Radio Communication Base Station Apparatus and Radio Communication Method Used for Multi-Carrier Communication

The present invention<u style="single">Base station equipment and communication method</u>Regarding.

In recent years, in wireless communication, especially in mobile communication, various information such as images and data other than voice has become a target of transmission. In the future, it is expected that the demand for even higher speed transmission will increase further, and in order to perform high speed transmission, wireless transmission technology that realizes high transmission efficiency by more efficiently using limited frequency resources is required. ing.

OFDM (Orthogonal Frequency Division Multiplexing) is one of the wireless transmission technologies that can meet such demands. OFDM is a multi-carrier transmission technology that transmits data in parallel using a large number of subcarriers, and has features such as high frequency utilization efficiency and reduction of intersymbol interference in a multipath environment, and is effective in improving transmission efficiency. It is known.

When using this OFDM as a downlink and allocating data to a plurality of wireless communication mobile station devices (hereinafter, simply referred to as mobile stations) to a plurality of subcarriers, it is considered to perform frequency scheduling (for example, non-mobile station). See Patent Document 1). In frequency scheduling, the radio communication base station equipment (hereinafter, simply referred to as a base station) allocates subcarriers to each mobile station adaptively based on the reception quality of each frequency band in each mobile station, so that the maximum is possible. A multi-user diversity effect can be obtained, and communication can be performed very efficiently.

Frequency scheduling is usually performed for each resource block (RB), which is a block of several subcarriers. In addition, there are two allocation methods in frequency scheduling: Localized allocation, which is an allocation in units of a plurality of consecutive subcarriers, and Distributed allocation, which is an allocation distributed among a plurality of discontinuous subcarriers.

In addition, the notification of the frequency scheduling allocation result performed at the base station to the mobile station is performed using SCCH (Shared Control Channel). Then, it is considered that one SCCH notifies the allocation result for the frequency bandwidth of 5 MHz (see, for example, Non-Patent Document 2).<nplcit num="1"><text>R1-050604 Downlink Channelization and Multiplexing for EUTRA, 3GPP TSG-RAN WG1 Ad Hoc on LTE, Sophia Antipolis, France, 20-21 June, 2005</text></nplcit><nplcit num="2"><text>R1-060032, L1 / L2 Control Channel Structure for E-UTRA Downlink, NTT DoCoMo, 3GPP TSG-RAN WG1 LTE Ad Hoc Meeting Contribution, 2006/01</text></nplcit>

<p> Here, in order to enhance the frequency diversity effect in the distributed allocation, it is conceivable to widen the frequency bandwidth subject to the distributed allocation, that is, to increase the number of subcarriers to which the distributed allocation is made. However, as the number of subcarriers to which distributed allocation is made increases, the allocation pattern also increases, and as the number increases, more signaling bits are required to notify the allocation result. As a result, the overhead of notifying the allocation result in SCCH becomes large. In this way, in frequency scheduling, there is a trade-off relationship between the frequency diversity effect and the overhead of notification of allocation results. ..</p><p> An object of the present invention is to obtain a sufficient frequency diversity effect in frequency scheduling while suppressing an increase in the overhead of notification of allocation results.<u style="single">Base station equipment and communication method</u>Is to provide.</p>

<p> Of the present invention<u style="single">One aspect</u>A base station is a base station used in a wireless communication system in which a plurality of subcarriers constituting a multicarrier signal are divided into a plurality of resource blocks, and is uniformly extracted from the plurality of resource blocks. A scheduling means that evenly allocates data to the mobile station to the resource block of the unit, a generation means that generates control information for notifying the mobile station of the allocation result by the scheduling means, and the movement of the control information. A configuration is adopted in which a transmission means for transmitting to a station is provided.</p>

<p> According to the present invention, it is possible to obtain a sufficient frequency diversity effect in frequency scheduling while suppressing an increase in the overhead of notification of the allocation result.</p>

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

FIG. 1 shows the configuration of the base station 100 according to the present embodiment. The base station 100 is a base station used in a wireless communication system in which a plurality of subcarriers constituting an OFDM symbol which is a multicarrier signal is divided into a plurality of RBs, and frequency scheduling is performed using the plurality of RBs.

