Wireless communication apparatus and wireless communication method

Abstract

A wireless communication apparatus is capable of improving communication efficiency by reducing the amount of control information transmitted. A channel quality information extraction section extracts CQI's from a received signal. An allocation control section allocates subcarriers for every communication terminal apparatus and selects a modulation scheme in such a manner that required transmission rate is satisfied for each communication terminal apparatus based on required transmission rate information, etc. and CQI's for communication terminal apparatus of each user. A required subcarrier number determining section decides the number of subcarriers allocated to every communication terminal apparatus so as to satisfy the required transmission rate for each communication terminal apparatus. A required subcarrier number information generating section generates information for the number of subcarriers allocated to every communication terminal apparatus. A subcarrier allocation section allocates packet data to selected subcarriers. Modulating sections adaptively modulate packet data allocated to each subcarrier.

Claims

1. An integrated circuit, comprising: circuitry, which, in operation, controls a process, the process comprising: transmitting control information to a terminal, the control information including one of a plurality of indications, the plurality of indications including: an indication to transmit a first set of channel quality indicators (CQIs) representing channel qualities for all subcarriers in a communication band; and an indication to transmit a second CQI representing channel quality for subcarriers selected among the all subcarriers and position information of the selected subcarriers, wherein a first data volume associated with the second CQI and the position information is less than a second data volume associated with the first set of CQIs; and receiving, from the terminal based on the indication included in the transmitted control information, one of: the first set of CQIs; and the second CQI and the position information.

2. The integrated circuit according to claim 1, comprising: at least one input coupled to the circuitry, wherein the at least one input, in operation, inputs data; and at least one output coupled to the circuitry, wherein the at least one output, in operation, outputs data.

3. The integrated circuit of claim 1 wherein the control information is based in part on the first data volume.

4. The integrated circuit of claim 1 wherein the control information includes information related to a quantity of subcarriers to be selected among the all subcarriers.

5. The integrated circuit according to claim 2, wherein the at least one output and the at least one input, in operation, are coupled to an antenna.

6. An integrated circuit, comprising: circuitry, which, in operation: controls transmission of control information to a terminal, the control information including one of a plurality of indications, the plurality of indications including: an indication to transmit a first set of channel quality indicators (CQIs) representing channel qualities for all subcarriers in a communication band; and an indication to transmit a second CQI representing channel quality for subcarriers selected among the all subcarriers and position information of the selected subcarriers, wherein a first data volume associated with the second CQI and the position information is less than a second data volume associated with the first set of CQIs; and controls reception of, from the terminal based on the indication included in the transmitted control information, one of: the first set of CQIs; and the second CQI and the position information.

7. The integrated circuit according to claim 6, comprising: at least one input coupled to the circuitry, wherein the at least one input, in operation, inputs data; and at least one output coupled to the circuitry, wherein the at least one output, in operation, outputs data.

8. The integrated circuit of claim 6 wherein the control information is based in part on the first data volume.

9. The integrated circuit of claim 6 wherein the control information includes information related to a quantity of subcarriers to be selected among the all subcarriers.

10. The integrated circuit according to claim 7, wherein the at least one output and the at least one input, in operation, are coupled to an antenna.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) FIG. 1 is a view showing an SNR reporting format of the related art;

(2) FIG. 2 is a view showing a relationship between SNR report bits and modulation scheme;

(3) FIG. 3 is a block diagram showing a configuration for a wireless communication apparatus of a first embodiment of the present invention;

(4) FIG. 4 is a block diagram showing a configuration for a communication terminal apparatus of the first embodiment of the present invention;

(5) FIG. 5 is a flowchart showing a method of allocating subcarriers of the first embodiment of the present invention;

(6) FIG. 6 is a view showing an SNR reporting format for the first embodiment of the present invention;

(7) FIG. 7 is a block diagram showing a configuration for a wireless communication apparatus of a second embodiment of the present invention; and

(8) FIG. 8 is a flowchart showing a method of allocating subcarriers of the second embodiment of the present invention.

DETAILED DESCRIPTION

(9) The following is a detailed description with reference to the drawings of preferred embodiments of the present invention.

First Embodiment

(10) FIG. 3 is a block diagram showing a configuration for wireless communication apparatus 100 of a first embodiment of the present invention.

(11) RF receiving section 102 down-converts etc. a received signal received by antenna 101 from a radio frequency to a baseband frequency for output to channel quality information extraction section 103.

