JP2009021863A - Mobile station device, search method of mobile station device, search program, and computer readable recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mobile station device capable of providing the reduction of time necessary to search, to provide a search method thereof, to provide a search program, and to provide a computer readable recording medium. <P>SOLUTION: The mobile station device 1 is equipped with a wireless unit 20, capable of receiving the signals of a plurality of frequency channels, a detecting unit 41, detecting whether a signal from a base station is included in the signal of a first frequency channel received by the wireless unit 20 or not, and a frequency channel control unit 42, determining a second frequency channel which becomes the frequency channel of a next receiving object based on the detecting result to control the wireless unit 20. Further, the frequency channel control unit 42 determines the second frequency channel so that a first zone consisting of whole zone or the like of the first frequency channel will not be superposed on a second zone consisting of whole zones or the like of the second frequency channel. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a mobile station device, a mobile station device search method, a search program, and a computer-readable recording medium.

  In recent years, third generation mobile communication systems (3G) including a W-CDMA (Wideband-Code Division Multiplexing Access) system have been widely used worldwide. In order to realize further high-speed communication, next-generation mobile communication systems are being studied. As a next-generation mobile communication system, a fourth-generation mobile communication system (4G) in which a downlink communication speed is 100 Mbps to 1 Gbps is being studied. However, there is a big difference in system configuration between 3G and 4G. Therefore, in order to bridge the technical and time gap between 3G and 4G, and to achieve a smooth transition to 4G, the same frequency as 3G was used and 4G candidate technology was introduced. Thus, E-UTRA (Evolved Universal Terrestrial Radio Access) that realizes a downlink communication speed of about 100 Mbps is actively discussed in 3GPP (3rd Generation Partnership Project).

  In a mobile communication system, a signal transmitted from a base station so that the mobile station apparatus communicates with the base station when the power of the mobile station apparatus is turned on or when a network re-search is performed by a user operation. And a search process for timing and frequency synchronization is performed. For example, in the W-CDMA system, a method called three-step cell search is adopted.

  The three-stage cell search is a search method using a primary synchronization channel PSCH (Primary Synchronization Channel), a secondary synchronization channel SSCH (Secondary Synchronization Channel), and a common pilot channel CPICH (Common Pilot Channel). In this three-stage cell search, first, slot timing is detected by correlation detection using a primary synchronization code PSC (Primary Synchronization Code) (first stage). Next, frame timing and a scrambling code group (Scramble Code Group) are detected by correlation detection using a secondary synchronization code SSC (Secondary Synchronization Code) (second stage). Finally, a scrambling code is detected by correlation detection using a scrambling code (Scramble Code) (third stage).

  In E-UTRA, which is a next-generation mobile communication system, an OFDMA (Orthogonal Frequency Division Multiplexing Access) scheme different from the 3G W-CDMA scheme is adopted. In this E-UTRA, six transmission frequency bandwidths (1.25 MHz, 2.5 MHz, 5 MHz, 10 MHz, 15 MHz, and 20 MHz) are defined as the transmission frequency bandwidths from the base station. Each of the countries and network operators is assigned one of six transmission frequency bandwidths so that proper operation according to the operation policy can be performed. In E-UTRA, a method of performing a cell search based on the same idea as the above-described three-stage cell search has been studied (see Non-Patent Documents 1 and 2).

  In Non-Patent Documents 1 and 2, a synchronization channel SCH (Synchronization Channel), a broadcast channel BCH (Broadcast Channel), and a reference signal (Reference signal) are used in the above three-stage cell search. Further, in Non-Patent Documents 1 and 2, some candidates such as transmission timing on the time axis and allocation of subcarriers on the frequency axis are considered for the synchronization channel SCH, the broadcast channel BCH, and the reference signal. Has been.

  13 and 14 are conceptual diagrams showing a basic downlink radio frame configuration. One radio frame is configured with a length of 10 msec, and is composed of ten subframes with a length of 1 msec. One subframe is composed of two 0.5 msec long slots. Furthermore, the downlink radio frame is configured by a two-dimensional resource block including a plurality of subcarriers assigned for each frequency and one slot on the time axis. One slot is composed of 7 symbols, and at present, 12 subcarriers are promising for resource blocks.

  As described above, signals used in cell search include SCH, BCH, and reference signals. Each signal is advantageously mapped to a radio frame as follows. Two SCHs, PSCH (Primary SCH) and SSCH (Secondary SCH), are defined. The PSCH is mapped to the last one symbol of the 0th slot and the 10th slot of the radio frame. The PSCH is mapped to 72 subcarriers around the center frequency in the transmission band. The SSCH is mapped to the symbol immediately before the PSCH. Similarly to PSCH, BCH is mapped to 72 subcarriers around the center frequency. However, regarding the BCH, the symbol to be mapped in the radio frame is still fluid. As shown in FIG. 14, the reference signal is mapped to all transmission bands and all slots so as to alternate between the 0th symbol and the 4th symbol of each slot.

  Next, a cell search method in E-UTRA will be described. In E-UTRA, first, a mobile station apparatus detects symbol timing by receiving PSCH. PSCH is defined as 72 symbols existing in the frequency axis direction in a certain symbol section. The PSCH is transmitted from the base station as a symbol sequence common to all base stations. In the mobile station apparatus, the PSCH is detected by correlation detection based on autocorrelation or cross-correlation based on the common symbol sequence, and the symbol timing is specified. Here, the autocorrelation is performed as follows, for example. First, the base station transmits, as a PSCH, a symbol sequence that has the same time waveform in half the time of one symbol period. The mobile station apparatus obtains a correlation between received signals shifted by a half time of one symbol period. Thereby, the mobile station apparatus can detect the correlation peak only at the timing of transmitting the PSCH, and detects the PSCH using this correlation peak. Further, the cross correlation is performed as follows, for example. First, the mobile station apparatus creates a replica of a time waveform of a symbol sequence transmitted as a PSCH on the receiving side. The mobile station apparatus then correlates the received signal with the replica. Thereby, the mobile station apparatus can detect the correlation peak only at the timing of transmitting the PSCH, and detects the PSCH using this correlation peak.

  Next, the mobile station apparatus detects the radio frame timing and the cell ID group by receiving the SSCH. The SSCH is defined differently for the 0th slot and the 10th slot of the radio frame. The SSCH is defined as a different symbol sequence for each group in which the cell ID is divided into several groups. Based on this symbol sequence, the mobile station apparatus detects SSCH by correlation detection based on autocorrelation or cross-correlation, similar to PSCH. As a result, the mobile station apparatus identifies the radio frame timing and the cell ID group.