In the base station 100, the coding units 101-1 to 101-n and the modulation units 102-1 to 102-n are provided as many n as the number of mobile stations (MS) with which the base station 100 can communicate.

The coding units 101-1 to 101-n perform coding processing on the data # 1 to # n to the mobile stations # 1 to # n, and the modulation units 102-1 to 102-n after coding. Modulation processing for the data of Make sense to generate data symbols.

The scheduler 103 performs frequency scheduling based on the CQI (Channel Quality Indicator) from each mobile station, allocates data to each mobile station to each RB, and outputs the data to the multiplexing unit 104. Scheduling methods based on CQI include the Max CIR method and the Proportional-Fairness method. In addition, the scheduler 103 outputs the allocation result (which mobile station data symbol is assigned to which RB and which subcarrier) to the SCCH generation unit 105.

The SCCH generation unit 105 generates control information (SCCH information) for notifying each mobile station of the allocation result in the scheduler 103 according to the format shown in FIG. In the format shown in FIG. 2, the ID of the mobile station to which the data symbol is transmitted is set in the'mobile station ID', and the information indicating the Localized allocation or the distributed allocation is set in the'allocation type'(for example, the Localized allocation is '0'. , Distributed allocation is set to '1'), and the information of VRB assigned to the mobile station is set to'Allocated VRB (Virtual Resource Block)'.

The coding unit 106 performs coding processing on the SCCH information, and the modulation unit 107 performs modulation processing on the encoded SCCH information and outputs it to the multiplexing unit 104.

The multiplexing unit 104 multiplexes the SCCH information and the pilot on each data symbol input from the scheduler 103 and outputs the SCCH information and the pilot to the IFFT (Inverse Fast Fourier Transform) unit 108. The SCCH information and pilot multiplexing are performed for each subframe, for example, as shown in FIG. FIG. 3 shows a case where one subframe is composed of 7 OFDM symbols. In this case, for example, the pilot and SCCH information are arranged in the 1st and 2nd OFDM symbols, and the data is arranged in the 3rd to 7th OFDM symbols. Will be done.

The IFFT unit 108 performs IFFT on a plurality of subcarriers to which SCCH information, pilot and data symbols are assigned, and generates an OFDM symbol which is a multicarrier signal.

The CP (Cyclic Prefix) addition unit 109 adds the same signal as the tail portion of the OFDM symbol to the beginning of the OFDM symbol as a CP.

The radio transmission unit 110 performs transmission processing such as D / A conversion, amplification, and up-conversion on the OFDM symbol after CP addition, and transmits the OFDM symbol from the antenna 111 to each mobile station.

On the other hand, the wireless receiving unit 112 receives the CQI transmitted from each mobile station via the antenna 111, and performs reception processing such as down-conversion and D / A conversion. The CQI here is the reception quality information reported from each mobile station. In each mobile station, the reception quality of each RB is measured by the reception SNR, reception SIR, reception SINR, reception CINR, reception power, interference power, bit error rate, throughput, MCS that can achieve a predetermined error rate, etc. It can be carried out. In addition, CQI is sometimes expressed as CSI (Channel State Information).

The demodulation unit 113 performs modulation processing on the CQI after reception processing, and the decoding unit 114 performs decoding processing on the CQI after demodulation and outputs it to the scheduler 103.

Next, FIG. 4 shows the configuration of the mobile station 200 according to the present embodiment.

In the mobile station 200, the radio receiver 202 receives the OFDM symbol transmitted from the base station 100 (FIG. 1) via the antenna 201, and receives down-conversion, D / A conversion, etc. Processes and outputs to CP removal unit 203.

The CP removal unit 203 removes the CP added to the OFDM symbol and outputs it to the FFT (Fast Fourier Transform) unit 204.

The FFT unit 204 performs FFT on the OFDM symbol, converts it into a signal in the frequency domain, outputs SCCH information and data symbols of the signal to the equalization unit 205, and outputs a pilot to the transmission line estimation unit 206. ..