(12) Channel quality information extraction section 103 extracts CQI's (Channel Quality Indicators) constituting channel quality information from the received signal input by RF receiving section 102 for output to allocation control section 104. Further, channel quality information extraction section 103 extracts subcarrier identification information indicating subcarriers selected by each communication terminal apparatus from the received signal for output to allocation control section 104.

(13) Allocation control section 104 allocates some of the subcarriers from within all of the subcarriers within a predetermined communication band to CQI's inputted by channel quality information extraction section 103 and transmission information inputted to each communication terminal apparatus from user information accumulation section 106 described later, and selects modulation schemes for allocated subcarriers for every subcarrier. Namely, allocation control section 104 selects subcarriers and modulation schemes in such a manner as to achieve the required transmission rate or more for each communication terminal apparatus and carries out allocation of subcarriers and modulation schemes to each communication terminal apparatus in such a manner as to give less than a predetermined PER value for every subcarrier. Allocation control section 104 then outputs allocated subcarrier allocation information to subcarrier allocation section 110 and outputs modulation scheme information for the selected modulation scheme to modulation sections 111-1 to 111-N. Required subcarrier number determining section 105 constituting a section for determining the number of subcarriers obtains the number of subcarriers that can be allocated to each communication terminal apparatus from user information for the communication terminal apparatus of each user inputted by user information accumulation section 106.

(14) Namely, required subcarrier number determining section 105 determines the number of subcarriers in such a manner as to give the required transmission rate or more at each user communication terminal apparatus. During this time, required subcarrier number determining section 105 determines the number of subcarriers while giving a view to maintaining a slight margin with respect to the required transmission rate in anticipation of a drop in reception quality due to fading fluctuation. Further, in the event that the total amount of data for CQI's for the acquired number of subcarriers and subcarrier number information is less than the total amount of data for only the CQI's for all of the subcarriers, the required subcarrier number determining section 105 outputs the obtained number of subcarriers to required subcarrier number information generating section 107 as subcarrier number information, and, in the event that the total amount of data for the CQI's and the subcarrier number information for the obtained number of subcarriers is greater than the total amount of data for only CQI's for all of the subcarriers, the total number of subcarriers (for example, 64) within the communication band is outputted to the required subcarrier number information generating section 107 as subcarrier number information.

(15) User information accumulation section 106 stores user information for the required transmission rates and data type, etc., together with data to be transmitted to each communication terminal apparatus and outputs this to allocation control section 104, required subcarrier number determining section 105 and subcarrier allocation section 110, as necessary. Here, required transmission rate information is, for example, information about the proportion of the amount of data per unit time required by a communication terminal apparatus of one user with respect to the amount of data per unit time required by all communication terminal apparatus. User information accumulation section 106 can update the stored user information by inputting user information from a control section (not shown) at a predetermined timing.

(16) Required subcarrier number information generating section 107 outputs subcarrier number information inputted by required subcarrier number determining section 105 to control information multiplexer 109 as control channel information.

(17) Allocation information generating section 108 generates control information constituted by a pair consisting of identification information indicating each subcarrier inputted by allocation control section 104 and subcarrier modulation scheme information and outputs the generated control information to control information multiplexer 109.

(18) Control information multiplexer 109 multiplexes control information for the number of subcarriers inputted by the required subcarrier number information generating section 107 and allocation information and modulation scheme information inputted by allocation information generating section 108 and outputs multiplexed control information to switching section 112 for every subcarrier. Control information multiplexer 109 multiplexes subcarrier number information and allocation information, as well as control information other than modulation scheme information.

(19) Subcarrier allocation section 110 allocates packet data to communication terminal apparatus for each user for all of the subcarriers within the communication band using allocation information inputted by allocation control section 104 and user information inputted by user information accumulation section 106 and outputs packet data allocated to each subcarrier to modulation sections 111-1 to 111-N carrying out modulation using modulation schemes selected for every subcarrier.

(20) Modulation sections 111-1 to 111-N are provided in the same number as there are subcarriers, and modulate packet data inputted by subcarrier allocation section 110 using a modulation scheme of the modulation scheme information inputted by allocation control section 104 and output the result to switching section 112.

(21) Switching section 112 switches control information outputted by control information multiplexer 109 and inputted after modulation by modulators (not shown) and packet data modulated at modulation sections 111-1 to 111-N and outputs this information to inverse fast Fourier transform (hereinafter referred to as IFFT) section 113.

