MX2007011897A - Transmitting apparatus and transmitting method. - Google Patents

Abstract

A transmitting apparatus uses one or more frequency blocks, each of which includes one or more carrier frequencies, to transmit data to the other end(s) of communication, which is in a better channel condition, on a priority basis. The transmitting apparatus comprises a selecting means that evaluates the channel condition of each of the other ends of communication for each frequency block and selects at least one of the other ends of communication; a deciding means that decides at least a modulation scheme in accordance with the evaluated channel condition; a means that creates a control channel indicative of the decided modulation scheme and also indicative of one or more frequency blocks that can be used for the selected other end of communication to receive the data; and a transmitting means that transmits, to the selected other end of communication, the control channel and a data channel modified by use of the foregoing modulation scheme.

Description

TRANSMISSION APPARATUS AND TRANSMISSION METHOD FIELD OF THE INVENTION The present invention relates to the technical field of radio communication. More specifically, the present invention relates to a transmission apparatus and a transmission method for use in a communication system for programming packets in a downlink.

BACKGROUND OF THE INVENTION In the third generation communications scheme, typically IMT-2000 (Mobile Telecommunications International 2000), the transmission information rate greater than 2 Mbps is implemented with the use of a 5 MHz frequency band in the downlink. At IMT-2000, the W-CDMA simple carrier type (broadband CDMA) scheme is adopted. In addition, the Modulation scheme Adaptive and Channel Coding (AMC, for its acronym in English), the Automatic Repetition Request scheme (ARQ) for packets in the MAC layer, fast packet programming and others are employed for High Speed Downlink Packet Access (HSDPA) in order to achieve higher transmission speeds and higher quality. For REF .: 186403 example, the non-patent document 1 describes the AMC scheme, and the non-patent document 2 describes the ARQ scheme. Figure 1 is a schematic view illustrating the AMC scheme. Assuming that the transmission energy from a base station is constant, in general, it is estimated that a terminal 11 closest to a base station 10 can receive signals with higher energy than a terminal 12 further away from the base station can receive. 10. In this way, since it is estimated that the terminal 11 can have better channel conditions, a higher modulation level and a higher coding rate are adopted. On the other hand, the terminal 12 can receive signals with lower energy than the terminal 11. As a result, since it is estimated that the terminal 12 can have worse channel conditions, a smaller modulation level and a lower coding rate are adopted. Figure 2 shows an exemplary combination of different modulation schemes (modulation level) and different channel coding rates. In the table illustrated, the rightmost column represents the relative bit rates in the case of the bit rate that is "1" under the modulation scheme M of "QPSK" and the R-channel coding rate of " 1/3". For example, if M = "QPSK" and R = "1/2", the bit rate is obtained by 1.5. In general, there is a tendency that the higher the bit rate, the lower the reliability. More specifically, combinations between different modulation schemes and coding rates and different indicator quantities of the channel states are predefined in a listing table, and the modulation schemes and others are changed depending on the state of the channel, if necessary. The channel status indicator quantity is handled as a Channel Quality Indicator (CQI), which is typically the ratio of signal to interference energy (SIR, for its acronym in English) and SINR of a received signal. Figure 3 is a schematic view to explain the ARQ (more precisely, hybrid ARQ). The hybrid ARQ scheme is a technique derived from a combination of the packet retransmission request ARQ scheme, depending on the error detection results (CRC: Cyclic Redundancy Check) and some error correction coding scheme (also referred to as channel coding) for error correction. As illustrated, a CRC bit is added to a transmission data SI sequence), and the resulting signal is sent after the completion of the error correction coding (S2). In response to receiving the signal, the error correction decoding (also referred to as "channel decoding") is carried out (S3), and error detection (S4) is carried out. If an error is detected, the retransmission of the packet to the transmission side (S5) is required. As illustrated in Figure 4, there are several methods for such retransmission. In an exemplary method illustrated in Figure 4A, the packet Pl is sent from the transmitting side to the receiving side. If any error is detected on the receiving side the packet Pl is discarded and then retransmission is required. In response to the retransmission request, the transmission side forwards the same packet (represented as "P2") as the packet Pl. In an exemplary method illustrated in Figure 4B, the packet Pl is sent from the transmission side to the receiving side. If an error is detected on the receiving side, the receiving side keeps the packet Pl without discarding it. In response to the retransmission request, the transmission side forwards the same packet (represented as "P2") as the packet PI. Then, the receiving side generates the P3 packet by combining the previously received packet with the packet currently received. Since the P3 packet corresponds to one transmitted with twice the power of the Pl packet, the accuracy of the demodulation is improved. Also in an exemplary method illustrated in Figure 4C, the packet Pl is sent from the transmitting side to the receiving side. If an error is detected on the receiving side, the receiving side keeps the packet Pl without discarding it. In response to the retransmission request, the transmission side sends the redundancy data derived by carrying out certain operations on the packet Pl as packet P2. For example, assuming that a sequence of packets such as "Pl, Pl ', Pl", ... "has been derived by the coding of the Pl packet. The derived sequence is predefined as a" puncture pattern ", and may differ depending on the coding algorithms adopted In the illustrated example, in response to the reception of a retransmission request, the transmitting side sends Pl 'as the packet P2, the receiving side generates the packet P3 when combining the previously received packet with the packet currently received, since the P3 packet has increased the redundancy, the demodulation accuracy will be improved, for example, assuming that the packet coding speed of the packet Pl equals "1/2", the coding speed of the packet P3 becomes equal to "1/4" which results in improved reliability Note that the receiving side must already know some information about which coding algorithm is adopted, what gives Redundancy coughs are sent (puncture pattern), and others. The fast packet programming scheme is a technique designed to improve the efficiency of frequency utilization in the downlink. In a mobile communication environment, the channel condition between a mobile station (user) and a base station varies over time. In this case, even when the transmission of a large amount of data to a user with a poor channel condition is attempted, it is difficult to improve performance. On the other hand, the highest performance would be achieved for a user with a good channel condition. From this point of view, it is possible to improve the frequency utilization efficiency by determining if the channel condition is good for each user, and allocating a shared data packet in favor of the user with the best channel condition. Figure 5 is a schematic diagram for explaining the fast packet programming scheme. As illustrated, a shared data packet is assigned to a user with the best channel condition (a user associated with the largest SINR) in each time lapse. As illustrated in figure 6, multiple codes can be used to multiplex data intended for different users within a simple time frame (frame) in the allocation of a shared data packet. In the illustrated example, codes # 1- # 10 are used and in the third frame of five frames, two types of data are multiplexed for user # 1 and # 2.