The transmission line estimation unit 206 estimates the transmission line response for each subcarrier using a pilot and outputs the estimation result to the equalization unit 205, and also measures the reception quality for each RB using the pilot to measure the measurement result. Output to CQI generator 213.

The equalization unit 205 corrects the transmission line variation of the SCCH information and the data symbol based on the estimation result of the transmission line response, and outputs the result to the separation unit 207.

The separation unit 207 separates the SCCH information and the data symbol, and outputs the SCCH information to the demodulation unit 209.

The demodulation unit 209 performs demodulation processing on the SCCH information, and the decoding unit 210 performs decoding processing on the demodulated SCCH information and outputs it to the separation unit 207. The demodulation unit 209 and the decoding unit 210 constitute the SCCH processing unit 208.

Then, the separation unit 207 extracts only the data symbol addressed to its own station from the data symbols input from the equalization unit 205 according to the SCCH information after decoding, and outputs the data symbol to the demodulation unit 211.

The demodulation unit 211 demodulates the data symbol input from the separation unit 207 and outputs it to the decoding unit 212.

The decoding unit 212 decodes the demodulated data symbol. As a result, received data can be obtained.

The CQI generation unit 213 generates a CQI indicating the reception quality for each RB measured by the transmission line estimation unit 206 and outputs it to the coding unit 214.

The coding unit 214 performs coding processing on the CQI, and the modulation unit 215 performs modulation processing on the coded CQI and outputs it to the wireless transmission unit 216.

The radio transmission unit 216 performs transmission processing such as D / A conversion, amplification, and up-conversion on the modulated CQI, and transmits the modulation from the antenna 201 to the base station 100.

Next, an example of distributed allocation of frequency scheduling performed by the scheduler 103 of the base station 100 will be specifically described. In the following explanation, assuming an OFDM symbol with a frequency bandwidth of 10 MHz consisting of 96 subcarriers, wireless communication in which 96 subcarriers are divided into 24 PRBs (Physical Resource Blocks) of 4 each. Imagine a system.

&lt;Distributed allocation example 1&gt; In this example, some PRBs extracted evenly from PRBs 1 to 24 are displayed as mobile stations. Allocate data evenly.

First, in this example, as shown in FIG. 5, only the even-numbered PRBs from PRBs 1 to 24 having a frequency bandwidth of 10 MHz are extracted to form a distributed allocation subband having a frequency bandwidth of 5 MHz, which is set in the scheduler 103. To do. By extracting only the even-numbered PRBs, it is possible to form a distributed allocation subband by some PRBs evenly extracted from PRBs 1 to 24. A similar distributed allocation subband can be formed by extracting only the odd-numbered PRBs.

The plurality of PRBs forming the distributed allocation subband are divided into VRBs 1 to 12 as shown in FIG. For example, VRB1 consists of the first subcarrier of PRB2,8,14,20, VRB2 consists of the second subcarrier of PRB2,8,14,20, VRB3 consists of the third subcarrier of PRB2,8,14,20. Composed of subcarriers, VRB4 consists of the fourth subcarrier of PRB2,8,14,20. Also, VRB5 consists of the first subcarrier of PRB4,10,16,22, VRB6 consists of the second subcarrier of PRB4,10,16,22, and VRB7 consists of the third subcarrier of PRB4,10,16,22. VRB8 consists of the 4th subcarrier of PRB4,10,16,22. The same applies to VRB9 ~ 12.

The scheduler 103 allocates any one of VRBs 1 to 12 to one mobile station by frequency scheduling, and allocates data to the mobile station to a plurality of PRBs corresponding to the one VRB. For example, when the scheduler 103 allocates VRB1 to a mobile station, it allocates the data to that mobile station to the first subcarrier of PRB2,8,14,20. With such allocation, data to mobile stations can be evenly allocated to a plurality of PRBs forming a distributed allocation subband. Further, the scheduler 103 outputs the allocation result to the SCCH generation unit 105.

