WO2007023810A1

WO2007023810A1 - Scalable bandwidth system, radio base station apparatus, synchronous channel transmitting method and transmission method

Info

Publication number: WO2007023810A1
Application number: PCT/JP2006/316412
Authority: WO
Inventors: Hiroki Haga; Hidenori Matsuo; Katsuyoshi Naka
Original assignee: Matsushita Electric Industrial Co., Ltd.
Priority date: 2005-08-23
Filing date: 2006-08-22
Publication date: 2007-03-01

Abstract

A scalable bandwidth system wherein even if a terminal does not know the breakdowns of the services in all of the bandwidths, it can perform a correlation processing of synchronous channels (SCH). A base station repetitively transmits a synchronous channel, by unit of the shortest bandwidth (e.g., 1.25 MHz) of a plurality of bandwidths served by the system, over the whole band of the longest bandwidth (e.g., 5 MHz). The terminal calculates the correlation between a synchronous channel sequence signal of the unit of the shortest bandwidth held in advance and the repetitively transmitted synchronous channel, and determines, as a frame timing, a timing at which the maximum correlation value is obtained.

Description

Specification

Scalable bandwidth system, radio base station apparatus, synchronization channel transmission method, and transmission method

Technical field

[0001] In particular, the present invention enables a radio base station apparatus to support a plurality of maximum bandwidths, and among the maximum bandwidths, it is possible to flexibly allocate a bandwidth in which each wireless terminal apparatus actually performs communication. The present invention relates to a scalable bandwidth system, a radio base station apparatus used in the scalable bandwidth system, a synchronization channel transmission method, and a transmission method.

Background art

[0002] Conventionally, when performing multicarrier communication represented by OFDM (Orthogonal Frequency Division Multiplexing), a radio base station apparatus (hereinafter simply referred to as a base station) supports a plurality of maximum bandwidths. A wireless communication system has been proposed in which each wireless terminal device (hereinafter simply referred to as a terminal) can flexibly allocate a bandwidth for actual communication within the maximum bandwidth. Such a wireless communication system is called a scalable bandwidth system (see Non-Patent Document 1, for example).

[0003] By the way, in a multicarrier communication system, different scramble codes are assigned to each cell in order to identify a cell covered by a base station. The terminal (mobile station) needs to perform a cell search, that is, identify a scramble code to identify the cell when switching cells (no, over) or intermittently receiving due to movement.

[0004] In a cell search in a multicarrier communication system in which the bandwidth allocated to each terminal is fixed, the terminal performs a cell search using a synchronization channel (SCH: Synchronization Channel) received in accordance with the bandwidth of the system. Do it! A cell search method using SCH is generally described in Non-Patent Document 2.

[0005] The terminal first detects symbol timing (FFT window timing) as the first stage, and then detects the frame timing using the SCH as the second stage. Specifically, the received signal is FFTed to separate the SCH and correlate with the SCH replica. The timing at which the largest correlation value among the obtained correlation values is obtained is detected as the frame timing. That Later, as a third step, a scramble code is identified using a pilot channel or the like.

[0006] As a configuration of this synchronization channel, for example, there is one proposed in Non-Patent Document 3. Non-Patent Document 3 proposes a method in which two SCHs are arranged in a frequency direction in lOFDM symbols as shown in FIG. Here, lOFDM symbols are arranged in one frame, Primary SCH (P—SCH) is a pattern common to all cells, and S econdary SCH (S—SCH) is a different pattern (pattern representing a code group) for each cell. It is.

Non-Patent Document 1: 3GPP TR 25.913 v7.0.0 (2005-06) "Requirements for Evolved UTRA and UTRAN"

Non-Patent Document 2: Hanada, Shin, Higuchi, Sawahashi (NTT DoCoMo), RCS2001-091 (2001-07) "Three-stage cell search characteristics using frequency-multiplexed synchronization channels in broadband multicarrier CDMA transmission

Non-Patent Document 3: 3GPP Rl-050590, NTT DoCoMo "Physical Channels and Multiplexing in Evolved UTRA Downlink" (June 2005)

Disclosure of the invention

Problems to be solved by the invention

However, for example, the bandwidth that should be supported by the scalable bandwidth system of Non-Patent Document 1 is specified as 1.25 MHz, 2.5 MHz, 5 MHz, 10 MHz, 15 MHz, and 20 MHz.