With document 1 not patent: T. Ue, S. Aampei, N. Morinaga and K. Hamaguchi, "Symbol Rate and Modulation Level-Controlled Adaptive Modulation / TDMA / TDD System for High-Bit-Rate Wireless Data Transmission ", IEEE Trans.VT, pp. 1134-1147, vol.47, No. 4, Nov. 1998. With document 2 not patent: S. Lin, Costello, Jr. M. Millar, "Automatic-Repeat-Request Error Control Schemes", IEEE Communication Magazine, vol 12, No. 12, pp. 5-17, December 1984.

BRIEF DESCRIPTION OF THE INVENTION (PROBLEM TO BE RESOLVED BY THE INVENTION) In this technical field, there is a strong need for increased radio transmission capacity speed, and in a future communication system, it may be required to use a radio frequency band. wider than in current systems. However, the wider the frequency band used for radio communication, the more adverse are the effects of selective sequence attenuation due to multipath attenuation. Figures 19A and 19B schematically show the level of reception of a signal affected by selective frequency attenuation. As illustrated in Figure 19A, if a relatively narrow frequency band is used for radio transmission, the level of reception within the frequency band can be considered constant. As illustrated in FIG. 19B, on the other hand, if a wider frequency band is used, the reception level shows significant frequency dependence. Therefore, it may be advantageous to improve the speed of the capacity by dividing the entire radio band into multiple frequency blocks and applying AMC, ARQ and packet programming for each frequency block. In the case of these controls are fully carried out in minimum data units, however, a large number of control signals are required, and the efficiency of data transmission may become worse. An object of the present invention is to provide a transmission apparatus and a transmission method that make it possible for the control signals required for improved frequency utilization efficiency to be efficiently transmitted in a communication system where the data transmission is brought to out in favor of a communication opponent with a better channel condition.

(MEANS FOR RESOLVING THE PROBLEM) In order to solve the problem, the present invention relates to a transmitter that transmits data to a communication opponent with a better channel condition, with the use of one or more frequency blocks that include one or more carrier frequencies. The transmitter includes a communication opponent selection unit, which evaluates the condition of the channel for each frequency block for each of the multiple communication opponents and the selection of one or more communication opponents from the multiple communication opponents. , a unit for determining the modulation scheme, which determines at least one modulation scheme depending on the evaluated channel condition, a generation unit of the control channel that generates a control channel, indicator of the determined modulation scheme, and one or more available frequency blocks for the selected communication opponents to receive a data channel, and a channel transmission unit that provides the selected communication opponents with the control channel and the modulated data channel according to the scheme of modulation.

(ADVANTAGES OF THE INVENTION) According to the embodiment of the present invention, frequency utilization efficiency can be improved in systems for transmitting data to a communication opponent with a better channel condition.

BRIEF DESCRIPTION OF THE FIGURES Figure 1 is a schematic view to explain the AMC scheme; Figure 2 is a diagram illustrating the exemplary combinations between different modulation schemes and different channel coding rates; Figure 3 is a schematic view for explaining the hybrid ARQ scheme; Figures 4A-4C are diagrams illustrating an exemplary transmission scheme; Figure 5 is a diagram illustrating the quality of reception that varies over time; Figure 6 is a diagram illustrating exemplary code multiplexing for multiple users. Figure 7 is a blog diagram of a transmitter according to an embodiment of the present invention; Figure 8 is a diagram illustrating exemplary time multiplexing in a radio resource allocation unit; Fig. 9 is a diagram illustrating exemplary frequency multiplexing in the radio resource allocation unit; Figure 10 is a diagram illustrating the exemplary code multiplexing in the radio resource allocation unit; Figure 11 is a diagram illustrating the exemplary allocation of radio resources with the use of multiple frequency blocks; Figure 12A is a diagram illustrating a procedure of 'transmission in a base station according to an embodiment of the present invention; Figure 12B is a flow chart (1) to explain the transmission procedure in detail; Figure 12C is a flow chart (2) to explain the transmission procedure in detail; Figure 12D is a flow chart (3) to explain the transmission procedure in detail; Figure 13 shows an exemplary table where the contents of the control information are listed; Figure 14 is a diagram illustrating several examples for illustrating mapping control information and other information in a physical downlink channel; Figure 15A is a diagram illustrating a mode where the control information is mapped by frequency block in a physical downlink channel; Figure 15B is a diagram illustrating a localized, exemplary FDM; Figure 15C is a diagram illustrating an exemplary distributed, localized FDM; Figures 16A and 16B are diagrams illustrating a mode where the error detection coding is performed on the control information; Figures 17A and 17B are diagrams illustrating a mode where the error correction coding is performed in the control information; Figure 18 shows an exemplary table for comparing different transmission schemes; Figures 19A and 19B are schematic diagrams illustrating the exemplary frequency selective attenuation; Fig. 20 is a flow diagram (1) to explain an exemplary transmission method; Fig. 21 is a flow diagram (1) to explain an exemplary transmission method; Fig. 22 is a flowchart (2) to explain an exemplary transmission method; Fig. 23 is a flow diagram (2) 'to explain an exemplary transmission method; Fig. 24 is a flow diagram (2) "to explain an exemplary transmission method; Fig. 25 is a flow diagram (3) to explain an exemplary transmission method; Fig. 26 is a flow diagram (1); to explain an exemplary transmission procedure; Fig. 27 is a flow diagram (2) to explain an exemplary transmission method; Fig. 28 is a flow diagram (3) to explain an exemplary transmission method; Fig. 29 is a flowchart (1) to explain an exemplary transmission method; Fig. 30 is a flowchart (2) to explain an exemplary transmission method; Figure 31 is a flow diagram (3) to explain an exemplary transmission method; Figure 32 is a block diagram illustrating a transmitter according to an embodiment of the present invention; Figure 33 is a diagram illustratively showing an exemplary correspondence between different modulation schemes and different levels of transmission energy; Fig. 34 is a diagram illustratively showing an exemplary mapping between different numbers of MCS and different levels of transmission energy; Figure 35A is a diagram illustrating the transmission energy levels of different resource blocks in the case of a conventional AMC control; Figure 35B is a diagram illustrating the transmission energy levels of different resource blocks in the case of the AMC control and the control of the transmission energy according to an embodiment of the present invention; Figure 36 is a schematic diagram illustrating an exemplary relationship between achievable performances in MCSl, MCS2, MCS3 and different signal-to-noise ratios; Figure 37 is a schematic diagram illustrating the exemplary allocation of resource blocks; Figures 38A and 38B are diagrams illustrating exemplary levels of transmission energy of individual resource blocks; Figures 39A and 39B are other diagrams illustrating exemplary transmit power levels of individual resource blocks; LIST OF REFERENCE SYMBOLS 10: base station 11, 12: terminal 702: radio resource allocation unit 704: fast and inverse Fourier transformation unit 706: protection interval insertion unit 720: channel processing unit common control 740: shared control channel processing unit 760: shared data processing unit 761: packet programming unit 722, 742, 762: channel coding unit 724, 744, 764: data modulation unit 726 , 746, 747, 766: data dispersion unit 745: control information division unit 768: power control unit DETAILED DESCRIPTION OF THE INVENTION In one embodiment of the present invention, the condition of the channel on each of the multiple communication opponents is evaluated for each frequency block. Based on the evaluation, one or more or more communication opponents are selected, and at least one modulation scheme is determined depending on the assessed channel condition. Then, a control channel is generated to indicate the determined modulation scheme and one or more frequency blocks available for the selected communication opponents to receive data, and the control channel and a modulated data channel according to the scheme of determined modulation, are provided or transmitted to the selected modulation opponents. The modulation scheme is allowed to be identified with a smaller number of bits, resulting in a considerable influence on the data transmission efficiency. As a result, it is possible to efficiently transmit the control information to a mobile station and thereby further improve the efficiency of frequency utilization in a communication system that uses a wider frequency band for packet programming and control of AMC. The channel coding rate can be determined depending on the condition of the channel for each frequency block. Also, a data channel and a control channel that have been modulated according to the determined modulation scheme and encoded at the coding rate of the channel may be provided or transmitted. The channel coding rate can be determined for each frequency block. As a result, the AMC can be carried out for each frequency block. From the point of view of simplification of control, the channel coding rate can be adjusted to a uniform value over multiple frequency blocks. The reason is that the channel coding rate has less influence on the data transmission efficiency than the modulation level.