The SCCH generation unit 105 sets the signaling bits corresponding to the VRB assigned by the scheduler 103 in the'assigned VRB'of FIG. 2 according to the table shown in FIG. For example, when VRB1 is assigned to a mobile station, SCCH generator 105 sets '0001' to'assigned VRB'. At this time, the SCCH generation unit 105 sets the'allocation type' to be a distributed allocation.

Here, if VRBs are set for all of PRBs 1 to 24 in the same manner as above, 24 VRBs (VRBs 1 to 24) are required. Therefore, in this case, 5 signaling bits are required as shown in FIG. On the other hand, in this example, VRB is set for 12 PRBs extracted from PRBs 1 to 24. Therefore, according to this example, as shown in FIG. 7, 4 bits are sufficient as the signaling bit. As described above, in this example, the increase in the amount of signaling bits can be suppressed by one bit for the allocation of one mobile station. Therefore, in the entire allocation result notification, the increase in the amount of signaling bits can be suppressed by the same number of bits as the number of allocated mobile stations.

On the other hand, in this example, since distributed allocation is performed for a subband consisting of some PRBs evenly extracted from PRBs 1 to 24 having a frequency bandwidth of 10 MHz, distributed allocation is performed for all PRBs 1 to 24. It is possible to obtain almost the same frequency diversity effect as in the case of performing.

In other words, according to this example, even if the frequency bandwidth targeted for distributed allocation is expanded from 5 MHz to 10 MHz in order to enhance the frequency diversity effect in distributed allocation, frequency scheduling is performed while suppressing an increase in the overhead of allocation result notification. Enough laps in The wave number diversity effect can be obtained.

&lt;Distributed allocation example 2&gt; Hereinafter, only the differences from the distributed allocation example 1 will be described.

In this example, as shown in FIG. 8, PRBs 1 to 24 having a frequency bandwidth of 10 MHz are divided into two PRB groups having a frequency bandwidth of 5 MHz each. That is, PRB group 1 is composed of PRB1 to 12, and PRB group 2 is composed of PRB13 to 24.

Then, in this example, as shown in FIG. 8, only the even-numbered PRBs are extracted from the PRB group 1, and only the odd-numbered PRBs are extracted from the PRB group 2 for distributed allocation with a frequency bandwidth of 5 MHz. A subband is formed and set in the scheduler 103. Even with such an extraction method, a distributed allocation subband can be formed by a part of PRBs evenly extracted from PRBs 1 to 24. A similar distributed allocation subband can be formed by extracting only the odd-numbered PRBs from the PRB group 1 and extracting only the even-numbered PRBs from the PRB group 2.

The plurality of PRBs forming the distributed allocation subband are divided into VRBs 1 to 12 as shown in FIG. For example, VRB1 consists of the first subcarrier of PRB2,8,13,19, VRB2 consists of the second subcarrier of PRB2,8,13,19, and VRB3 consists of the third subcarrier of PRB2,8,13,19. Composed of subcarriers, VRB4 consists of the fourth subcarrier of PRB2,8,13,19. Also, VRB5 consists of the first subcarrier of PRB4,10,15,21, VRB6 consists of the second subcarrier of PRB4,10,15,21, and VRB7 consists of the third subcarrier of PRB4,10,15,21. VRB8 consists of the 4th subcarrier of PRB4,10,15,21. The same applies to VRB9 ~ 12.

In this way, according to this example, the same effect as that of Distributed allocation example 1 can be obtained.

&lt;Distributed allocation example 3&gt; In this example, as shown in FIG. 10, PRB groups 1 and 2 in Distributed allocation example 2 are further divided into two PRB groups with a frequency bandwidth of 2.5 MHz each, and PRBs 1 to 24 having a frequency bandwidth of 10 MHz are divided into frequency bandwidths. Divide into 4 PRB groups of 2.5MHz each. In other words, in this example, PRB group 1-1 consisting of PRB1 ~ 6, PRB group 1-2 consisting of PRB7 ~ 12, PRB group 2-1 consisting of PRB13 ~ 18, and PRB group 2-2 consisting of PRB19 ~ 24 Four PRB groups are formed.