[0008] Since the terminal does not know which bandwidth the base station is serving at the time of initial cell search, it has no power to start the initial cell search attempt at which center frequency and bandwidth within a maximum of 20 MHz. . Therefore, the terminal needs to start the initial cell search process after detecting the total service bandwidth of the base station.

[0009] However, since the terminal cannot know the breakdown of the service bandwidth during cell search, the position and size of the SCH pattern are not divided, and as a result, SCH correlation cannot be obtained. As a result, there is a problem that processing after frame synchronization cannot be performed.

This will be described with reference to FIGS. 2 and 3. Figure 2 shows the fixed bandwidth allocated to the terminal. This shows how correlation is acquired in a fixed (5 MHz) multi-carrier communication system. Since the bandwidth is fixed, correlation values can be easily acquired using a SCH replica signal with a period corresponding to this bandwidth.

[0011] On the other hand, FIG. 3 shows a state of correlation acquisition in a scalable bandwidth system in which the bandwidth allocated to the terminal is variable. The terminal transmits the base station to each terminal during cell search. Since it is impossible to know the breakdown of the service bandwidth being used, the position and size of the SCH pattern are not known (that is, what SCH replica can be used! It becomes difficult.

[0012] An object of the present invention is to provide a scalable bandwidth system, a radio base station apparatus, and a radio base station apparatus that can correctly acquire a correlation value of a synchronization channel (SCH) without knowing a breakdown of services within the entire bandwidth. A synchronization channel transmission method and a transmission method are provided.

Means for solving the problem

[0013] In the scalable bandwidth system of the present invention, a radio base station apparatus supports a plurality of maximum bandwidths, and among the maximum bandwidths, a bandwidth in which each wireless terminal apparatus actually performs communication is flexibly allocated. A scalable bandwidth system that enables a wireless base station apparatus that repeatedly transmits a synchronization channel in the frequency direction in a minimum bandwidth unit among a plurality of bandwidths to be serviced. ! /, Calculating a correlation between the synchronization channel sequence signal in the minimum bandwidth unit and the repeatedly transmitted synchronization channel, and detecting a timing at which the maximum correlation value is obtained as a frame timing. Adopt the structure that has.

[0014] With this configuration, the terminal can correctly acquire the SCH correlation value without knowing the breakdown of services within the entire bandwidth of the base station.

The invention's effect

[0015] According to the present invention, it is possible to correctly acquire the correlation value of the synchronization channel (SCH) even if the terminal does not know the breakdown of the service within the entire bandwidth, and the processing after frame synchronization is improved. You will be able to do well.

Brief Description of Drawings

[0016] FIG. 1 is a diagram showing a configuration example of a synchronization channel [Fig. 2] Diagram showing how correlation is acquired in a multi-carrier communication system where the bandwidth allocated to a terminal is fixed

[Fig. 3] Diagram showing how correlation is acquired in a scalable bandwidth system with variable bandwidth allocated to terminals.

FIG. 4 is a block diagram showing the configuration of the base station according to the embodiment

FIG. 5 is a block diagram showing the configuration of the terminal according to the embodiment

FIG. 6 is a diagram for explaining the operation of the embodiment.

FIG. 7 is a diagram for explaining a transmission method of a base station according to another embodiment.

FIG. 8 is a diagram for explaining a base station transmission method according to another embodiment.

[Fig.9] Diagram showing an example when the SCH pattern is different at the center

[Fig. 10] Diagram showing an example when the SCH pattern is different at the center.