The receiving means for receiving a request for data transmission from a communication opponent may be provided in a transmitter and the transmission means may retransmit data in response to a request for retransmission. The retransmission of the data in response to the retransmission request can be carried out for each frequency block. As a result, retransmission control is achieved for each frequency block. The error correction coding means for performing error correction coding on a control channel can be provided by the hybrid ARQ. The error correction coding can be performed for the control channel for each frequency block from the point of view of the reduced occurrence of errors. Among the control channels, the control information on a physical level and the control information on some layers above the physical layer can be encoded in error correction, separately. In order to face some problems such as that a communication opponent can perform the improper operation accidentally, the data transmitted from the transmission means may include an error detection code for the control information. An error detection code can be coupled to two types of control information for the physical layer and its upper layer, separately.

(First Modality) Although the systems that adopt the scheme of Orthogonal Frequency Division Multiplexing (OFDM) in the downlink is focused on a modality presented below, the present invention can be applied to other types of multiple carrier systems. A wide downlink frequency band can be divided into multiple frequency blocks. A simple frequency block may generally include one or more carriers. It is assumed in this modality that multiple subcarriers are included in each frequency block. Such a frequency block may also be referred to as a resource block or a piece of information. A block of frequency or piece of information can be used as a unit of allocation of radio resources. Figure 7 shows a transmitter 700 according to an embodiment of the present invention. The transmitter 700 is typically provided in a base station of a mobile communication system as described in this embodiment, but may be provided in other apparatuses. If not specifically stated, it is assumed that a base station and a transmitter can be used equivalently from now on. In Figure 7 illustrating a portion of the transmitter 700, a common control channel processing unit 720, a shared control channel processing unit 740, a shared data channel processing unit 760, an assignment unit 702 of radio resources, a reverse Fourier transformation unit 704 and a protection interval processing unit 706 are illustrated. The common control channel processing unit 720 conducts channel coding, modulation and dispersion to transmit shared control channels. A shared channel control includes certain information such as a secret code of the base station. The shared control channel processing unit 740 conducts coding, modulation and dispersion to transmit shared control channels. A shared control channel includes certain information such as programming information for a mobile station to demodulate a shared data channel. The common control channel processing unit 720 includes a channel coding unit 722, a data modulation unit 724 and a dispersion unit 726. Also, the shared control channel processing unit 740 includes a unit 742 of channel coding, a data modulation unit 744 and a dispersion unit 746. The channel coding units 722 and channel coding 742 encode the incoming signals according to a certain coding algorithm and supply the encoded signals. In the channel coding units, for example, convolution coding can be conducted. The data modulation units 724 and data modulation 744 modulate the incoming signals and supply the modulated signals. In the data modulation units, for example, some modulation schemes such as QPSK can be carried out. The scattering units 726 and 746 disperse the incoming signals and supply the resulting signals. The shared data channel processing unit 760 conducts packet programming as well as channel coding, modulation and dispersion over the shared data channels (transmitted data). The shared data channel processing unit 760 includes a packet programming unit 761, a data modulation unit 764 and a dispersion unit 766. The packet programming unit 761 receives individual data items to be transmitted to one or more mobile stations, and programs the transmission of data based on the feedback information and other supplies of the respective mobile stations. The data to be transmitted to the mobile stations are received from the higher devices or different networks of a base station, and are separately stored in a transmission buffer (not shown) for the respective mobile stations. The feedback information includes a channel quality indicator (CQI) measured at each mobile station, and the CQI is represented as SIR in this mode. The packet programming unit 761 evaluates the channel condition for each mobile station based on the reported channel quality indicator CQI of the mobile station, and selects one or more mobile stations with a better channel condition. As stated below, the CQI channel quality indicators supplied from the mobile stations are reported for each frequency block (or piece of information). The packet programming unit 761 determines a combination (MCS number) of a modulation scheme and a channel coding rate, corresponding to the downlink data transmission based on the CQI channel quality indicators supplied from the mobile stations respective. The MCS number can be determined according to a table as illustrated in Figure 2. Also, the packet programming unit 761 conducts operations associated with the retransmission of packets based on the feedback information. Such information items, the selected mobile stations, the MCS number and the retransmission control information, are supplied as control information to the shared control channel processing unit 740. The data to be transmitted to the selected mobile stations are supplied as data transmitted to the channel coding unit 762. The channel encoding unit 762 encodes the input signals according to a certain coding algorithm and supplies the encoded signals. In the channel coding unit, for example, turbo coding can be carried out. The data modulation unit 764 modulates the input signals and supplies the modulated signals. In the data modulation unit, for example, various types of modulation schemes such as QPSK, 16QAM and 64QAM can be used. The dispersion unit 766 disperses the incoming signals and supplies the scattered signals. The radio resource allocation unit 702 multiplexes the scattered signals for a common control channel, a shared control channel and a shared data channel for the output signal. This multiplexing can be carried out according to any of the multiplexing over time, frequency multiplexing and code multiplexing and any combination thereof. Figure 8 shows the exemplary time multiplexing of two signals. In this illustration, "channel # 1" and "channel # 2" represent any two of a common control, a shared control channel and a shared data channel. Although the multiplexing of two signals is illustrated here for simplicity, three signals can be multiplexed in time. Figure 9 shows the exemplary frequency multiplexing of two signals and Figure 10 shows the exemplary code multiplexing of two signals. An appropriate radio resource (a time lapse, a frequency band and / or a code) can be assigned to a common control channel and a shared control channel and a shared data channel through certain multiplexing in the unit 702 of radio resource allocation of Figure 7. The inverse Fourier transformation unit 704 conducts fast inverse Fourier transformation (IFFT) on the incoming signals for modulation according to the OFDM scheme, and supplies the modulated signals. The protection interval processing unit 706 adds a protection interval to an incoming signal, and generates a symbol in compliance with the OFDM scheme (OFDM symbol) for the output signal. The OFDM symbol is supplied to a radio unit (not shown) for radio transmission. Figure 11 is a schematic diagram for explaining an exemplary operation of a transmitter according to the embodiment of the present invention. As stated above, a wide frequency downlink band is divided into multiple frequency blocks or pieces of information. In this mode, each frequency block includes multiple subcarriers. In this mode, radio resources are assigned only for each time lapse (referred to as "transmission time" in the illustration) but also for each frequency block. As stated below, such a lapse of time may consist of a transmission time interval (TTI) or any packet time duration. In the illustrated example, the entire uplink frequency band is divided into eight frequency blocks where each of the frequency blocks includes the same number of subcarriers. For each of the eight frequency blocks, the condition of the channel is monitored, and the frequency block is assigned to a mobile station for a better channel condition. Figure 12A is a flow chart illustrating an exemplary transmission procedure in a base station. In step S121, the base station receives the channel quality indicators (SQIs) from one or more mobile stations, and analyzes the quality indicators of the received CQIs channel. The quality indicators of the CQIs channel such as the reception SIRs are reported for each frequency block. In this case, before starting this flow, the mobile stations measure the quality of a received signal such as a pilot signal and evaluate the downlink channel condition for each frequency block. In step 122, it is determined which mobile station has a better channel condition for each frequency block, based on the reported SIR of reception for the frequency block, and a mobile station with the best reception SIR in the SIRs of Reported channel is selected for the frequency block. In addition, a combination (MCS number) of a modulation scheme and a channel coding rate corresponding to the reception SIR is determined. This determination of the combination can be made for each frequency block. These steps S121 and S122 are mainly carried out in the packet programming unit 761 of FIG. 7. Although the modulation scheme can be determined for each frequency block as set forth below, it can be used at a coding rate. of uniform channel for multiple frequency blocks. In step S123 of Figure 12A, a common control channel, a shared channel and a shared data channel are generated. These generations are carried out in the respective processing units 720, 740 and 760 in Figure 7. Note that the respective channels do not have to be generated simultaneously in this step. The shared control channel is generated based on the control information supplied from the packet programming unit 761, in figure 7. This control information includes certain information (the MCS number, etc.) required to demodulate the channel. shared data The specifications of the control information and the transmission methods thereof will be described later. In step S124 in Fig. 12A, an OFDM symbol is generated. This generation is mainly carried out in the radio resource allocation unit 702, the IFFT unit 704 and the protection interval processing unit 706. In step S125 in FIG. 12A, for the mobile station selected in step S122, the transmission of downlink data in one or more frequency blocks according to the determined MCS number is carried out.