(22) IFFT section 113 then subjects control information inputted by switching section 112 for every subcarrier or packet data for every subcarrier to IFFT and outputs the result to guard interval (hereinafter referred to as “GI”) insertion section 114.

(23) GI insertion section 114 inserts GI's into control information or packet data inputted by IFFT section 113 and outputs this to RF transmission section 115.

(24) RF transmission section 115 up-converts etc. control information or packet data inputted from GI insertion section 114 from a baseband frequency to a radio frequency for transmission to antenna 101.

(25) Next, a description is given of a configuration for communication terminal apparatus 200 using FIG. 4. FIG. 4 is a block diagram showing a configuration for communication terminal apparatus 200.

(26) RF receiving section 202 down-converts a signal received by antenna 201 from a radio frequency to a baseband frequency etc., for output to a GI removal section 203.

(27) GI removal section 203 removes GI's from a received signal inputted from RF receiving section 202 for output to a fast Fourier transform (hereinafter referred to as “FFT”) section 204.

(28) After a received signal inputted by GI removal section 203 is converted from a serial data format to a parallel data format, FFT section 204 despreads each item of data converted to parallel data formed using a spreading code, subjects this to fast Fourier transformation, and outputs this to equalizer 207, channel estimation section 206 and channel quality estimation section 205.

(29) Channel quality estimation section 205 estimates channel quality from a received signal subjected to FFT inputted by FFT section 204 and outputs the estimation results to subcarrier selecting section 214 and channel quality information forming section 215.

(30) Channel quality estimation section 205 takes, for example, an SIR (Signal to Interferer Ratio) as estimation results. The estimation results are not limited to SIR, and arbitrary estimation results such as CIR (Carrier to Interferer Ratio), etc., can also be used.

(31) Channel estimation section 206 performs channel estimation using a received signal subjected to FFT inputted by FFT section 204 and outputs estimation results to equalizer 207.

(32) Equalizer 207 corrects amplitude and phase distortion using estimation results inputted by channel estimation section 206 for received signals subjected to FFT inputted by FFT section 204 for output to separating section 208.

(33) Separating section 208 separates the received signal input by equalizer 207 into a control channel signal and a data channel signal, outputs the control channel signal to control information extraction section 211, and outputs the data channel signal to demodulating sections 209-1 to 209-N.

(34) Demodulating sections 209-1 to 209-N subject a received signal inputted by separating section 208 to adaptive modulation in accordance with modulation scheme information inputted by allocation information extraction section 212 for every subcarrier and output the result to parallel/serial (hereinafter abbreviated to “P/S”) converter 210.

(35) P/S converter 210 converts the received signals inputted by decoding sections 209-1 to 209-N from parallel data format to serial data format to acquire received signal data.

(36) Control information extraction section 211 extracts control information from the received signal inputted by separating section 208 and outputs this to allocation information extraction section 212 and subcarrier number information extraction section 213.

(37) Allocation information extraction section 212 extracts modulation scheme information and subcarrier number information from control information inputted by control information extraction section 211 and outputs modulation scheme information for each subcarrier to corresponding demodulating section 209-1 to 209-N by referring to the subcarrier number information.

(38) Subcarrier number information extraction section 213 extracts subcarrier number information from control information inputted by control information extraction section 211 and outputs this to subcarrier selecting section 214.

(39) Subcarrier selecting section 214 selects subcarriers for the number of subcarriers designated by the base station apparatus using subcarrier number information inputted by subcarrier number information extraction section 213 in order of good channel quality using SIR measurement results inputted by channel quality estimation section 205. Subcarrier selecting section 214 outputs selected subcarrier information to channel quality information forming section 215.

(40) Channel quality information forming section 215 constituting a channel quality information generating section has a reference table storing channel quality selection information associating SIR's and CQI's, and selects CQI's by referring to channel quality selection information employing SIR inputted by channel quality estimation section 205 for each subcarrier selected using subcarrier information inputted by subcarrier selecting section 214. Channel quality information forming section 215 outputs CQI's to RF transmission section 216 for every selected subcarrier.

(41) RF transmission section 216 up-converts etc. a transmission signal containing CQI's inputted by channel quality information forming section 215 from a baseband frequency to a radio frequency and transmits this to antenna 201.

(42) Next, a description is given of a subcarrier allocation method using FIG. 5. FIG. 5 is a flowchart showing a method for allocating subcarriers.

