a predetermined threshold value, the timer 144 newly detects the measurement result of the received signal of the base station in a standby state. An instruction to lengthen the execution cycle of the cell search is sent. If the level of the received signal is less than a predetermined threshold, an instruction to shorten the execution cycle of the newly detected cell search is sent to the timer 144.
[0041]
The timer 144 outputs an instruction for controlling the start and stop of the operation of the entire mobile station, and has a new detection cell search execution cycle timer for measuring the execution cycle of the new detection cell search. In response to the instruction, control is performed to switch the execution cycle of the newly detected cell search. More specifically, the timer 144 instructs the radio unit 102 to start activation, instructs the clock control unit 105 to start clock operation when the cell search start time comes, and determines when the previous cell search was executed. In accordance with the new cell search execution cycle instructed by section 142, it is determined whether to perform a newly detected cell search or a known detected cell search.
[0042]
When performing a new detection cell search, the timer 144 activates the delay profile calculation unit 133 without instructing the storage unit 141 to use the spreading code and the spreading timing. On the other hand, when performing a cell search of a base station that has already been detected using the detected spread timing and spread code, that is, a known detected cell search, the timer 144 stores the spread code and the spread timing in the storage unit 141. Is started, and the delay profile calculation unit 133 is activated.
[0043]
Further, when the time of the cell search end is reached, the timer 144 instructs the radio unit 102 to end the activation and instructs the clock control unit 105 to end the clock operation. As described above, the timer 144 controls the execution cycle of the newly detected cell search and outputs the instruction of starting and ending the cell search according to the instruction received from the previous determination unit 142 at regular intervals.
[0044]
The clock control unit 105 supplies and stops the clock to the signal processing unit 103 according to the instruction of the timer 144.
[0045]
Next, the operation of the mobile station device according to the present embodiment will be described. FIG. 2 is a flowchart illustrating an example of an operation procedure of a cell search in the mobile station device according to the present embodiment.
[0046]
First, the timer 144 counts the timing of the regular cell search, and determines whether or not it is the timing of the cell search (step ST201). Here, when the cell search timing comes, the process proceeds to the next step, and the timer 144 instructs the wireless unit 102 and the clock control unit 105 to start (step ST202).
[0047]
Next, timer 144 determines whether or not the new detection cell search execution cycle timer for measuring the execution cycle of the newly detected cell search has expired (counted up) (step ST203). Here, when the newly detected cell search execution cycle timer has expired, the process proceeds to step ST204. On the other hand, when the newly detected cell search execution cycle timer has not expired, the process proceeds to step ST205.
[0048]
In step ST204, the timer 144 activates the delay profile calculation unit 133 to execute a newly detected cell search without sending an instruction to use the spreading code and the spreading timing to the storage unit 141.
[0049]
In step ST205, the timer 144 instructs the storage unit 141 to use the spreading code and the spreading timing, activates the delay profile calculation unit 133, and executes a known detection cell search.
[0050]
Next, the determination unit 142 determines whether or not the line quality level of the base station in standby (to be standby) is equal to or higher than a threshold based on the measurement level information measured and output by the level measurement unit 136 (step ST206). Here, if the line quality level is equal to or higher than the threshold, the process proceeds to step ST207, while if the line quality level is lower than the threshold, the process proceeds to step ST208.
[0051]
In step ST207, based on the instruction from the determination unit 142, the timer 144 sets the newly detected cell search execution cycle timer to a long cycle to prepare for the next cell search start timing. That is, the execution cycle of the newly detected cell search in the timer 144 is lengthened. Also, in step ST208, based on the instruction of the determination unit 142, the timer 144 sets the newly detected cell search execution cycle timer to a short cycle, and prepares for the next cell search start timing. That is, the execution cycle of the newly detected cell search in the timer 144 is shortened.
[0052]
Then, in response to the instruction from the timer 144, the wireless unit 102 and the clock control unit 105 stop operating (step ST209), and return to step ST201.
[0053]
As described above, in the present embodiment, when the level indicating the line quality of the base station in a standby state is equal to or higher than a predetermined threshold, the mobile station apparatus itself is in a stationary state, and the surrounding line conditions are good. It is determined that the state is the state, and the frequency of execution of a newly detected cell search for newly detecting a base station is reduced. As a result, it is possible to suppress unnecessary execution of a newly detected cell search requiring a long processing time, and to reduce power consumption without lowering the call rate or the call rate. Therefore, the battery life of the mobile station device can be extended, and the driving time can be extended.
[0054]
Further, in the present embodiment, even if it is time to perform the cell search, if the execution cycle of the new detection cell search has not been reached, the known detection cell search is performed, and the new detection cell search and the known detection cell search are performed. By properly using the above, it becomes possible to execute an appropriate cell search at an appropriate timing in response to a change in the radio wave condition or the like. That is, the measurement of the line quality and the adjustment of the frequency of the cell search in the present embodiment are performed at the timing of performing one cell search (every time the cell search is performed), so that the change of the line state can be quickly and accurately performed. Can be handled. As described above, by enabling the cell search to be performed in response to the change in the line condition, the power consumption can be reduced without lowering the call rate or the call rate, and the optimal base station can be awaited. it can.
[0055]
The present invention is not limited to the above embodiment, and can be implemented with various modifications without departing from the scope of the invention. For example, in the above embodiment, the configuration example of the mobile station apparatus and the cell search control method based on the operation are described. However, the present invention is not limited to this, and the cell search control method of the present invention may be executed by a software program. Can also be implemented.
[0056]
For example, a program for executing the cell search control method is stored in a storage means such as a ROM (Read Only Memory) or a flash RAM (Random Access Memory) provided in the apparatus in advance, and the program is stored in a CPU (Central Processor Unit). ) May be operated. A program for executing the cell search control method is stored in a computer-readable storage medium such as a semiconductor memory such as a ROM, an optical recording medium such as a CD-ROM, and a magnetic recording medium such as a hard disk. May be transferred to and stored in a memory of a computer having a CPU or the like, and the computer may be operated according to the program.
[0057]
Further, in the above embodiment, the level indicating the line quality of the waiting base station is compared with one threshold value, and a method is used in which the execution cycle of the newly detected cell search is properly used for a long cycle and a short cycle. A method of assigning a plurality of judgment thresholds of the line quality of a waiting base station, assigning a plurality of new detection cell search execution periods according to each threshold, and frequently controlling the execution timing of the new detection cell search. Is also possible.
[0058]
【The invention's effect】
As described above, according to the present invention, it is possible to execute a cell search quickly and accurately in response to a change in line condition, and to reduce power consumption without lowering the call rate or the call rate. A mobile station device, a cell search control method, and a program can be provided.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a mobile station device according to an embodiment of the present invention.
FIG. 2 is a flowchart illustrating an example of an operation procedure of a cell search in the mobile station device according to the present embodiment.
[Explanation of symbols]
101 antenna
102 Radio unit
103 signal processing unit
104 control unit
105 Clock control unit
131 AD section
132 Received data processing unit
133 Delay Profile Calculator
134 Spreading code detector
135 Spread timing detector
136 Level measurement unit
137 Spreading code generator
138 Spreading timing control unit
141 storage unit
142 Judgment unit
144 timer