Figure 12B is a flowchart for explaining the exemplary detailed operations of steps S123 and S124 in Figure 12A. In step SI, a bit of error detection is added to a sequence of transmitted data. Although a bit of cyclic redundancy check (CRC) is added in the illustration, other correction detection bits can be added. In step S2, channel coding is performed. As stated above, the channel coding is carried out in the channel coding units 722, 742 and 762 in Figure 7, and particularly the channel coding for the data channels is carried out in the data unit 762. channel coding. In step S3, the operation involved in the hybrid ARQ is performed. More specifically, an information item is generated to indicate whether a transmitted packet is either a packet to be retransmitted or a new packet, and additionally, other information items may be generated to identify the redundancy version of a retransmitter packet. . This version of redundancy can be modified through puncture or repetition. Also, the channel coding rate can be modified in this step. In step S4, an assignment to a physical channel, the coded symbol is assigned for each frequency block. This assignment is mainly carried out in the radio resource allocation unit 702 in FIG. 7. By frequency programming, it is determined for which block of frequencies the symbol of the user must be assigned. In steps S5-1 to S5-N (N represents the total number of frequency blocks) in order to generate a transmission symbol, the data modulation is generated for each frequency block. Subsequently, a certain operation (not shown) is carried for radio transmission of the transmission symbol. In the illustration of Figure 12B, a modulation scheme for each frequency block is determined, and the different transmission rates suitable for the respective frequency blocks can be established. In this way, the illustrated operation is preferred from the viewpoint of improved transmission performance. In the illustration of figure 12C, the steps SI to S4, are the same as those in Figure 12B, except that the step S5 'is uniformly carried out on some frequency blocks. In step S5 ', a uniform modulation scheme is determined for all frequency blocks. More generally, such uniform modulation scheme can be determined for multiple frequency blocks. In the case where such a uniform modulation scheme is used for multiple frequency blocks, it is possible to reduce the number of control bits (amount of information) required to report the modulation scheme to the receiver side, as compared to the case of FIG. 12B. As illustrated in Figure 12D, not only the modulation scheme but also the channel coding rate can be determined for each frequency block. Note that the transmission of the signal may preferably be carried out according to any of the schemes illustrated in FIGS. 12B and 12C, in order to simplify the associated operation and encode the data for different frequency blocks with the same precision. In the illustration in Figure 11, user # 1 is selected for a certain transmission span of frequency block # 1 including the lowest subcarrier, and user # 2 is selected for the next transmission period. This means that user # 1 has the best channel condition in the first transmission period of the frequency block, and user # 2 has the best channel condition in the next transmission period. By determining a mobile station with the best channel condition for each transmission lapse in each frequency block and performing the data transmission adaptively in accordance with a suitable modulation for the mobile station, the efficient utilization of a wide frequency band is achieved. . Figure 13 shows the primary items of control information supplied to the control channel processing unit 740 shared by the packet programming unit 761 in Figure 1 in detail. As illustrated in the leftmost column "FIELD NAMES" in the illustration, the control information includes the piece information allocation information, the modulation scheme information, the coding rate information, the information of hybrid ARQ process, redundancy version, package status information and UE identity. The piece of information information specifies which frequency block is assigned for which mobile station (user). The number of frequency blocks allocated for a certain mobile station (user) may be determined depending on a data rate required, and may be greater than or equal to one in general. In the illustration of figure 11, user # 1 is assigned to two frequency blocks # 1 and # 4 in the first transmission lapse, and each of user # 2 to user # 6 and user # 8 is assigned to a block of frequency. In the subsequent transmission period, each user is assigned to a frequency block. Such allocation to the frequency blocks is described in the information piece allocation information. This information belongs to the control information for the physical layer. Since this information is described as assigning multiple frequency blocks, the information does not have to be reported to the individual mobile stations for each frequency block. The modulation scheme information specifies the modulation schemes for use in the downlink data transmission and is identified by the MCS number. Here, various types of multi-level modulation can be employed, such as QPSK, 16QAM, 65QAM and 128QAM. This information belongs to the control information for the physical layer. The information is preferably reported to mobile stations for each frequency block, but it can be reported for multiple frequency blocks. The encoding rate information specifies the channel coding rates for use in the downlink data transmission, and can be identified by the MCS number. For example, the channel coding rate can be specified by a multiple such as 1/8 = 0.125. This information belongs to the control information for layer 2 above the physical layer. The coding rate can be handled for each modulation scheme, as well as for each frequency block, and can be reported to the mobile stations for each frequency block. On the other hand, the channel coding rate can be handled apart from the modulation scheme, and a uniform channel coding rate can be employed over multiple frequency blocks. In Figure 13, "REQUIRED" in the column to the right corresponds to the first case, while "NOT REQUIRED" corresponds to the last case. The hybrid ARQ process information specifies a packet number associated with the retransmission control. This information belongs to the control information for layer 2. A packet can be retransmitted for each frequency block according to the hybrid ARQ. Alternatively, a packet can be retransmitted for each transmission lapse without distinguishing between the different frequency blocks. In Figure 13, "REQUIRED" in the column to the right corresponds to the first case, while "NOT REQUIRED" corresponds to the last case. The redundancy version specifies which puncture pattern is used in the retransmission control. This information belongs to the control information for layer 2. Similar to the hybrid ARQ process information, the redundancy data can be transmitted for each frequency block. Alternatively, the redundancy data can be transmitted for each transmission lapse without distinguishing between the different frequency blocks. In Figure 13, "REQUIRED" in the column to the right corresponds to the first case, while "NOT REQUIRED" corresponds to the last case. The packet state information specifies whether a packet transmitted from a base station to a mobile station is a newly transmitted packet (new packet) or a retransmitted packet. This information belongs to a control information for layer 2. A packet can be retransmitted for each block of frequency according to the hybrid ARQ. Alternatively, it can be retransmitted for each transmission lapse without distinguishing between different frequency blocks. In Figure 13, "REQUIRED" in the column to the right corresponds to the first case, while, "NOT REQUIRED" corresponds to the last case. The UE identity identifies which mobile station or user receives the data transmitted in the downlink, and is also called a user identifier or identification information. This information belongs to the control information for the physical layer. Similarly, to the piece of information allocation information, the identity of UE does not have to be reported to the mobile stations for each frequency block. Figure 14 shows the exemplary mapping of a control channel and the other channels in the physical downlink channels. In configuration 1, the control channel is mapped or multiplexed at a certain frequency interval over the entire time duration. The frequency range may or may not be the same as the interval of the frequency block. In configuration 2, the control channel is mapped in the entire frequency range over a certain time duration. In configuration 3, the mappings of configurations 1 and 2 are combined. In configuration 3, the control channel is mapped at certain frequency intervals in a certain time duration. In general, since the control channel is more widely mapped in the frequency direction, the frequency diversity has more advantage, which is desirable from the point of view of improving the reception quality of the signals. In configuration 4, the control channel is mapped to each frequency block in the physical downlink channel. The control channel may have a variable size of data depending on the number of users or the number of frequency blocks. So if all the channels are mapped according to the configuration 2, the control channel occupies the variable duration, which can complicate the demodulation. When combining configuration 2, with configuration 4, for example, the control channels associated with all frequency blocks (unspecified control channels) are mapped to the complex frequency range as in configuration 2, and with this one channel specific control for a certain frequency block (specified control channel) can only be mapped to the frequency block. As a result, the efficiency and quality of the demodulation of the control channels is improved. In order to map a control channel for each frequency block, as illustrated in FIG. 15A, it is desirable to provide a control information division unit 745 for separating the control channel associated with a certain frequency block from of other control channels. The mapping configurations as illustrated in Figure 14 are merely illustrative, and the control channel and the other channels can be multiplexed in various schemes including simple time multiplexing, frequency multiplexing or code multiplication or any combination of the same. In addition, multiplexing is not limited to the control channel and the other channels, and can be enhanced on any channels. For example, in the case of multiplexing data channels for individual users, various modulation schemes may be employed. As an example, each of the multiple users may be assigned to one or more frequency blocks, and the modulation scheme may be determined in such a manner as illustrated in FIG. 12B. In the example illustrated in Figure 15B, each of the four users can be assigned to a frequency block, and different modulation schemes can be adjusted for each of the frequency blocks. Alternatively, a uniform modulation scheme can be determined over multiple frequency blocks, as illustrated in FIG. 12C. Multiplexing in the frequency