Then, in this example, either PRB group 1-1 or 1-2 is extracted from PRB group 1, and either PRB group 2-1 or 2-2 is extracted from PRB group 2. A subband for distributed allocation with a frequency bandwidth of 5 MHz is formed and set in the scheduler 103. FIG. 10 shows a case where PRB group 1-1 is extracted from PRB group 1 and PRB group 2-1 is extracted from PRB group 2. When extracting PRB group 1-1 from PRB group 1, either PRB group 2-1 or 2-2 may be extracted from PRB group 2, but PRB group 1 to PRB group 1-2 In order not to reduce the frequency diversity effect, PRB group 2-2 should be extracted from PRB group 2.

The multiple PRBs that form the distributed allocation subband are VRBs, as shown in Figure 11. Divided into 1-12. For example, VRB1 consists of the first subcarrier of PRB1,4,13,16, VRB2 consists of the second subcarrier of PRB1,4,13,16, and VRB3 consists of the third subcarrier of PRB1,4,13,16. Composed of subcarriers, VRB4 consists of the fourth subcarriers of PRB1,4,13,16. Also, VRB5 consists of the first subcarrier of PRB2,5,14,17, VRB6 consists of the second subcarrier of PRB2,5,14,17, and VRB7 consists of the third subcarrier of PRB2,5,14,17. VRB8 consists of the 4th subcarrier of PRB2,5,14,17. The same applies to VRB9 ~ 12.

As described above, according to this example, the distributed allocation sub-band is formed in units of PRB groups composed of a plurality of continuous subcarriers, and the continuous PRB groups are not extracted, so that the decrease in the frequency diversity effect is suppressed while suppressing the decrease in the frequency diversity effect. Localized allocation can be easily performed in parallel with distributed allocation.

&lt;Distributed allocation example 4&gt; In this example, as shown in FIG. 12, PRB groups 1 and 2 in Distributed allocation example 2 are further divided into four PRB groups having a frequency bandwidth of 1.25 MHz, and PRBs 1 to 24 having a frequency bandwidth of 10 MHz are divided into frequency bandwidths. Divide into 8 PRB groups of 1.25MHz each. In other words, in this example, PRB group 1-1 consisting of PRB1 ~ 3, PRB group 1-2 consisting of PRB4 ~ 6, PRB group 1-3 consisting of PRB7 ~ 9, PRB group 1-4 consisting of PRB10 ~ 12, PRB group 2-1 consisting of PRB13 ~ 15, PRB group 2-2 consisting of PRB16 ~ 18, PRB group 2-3 consisting of PRB19 ~ 21, and PRB group 2-4 consisting of PRB22 ~ 24 are formed.

Then, in this example, PRB group 1 extracts any two PRB groups from PRB groups 1-1 to 1-4, and PRB group 2 extracts any two PRB groups from PRB groups 2-1 to 2-4. Extract these two PRB groups to form a distributed allocation subband with a frequency bandwidth of 5 MHz and set it in the scheduler 103. At this time, in order not to reduce the frequency diversity effect, a distributed allocation sub-band is formed by a combination other than the combinations of PRB groups 1-3, 1-4, 2-1 and 2-2. FIG. 12 shows the case where PRB groups 1-1 and 1-3 are extracted in PRB group 1 and PRB groups 2-2 and 2-4 are extracted in PRB group 2.

The plurality of PRBs forming the distributed allocation subband are divided into VRBs 1 to 12 as shown in FIG. For example, VRB1 consists of the first subcarrier of PRB1,7,16,22, VRB2 consists of the second subcarrier of PRB1,7,16,22, and VRB3 consists of the third subcarrier of PRB1,7,16,22. Composed of subcarriers, VRB4 consists of the fourth subcarrier of PRB1,7,16,22. Also, VRB5 consists of the first subcarrier of PRB2,8,17,23, VRB6 consists of the second subcarrier of PRB2,8,17,23, and VRB7 consists of the third subcarrier of PRB2,8,17,23. VRB8 consists of the 4th subcarrier of PRB2,8,17,23. The same applies to VRB9 ~ 12.