(43) First, required subcarrier number determining section 105 determines the subcarrier number S.sub.k (where k is a user number and is an arbitrary natural number of two or more) allocated to each communication terminal apparatus 200 using the user information (step ST301).

(44) Required subcarrier number determining section 105 obtains the subcarrier number S.sub.k from the following equation (1) or (2).
S.sub.k=┌α×R.sub.k/r┐  (1)

(45) where S.sub.k: subcarrier number (where k is a user number that is a natural number of 2 or more),

(46) α: constant,

(47) R.sub.k: required transmission rate of communication terminal apparatus 200-k (where k is user number and is a natural number of 2 or more),

(48) r: transmission rate for one subcarrier while employing modulation coding schemes having a highest transmission rate or having a transmission rate for one subcarrier while using modulation coding schemes satisfying a required packet error rate using a channel quality value of a value that is a sum of average signal to noise ratio and a constant γ (for example, a constant of γ=0 to 3 dB); and ┌α×R.sub.k/r┐: integer larger than (α×R.sub.k/r).
S.sub.k=┌(β×R.sub.k×N)/(R.sub.1+R.sub.2+ . . . +R.sub.k)┐  (2)

(49) where S.sub.k: subcarrier number (where k is a user number that is a natural number of 2 or more),

(50) β: constant (for example, β=2.0 to 4.0),

(51) R.sub.k: required transmission rate of communication terminal apparatus 200-k (where k is user number and is a natural number of 2 or more),

(52) N: the total number of subcarriers, and

(53) ┌(β×R.sub.k×N)/(R.sub.1+R.sub.2+ . . . +R.sub.k)┐: integer larger than

(54) ((β×R.sub.k×N)/(R.sub.1+R.sub.2+ . . . +R.sub.k))

(55) Equation (1) is for determining the number of subcarriers by using the required transmission rate for each communication terminal apparatus and the modulation scheme and encoding rates for which transmission rate is a maximum, or determining the number of subcarriers by using the required transmission rate for each communication terminal apparatus and a transmission rate per subcarrier when using a modulation scheme and encoding rate satisfying the desired error rate for the average reception quality of each communication terminal apparatus. Further, equation (2) is for determining the number of subcarriers using the ratio of the number of all subcarriers within the frequency band and the required transmission rate for each communication terminal apparatus, and the total of the required transmission rate for all communicating parties.

(56) Next, required subcarrier number determining section 105 calculates the total amount of data for the CQI's and subcarrier number information for the selected subcarriers for each communication terminal apparatus 200 and determines whether or not the total amount of data for the CQI's and subcarrier number information for the selected subcarriers is larger than the total amount of data for CQI's for all subcarriers (for example, 64 subcarriers) within a predetermined communication band (step ST302). Namely, required subcarrier number determining section 105 determines whether or not equation (3) is satisfied.
Sk>(Q×N)/(Q+log.sub.2N)  (3)

(57) Here, Q: encoding bit number required for quantizing SNR information; and

(58) N: total number of subcarriers.

(59) In the event that the total amount of data for the selected subcarrier CQI's and subcarrier number information is not larger than the total amount of data for CQI's for all of the subcarriers within a predetermined communication band (i.e., when equation (3) is not satisfied), required subcarrier number determining section 105 determines the subcarrier number S.sub.k as the subcarrier number information to be sent to communication terminal apparatus 200-k. Required subcarrier number information generating section 107 then generates the subcarrier number S.sub.k as subcarrier number information and transmits and reports the subcarrier number information to communication terminal apparatus 200-k (step ST303).

(60) Next, communication terminal apparatus 200-k that received the subcarrier number information extracts subcarrier number information from the received signal at the subcarrier number information extraction section 213, and S.sub.k subcarriers are then selected at the channel quality information forming section 215 in order of good reception quality (step ST304).

(61) On the other hand, in step ST302, in the event that the total amount of data for the selected subcarrier CQI's and subcarrier number information is larger than the total amount of data for CQI's for all of the subcarriers within a predetermined communication band (i.e. equation (3) is satisfied), required subcarrier number determining section 105 determines to have CQI's transmitted from communication terminal apparatus 200-k for all of the subcarriers and determines to select the number of all the subcarriers. Required subcarrier number information generating section 107 then generates subcarrier number information selecting all of the subcarriers, and this subcarrier number information is reported to communication terminal apparatus 200-k (step ST305).