direction as illustrated in FIG. 15B is referred to as a localized frequency division multiplexing scheme (localized FDM) due to a certain band that is occupied by a certain user. On the other hand, a scheme for distributing a channel associated with a certain user over a broadband is referred to as the distributed FDM scheme. In the last scheme, each channel includes multiple frequency components (subcarrier components) allocated in a uniform or non-uniform range on the frequency axis and different channels are made orthogonal to one another in the frequency range. In the illustration of Figure 15C, individual user channels are distributed over the entire system band, and are made orthogonal to each other in the frequency range. At least one of a modulation scheme and a channel coding rate can be determined for each frequency block or can be determined for multiple frequency blocks in a uniform manner. Also, these can be determined in smaller, additional frequency units. Thus, according to the multiplexing as illustrated in FIG. 15C, a modulation scheme for each subcarrier can be determined. Even if the modulation scheme is determined in such smaller unitHowever, it is estimated that the performance can not be improved that much. Also, since additional control channels to identify all of them are required, there is a risk of increasing the processing workload and the amount of control information. On the other hand, according to the distributed FDM, the frequency diversity has more advantage, and in this way, the improved quality of the signal can be expected. Therefore, in the case of distributed FMD, it is desirable that the modulation scheme and signal coding rate be uniformly determined on all subcarriers, resulting in a reduced amount of control information. Figures 16A and 16B show exemplary error detection coding on a control channel. The error detection coding can be carried out, for example, with the use of the CRC code for cyclic redundancy verification. The error detection coding makes it possible to prevent a user from demodulating the data by another user and performing erroneous control of the retransmission, for example. In the illustration in Figure 16A, the control information for the physical layer and the control information for the upper layer 2 are separately encoded by error detection. It is advantageous in terms of frequency block mapping as configuration 4 in FIG. 14 to conduct the error detection coding depending on the type of control information. In the illustration in FIG. 16B, the control information for the physical layer and the control information for the upper layer 2 can be coded by error detection together. In comparison to the case where the error detection encodings are separately carried out, this scheme is advantageous due to the reduced overload. Preferably, these are coded by error detection separately to improve the error detection capability and meet a smaller retransmission unit as illustrated in Figure 16A. Figures 17A and 17B show the exemplary error correction coding on the control information. The error correction coding can be carried out, for example, by the use of convolution coding. The error correction coding can improve the tolerance on the fading of paths or multiple paths, for example. In the illustration in Figure 17A, the control information for the physical layer and the control information for the upper layer 2 are encoded by error correction separately. In the illustration of FIG. 17B, the control information for the physical layer and the control information for the upper layer 2 are coded by error correction together. In other words, the error correction coding is performed on the complete control information. This is desirable from the point of view of reduced overload. In addition, the error correction capability (coding gain) is advantageous for the case (B) of a longer coding unit. However, such a longer encoding unit may cause the chaining of a bit error to subsequent bits. In other words, the longer coding unit may tend to increase the probability of error occurrence. In fact, the coding unit can be determined by the balance of these characteristics. Figure 18 shows an exemplary table for listing various methods where one or more of the packet schedules based on frequency range, adaptive modulation coding (AMC) and hybrid ARQ are carried out for each frequency block. In a row, some characteristics of a method are illustrated. In method 1, all packet programming based on frequency range, data modulation, channel coding rate and hybrid ARQ are controlled for each frequency block. In this way, frequency resources can be used more efficiently, resulting in extremely efficient data transmission. However, many of the control information items listed in Figure 13 have to be handled for each frequency block, resulting in a considerable increase in overload. More specifically, all the information of the modulation scheme, the coding rate information, the hybrid ARQ process information, the redundancy version and the status or packet condition information are reported to the mobile stations for each block of data. frequency. In the "CHARACTERISTICS" column in the table, the double circle symbol "®" indicates that the data transmission is extremely efficient. The circle symbol "O" indicates that the data transmission is very efficient. The symbol "?" indicates that the data transmission is moderately efficient. The "X" symbol indicates that the data transmission is inefficient. Also in the column "OVERLOAD" in the table, the symbol "<; § > "indicates that the overload is too low, the symbol" O "indicates that the overload is low, the symbol"? "indicates that the overload is high, the symbol" X "indicates that the overload is too high. used in the present simply indicate the trend of relative merits and availability is not necessarily determined.In method 2, programming based on frequency range, data modulation and hybrid ARQ are controlled for each frequency block, while the channel coding rate is controlled for each TTI transmission time interval The transmission time interval is a specific time unit specific to a system In method 2, only the channel coding rate is adjusted To have a uniform value over all the frequency blocks, in this way, method 2 achieves the reduction in overload compared to method 1 since the speed Channel coding does not have to be handled for each frequency block. More specifically, the modulation scheme information, the hybrid ARQ process information, the redundancy version and the packet status information are reported to the mobile stations for each frequency block, while a uniform coding rate information about all blocks of frequency is reported. In method 3, packet programming based on frequency range, data modulation and hybrid ARQ are controlled for each frequency block, while the coding rate of the channel is controlled for each packet. The length (duration) of a packet can be a relative amount defined in a higher network, for example, it may or may not be the same as the absolute unit time (TTI) specific to a system. In method 3, only the channel coding rate is adjusted to have a uniform value over all frequency blocks. In this way, method 3 can also reduce the overload compared to method 1, since the channel coding rate does not have to be handled for each frequency block. More specifically, the modulation scheme information, the hybrid ARQ process information, the redundancy version and the packet status information are reported to the mobile stations for each frequency block, while the information of the uniform coding rate over all the blocks of frequency is reported. Note that the coding rate information has to be reported for each packet. In method 4, packet programming is based on frequency range, data modulation and channel coding are controlled for each frequency block, while hybrid ARQ is controlled for each packet. In other words, the retransmission is controlled without distinguishing between the different frequency groups, resulting in reduced overload as a result. Also, the length of a packet is equal to an information unit effectively communicated, and the retransmission is carried out for each packet. This is preferable from the point of view of improving performance. More specifically, the modulation scheme information and the coding rate information are reported to the mobile stations for each frequency block, while the hybrid ARQ process information, the redundancy version and the package status information are reported uniformly over all frequency blocks. Note that the information associated with the retransmission control has to be reported for each packet. In method 5, frequency programming based on frequency range and data modulation are controlled for each frequency block, channel coding is controlled for each transmission time interval, and the hybrid ARQ is controlled for each package. In other words, the channel coding rate and the retransmission are controlled without distinguishing between the different frequency blocks, resulting in consequently reduced overload. More specifically, the information of the modulation scheme is reported to the mobile stations for each frequency block, while the information of the coding rate, the hybrid ARQ process information, the redundancy version and the package status information are reported uniformly over all frequency blocks. Note that the information associated with the retransmission control has to be reported for each packet. In method 6, packet programming based on frequency range and data modulation are controlled for each frequency block, while channel coding rate and hybrid ARQ are controlled for each packet. In other words, the channel coding rate and the retransmission are controlled without distinguishing between different frequency blocks, consequently resulting in reduced overload. More specifically, the information of the modulation scheme is reported to the mobile stations for each frequency block, while the information of the coding rate, the hybrid ARQ process information, the redundancy version and the package status information, they are reported uniformly on all frequency blocks. Note that some of the information associated with the coding rate and the retransmission control has to be reported for each packet. In method 7, packet programming based on frequency ranges, data modulation and channel coding are controlled for each frequency block, while hybrid ARQ is controlled for each TTI transmission time interval. In other words, only the retransmission is controlled without distinguishing between the different frequency blocks. Method 7 can reduce the overload since the retransmission does not have to be controlled for each frequency block. Also, since the retransmission is carried out for each TTI transmission time slot, notwithstanding the length of the packet, the retransmission control can be simplified. More specifically, the modulation scheme information and the coding rate information are reported to the mobile stations for each frequency block, while the hybrid ARQ process information, the redundancy version and the package status information are reported uniformly over all frequency blocks. Note that some of the information associated with the retransmission control has to be reported for each TTI transmission time interval.