Claims (5)

A mobile station comprising a cell search means for detecting a synchronization radio channel of a base station arranged for each of a plurality of cells constituting a radio area and performing a cell search for measuring a line quality level of the detected synchronization radio channel. A device,
The cell search means can execute a newly detected cell search to search for a new base station and a known detection cell search to search for a base station that has already been searched,
Clocking means for clocking the execution cycle of the newly detected cell search,
When the timing to execute the cell search arrives, if the execution cycle of the new detection cell search has not been reached, the known detection cell search is executed, and the execution cycle of the new detection cell search has been reached. In the case, a cell search execution control means for executing the newly detected cell search,
If the line quality level of the standby base station measured in the known detected cell search or the newly detected cell search is less than a predetermined value, the execution cycle of the newly detected cell search in the timer is set shorter. When the quality level is equal to or more than a predetermined value, an execution cycle control unit that sets a long execution cycle of the newly detected cell search in the clock unit,
A mobile station device comprising: The cell search execution control means activates a radio unit and a signal processing unit when the timing to execute the cell search arrives, executes the known detection cell search or the new detection cell search, and The mobile station apparatus according to claim 1, wherein the operation of the radio unit is stopped after the measurement of the channel quality level of the synchronization radio channel is completed. Cell search control method in a mobile station apparatus for detecting a synchronization radio channel of a base station arranged for each of a plurality of cells constituting a radio area and performing a cell search for measuring a channel quality level of the detected synchronization radio channel And
A clocking step of clocking the execution cycle of a newly detected cell search to be searched for a new base station as the cell search,
When the timing at which the cell search should be executed has arrived, if the execution cycle of the newly detected cell search has not been reached, a known detection cell search is performed as the cell search to search for a base station that has already been searched. A cell search execution control step of executing the newly detected cell search when the execution cycle of the newly detected cell search has been reached,
If the line quality level of the standby base station measured in the known detection cell search or the new detection cell search is less than a predetermined value, the execution cycle of the new detection cell search in the timing step is set short, An execution cycle control step of setting a longer execution cycle of the newly detected cell search in the timing step if the quality level is equal to or more than a predetermined value;
A cell search control method, comprising: In the cell search execution control step, when the timing to execute the cell search arrives, activates the radio unit and the signal processing unit to execute the known detection cell search or the new detection cell search, and from the corresponding base station 4. The cell search control method according to claim 3, wherein the operation of the radio unit is stopped after the measurement of the channel quality level of the synchronization radio channel is completed. A cell search control program for executing each step of the cell search control method according to claim 3 using a computer.

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