[Figure 11] Diagram showing the correspondence between when correlation can be acquired and when correlation cannot be acquired

FIG. 12 shows an example of SCH pattern according to the second embodiment.

FIG. 13 shows an example of SCH pattern according to the second embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0018] (Embodiment 1)

FIG. 4 shows the configuration of a radio base station apparatus (hereinafter referred to as a base station) used in the scalable bandwidth system of the present embodiment, and FIG. 5 shows a radio terminal apparatus (communication with base station 100) ( Hereinafter, the configuration of the terminal is shown.

[0019] Base station 100 flexibly allocates a bandwidth that is equal to or smaller than the maximum supported bandwidth to each terminal as a communication bandwidth of each terminal, OFDM communication is performed with each terminal.

First, the configuration of base station 100 shown in FIG. 1 will be described. Base station 100 inputs transmission data l to n addressed to terminals l to n to transmission control section 101. The transmission control unit 101 selectively outputs the input transmission data 1 to n to the error correction code key unit 102.

Error correction code unit 102 performs error correction encoding processing on the data input from transmission control unit 101, and sends the encoded data obtained thereby to modulation unit 103. Modulator 103 The encoded data is subjected to a modulation process such as QPSK (Quadrature Phase Shift Keying) or 16QAM (Quadrature Amplitude Modulation), and the resulting modulation signal is sent to the frame forming unit 104.

[0022] Frame forming section 104 forms a transmission frame signal by adding a pilot signal (PL) to the modulated signal, and sends it to scrambling section 105. Scrambling section 105 performs scrambling processing using a cell-specific scrambling code, and sends the scrambled signal to subcarrier allocation section 106.

The subcarrier allocation unit 106 receives the synchronization channel sequence signal formed by the synchronization channel sequence signal formation unit 107 in addition to the transmission data from the scrambling processing unit 105. The subcarrier allocation unit 106 is configured so that the synchronization channel sequence signal is repeatedly allocated in the minimum bandwidth unit among the multiple bandwidths supported by the base station over the entire bandwidth of the maximum bandwidth. Subcarrier allocation of synchronization channel sequence signals is performed. Although not described in detail here, subcarrier allocation section 106 arranges the signal after scrambling processing addressed to each terminal in the subcarrier of the position and bandwidth based on the scheduling information and the like. The subcarrier allocation unit 106 includes a serial / parallel conversion circuit.

[0024] The output of subcarrier allocation section 106 is processed by fast inverse Fourier transform section (IFFT) 108, a guard interval is inserted by subsequent guard interval (GI) insertion section 109, and digital / analog conversion is performed by radio transmission section 110. After being subjected to predetermined radio processing such as processing and up-conversion processing to radio frequency, it is output from the antenna 111.

Next, the configuration of terminal 200 shown in FIG. 5 will be described. Terminal 200 inputs a signal received by antenna 201 to radio reception section 202. Radio receiving section 202 obtains a baseband OFDM signal by performing predetermined radio processing such as down-conversion processing or analog-digital conversion processing on the received signal.

The baseband OFDM signal output from radio reception section 202 is input to fast Fourier transform section (FFT) 206 after the guard interval (GI) removal section 205 removes the guard interval.

In addition, the baseband OFDM signal is input to the bandwidth determination unit 203. Bandwidth format For example, for the OFDM signal obtained in each band, the fixed unit 203 is the magnitude of the correlation value between the part that became the source of the guard interval and the guard interval part in the signal that is obtained by shifting the OFDM signal by the effective symbol length. And the maximum bandwidth supported by the base station 100 is determined based on the magnitude of this correlation value. The symbol timing detection unit 204 detects the symbol timing by detecting the peak of the correlation value obtained by the bandwidth determination unit 203, for example. The FFT 206 performs FFT processing at the symbol timing (FFT window timing) detected by the symbol timing detection unit 204 to obtain a signal before IFFT processing, and sends this to the subcarrier selection units 207 and 209. The subcarrier selection unit 207 sends, for example, a signal of the subcarrier indicated by the scheduling information sent on the control channel to the descrambling processing unit 208.