In this way, according to this example, the same effect as that of Distributed allocation example 3 can be obtained, and a distributed allocation sub-band can be formed by combining various PRB groups.

&lt;Distributed allocation example 5&gt; In this example, as shown in FIG. 14, PRB groups 1 and 2 are further divided into four PRB groups with a frequency bandwidth of 1.25 MHz, as in the case of Distributed allocation example 4.

Then, in this example, PRB group 1 extracts any one of the PRB groups from PRB groups 1-1 to 1-4, and PRB group 2 extracts any one of the PRB groups 2-1 to 2-4. Extract these three PRB groups to form a distributed allocation subband with a frequency bandwidth of 5 MHz and set it in the scheduler 103. At this time, in order not to reduce the frequency diversity effect, a distributed allocation sub-band is formed by a combination other than the combination of PRB groups 1-4, 2-1, 2-2, 2-3. FIG. 14 shows the case where PRB group 1-1 is extracted in PRB group 1 and PRB groups 2-1, 2-2 and 2-4 are extracted in PRB group 2.

In PRB group 1, any three PRB groups are extracted from PRB groups 1-1 to 1-4, and in PRB group 2, any one PRB is extracted from PRB groups 2-1 to 2-4. Groups may be extracted. However, in this case, in order not to reduce the frequency diversity effect, a distributed allocation sub-band is formed by a combination other than the combination of PRB groups 1-2, 1-3, 1-4, 2-1.

The plurality of PRBs forming the distributed allocation subband are divided into VRBs 1 to 12 as shown in FIG. For example, VRB1 consists of the first subcarrier of PRB1,13,16,22, VRB2 consists of the second subcarrier of PRB1,13,16,22, and VRB3 consists of the third subcarrier of PRB1,13,16,22. Composed of subcarriers, VRB4 consists of the fourth subcarrier of PRB1,13,16,22. Also, VRB5 consists of the first subcarrier of PRB2,14,17,23, VRB6 consists of the second subcarrier of PRB2,14,17,23, and VRB7 consists of the third subcarrier of PRB2,14,17,23. VRB8 consists of the 4th subcarrier of PRB2,14,17,23. The same applies to VRB9 ~ 12.

In this way, according to this example, the same effect as that of Distributed allocation example 4 can be obtained.

&lt;Distributed allocation example 6&gt; In this example, only the even-numbered PRBs from PRB1 to 24 are extracted to form the distributed allocation subband 1 (Fig. 6) with a frequency bandwidth of 5 MHz, and only the odd-numbered PRBs from PRB1 to 24 are extracted. Then, a distributed allocation subband 2 (Fig. 16) with a frequency bandwidth of 5 MHz is formed and set in the scheduler 103. Then, SCCH1 and 2 are set corresponding to each subband 1 and 2. In other words, while distributed allocation examples 1 to 5 used one SCCH in 5MHz units, in this example, two SCCHs in 5MHz units were used and the allocation result in the distributed allocation subband 1 using SCCH1. Is notified, and SCCH2 is used to notify the allocation result in the distributed allocation subband 2.

The plurality of PRBs forming the distributed allocation subband 1 are divided into VRBs 1 to 12 as shown in FIG. Similarly, the plurality of PRBs forming the Distributed allocation subband 2 are divided into VRBs 1 to 12 as shown in FIG.

The scheduler 103 allocates any one of VRBs 1 to 12 of distributed allocation subbands 1 or 2 to one mobile station by frequency scheduling, and data to the mobile station is assigned to a plurality of PRBs corresponding to the one VRB. To assign. For example, when the scheduler 103 allocates VRB1 of the distributed allocation subband 1 to a mobile station, the scheduler 103 allocates the data to the mobile station to the first subcarrier of PRB2,8,14,20. Further, for example, when the scheduler 103 allocates VRB1 of the distributed allocation subband 2 to a certain mobile station, the data to that mobile station is transferred to PRB1,7,1. Assign to the first subcarrier of 3,19. Then, the scheduler 103 outputs the allocation result to the SCCH generation unit 105.