In method 8, packet programming is based on the frequency range, and data modulation is controlled for each block, while channel coding and hybrid ARQ are controlled for each transmission time interval. In other words, the channel coding rate and the retransmission are controlled without distinguishing between the different frequency blocks, resulting in consequently reduced overload. More specifically, the information of the modulation scheme is reported to the mobile stations for each frequency block, while the information of the coding rate, the hybrid ARQ process information, the redundancy version and the packet status information are reported uniformly over all frequency blocks. Note that some of the information associated with the information of the coding rate and the retransmission control has to be reported for each transmission time interval. In method 9, packet programming based on the frequency range and data modulation are controlled for each frequency block, channel coding is controlled for each packet, and the hybrid ARQ is controlled for each time slot of each packet. transmission. In other words, the channel coding rate and the retransmission control are controlled without distinguishing between the different frequency blocks, resulting in consequently reduced overload. More specifically, the information of the modulation scheme is reported to the mobile stations for each frequency block, while the information of the coding rate, the hybrid ARQ process information, the redundancy version and the package status information are reported uniformly over all frequency blocks. Note that the information of the coding rate has to be reported for each packet and that the information associated with the retransmission control has to be reported for each transmission time interval. In method 10, packet programming is based on the frequency range is controlled for each frequency batch. While data modulation, channel coding and hybrid ARQ are controlled for each transmission time interval. In other words, the data modulation, the channel coding rate and the transmission are controlled without distinguishing between the different frequency blocks, resulting in extremely low load. More specifically, the information of the modulation scheme, the information of the coding rate, the hybrid ARQ process information, the redundancy version and the packet state information are reported uniformly on frequency blocks. Note that these information items have to be reported for each TTI transmission time interval. In conjunction with methods 1-10, while control over modulation schemes (multiple levels of modulation) have a strong influence on data transmission efficiency, performance or frequency utilion, a smaller amount of information is required to specify modulation schemes compared to retransmission or other control information. In this way, the data modulation must be controlled for each frequency block. When comparing these methods, on the other hand, it can be recognized that control over the channel coding speed has little influence on transmission efficiency and overload (characteristics). In this way, it is windy to control the channel coding rate for each TTI transmission time interval from the point of view of simplified processing of the signal. The retransmitted unit of the retransmission control ARQ influences the overload, and it will be understood that a higher overload leads to a higher efficiency of data transmission. On the other hand, it is desirable to use an effectively communicated information unit, as a criterion (to control the channel coding rate for each packet), instead of the transmission time slot TTI from the viewpoint of retransmission efficiency. Note that the channel coding rate is desirably controlled for each TTI transmission time interval from the simplified retransmission control point of view.