[0028] Subcarrier selection section 209 selects a subcarrier signal in a minimum bandwidth unit from among a plurality of bandwidths supported by the base station, and calculates SCH correlation value calculation section 210 and pilot correlation value calculation. Send to part 212.

[0029] SCH correlation value calculation section 210 calculates a correlation value between the synchronization channel signal output from subcarrier selection section 209 and a replica of the synchronization channel sequence signal in the minimum bandwidth unit, Timing The data is sent to the Z code group detection unit 211.

Frame timing The Z code group detection unit 211 detects the frame timing and the code group by detecting the peak of the correlation value. The nolot correlation calculation unit 212 calculates a correlation value between the signal output from the FFT 206 and a plurality of candidate scramble codes at the start timing of the frame (that is, the scrambling process arranged at the start of the frame is performed). The correlation value between the pilot and a plurality of candidate scramble codes is calculated), and the correlation value is sent to the scramble code identifying unit 213. The scramble code identifying unit 213 identifies the scramble code having the largest correlation value as the scramble code used in the base station 100, and sends the identified scramble code to the descrambling processing unit 208.

[0031] The descrambling processing unit 208 descrambles the signal output from the subcarrier selection unit 207 with the identified scramble code. The descrambled signal is demodulated by the demodulator 214 and decoded by the decoder 215, thereby receiving the received data. Data.

Next, the operations of base station 100 and terminal 200 of the present embodiment will be described using FIG.

For example, as shown in FIG. 1, base station 100 generates an SCH OFDM symbol from a symbol sequence common to all base stations, time-multiplexes the frame data, and inserts it into the frame after the scrambling process To do.

[0034] Here, the SCH symbol sequence pattern has a size corresponding to the number of subcarriers of the minimum bandwidth of the scalable bandwidth (eg, 1.25 MHz). Subcarrier allocation section 106 repeatedly arranges the SCH having the minimum bandwidth size.

The SCH arrangement method will be specifically described with reference to FIG. Assume that the maximum bandwidth that base station 100 can transmit is 5 MHz, and that data signals are transmitted in three parts: 1.25 MHz, 2.5 MHz, and 1.25 MHz. For simplicity of explanation, the number of subcarriers corresponding to the minimum bandwidth (1.25 MHz) of the scalable bandwidth is assumed to be 8. As shown in FIG. 6, the base station 100 repeatedly arranges SCH patterns having a size equivalent to the width of 1.25 MHz regardless of the service breakdown width.

[0036] Upon receiving such a signal, the terminal 200 performs the following processing. If the upper limit of the frequency bandwidth (capability) that can be received by terminal 200 is larger than the minimum bandwidth (1.25 MHz) (2.5 MHz, 5 MHz, 10 MHz, 15 MHz, 20 MHz), SCH correlation value calculation section 210 of terminal 200 Synthesizes SCH correlation values as shown in FIG. That is, the SCH correlation value calculation unit 210 synthesizes the correlation values obtained for each minimum bandwidth, and detects the timing at which the maximum value is obtained from the combined correlation values as a frame. This can improve the accuracy of frame timing detection. In addition, the SCH correlation value calculation unit 210 selects a synchronization channel transmitted with one or a plurality of minimum bandwidths from among the synchronization channels repeatedly transmitted over the entire maximum bandwidth. Correlation can also be performed. In this way, it is not necessary to perform correlation processing with all the minimum bandwidths, and the amount of cell search processing can be reduced.

[0037] As described above, according to the present embodiment, the maximum bandwidth (for example, 5 MHz) in the minimum bandwidth unit (for example, 1.25 MHz unit) of the multiple bandwidths serviced by the system. The correlation between the base station 100 that repeatedly transmits the synchronization channel, the synchronization channel sequence signal in the minimum bandwidth unit, and the synchronization channel that is repeatedly transmitted is calculated over the entire band of z). Terminal 200 that detects the timing at which the correlation value is obtained as the frame timing is provided, so that terminal 200 can obtain the SCH correlation value without knowing the breakdown of services within the entire bandwidth of base station 100. You can get it correctly.