(62) Next, channel quality information forming section 215 of communication terminal apparatus 200 generates CQI's for each selected subcarrier or for all of the subcarriers (step ST306).

(63) After this, communication terminal apparatus 200 sends generated CQI's and subcarrier number information generated by the CQI's in the SNR reporting format shown in FIG. 6, to wireless communication apparatus 100 (step ST307). FIG. 6 shows SNR report bits and subcarrier number information for two subcarriers. As shown in FIG. 6, the SNR report bit is “3” and the subcarrier number information is “0” for the first subcarrier, and the SNR report bit is “3” and subcarrier number information is “4” for the second subcarrier.

(64) Next, CQI's are extracted from the received signal at channel quality information extraction section 103 of wireless communication apparatus 100 and subcarriers are allocated to communication terminal apparatus 200-k at allocation control section 104 (step ST308).

(65) According to the first embodiment, the base station apparatus determines the number of subcarriers allocated every communication terminal apparatus based on required transmission rate of each communication terminal apparatus and transmits the determined subcarrier number information to communication terminal apparatus. This means that the communication terminal apparatus only has to generate and transmit CQI's for the number of subcarriers allocated by the base station apparatus. As a result, it is possible to reduce the amount of control information and improve communication efficiency.

(66) Moreover, according to the first embodiment, in the event that the total amount of data for CQI's and subcarrier number information for the number of subcarriers allocated to the communication terminal apparatus of each user is larger than the total amount of data for CQI's for all of the subcarriers, the base station apparatus only has to transmit CQI's for all of the subcarriers to the communication terminal apparatus. This means that amount of data transmitted to the uplink can be reduced by that proportion of subcarrier number information that the communication terminal apparatus does not transmit.

(67) Moreover, according to the first embodiment, the communication terminal apparatus selects a number of subcarriers designated by base station apparatus using subcarrier number information in order of good channel quality and reports this to the base station apparatus. It is therefore possible to obtain a user diversity effect as a result of it being possible for the base station apparatus to allocate packet data to subcarriers of good reception quality, the throughput of the system as a whole can be improved, and frequency utilization efficiency can be improved.

Second Embodiment

(68) FIG. 7 is a block diagram showing a configuration for wireless communication apparatus 500 of a second embodiment of the present invention. In FIG. 7, portions with the same configuration as for FIG. 3 are given the same numerals and are not described. Further, the configuration of the communication terminal apparatus is the same as the configuration of FIG. 4 and is therefore not described.

(69) Allocation control section 104 allocates subcarriers to communication terminal apparatus of each user using CQI's inputted by channel quality information extraction section 103 and user information for communication terminal apparatus of each user inputted by user information accumulation section 106. Allocation control section 104 then outputs allocated subcarrier allocation information to subcarrier allocation section 110 and outputs modulation scheme information for the selected modulation scheme to modulation sections 111-1 to 111-N. Allocation control section 104 carries out allocation of subcarriers and modulation schemes to each communicating party so as to achieve less than a predetermined PER value for every subcarrier. Allocation control section 104 outputs subcarrier number information at communication terminal apparatus of each user allocated with actual packet data to required subcarrier number determining section 105 in frame units.

(70) Required subcarrier number determining section 105 determines the number of subcarriers for the communication terminal apparatus for which a subcarrier is allocated for one frame previous to the current frame using subcarrier number information actually allocated at allocation control section 104 inputted by allocation control section 104, and outputs the determined subcarrier number information to required subcarrier number information generating section 107. On the other hand, for communication terminal apparatus to which subcarriers are not allocated in one frame previous to the current frame, required subcarrier number determining section 105 determines the number of subcarriers that can be allocated from user information for each communication terminal apparatus inputted by user information accumulation section 106 and outputs the determined subcarrier number information to required subcarrier number information generating section 107.

(71) Next, a description is given of a subcarrier allocation method using FIG. 8. FIG. 8 is a flowchart showing a method for allocating subcarriers.

(72) First, allocation control section 104 determines whether or not a subcarrier is allocated to the immediately preceding frame one frame previous to the current frame (step ST601).

(73) In the event that a subcarrier is allocated to the immediately preceding frame, subcarrier number S.sub.k(t) is determined for subcarrier number information transmitted at the current frame from equation (4) (step ST602).
S.sub.k(t)=δ×S′.sub.k(t−1)  (4)
Here, S.sub.k(t): number of subcarriers of the current frame,

(74) S′.sub.k(t−1): the number of subcarriers actually allocated to communication terminal apparatus 200-k one frame previous to the current frame, and

(75) δ: constant (where 2.0□δ).