  Next, the mobile station apparatus detects the cell ID by receiving the reference signal. Within the cell ID group, a different symbol series is defined for each cell ID. The base station transmits a reference signal as a symbol sequence corresponding to the cell ID of the base station. Then, the mobile station apparatus obtains a correlation with the received signal based on the symbol sequence of the reference signal corresponding to some cell IDs in the group of cell IDs identified by the SSCH detection. Thereby, the mobile station apparatus detects the reference signal and identifies the cell ID.

  As described above, in the cell search method, a plurality of signals are generally received in order, and whether or not signals can be received in each transmission frequency channel by performing correlation detection for each signal, Eventually, synchronization with the base station is performed.

In addition, the transmission frequency channel of the base station is defined by a center frequency interval of 200 KHz, for example, in the case of 3G W-CDMA. This transmission frequency channel is 277 defined in a certain frequency band (60 MHz). The frequency band is not limited to 60 MHz, but a plurality of other bands are defined. Therefore, a substantial number of transmission frequency channels are actually defined. In addition, which transmission frequency channel is actually used by the base station differs for each operator. In E-UTRA, the use of the same frequency as 3G is being studied, and the frequency channel is scheduled to be similarly defined.
3GPP TR (Technical Report) 25.814, V7.1.0 (2006-09), Physical layer aspects for evolved Universal Terrestrial Radio Access (UTRA). http: // www. 3 gpp. org / ftp / Specs / html-info / 25814. htm 3GPP TS 36.211, V1.1.0 (2007-03), Physical Channels and Modulation. http: // www. 3 gpp. org / ftp / Specs / html-info / 36211. htm

  As described above, the mobile station apparatus performs a cell search in each reception frequency channel while sequentially setting reception frequency channels corresponding to all transmission frequency channels of the base station defined in the system, thereby performing a desired search. Communication with the base station needs to be established. That is, there is a problem that it takes a very long time to establish communication with a desired base station when the mobile station device is turned on or when a network search is performed again by a user operation. is there.

  The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a mobile station apparatus and a mobile station apparatus search method capable of providing a reduction in time required for search. Another object of the present invention is to provide a search program for causing a mobile station apparatus to execute the search method, and a computer-readable recording medium storing the search program.

  The mobile station apparatus of the present invention communicates with a base station, and can receive a signal of a plurality of frequency channels, and a base station receives a signal of a first frequency channel received by the receiver. A detection unit that detects whether or not a signal from is included, and based on a detection result by the detection unit, determines a second frequency channel to be a frequency channel to be received next, the reception unit, And a control unit that controls the second frequency channel to be receivable, and the first estimation is assumed to be used in the entire band of the first frequency channel or the first frequency channel. A first band composed of a use band and a second estimated use band estimated to be used in the entire band of the second frequency channel or in the second frequency channel. So that the band does not overlap, and determines the second frequency channel.

  According to this mobile station apparatus, it is detected whether the signal of the first frequency channel is received, and the second frequency channel to be the next frequency channel to be received is determined based on the detection result. In this determination, the second frequency channel is determined such that the first band and the second band, which are either the entire band of the first and second frequency channels or the estimated use band, do not overlap.

  Here, for example, when a signal of the first frequency channel is received and it is detected that a signal from the base station is included, it is determined that there is an operator using the frequency channel. Further, it is clear that there are no frequency channels used by other operators in the vicinity of the frequency channel band. For this reason, the frequency channel adjacent to the first frequency channel is not determined as the second frequency channel, and the first and second bands made up of the entire band or the estimated use band of the first and second frequency channels overlap. By determining the second frequency channel so that it does not occur, frequency channels that cannot be used by other operators or the like are skipped, and the time required for the search can be reduced.

  Further, in the mobile station apparatus of the present invention, the control unit obtains the second band from the minimum bandwidth among the bandwidths of transmission frequency channels set in advance from the base station, and obtains the second band obtained. Preferably, the second frequency channel is determined based on a band.

  According to this mobile station apparatus, the minimum bandwidth among the bandwidths of a plurality of transmission frequencies set in advance by the operator or the like is adopted, and the second band consisting of the entire band of the second frequency channel or the estimated use band. Two bands will be obtained. As a result, when the bandwidth of the frequency channel used by another operator or the like is the minimum, the second frequency channel is assumed to be larger than the minimum bandwidth of the second frequency channel. It is possible to suppress a situation where a frequency channel is determined and a frequency channel used by another business operator is skipped and searched.

  In the mobile station apparatus of the present invention, the control unit obtains the second band from a bandwidth of a predetermined transmission frequency in a frequency band to which the first frequency channel belongs, and sets the second band to the obtained second band. Preferably, the second frequency channel is determined based on the basis.

  According to this mobile station apparatus, for example, in the case of the 800 MHz band, when the bandwidth of the transmission frequency is predetermined such as 10 MHz, the bandwidth of the transmission frequency of the second frequency channel from the frequency band to which the first frequency channel belongs. Will be required. Thereby, it is possible to accurately obtain the second band and improve the determination accuracy for the second frequency channel.

  Further, in the mobile station apparatus of the present invention, the control unit specifies the first band from the signal of the first frequency channel, and determines the second frequency channel based on the specified first band. It is preferable to determine.

  According to this mobile station apparatus, the entire frequency band or the estimated use band of the first frequency channel is obtained from the actually received signal of the first frequency channel, and the second frequency channel is determined based on the received signal. The accuracy can be improved.

  In the mobile station apparatus of the present invention, it is preferable that the control unit specifies the first band based on a specific symbol sequence included in a signal from the base station.

  According to this mobile station apparatus, for example, when a specific symbol sequence indicating the frequency bandwidth is included from the base station, the first frequency channel full band or estimated use band is formed based on this symbol sequence. One band is obtained. Thereby, it is possible to improve the accuracy when obtaining the first band, and it is possible to improve the determination accuracy for the second frequency channel.

  In the mobile station apparatus of the present invention, it is preferable that the control unit specifies the first band from a decoding result of a specific signal encoded and transmitted from the base station.

  According to this mobile station apparatus, for example, when a specific signal that indicates a frequency bandwidth from the base station and is encoded is included, based on the decoding result of the specific signal, the entire band of the first frequency channel or The first band consisting of the estimated use band is obtained. Thereby, it is possible to improve the accuracy when obtaining the first band, and it is possible to improve the determination accuracy for the second frequency channel.

  Further, in the mobile station apparatus of the present invention, the control unit specifies the first band from a predetermined transmission frequency bandwidth in the frequency band to which the first frequency channel belongs, and sets the first band to the specified first band. Preferably, the second frequency channel is determined based on the basis.