[0038] In the above-described embodiment, base station 100 has a minimum bandwidth unit (for example, 1.25 MHz unit) among a plurality of bandwidths served by the system, and a maximum bandwidth (for example, 5 MHz). In the above description, the synchronization channel is repeatedly transmitted without leaving an interval over the entire bandwidth, but the present invention is not limited to this. For example, the synchronization channel in the minimum bandwidth unit is repeated at a certain interval in the frequency direction. You may make it transmit. Further, the present invention is not limited to the case where the synchronization channel of the minimum bandwidth unit is repeatedly transmitted over the entire maximum bandwidth supported by the base station. This is because, for example, when the band to be used is limited in advance within the maximum bandwidth, the synchronization channel may be repeatedly transmitted in the minimum bandwidth unit in the frequency direction only for the limited band. !

[0039] Also, in the above-described embodiment, the case where the synchronization channel is repeatedly transmitted has been described. However, as shown in Fig. 7, the base station performs a minimum bandwidth unit among a plurality of bandwidths to be serviced. The common control channel may be repeatedly transmitted over the frequency direction. In this way, the terminal can know the common control information sent on the common control channel without knowing the breakdown of the services within the entire bandwidth of the base station, so the SCH correlation processing must be performed. Will be able to.

[0040] Furthermore, base station 100 power SCH and the common channel are repeatedly transmitted such that the center frequency of the common channel matches the raster frequency, and terminal 200 uses the signal received with reference to the raster frequency as described above. If the frame timing detection process as described above is performed, the terminal can easily detect the used frequency during the carrier frequency search, which is more preferable.

[0041] This will be described. The terminal generally performs a carrier frequency search before performing a cell search. The carrier frequency search is for checking whether or not the frequency that each operator can use for the service is used. It detects the frequency to use based on the RSSI (Received Signal Strength Indicator). This carrier frequency search (see, for example, Japanese Patent Laid-Open No. 2002-300136 and Japanese Patent Laid-Open No. 2003-134569) and raster frequency (see, for example, 3GPP TS 25. 101 V6.9.0) are known techniques. Detailed explanation is omitted.

[0042] In the present invention, using this carrier frequency search and the concept of raster frequency, in addition to the above-described embodiment, the base station arranges the SCH based on the raster frequency, and at the same time, the terminal uses the raster frequency step. It is also proposed to perform a carrier frequency search. That is, as shown in FIG. 8, the base station is arranged so that the center frequency of the SCH having the minimum bandwidth (1.25 MHz) matches the raster frequency. Specifically, the base station 100 in FIG. 4 sets the SCH so that the center frequency of the synchronization channel (SCH) formed by the synchronization channel sequence signal forming unit 107 matches the raster frequency by the subcarrier allocation unit 106. Subcarrier placement. The terminal 200 in FIG. 5 performs reception processing by the radio reception unit 202 in increments of raster frequencies.

[Embodiment 2]

The feature of this embodiment is that, for a specific band, the base station repeatedly transmits the synchronization channel so that the sequence signals of the synchronization channel match among a plurality of serviced bandwidths. is there. In this way, even if the bandwidth to be serviced is changed, the contents of the synchronization channel in the specific band are the same, so the terminal can correctly acquire the correlation value of the synchronization channel in the specific band. become able to.

[0044] First, the reason for presenting the present embodiment will be described with reference to FIGS.

In the scalable bandwidth system, the inventors of the present invention have proposed a method in which a synchronization channel (SCH) is arranged and transmitted in the central portion of the maximum bandwidth (for example, 20 MHz). Pay attention.