(Second Mode) According to the first mode, the CRC bit coupling, the channel coding and the retransmission control are carried out only for a simple data sequence. In the second embodiment, the CRC bit coupling, the channel coding and the retransmission control are carried out for each of the plurality of data sequences. Figure 20 is a flow diagram (1) illustrating an exemplary transmission method according to one embodiment of the present invention. In step SI, a sequence of transmitted data is divided into multiple sequences. The operation on the divided sequences is performed as in the flow diagram (1) in Figure 12B. The division into the data sequence can be carried out, for example, in a serial to parallel (S / P) conversion unit. The division can be called as partition and segmentation. In any case, the size of the split data can be the minimum unit for retransmission. It is desirable that the size of the divided data be made smaller from the point of view of retransmission of the minimum required information. On the one hand, it is desirable that the size of the divided data be made larger from the point of view of reducing the overhead associated with retransmission. However, if the size of the split data is too large in the latter case, a larger amount of data may have to be retransmitted due to the occurrence of a slight error. Thus, it is desirable if the data size exceeds a certain upper limit (predefined threshold) in the latter case, the division can be triggered. Although it is illustrated in Figure 20 that the transmitted data sequence is divided into two sequences for simplicity, the transmitted data sequence can be divided into more than two sequences. Also, in the case of division is triggered by the size of the data that exceeds a threshold, the two flow lines in Figure 20 may not necessarily be driven simultaneously. (If the data size is small, only one of the flow on the left and the flow on the right hand can be driven). In steps S12 and S22, an error detection bit is coupled to each of the transmitted, divided data streams. The size of the data of the divided sequences may or may not be uniform over the sequences. In steps S13 and S23, each of the split transmission data sequences is encoded in channel. The channel coding rate Rl for the step S13 and the channel coding rate for the S23 can be determined independently. Also, these can be adjusted to be different values or the same value. In steps S14 and S24, an operation associated with Hybrid ARQ is performed on each of the transmitted, divided data sequences. More specifically, certain information is generated to indicate whether a packet to be transmitted is a retransmitted packet or a new packet. In addition, some information may be generated to indicate the redundancy pressure of the transmitted packet and others. The redundancy version for step S14 and the redundancy version for step S24 can be determined independently. Also, this can be adjusted to be of different versions or of the same version. In steps S15 and S25, a physical channel is assigned to each of the transmitted, divided data streams, and a coded symbol is assigned to each frequency block. This operation is mainly conducted in the radio resource allocation unit 702. It is determined in the frequency determination which frequency block is assigned to the symbol of which user. In steps S16-1 to S16-K and S26-1 to S26-L, the data modulation for each frequency block is carried out to generate a transmission symbol. Note that K and L represent the total number of frequency blocks in the respective sequences. Subsequently, a certain operation (not shown) is conducted for radio transmission of the transmission symbol. In the illustration in Figure 20, since a modulation scheme is determined for each divided sequence for each frequency block, the transmission rate is adjusted to have a suitable value for each frequency block. In this way, the illustrated exemplary speed is preferable from the viewpoint of improved transmission performance. Fig. 21 is a flow chart (1) 'illustrating an exemplary transmission method. This flow chart is the same as in Figure 20, except for step 3. In the illustration, the two transmitted, split data streams are separately coded per channel, but the respective channel coding rates are adjusted to have a uniform value (Rl = R2). Since the same channel coding rate is used for the respective sequences, it is possible to reduce the number of control bits required to report the channel rate to the receiver side. Fig. 22 is another flow chart (2) illustrating a transmission procedure. The operation subsequent to division in step SI is the same as the flow diagram (2) in figure 12C. This flow is the same as the flow in figure 20, except for steps S16 'and S26'. In the illustration, the modulation schemes are determined for two divided sequences of data transmitted independently, but the same modulation scheme is applied to the same data sequence. In the illustration in Figure 20, however, different modulation schemes can be applied to different frequency blocks. Since the same modulation scheme is applied to multiple frequency blocks, it is possible to reduce the number of control bits required to report the modulation scheme to the receiver side. Figure 23 is a flow chart (2) 'illustrating an exemplary transmission method. This flow is the same as the flow in Figure 22, except for step S3. In the illustration, channel coding is performed on two divided data streams separately transmitted, but the same channel coding rate is adjusted for them (R1 = R2). Also, the same modulation scheme is applied to the same data sequence.