  According to this mobile station apparatus, the entire band of the first frequency channel or the estimated use band is obtained from the frequency band of the first frequency channel actually received, and the second band is determined based on the bandwidth determined by the frequency band. It is possible to improve the determination accuracy for the frequency channels.

  Also, the mobile station apparatus search method of the present invention is executed by the mobile station apparatus when the mobile station apparatus communicating with the base station establishes communication with the base station, and is capable of receiving signals of a plurality of frequency channels. Based on the detection result in the detection step, the detection step for detecting whether the signal of the first frequency channel received in the reception step includes a signal from the base station, and A control step of determining a second frequency channel to be a frequency channel to be received and controlling the mobile station apparatus to be able to receive a signal of the second frequency channel. In the control step, A first band consisting of a first estimated use band estimated to be used in the entire band of one frequency channel or the first frequency channel; and the second frequency channel So as not to overlap with each other and the second band of a second estimation using bands that are expected to be used in the entire band or the second frequency channel, and determines the second frequency channel.

  According to this mobile station device search method, it is detected whether or not the signal of the first frequency channel is received, and the second frequency channel to be the next frequency channel to be received is determined based on the detection result. The In this determination, the second frequency channel is determined such that the first band and the second band, which are either the entire band of the first and second frequency channels or the estimated use band, do not overlap.

  Here, for example, when a signal of the first frequency channel is received and it is detected that a signal from the base station is included, it is determined that there is an operator using the frequency channel. Further, it is clear that there are no frequency channels used by other operators in the vicinity of the frequency channel band. For this reason, the frequency channel adjacent to the first frequency channel is not determined as the second frequency channel, and the first and second bands made up of the entire band or the estimated use band of the first and second frequency channels overlap. By determining the second frequency channel so that it does not occur, frequency channels that cannot be used by other operators or the like are skipped, and the time required for the search can be reduced.

  Further, in the mobile station device search method of the present invention, in the control step, the second band is obtained from the bandwidth of the minimum frequency among the preset bandwidths of the transmission frequency from the base station, It is preferable to determine the second frequency channel based on the obtained second band.

  According to this mobile station apparatus search method, the entire bandwidth of the second frequency channel or the estimated use bandwidth is adopted by adopting the minimum bandwidth among the bandwidths of a plurality of transmission frequencies set in advance by the operator or the like. The second band consisting of As a result, when the bandwidth of the frequency channel used by another operator or the like is the minimum, the second frequency channel is assumed to be larger than the minimum bandwidth of the second frequency channel. It is possible to suppress a situation where a frequency channel is determined and a frequency channel used by another business operator is skipped and searched.

  Further, in the mobile station apparatus search method of the present invention, in the control step, the second band is obtained from the bandwidth of the transmission frequency predetermined in the frequency band to which the first frequency channel belongs, and the obtained second band is obtained. Preferably, the second frequency channel is determined based on two bands.

  According to this mobile station apparatus search method, for example, in the case of the 800 MHz band, when the bandwidth of the transmission frequency is predetermined such as 10 MHz, the transmission frequency of the second frequency channel is determined from the frequency band to which the first frequency channel belongs. Bandwidth is required. Thereby, it is possible to accurately obtain the second band and improve the determination accuracy for the second frequency channel.

  In the mobile station apparatus search method of the present invention, in the control step, the first band is obtained from the signal of the first frequency channel, and the second frequency channel is determined based on the obtained first band. Is preferably determined.

  According to the search method of the mobile station apparatus, the entire frequency band or the estimated use band of the first frequency channel is obtained from the actually received signal of the first frequency channel, and the second frequency is determined based on the received signal. It is possible to improve the determination accuracy for the channel.

  In the mobile station apparatus search method of the present invention, it is preferable that, in the control step, the first band is specified based on a specific symbol sequence included in a signal from the base station.

  According to the search method of this mobile station apparatus, for example, when a specific symbol sequence indicating a frequency bandwidth is included from the base station, the entire band of the first frequency channel or the estimated use band based on this symbol sequence The first band consisting of Thereby, it is possible to improve the accuracy when obtaining the first band, and it is possible to improve the determination accuracy for the second frequency channel.

  In the mobile station apparatus search method of the present invention, it is preferable that, in the control step, the first band is specified from a decoding result of a specific signal encoded and transmitted from the base station.

  According to this mobile station apparatus search method, for example, when a specific signal that indicates the frequency bandwidth from the base station and is encoded is included, based on the decoding result of the specific signal, the first frequency channel The first band consisting of the entire band or the estimated use band is obtained. Thereby, it is possible to improve the accuracy when obtaining the first band, and it is possible to improve the determination accuracy for the second frequency channel.

    In the mobile station apparatus search method of the present invention, in the control step, the first band is specified by specifying the first band from the bandwidth of the transmission frequency predetermined in the frequency band to which the first frequency channel belongs. Preferably, the second frequency channel is determined based on one band.

  According to the search method of the mobile station apparatus, the entire band of the first frequency channel or the estimated use band is obtained from the frequency band of the first frequency channel actually received, and the bandwidth determined by the frequency band is obtained. Based on this, it is possible to improve the determination accuracy for the second frequency channel.

  A search program according to the present invention causes a computer to execute the search method.

  According to this search program, it is possible to cause the computer to execute the above search method and reduce the time required for searching the computer such as the mobile station apparatus.

  The recording medium of the present invention is characterized in that the search program is recorded.

  According to the recording medium of the mobile station device, the search program can be read and executed by a computer, and the time required for searching the computer such as the mobile station device can be reduced.

  The mobile station apparatus of the present invention is characterized in that the search program is read and executed.

  According to this mobile station device, the search program can be read by the mobile station device and the time required for the search can be reduced.

  According to the present invention, in order to determine the second frequency channel so that the first and second bands composed of the entire band or the used band of the first and second frequency channels do not overlap with each other, the frequency channel to be searched is determined. By reducing the number, it is possible to shorten the time required to establish communication with the base station.

[First Embodiment]
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a first embodiment of the invention will be described with reference to the drawings. In addition, in each following figure, the same code | symbol is attached | subjected to the same element and the overlapping description shall be abbreviate | omitted. FIG. 1 is a configuration diagram showing a mobile station apparatus according to the first embodiment of the present invention. As shown in FIG. 1, the mobile station apparatus 1 communicates with a base station, and includes an antenna 10, a radio unit 20, a signal processing unit 30, a control unit 40, and an application unit 50. Yes.