FIG. 9 shows the relationship between the service bandwidth and the SCH in such a scalable bandwidth system. As can be seen from Fig. 9, the base station has the same center frequency between the bandwidths to be serviced (1.25 MHz, 2.5 MHz, 5 MHz, 10 MHz, 20 MHz). Try to match. Also, the base station transmits an SCH with a 1.25 MHz width when the service bandwidth is less than 5 MHz, and transmits an SCH with a 5 MHz width when the service bandwidth is 5 MHz or more. Further, the base station makes the center frequencies of the SCHs coincide with each other for each bandwidth.

[0047] In such a scalable bandwidth system, even if the service bandwidth is changed, the SCH always exists within a certain band including the center frequency, so the terminal changes the service bandwidth. Even in such a case, there is an advantage that the SCH can be easily detected.

By the way, in such a scalable bandwidth system, as described in the first embodiment, the synchronization channel is repeated in the frequency direction in the minimum bandwidth unit among the plurality of bandwidths to be serviced. When trying to apply the transmission method, the following problems may occur.

[0049] For example, when the contents of the SCH (ie, the pattern of the sequence signal forming the SCH: hereinafter referred to as the SCH pattern) are different at the center as shown in FIG. 9, the base station When the bandwidth (Node B BW) and the terminal bandwidth (UE bandwidth) are different, the terminal may not be able to acquire SCH correlation, and cell search processing may not be possible.

[0050] FIG. 10 shows a comparison between the case where the service bandwidth is 1.25 MHz and 5 MHz as an example in the case where the SCH patterns in the central portion are different. As shown in Fig. 10, when the SCH pattern of pattern "1, 2" is repeatedly transmitted in units of the minimum bandwidth (1.25 MHz), the SCH pattern becomes "2, 1" at the center of 5 MHz. End up. In this case, if the terminal prepares only the signal of pattern “1, 2” as the SCH replica to be correlated, the correlation cannot be acquired correctly. In order to avoid this situation, it is possible to prepare SCH replicas with pattern “1, 2” and pattern “2, 1” as SCH replicas. It becomes complicated.

Therefore, in this embodiment, as shown in FIGS. 12 and 13, a plurality of bands to be serviced by operating any one of the SCH patterns for a plurality of bandwidths to be serviced. The SCH pattern in the center is always matched between the widths. In the examples of Fig. 12 and Fig. 13, the SCH patterns with service bandwidths of 1.25 MHz and 2.5 MHz are reversed. I made it. As a result, the SCH pattern of the central part matches between all bandwidths to be serviced (1.25 MHz, 2.5 MHz, 5 MHz, 1 OMHz, 20 MHz). As a result, the terminal can correctly acquire correlation values in all bandwidths (1.25 MHz, 2.5 MHz, 5 MHz, 10 MHz, and 20 MHz) with only one SCH replica having the pattern “2, 1”. It becomes like this.

Incidentally, the operation as described above can be easily realized by changing the formed synchronization channel sequence signal by the synchronization channel sequence signal forming unit 107 in FIG.

[0053] As described above, according to the present embodiment, when applying the method described in Embodiment 1 to the method of transmitting the SCH by placing it in the central portion of the maximum bandwidth, For all the bandwidths (1.25 MHz, 2.5 MHz, 5 MHz, only one sequence signal), the SCH sequence signals are matched between the multiple bandwidths to be serviced. Correlation values at 10MHz and 20MHz) can be obtained correctly.

In the above-described embodiment, since it is assumed that the method described in Embodiment 1 is applied to the method of transmitting the SCH by placing it in the central portion of the maximum bandwidth, the SCH sequence signal is used. Although the case where the band to be matched is the central part (center band) of the maximum bandwidth has been described, the band for matching the SCH sequence signals among a plurality of serviced bandwidths is not limited to this. In short, if the SCH pattern is to be detected, the SCH sequence signal should be matched in the specific band.

[0055] This specification is based on PCTZJP05Z015296 filed on August 23, 2005, PCTZJP05Z020311 filed on November 4, 2005, and Japanese Patent Application 2006-004152 filed on January 11, 2006. All the contents are included here.