In the same manner as described above, the SCCH generation unit 105 sets the signaling bits corresponding to the VRB assigned by the scheduler 103 in the'assigned VRB'of FIG. For example, when VRB1 of the distributed allocation subband 1 is assigned to a certain mobile station, the SCCH generation unit 105 generates SCCH1 in which '0001' is set in the'assignment VRB'. Further, for example, when VRB1 of subband 2 is assigned to a certain mobile station, SCCH generation unit 105 generates SCCH2 in which '0001' is set in'assigned VRB'.

In this way, according to this example, two Distributed allocation subbands with a frequency bandwidth of 5 MHz are formed, and the allocation result is obtained using two SCCHs corresponding to the two Distributed allocation subbands. For notification, all PRBs 1 to 24 with a frequency bandwidth of 10 MHz can be subject to distributed allocation while making the signaling bits of'VRB allocation'the same as those of Distributed allocation examples 1 to 5.

In this example, the case where SCCH1 and 2 set in different frequency bands and subbands 1 and 2 are associated with each other and subbands 1 and 2 are specified from SCCH1 and 2 has been described. Information for identifying subbands 1 and 2 may be added to the SCCH information shown in (1) to identify subbands 1 and 2.

The distributed allocation examples 1 to 6 have been described above.

Next, frequency scheduling that considers both distributed allocation and localized allocation will be described. Here, it is assumed that there are a mobile station A to which the distributed allocation is made and a mobile station B to which the localized allocation is made.

As shown in FIG. 17, the scheduler 103 makes a distributed allocation to any VRB in FIG. 6 based on the distributed allocation example 1 for the mobile station A. Here, it is assumed that the VDRB (Virtual Distributed Resource Block) assigned to the mobile station A consists of the first subcarriers of PRB2,8,14,20.

On the other hand, for mobile station B, PRB group 1 (Fig. 8) defined in Distributed allocation example 2 is used as the Localized allocation subband. Then, the scheduler 103 makes a Localized allocation as shown in FIG. Here, it is assumed that the VLRB (Virtual Localized Resource Block) assigned to the mobile station B consists of PRBs 9, 10, and 11.

In this way, the distributed allocation sub-band is formed by the PRB for 5 MHz extracted evenly in order to obtain a sufficient frequency diversity effect, while the localized allocation sub-band has a sufficient frequency scheduling effect. Therefore, it is formed by continuous PRB for 5MHz. As a result, the number of signaling bits of the allocation result of the distributed allocation and the number of signaling bits of the allocation result of the localized allocation can be made the same. In addition, when both Distributed allocation and Localized allocation are performed at the same time in frequency scheduling, the PRB allocated to Distributed and the PRB allocated to Localized should not overlap.

At present, in the LTE standardization of 3GPP, it is considered to enable the use of a plurality of mobile stations having different frequency bandwidths in an OFDM mobile communication system. More specifically, in a mobile communication system having a frequency bandwidth of 20 MHz, it is being studied to enable the use of a plurality of mobile stations having a communication capability of 10 MHz, 15 MHz, or 20 MHz. In such a mobile communication system, a mobile station (1) having a communication capacity of 10 MHz. 5MHz x 2 (10MHz) of the 20MHz bandwidth is allocated to the 0MHz mobile station), and the 20MHz bandwidth is allocated to the mobile station (15MHz mobile station) having a communication capacity of 15MHz. Of which, 5MHz x 3 (15MHz) bandwidth is allocated. In addition, a mobile station with a communication capacity of 20 MHz (20 MHz mobile station) can use 5 MHz x 4 (entire 20 MHz). Therefore, in the present embodiment, considering that the present invention is applied to such a mobile communication system, the frequency bandwidth of the distributed allocation subband composed of a part of PRB is set to 5 MHz. By doing so, the above-mentioned Distributed allocation can be performed for any of the 10 MHz mobile station, the 15 MHz mobile station, and the 20 MHz mobile station.