  The antenna 10 receives a transmission signal from the base station and transmits it to the radio unit 20. The antenna 10 has a function of transmitting a transmission signal transmitted from the radio unit 20 to the base station. The radio unit 20 extracts a desired signal from the received signal received by the antenna 10 and transmits it to the signal processing unit 30. Here, the desired signal is a signal based on the reception frequency channel number set in the control unit 40. For this reason, the radio | wireless part 20 can receive the signal of a several frequency channel by changing the setting of a frequency channel number sequentially. The radio unit 20 also has a function of transmitting the signal transmitted from the signal processing unit 30 to the antenna 10 based on the transmission frequency channel number set in the control unit 40.

  The signal processing unit 30 performs correlation detection, symbol sequence detection, control data demodulation, and the like on the signal extracted by the radio unit 20. The signal processing unit 30 also has a function of transmitting result information such as correlation detection, symbol sequence detection, and control data demodulation to the control unit 40. The signal processing unit 30 has a function of demodulating user data and transmitting it to the application unit 50. Further, the signal processing unit 30 has a function of modulating the user data transmitted from the application unit 50 and the control data transmitted from the control unit 40, and transmitting the modulated signal to the radio unit 20. ing.

  The control unit 40 controls the entire mobile station apparatus 1, and includes a detection unit 41 and a frequency channel control unit (control unit) 42. The detection unit 41 detects whether the frequency channel signal received by the radio unit 20 includes a signal from the base station based on the detection result transmitted from the signal processing unit 30. Is. The frequency channel control unit 42 determines the next reception target frequency channel based on the detection result of the detection unit 41. Further, the frequency channel control unit 42 controls the radio unit 20 so that the radio unit 20 can receive a signal of the determined frequency channel.

  Further, in the first embodiment, the base station receives information on the bandwidth of the transmission frequency channel used by the base station (for example, information such as 1.25 MHz, 2.5 MHz, 5 MHz, 10 MHz, 15 MHz, and 20 MHz described above). Has been sent. That is, the signal from the base station includes a symbol sequence indicating the transmission frequency bandwidth of the base station. Further, in the first embodiment, the control unit 40 is configured to determine the next reception target frequency channel from the transmission frequency bandwidth of the base station indicated by the symbol series.

  The application unit 50 holds various user interfaces, and transmits user data to the signal processing unit 30 and receives from the signal processing unit 30 based on user operations.

  Next, an outline of the search method of the mobile station apparatus 1 according to the first embodiment will be described. First, the frequency channel control unit 42 determines a reception frequency channel (first frequency channel). As a result, the radio unit 20 extracts the signal of the first frequency channel determined by the frequency channel control unit 42 from the signal received via the antenna 10. Next, the signal processing unit 30 performs correlation detection, symbol sequence demodulation, and the like on the signal extracted by the radio unit 20 and transmits the result to the control unit 40.

  And the detection part 41 of the control part 40 detects whether the signal from a base station is contained in the signal of a 1st frequency channel, and the bandwidth of the frequency channel. Here, when it is determined that the signal from the base station is included in the signal of the first frequency channel, the center frequency of the transmission frequency bandwidth allocated to the operator and the first frequency channel are This is a case where the indicated frequency matches.

  Next, the frequency channel control unit 42 determines the second frequency channel to be received next based on the detection result of the detection unit 41. At this time, the frequency channel control unit 42 determines the second frequency channel as follows. For example, when a signal of the first frequency channel is received and it is detected that a signal from the base station (primary synchronization channel PSCH, secondary synchronization channel SSCH, reference signal, etc.) is included, the frequency channel control unit 42 Then, it is determined that there is an operator who uses the frequency indicated by the first frequency channel as the center frequency. In this case, since there is a business operator that uses the frequency indicated by the first frequency channel as the center frequency, a frequency channel that is used by the other business operators as the center frequency at a frequency near the first frequency channel. It is clear that does not exist. For this reason, the frequency channel control unit 42 determines a frequency channel separated from the first frequency channel by a plurality of channels as the second frequency channel to be received next.

  Furthermore, when the frequency channel control unit 42 determines a frequency channel separated by a plurality of channels as the second frequency channel, the frequency channel control unit 42 determines the second frequency channel in consideration of the transmission frequency bandwidth used by the operator. .

  FIG. 2 is a conceptual diagram showing how the second frequency channel is determined by the frequency channel controller 42 shown in FIG. For example, based on the received signal of the first frequency channel, the control unit 40 has determined that the transmission frequency bandwidth allocated to the operator who uses the first frequency channel is 2.5 MHz. To do. Further, it is assumed that the frequency channel is set at regular intervals every 200 KHz. In this case, as shown in FIG. 2, the second frequency channel is determined on the assumption that the frequency channel 2 MHz away from the first frequency channel is operated with a transmission frequency bandwidth of 1.25 MHz.

  This will be specifically described. First, since the transmission frequency bandwidth allocated to the operator using the first frequency channel is 2.5 MHz, at least 6 channels ((2.5 MHz / 2) /0.2 MHz from the first frequency channel). ) It is considered that there is no frequency channel that is used by other operators in remote frequency channels. Moreover, since there is a possibility that the minimum bandwidth (for example, 1.25 MHz) among the transmission frequency bandwidths allocated to the operators, etc. may be allocated to other operators, the transmission frequencies of other operators, etc. Assume a bandwidth of 1.25 MHz. In this case, even if 1 channel or 2 channels are added to the above 6 channels and the second frequency channel is set, it is considered that the frequency channels used by other operators cannot be captured. For this reason, the frequency channel control unit 42 adds 3 channels ((1.25 MHz / 2) /0.2 MHz) to the above 6 channels, and there are frequency channels used by other operators in the frequency channels separated by 9 channels. Judge that it is possible. Furthermore, it is considered that the two transmission frequency bandwidths are operated so as not to overlap each other. For this reason, the frequency channel control unit 42 adds one more channel to the nine channels. The frequency channel control unit 42 then determines a frequency channel that is fdelta = 10 channels (6 + 3 + 1 channel = 2 MHz) away from the first frequency channel as the second frequency channel. In this way, the frequency channel control unit 42 determines the second frequency channel so that the entire band of the first frequency channel and the entire band of the second frequency channel do not overlap.

  FIG. 3 is a second conceptual diagram showing how the second frequency channel is determined by the frequency channel controller 42 shown in FIG. Each provider or the like does not always use the entire transmission frequency bandwidth for signal transmission. That is, each business operator may not use a band away from the center frequency for signal transmission. For this reason, as shown in FIG. 3, the frequency channel control unit 42 reduces the fdelta by several channels from FIG. 2 and sets the frequency channels separated from the first frequency channel, such as 8 channels and 9 channels, to the second frequency channel. May be determined as As described above, the frequency channel control unit 42 uses the first estimated use band estimated to be used in the first frequency channel and the second estimated use estimated to be used in the second frequency channel. The second frequency channel may be determined so as not to overlap the band. Thus, a search with less leakage than the example shown in FIG. 2 is performed.