(76) In the event where the communication terminal apparatus has stopped or the amount of movement of the communication terminal apparatus is small, it is possible to determine the number of subcarriers using equation (4) on the side of the communication terminal apparatus as a result of it being possible to estimate that fluctuation in channel quality will be slight.

(77) On the other hand, in step ST601, in the event that a subcarrier is not allocated to the immediately preceding frame, subcarrier number S.sub.k(t) is determined for subcarrier number information transmitted at the current frame from equation (1) or equation (2) (step ST603).

(78) Next, required subcarrier number information generating section 107 generates the subcarrier number S.sub.k(t) as subcarrier number information and reports the subcarrier number information to communication terminal apparatus 200-k (step ST604).

(79) After this, communication terminal apparatus 200-k that received the subcarrier number information extracts subcarrier number information from the received signal at the subcarrier number information extraction section 213, and S.sub.k subcarriers are then selected at the channel quality information forming section 215 in order of good reception quality (step ST605).

(80) Next, channel quality information forming section 215 of communication terminal apparatus 200 generates CQI's for each selected subcarrier or for all of the subcarriers (step ST606).

(81) After this, communication terminal apparatus 200 sends generated CQI's and subcarrier number information generated by the CQI's in the SNR reporting format shown in FIG. 6 to wireless communication apparatus 500 (step ST607).

(82) Next, CQI's are extracted from the received signal at channel quality information extraction section 103 of wireless communication apparatus 500 and subcarriers are allocated to communication terminal apparatus 200-k at allocation control section 104 (step ST608).

(83) According to the second embodiment, the base station apparatus determines the number of subcarriers allocated every communication terminal apparatus of each user based on required transmission rate of each communication terminal apparatus and transmits the determined subcarrier number information to communication terminal apparatus. This means that the communication terminal apparatus has only to generate and transmit CQI's for the number of subcarriers allocated by the base station apparatus. As a result, it is possible to reduce the amount of control information and improve communication efficiency.

(84) According to the second embodiment, the base station apparatus determines the number of subcarriers using a straightforward method of simply multiplying the number of subcarriers for one frame previous to the current frame with a constant. It is therefore possible to implement straightforward processing for allocating subcarriers and achieve high-speeds in cases where the speed of movement of communication terminal apparatus is slow or in cases where communication terminal apparatus have stopped.

(85) Moreover, according to the second embodiment, the communication terminal apparatus selects a number of subcarriers designated by base station apparatus using subcarrier information in order of good channel quality and reports the base station apparatus. It is therefore possible to obtain a user diversity effect as a result of it being possible for the base station apparatus to allocate packet data to subcarriers of good reception quality and to effectively improve the throughput of the system as a whole.

(86) In the first and second embodiments, CQI's are adopted as channel quality information but this is by no means limiting and arbitrary information other than CQI's may also be used. Further, wireless communication apparatus 100 of the first embodiment and wireless communication apparatus 500 of the second embodiment are applicable to base station apparatus.

(87) Each function block employed in the description of each of the aforementioned embodiments may typically be implemented as an LSI constituted by an integrated circuit. These may be individual chips or partially or totally contained on a single chip.

(88) “LSI” is adopted here but this may also be referred to as “IC”, “system LSI”, “super LSI”, or “ultra LSI” depending on differing extents of integration.

(89) Further, the method of circuit integration is not limited to LSI's, and implementation using dedicated circuitry or general purpose processors is also possible. After LSI manufacture, utilization of an FPGA (Field Programmable Gate Array) or a reconfigurable processor where connections and settings of circuit cells within an LSI can be reconfigured is also possible.

(90) Further, if integrated circuit technology comes out to replace LSI's as a result of the advancement of semiconductor technology or a derivative other technology, it is naturally also possible to carry out function block integration using this technology. Application in biotechnology is also possible.

(91) This specification is based on Japanese patent application No. 2003-295972, filed on Aug. 20, 2003, the entire content of which is incorporated herein by reference.

INDUSTRIAL APPLICABILITY

(92) The base station apparatus and subcarrier allocation method of the present invention reduce the amount of control information transmitted and as such are effective in improving communication efficiency, and are therefore useful in allocation of subcarriers.