The embodiments of the present invention have been described above.

The mobile station is sometimes called UE, the base station device is called Node B, and the subcarrier is sometimes called tone. RBs are also sometimes referred to as subchannels, subcarrier blocks, subbands, or chunks. The CP is also sometimes referred to as the Guard Interval (GI).

Further, the notification of the frequency scheduling allocation result to the mobile station may be performed by using PDCCH (Physical Downlink Control Channel) instead of SCCH.

Further, the definition of the distributed allocation sub-band may be set in advance for both the base station and the mobile station, or the base station may notify the mobile station. This notification may be performed using the broadcast channel or the SCCH of each subframe.

Further, in the above embodiment, an example of extracting PRB for a frequency bandwidth of 10 MHz to 5 MHz has been shown, but in other cases, for example, when extracting a PRB for a frequency bandwidth of 20 MHz to 10 MHz, the present invention is described above. It can be carried out in the same way.

Further, in the above embodiment, the VRB is set by combining a plurality of resources obtained by dividing 1PRB into four, but the number of divisions of 1PRB is not limited to four.

Further, in the above embodiment, the case of extracting the even-numbered PRB or the odd-numbered PRB, that is, the case of extracting the PRB every two is taken as an example, but the extraction of the PRB is performed every three or three. It may be every four.

Further, in each of the above embodiments, the case where the present invention is configured by hardware has been described as an example, but the present invention can also be realized by software.

Further, each functional block used in the description of each of the above embodiments is typically realized as an LSI which is an integrated circuit. These may be individually integrated into one chip, or may be integrated into one chip so as to include a part or all of them. Although it is referred to as LSI here, it may be referred to as IC, system LSI, super LSI, or ultra LSI depending on the degree of integration.

Further, the method of making an integrated circuit is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor. After manufacturing the LSI, a programmable FPGA (Field Programmable Gate Array) or a reconfigurable processor that can reconfigure the connection and settings of the circuit cells inside the LSI may be used.

Furthermore, if an integrated circuit technology that replaces an LSI appears due to advances in semiconductor technology or another technology derived from it, it is naturally possible to integrate functional blocks using that technology. There is a possibility of applying biotechnology.

All disclosures of the specifications, drawings and abstracts contained in the Japanese application of Japanese Patent Application No. 2006-126454 filed on April 28, 2006 are incorporated herein by reference.

The present invention can be applied to mobile communication systems and the like.

<figref num="1">Block configuration diagram of a base station according to an embodiment of the present invention</figref><figref num="2">Example of SCCH information format according to an embodiment of the present invention</figref><figref num="3">Multiple examples according to one embodiment of the present invention</figref><figref num="4">Block configuration diagram of a mobile station according to an embodiment of the present invention</figref><figref num="5">PRB extraction example according to an embodiment of the present invention (Distributed allocation example 1)</figref><figref num="6">VRB setting example according to an embodiment of the present invention (Distributed allocation example 1)</figref><figref num="7">Example of signaling bit according to an embodiment of the present invention</figref><figref num="8">PRB extraction example according to an embodiment of the present invention (Distributed allocation example 2)</figref><figref num="9">VRB setting example according to an embodiment of the present invention (Distributed allocation example 2)</figref><figref num="10">PRB extraction example according to an embodiment of the present invention (Distributed allocation example 3)</figref><figref num="11">VRB setting example according to an embodiment of the present invention (Distributed allocation example 3)</figref><figref num="12">PRB extraction example according to an embodiment of the present invention (Distributed allocation example 4)</figref><figref num="13">VRB setting example according to an embodiment of the present invention (Distributed allocation example 4)</figref><figref num="14">PRB extraction example according to an embodiment of the present invention (Distributed allocation example 5)</figref><figref num="15">VRB setting example according to an embodiment of the present invention (Distributed allocation example 5)</figref><figref num="16">VRB setting example according to an embodiment of the present invention (Distributed allocation example 6)</figref><figref num="17">Example of frequency scheduling according to an embodiment of the present invention</figref>