  Note that the second frequency channel may be determined by combining the examples shown in FIGS. For example, the frequency channel control unit 42 may control the second frequency channel so that the entire band of the first frequency channel does not overlap with the second estimated use band estimated to be used in the second frequency channel. May be determined. Further, the frequency channel control unit 42 controls the second frequency channel so that the first estimated use band estimated to be used in the first frequency channel does not overlap the entire band of the second frequency channel. May be determined. The bandwidth of the estimated use band of each frequency channel may be stored in advance in the storage unit of the mobile station device 1 or may be calculated by the mobile station device 1 as needed.

  By the way, when it is detected that the signal of the first frequency channel is not received and the signal from the base station is not included, the frequency channel control unit 42 has an operator who uses the first frequency channel. Judge not to. In this case, there is a possibility that a frequency channel used by the operator or the like exists at a frequency in the vicinity of the first frequency channel. Therefore, the frequency channel control unit 42 determines the frequency channel adjacent to the first frequency channel as the second frequency channel to be received next.

  Next, details of the search method of the mobile station apparatus 1 according to the first embodiment will be described. FIG. 4 is a flowchart showing details of the search method of the mobile station apparatus 1 according to the first embodiment. In FIG. 4, a search method assuming E-UTRA is described. In FIG. 4, there are 277 frequency channels defined at a constant interval (200 KHz) in a specific continuous frequency band (60 MHz), and frequency channel numbers from 0 to 276 are assigned in order from the lowest frequency. Is defined. Here, since the frequency channels are not arranged in the band of about 2.5 MHz at both ends (total of about 5 MHz) in the frequency band of 60 MHz, the number of frequency channels is 277 which is smaller than 60 MHz ÷ 200 KHz = 300. It has become. However, the method of defining the frequency channel, such as how to define the frequency channel number and whether or not the frequency channel interval is constant, is not particularly limited and may be defined in any way.

  First, as shown in FIG. 4, the frequency channel control unit 42 of the control unit 40 sets the reception frequency channel number to “0” (S1). That is, the frequency channel control unit 42 substitutes “0” for the variable fid_no indicating the reception frequency channel number. As a result, the radio unit 20 extracts a desired signal based on the reception frequency channel number from the reception signal received by the antenna 10 and sends it to the signal processing unit 30.

  Next, the signal processing unit 30 detects the symbol sequence of the primary synchronization channel PSCH designated by the control unit 40, and the detection unit 41 of the control unit 40 includes the primary synchronization channel PSCH in the signal from the base station. It is determined whether it has been received, that is, whether it has been received (S2). This determination is performed by correlation detection by autocorrelation or cross-correlation as described in the conventional example.

  When the primary synchronization channel PSCH is not received (S2: NO), the frequency channel control unit 42 substitutes “1” for the variable fdelta (S8). Thereafter, the frequency channel control unit 42 determines the frequency channel number (second frequency channel number) to be received next (S9). That is, the frequency channel control unit 42 performs a calculation of fid_no = fid_no + fdelta and determines a frequency channel number to be a next reception target. As described above, when the primary synchronization channel PSCH is not received (S2: NO), it can be determined that there is no operator using the current frequency channel (first frequency channel). In this case, there is a possibility that there is a frequency channel used by another operator or the like at a frequency near the current frequency channel. Therefore, the frequency channel control unit 42 determines a frequency channel adjacent to the current frequency channel as a frequency channel to be received next, as shown in step S8 and step S9.

  When the primary synchronization channel PSCH is received (S2: YES), the signal processing unit 30 detects the symbol sequence of the secondary synchronization channel SSCH designated by the control unit 40, and the detection unit 41 of the control unit 40 Then, it is determined whether or not the secondary synchronization channel SSCH is included in the signal from the base station, that is, whether or not the signal has been received (S3). This determination is performed by correlation detection by autocorrelation or cross-correlation as described in the conventional example.

  When the secondary synchronization channel SSCH is received (S3: YES), the signal processing unit 30 detects the symbol sequence of the reference signal specified by the control unit 40. And the detection part 41 determines whether the reference signal is contained in the signal from a base station, ie, whether it was able to receive (S4). This determination is performed by correlation detection by autocorrelation or cross-correlation as described in the conventional example.

  When the reference signal is received (S4: YES), the frequency channel control unit 42 determines the transmission frequency bandwidth of the currently received frequency channel from the reference signal (S5). Here, in the reference signal, for example, different symbol sequences are defined for each of six transmission frequency bandwidths (1.25 MHz, 2.5 MHz, 5 MHz, 10 MHz, 15 MHz, and 20 MHz). That is, when the base station side transmits a symbol sequence corresponding to the transmission frequency bandwidth, the mobile station device 1 side can determine the transmission frequency bandwidth when receiving the reference signal. Note that, in the reference signal, symbol sequences that are different for each cell ID are also defined as in the prior art.

  Thereafter, the frequency channel control unit 42 determines fdelta (S6). At this time, the frequency channel control unit 42 calculates fdelta as described with reference to FIG. For example, the frequency channel control unit 42 determines that the transmission frequency bandwidth allocated to the operator who uses the current frequency channel is 2.5 MHz, and the minimum transmission frequency bandwidth is 1.25 MHz. If it is determined, fdelta is determined to be “10”. Further, when searching without omission, as described with reference to FIG. 3, the frequency channel control unit 42 sets the fdelta to “8” or “9” which is smaller than “10” in FIG. 2 by a predetermined number. Or the like.

  Then, the frequency channel control unit 42 performs a calculation of fid_no = fid_no + fdelta and determines a frequency channel number to be a next reception target (S9). As described above, the frequency channel control unit 42 overlaps the first band composed of the entire band of the first frequency channel or the estimated use band with the second band composed of the entire band of the second frequency channel or the estimated use band. Therefore, the second frequency channel is determined so as not to occur. In order to perform a search without omission, it is desirable to set fdelta to a value slightly smaller than “10” as in the example shown in FIG. That is, when applied to an actual communication system, it is an indispensable condition that fdelta is appropriately set so that a normal search is performed according to the actual communication system.

  Further, when the secondary synchronization channel SSCH is not received (S3: NO), or when the reference signal is not received (S4: NO), the process proceeds to step S7. In these cases, since the reference signal is not received, the transmission frequency bandwidth of the currently received frequency channel cannot be determined. Therefore, the frequency channel control unit 42 determines fdelta based on a minimum frequency bandwidth among transmission frequency bandwidths set in advance by a business operator or the like (S7). Specifically, fdelta is determined as follows.