Industrial applicability

[0056] The scalable bandwidth system, radio base station apparatus, synchronization channel transmission method, and transmission method of the present invention provide a synchronization channel (SCH) correlation process even if the terminal does not know the breakdown of services within the entire bandwidth. It can be widely applied to scalable bandwidth systems, radio base station apparatuses, and wireless terminal apparatuses that are required to execute the above.

Claims

The scope of the claims

[1] A scalable bandwidth system in which a wireless base station device supports multiple maximum bandwidths, and within that maximum bandwidth, each wireless terminal device can flexibly allocate bandwidth for actual communication Because

A radio base station apparatus that repeatedly transmits a synchronous channel in a frequency direction in a minimum bandwidth unit among a plurality of bandwidths to be serviced;

A radio terminal apparatus that calculates a correlation between the synchronization channel sequence signal of the minimum bandwidth unit held in advance and the synchronization channel that is repeatedly transmitted, and detects a timing at which a maximum correlation value is obtained as a frame timing;

A scalable bandwidth system comprising:

[2] The wireless terminal device combines the correlation values obtained for each of the minimum bandwidths, and detects the timing at which the maximum value is obtained from the combined correlation values as a frame.

The scalable bandwidth system of claim 1.

[3] The wireless terminal apparatus calculates a correlation by selectively using a synchronization channel transmitted in any one or a plurality of frequency bands among the synchronization channels repeatedly transmitted in the frequency direction.

The scalable bandwidth system of claim 1.

[4] The minimum bandwidth is 1.25 MHz.

The scalable bandwidth system of claim 1.

[5] The radio base station apparatus repeatedly transmits the synchronization channel such that a center frequency of the synchronization channel matches a raster frequency,

The wireless terminal device performs the frame timing detection process using a signal received with reference to the raster frequency.

The scalable bandwidth system of claim 1.

[6] For a specific band, the radio base station repeatedly transmits the synchronization channel so that the sequence signals of the synchronization channel match among the plurality of bandwidths to be serviced.

The scalable bandwidth system of claim 1.

7. The scalable bandwidth system according to claim 6, wherein the specific band is a center band of the maximum bandwidth to be supported.

[8] A scalable bandwidth system in which a wireless base station device supports multiple maximum bandwidths, and within this maximum bandwidth, each wireless terminal device can flexibly allocate the bandwidth for actual communication. A wireless base station device used for

Repeated transmission of the synchronous channel in the frequency direction in the minimum bandwidth unit among the multiple bandwidths to be serviced

Wireless base station device.

[9] The synchronization channel is repeatedly transmitted so as to match the center frequency caster frequency of the synchronization channel.

The radio base station apparatus according to claim 8.

[10] For a specific band, the synchronization channel is repeatedly transmitted so that the sequence signals of the synchronization channel match among the plurality of serviced bandwidths.

The radio base station apparatus according to claim 8.

[11] The specific band is a central band of the maximum bandwidth to be supported.

The radio base station apparatus according to claim 10.

[12] A scalable bandwidth system in which a wireless base station device supports multiple maximum bandwidths, and within this maximum bandwidth, each wireless terminal device can flexibly allocate the bandwidth for actual communication. A synchronization channel transmission method used for

Synchronous channel transmission method.

[13] A scalable bandwidth system in which a wireless base station device supports multiple maximum bandwidths, and within that maximum bandwidth, each wireless terminal device can flexibly allocate the bandwidth for actual communication. A wireless base station device used for

The common control channel is repeatedly transmitted in the frequency direction in the minimum bandwidth unit of the multiple bandwidths to be serviced.

Wireless base station device. Used in a scalable bandwidth system in which a wireless base station device supports multiple maximum bandwidths, and within this maximum bandwidth, each wireless terminal device can flexibly allocate a bandwidth for actual communication. A transmission method for a radio base station apparatus,

Transmission method.