  FIG. 5 is a third conceptual diagram showing how the second frequency channel is determined by the process of step S7 of the frequency channel control unit 42 shown in FIG. When the reference signal is not received, the entire band of the first frequency channel and the estimated use band are unknown. However, since the primary synchronization channel PSCH is received in step S2, it is clear that a signal is transmitted from the base station on at least the currently received frequency channel. Therefore, the frequency channel control unit 42 assumes that the entire band of the first frequency channel is the minimum (for example, 1.25 MHz) of the transmission frequency bandwidth.

  Similarly, the frequency channel control unit 42 assumes that the entire band of the second frequency channel is the minimum (for example, 1.25 MHz) of the transmission frequency bandwidth. As a result, fdelta can be determined without skipping a frequency channel that may be operated closest to the current frequency channel. In the example shown in FIG. 5, the entire band of the first frequency channel is 1.25 MHz, and the entire band of the second frequency channel is 1.25 MHz. For this reason, the frequency channel control unit 42 sets fdelta to “7” (for 1.4 MHz). As a result, fdelta can be determined without skipping a frequency channel that may be operated closest. Note that the frequency channel control unit 42 may determine fdelta based on the estimated use band instead of the entire band as in FIG.

  Returning to FIG. 4, thereafter, the frequency channel control unit 42 performs a calculation of fid_no = fid_no + fdelta, and determines the frequency channel number to be the next reception target (S9). Thereby, even a little useless search can be omitted and a search without omission can be performed.

  After step S9, the frequency channel control unit 42 determines whether or not there are remaining reception frequency channels to be searched (S10). That is, if fid_no is smaller than 277 (not exceeding the maximum value) and there are remaining reception frequency channels to be searched (S10: YES), the process proceeds to step S2, and the frequency channel number fid_no defined in step S9 is obtained. Thus, the processing from step S2 is performed. On the other hand, if fid_no is 277 or more and there is no reception frequency channel to be searched (S10: NO), the processing shown in FIG. 4 ends.

  As described above, according to the mobile station apparatus 1 and the search method thereof according to the first embodiment, the frequency channel control unit 42 is either the entire band or the estimated use band of the first and second frequency channels. The second frequency channel is determined so that the first band and the second band formed from one side do not overlap. Here, for example, when a signal of the first frequency channel is received and it is detected that a signal from the base station is included, it is determined that there is an operator using the frequency channel. Further, it is clear that there are no frequency channels used by other operators in the vicinity of the frequency channel band. For this reason, the frequency channel adjacent to the first frequency channel is not determined as the second frequency channel, and the first and second bands made up of the entire band or the estimated use band of the first and second frequency channels overlap. By determining the second frequency channel so that it does not occur, frequency channels that cannot be used by other operators or the like are skipped, and the time required for the search can be reduced.

  Further, the frequency channel control unit 42 employs the minimum bandwidth among the plurality of transmission frequency bandwidths, and obtains the second band composed of the entire band of the second frequency channel or the estimated use band. This assumes that the bandwidth of the second frequency channel is greater than the minimum bandwidth when the bandwidth of the frequency channel used by other operators is actually the minimum. It is possible to suppress the situation where the second frequency channel is determined and the frequency channel used by another business operator is skipped.

  Further, the frequency channel control unit 42 specifies the first band of the first frequency channel from the actually received signal of the first frequency channel in order to identify the first band from the signal of the first frequency channel. The use band is obtained, and the determination accuracy of the second frequency channel can be improved based on the received signal.

  Further, since the frequency channel control unit 42 specifies the first band based on the specific symbol sequence included in the signal from the base station, the frequency channel control unit 42 includes a specific symbol sequence indicating the frequency bandwidth from the base station. In this case, based on this symbol sequence, the first band consisting of the entire band of the first frequency channel or the estimated use band is obtained. Thereby, it is possible to improve the accuracy when obtaining the first band, and it is possible to improve the determination accuracy for the second frequency channel.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. FIG. 6 is a schematic block diagram illustrating a configuration of the mobile station apparatus 2 according to the second embodiment. The configuration of the mobile station apparatus 2 and the search method thereof are partially different from the mobile station apparatus 1 of the first embodiment in the processing contents of the control unit 70, the detection unit 71, the frequency channel control unit 72, and the signal processing unit 60. However, the other parts (10, 20, 50) are the same. Hereinafter, differences from the first embodiment will be described.

  FIG. 7 is a flowchart showing details of the search method of the mobile station apparatus 1 according to the second embodiment. In FIG. 7, unlike E-UTRA, a search method for performing a search using only one signal will be described. In FIG. 7, there are 277 frequency channels defined at a constant interval (200 KHz) in a specific continuous frequency band (60 MHz), and the frequency channel numbers from 0 to 276 are assigned in order from the lowest frequency. Is defined.

  In the second embodiment, the signal processing unit 60 detects the signal 1 designated by the control unit 70, and the detection unit 71 of the control unit 70 determines whether or not the signal 1 is included in the signal from the base station. That is, it is determined whether or not signal 1 has been received (S11). This determination is performed by correlation detection by autocorrelation or cross-correlation as described in the conventional example.

  When the signal 1 cannot be received (S11: NO), the process proceeds to step S10 through step S8 and step S9. On the other hand, when the signal 1 is received (S11: YES), the control unit 70 determines the transmission frequency bandwidth of the currently received frequency channel from the signal 1 (S12). Here, as in the reference signal of the first embodiment, the signal 1 includes, for example, different symbol sequences for each of six transmission frequency bandwidths (for example, 1.25 MHz, 2.5 MHz, 5 MHz, 10 MHz, 15 MHz, and 20 MHz). Is defined. That is, when the base station side transmits a symbol sequence corresponding to the transmission frequency bandwidth, the mobile station device 2 side can determine the transmission frequency bandwidth when receiving the signal 1.

  The method for determining the transmission frequency bandwidth is not limited to this, and may be as follows. For example, even if the base station encodes and transmits a signal indicating the currently operating transmission frequency bandwidth, and the mobile station apparatus 2 receives and decodes the signal 1, the transmission frequency bandwidth is determined. Good.

  Thereafter, the frequency channel control unit 72 performs the same process as step S6 in FIG. 4 (S6). Then, the process goes through step S9 to step S10. In step S10, the frequency channel control unit 72 determines whether or not there are remaining reception frequency channels to be searched (S10). When the reception frequency channel to be searched remains (S10: NO), the process proceeds to step S11. On the other hand, when there are no remaining reception frequency channels to be searched (S10: YES), the processing shown in FIG. 7 ends.

  As described above, according to the mobile station apparatus 2 and the search method thereof according to the second embodiment, the time required for the search can be reduced as in the first embodiment. In addition, it is possible to suppress a situation where a search is performed by skipping a frequency channel used by another provider or the like. Further, it is possible to improve the determination accuracy for the second frequency channel.

  Further, the frequency channel control unit 72 indicates the first bandwidth from the decoding result of the specific signal encoded and transmitted from the base station, for example, indicating the frequency bandwidth from the base station and encoding the specific signal. Is included, the first band composed of the entire band of the first frequency channel or the estimated use band is obtained based on the decoding result of the specific signal. Thereby, it is possible to improve the accuracy when obtaining the first band, and it is possible to improve the determination accuracy for the second frequency channel.

[Third Embodiment]
Next, a third embodiment of the present invention will be described. FIG. 8 is a schematic block diagram illustrating a configuration of the mobile station apparatus 3 according to the third embodiment. The configuration of the mobile station apparatus 3 and the search method thereof are partially different from the mobile station apparatus 2 of the second embodiment in the processing contents of the control unit 80 and the frequency channel control unit 82, but the other parts (10, 20 , 50, 60, 71) are the same. Hereinafter, differences from the second embodiment will be described.

  FIG. 9 is a flowchart showing details of the search method of the mobile station apparatus 3 according to the third embodiment. In FIG. 9, unlike E-UTRA, a search method in a case where information specifying a transmission frequency bandwidth is not included in a signal from a base station will be described. In FIG. 9, there are 277 frequency channels defined at a constant interval (200 KHz) in a specific continuous frequency band (60 MHz), and frequency channel numbers from 0 to 276 are assigned in order from the lowest frequency. Is defined.

  First, in the third embodiment, the transmission frequency bandwidth of the currently received frequency channel cannot be determined. Therefore, when the signal 1 is received (S11: YES), the frequency channel control unit 82 determines fdelta based on the minimum transmission frequency bandwidth (step S7). At this time, the control unit 80 determines fdelta as shown in step S7 of FIG. 4 and FIG. Thereafter, the process ends through steps S9 and S10.

  As described above, according to the mobile station device 3 and the search method thereof according to the third embodiment, the time required for the search can be reduced as in the second embodiment. In addition, it is possible to suppress a situation where a search is performed by skipping a frequency channel used by another provider or the like. Further, it is possible to improve the determination accuracy for the second frequency channel.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described. FIG. 10 is a schematic block diagram showing the configuration of the mobile station apparatus 4 according to the fourth embodiment. The configuration of the mobile station apparatus 4 and the search method thereof are partially different from the mobile station apparatus 2 of the second embodiment in the processing contents of the control unit 90 and the frequency channel control unit 72, but the other parts (10, 20 , 50, 60, 71) are the same. Hereinafter, differences from the second embodiment will be described.

  FIG. 11 is a flowchart showing details of the search method of the mobile station apparatus 1 according to the fourth embodiment. In FIG. 11, the search method when the transmission frequency bandwidth is uniquely determined according to the frequency channel will be described. In FIG. 11, there are 277 frequency channels defined at a constant interval (200 KHz) in a specific continuous frequency band (60 MHz), and the frequency channel numbers from 0 to 276 are assigned in order from the lowest frequency. Is defined.

  The mobile station apparatus 4 according to the fourth embodiment is configured to be able to determine the transmission frequency bandwidth from the frequency band to which the first frequency channel belongs. FIG. 12 is a correlation diagram illustrating a correspondence relationship between a frequency band and a transmission frequency bandwidth of a frequency channel in the frequency band. As shown in FIG. 12, for example, it is assumed that the transmission frequency bandwidth in the 2 GHz band is 5 MHz, and the transmission frequency bandwidth in the 800 MHz band is predetermined as 10 MHz. In this case, if the current frequency channel belongs to the 2 MHz band, it can be determined that the entire band of the first frequency channel is 5 MHz, and the entire band of the second frequency channel can also be determined to be 5 MHz. Similarly, if the current frequency channel belongs to the 800 MHz band, it can be determined that the entire band of the first frequency channel is 10 MHz, and the entire band of the second frequency channel can also be determined to be 10 MHz.

  For this reason, when the signal 1 is received (S11: YES), the frequency channel control unit 92 determines the first and second frequencies from the bandwidth of the transmission frequency that is predetermined in the frequency band to which the current frequency channel belongs. The transmission frequency bandwidth of the channel is determined (S13). Thereafter, the frequency channel control unit 42 obtains the entire band of the first frequency channel, obtains the entire band of the second frequency channel, and determines fdelta (S14). Thereafter, the process ends through steps S9 and S10.

  Note that the mobile station apparatus 4 according to the fourth embodiment obtains the entire band of the first frequency channel and the entire band of the second frequency channel based on the frequency band to which the first frequency channel belongs. However, the present invention is not limited to this, and the configuration may be such that only one of the entire bands is obtained. Here, when the mobile station apparatus 4 obtains only the entire band of the first frequency channel, it is desirable to employ the minimum transmission frequency bandwidth for the entire band of the second frequency channel. This is because it is possible to prevent missing search. Furthermore, the mobile station apparatus 4 according to the fourth embodiment may be configured to obtain the estimated use band from the entire band and determine the fdelta.

  As described above, according to the mobile station apparatus 4 and the search method thereof according to the fourth embodiment, the time required for the search can be reduced as in the second embodiment. In addition, it is possible to suppress a situation where a search is performed by skipping a frequency channel used by another provider or the like.

  Further, the frequency channel control unit 92 obtains the second band from the bandwidth of the transmission frequency determined in advance in the frequency band to which the first frequency channel belongs, and the second frequency channel based on the obtained second band. To decide. Here, for example, in the case of the 800 MHz band, it is assumed that the bandwidth of the transmission frequency is predetermined such as 10 MHz. In this case, the frequency channel control unit 92 can obtain the transmission frequency bandwidth of the second frequency channel from the frequency band to which the first frequency channel belongs. Thereby, it is possible to accurately obtain the second band and improve the determination accuracy for the second frequency channel.

  As described above, the present invention has been described based on the embodiment, but the present invention is not limited to the above embodiment, and may be modified without departing from the gist of the present invention. For example, in the above embodiment, a communication system that performs cell search using E-UTRA or one signal has been described. However, the communication system is not limited to these, and any other communication system is applicable as long as a plurality of transmission frequency bandwidths from the base station are defined. Also, the number of signals used for cell search is not particularly limited.

  In the first to fourth embodiments, there are 277 frequency channels defined at a constant interval (200 KHz) in a specific continuous frequency band (60 MHz), and 0 in order from the lowest frequency. The example in which the frequency channel numbers are defined from 1 to 276 has been described. However, the frequency channels need not be defined at regular intervals, and the method of defining the frequency channel number is not particularly limited to this.

  In the first to fourth embodiments, the mobile station apparatuses 1 to 4 and the search method thereof have been described. However, the present invention is not limited to these. For example, even a mobile station apparatus that cannot execute the search method described above may be a mobile station apparatus that can execute the search method by programming the contents described in the above embodiments and taking in the program. The program can be imported by, for example, a configuration in which the mobile station apparatus is directly imported via a recording medium such as a memory card, or a search program stored in a CD-ROM or the like, and a program recorded on the CD-ROM. May be written to the mobile station apparatus by a PC or the like connected to the mobile station apparatus. Furthermore, the mobile station device may be configured to download the program via a base station.

It is a schematic block diagram which shows the structure of the mobile station apparatus 1 which concerns on the 1st Embodiment of this invention. It is a conceptual diagram which shows the mode of the determination of the 2nd frequency channel by the frequency channel control part 42 in the embodiment. It is a 2nd conceptual diagram which shows the mode of the determination of the 2nd frequency channel by the frequency channel control part 42 in the embodiment. 4 is a flowchart showing details of a search method of the mobile station apparatus 1 in the embodiment. It is a 3rd conceptual diagram which shows the mode of the determination of the 2nd frequency channel by the frequency channel control part 42 in the embodiment. It is a schematic block diagram which shows the structure of the mobile station apparatus 2 which concerns on the 2nd Embodiment of this invention. 7 is a flowchart showing details of a search method of the mobile station apparatus 2 in the same embodiment. It is a schematic block diagram which shows the structure of the mobile station apparatus 3 which concerns on the 3rd Embodiment of this invention. 4 is a flowchart showing details of a search method of the mobile station apparatus 3 in the same embodiment. It is a schematic block diagram which shows the structure of the mobile station apparatus 4 which concerns on the 4th Embodiment of this invention. It is a flowchart which shows the detail of the search method of the mobile station apparatus 4 in the embodiment. It is a correlation diagram which shows the correspondence of a frequency band and a transmission frequency bandwidth. It is the 1st conceptual diagram which showed the basic downlink radio frame structure. It is the 2nd conceptual diagram which showed the basic downlink radio frame structure.

Explanation of symbols

1, 2, 3, 4 ... mobile station device 10 ... antenna 20 ... radio unit 30, 60 ... signal processing unit 40, 70, 80, 90 ... control unit 41, 71 ... detection unit 42, 72, 82, 92 ... frequency Channel control part 50 ... Application part

Claims (17)

A mobile station device that communicates with a base station,
A receiver capable of receiving signals of a plurality of frequency channels;
A detector that detects whether or not a signal from a base station is included in the signal of the first frequency channel received by the receiver;
Control for determining a second frequency channel to be a next reception target frequency channel based on a detection result by the detection unit, and controlling the reception unit to be able to receive a signal of the second frequency channel And comprising
The control unit includes a first band consisting of a first estimated use band estimated to be used in the entire band of the first frequency channel or the first frequency channel, and all of the second frequency channel. The second frequency channel is determined such that the second frequency channel is not overlapped with a second band composed of a second estimated usage band estimated to be used in the band or the second frequency channel. apparatus. The control unit obtains the second band from a minimum bandwidth among bandwidths of transmission frequency channels from a preset base station, and the second frequency based on the obtained second band. The mobile station apparatus according to claim 1, wherein a channel is determined. The control unit obtains the second band from a bandwidth of a predetermined transmission frequency in a frequency band to which the first frequency channel belongs, and determines the second frequency channel based on the obtained second band. The mobile station apparatus according to claim 1, wherein the mobile station apparatus is determined. The control unit identifies the first band from the signal of the first frequency channel, and determines the second frequency channel based on the identified first band. The mobile station apparatus of any one of Claim 3. The mobile station apparatus according to claim 4, wherein the control unit specifies the first band based on a specific symbol sequence included in a signal from the base station. The mobile station apparatus according to claim 4, wherein the control unit specifies the first band from a decoding result of a specific signal encoded and transmitted from the base station. The control unit identifies the first band from a bandwidth of a predetermined transmission frequency in a frequency band to which the first frequency channel belongs, and determines the second frequency channel based on the identified first band. The mobile station apparatus according to any one of claims 1 to 3, wherein the mobile station apparatus is determined. A mobile station apparatus search method executed by a mobile station apparatus when a mobile station apparatus communicating with a base station establishes communication with the base station,
A reception stage capable of receiving signals of a plurality of frequency channels;
A detection step of detecting whether or not a signal from the base station is included in the signal of the first frequency channel received in the reception step;
A control step of determining a second frequency channel to be a next frequency channel to be received based on a detection result in the detection step and controlling the mobile station apparatus to be able to receive a signal of the second frequency channel. And having
In the control step, a first band consisting of a first estimated use band estimated to be used in the entire band of the first frequency channel or the first frequency channel, and the entire of the second frequency channel. The second frequency channel is determined such that the second frequency channel is not overlapped with a second band composed of a second estimated usage band estimated to be used in the band or the second frequency channel. Device search method. In the control step, the second band is obtained from a minimum bandwidth among the bandwidths of transmission frequency channels set in advance from the base station, and the second frequency is determined based on the obtained second band. The channel is determined. The search method of the mobile station apparatus of Claim 8 characterized by the above-mentioned. In the control step, the second band is obtained from a bandwidth of a predetermined transmission frequency in a frequency band to which the first frequency channel belongs, and the second frequency channel is determined based on the obtained second band. The mobile station apparatus search method according to claim 8, wherein the mobile station apparatus is determined. The said control step WHEREIN: The said 1st band is calculated | required from the signal of the said 1st frequency channel, The said 2nd frequency channel is determined based on the calculated | required 1st band. Item 11. The mobile station device search method according to any one of Items 10 above. The mobile station apparatus search method according to claim 11, wherein, in the control step, the first band is specified based on a specific symbol sequence included in a signal from the base station. The mobile station apparatus search method according to claim 11, wherein, in the control step, the first band is specified from a decoding result of a specific signal encoded and transmitted from the base station. In the control step, the first band is specified from a predetermined transmission frequency bandwidth in a frequency band to which the first frequency channel belongs, and the second frequency channel is determined based on the specified first band. The mobile station apparatus search method according to claim 8, wherein the mobile station apparatus search method is determined.   A search program for causing a computer to execute the search method according to any one of claims 8 to 14.   A computer-readable recording medium on which the search program according to claim 15 is recorded.   A mobile station apparatus that reads and executes the search program according to claim 15.

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