Since the same channel coding rate is applied to the different sequences and the same modulation scheme is applied to multiple frequency blocks, it is possible to reduce the number of control bits required to report the channel coding rate and the scheme of modulation towards the receiver side. Fig. 24 is another flow diagram (2), illustrating an exemplary transmission method.This flow is the same as the flow in Fig. 23, except for step S. In the illustration, channel coding is performed on the two divided sequences of the data transmitted separately, but the channel coding rate is adjusted for them (Rl = R2) Also, the same modulation scheme is applied to the data streams since the same coding rate When the channel is applied to different sequences and the same modulation scheme is applied to all frequency blocks, it is possible to further reduce the number of control bits required to report the channel coding rate and the modulation scheme. is another flow diagram (3) that illustrates an exemplary transmission procedure The operation subsequent to division in step SI is the same as the flow diagram (3) in Figure 12D. Also, this flow is the same as the flow in Figure 20, except for steps S13-1 to S13-K and S23-1 to S-23L. In the illustration, channel coding can be performed on each frequency block. In order to simplify the operation and decode data for individual frequency blocks with similar accuracy, it is preferable to transmit signals according to the procedures illustrated in Figures 20-24.

(Third Modality) The division of a data sequence that is to be transmitted in multiple sequences can be conducted by means of various products and applications under various processing environments. In the third embodiment of the present invention, the data sequence to be transmitted is divided corresponding to multiple receiving antennas. Figure 26 is a flow chart (1) illustrating an exemplary transmission method according to the third embodiment. Conventionally, a data stream is finally transmitted from a simple transmission antenna. According to the illustration in Figure 26, the split data streams are transmitted from different transmit antennas # 1 and # 2. Similar to the case of Figure 20, the number of split sequences can be adjusted to be an arbitrary value, that is, any number of transmit antennas can be provided. In addition, the operation associated with a simple transmission antenna (e.g., transmission antenna # 1) in Figure 26 can be replaced with any of the operations described in conjunction with Figures 20-25. In other words, a data stream transmitted from a single transmission antenna can be divided into multiple data sequences. In this case, such a sequence of data that is to be transmitted is divided into a greater number of data sequences than the number of transmission antennas. According to the third embodiment, in the case where the data transmission is carried out according to a MIMO multiplexing scheme by means of a multiple antenna device with a plurality of transmission antennas, a channel coding rate is adjusted for each of the transmit antennas and a modulation scheme is established for each frequency block. This procedure is preferred from the point of view of improved performance. Fig. 27 is another flow diagram (2) illustrating an exemplary transmission method. This flow is the same as the flow in Figure 22, except that the different split data streams are transmitted from different transmit antennas # 1 and # 2. In the illustration, for the data transmitted from the same transmission antenna, the same modulation scheme is applied to the multiple frequency blocks (all the frequency blocks in the illustration). In this way, it is possible to reduce the number of control bits required to report the modulation scheme to the receiver side. Since this reduction advantage grows proportionally to the number of transmission antennas, the number of control bits can also be significantly reduced compared to the second mode. Fig. 28 is another flow chart (3) illustrating an exemplary transmission method. This flow is the same as the flow in Figure 25, except that the different split data sequences are transmitted from different transmission antennas # 1 and # 2.

(Fourth Mode) Similar to the third method, the fourth embodiment of the present invention also refers to the multiple antenna pattern. Fig. 29 is a flow diagram (1) illustrating an exemplary transmission method. The individual steps have already been explained in detail, and in this way, the duplicative description thereof will be omitted. In this embodiment, before a data sequence is split for the respective transmission antennas, the coupling of a CRC bit, the channel coding and the retransmission control are carried out uniformly on all the retransmission antennas. As a result, the coupling of a CRC bit and the channel coding are performed on a packet with a relatively large data size. Subsequently, this packet is transmitted and divided via the transmit antennas. According to this embodiment, it is possible to reduce the number of control bits required to report the channel coding rate to the receiver side and provide the CRC bit. Figure 30 is a flow chart (2) illustrating an exemplary transmission procedure. In this flow, the coupling of a CRC bit, the channel coding and the retransmission control are carried out uniformly on all the transmit antennas as in FIG. 29. However, the same modulation scheme is applied to the data. transmitted from the same transmission antenna, notwithstanding the frequency blocks. Since the same modulation scheme is applied to multiple frequency blocks, it is possible to reduce the number of control bits required to report the modulation scheme to the receiver side. Figure 31 is a flow chart (3) illustrating the exemplary transmission procedure. In this flow, the coupling of the CRC bits, the channel coding and the retransmission control are carried out uniformly on all the transmit antennas as in Figure 29. In the illustration, the modulation scheme is not only determined for each frequency block, but also the channel coding rate is determined for each frequency block.

[Fifth Mode] As stated above, adaptive modulation coding (AMC) is controlled in transmission of transmitted data channel. As illustrated in Figure 1, the transmission energy is kept constant under the control of AMC. It is intended to maintain the quality of the signal by communicating under a combination (MCS) of a modulation scheme and a coding scheme suitable for the condition of the channel. In order to maintain the good quality of the signal even under various channel conditions, it is desirable to prepare various MCS as illustrated in Figure 2. If there is not a sufficient number of MCS combinations, a lower data transmission efficiency (performance) can be achieved particularly under the condition where the switching between MCSs is carried out. On the other hand, for the different combinations of modulation schemes and coding schemes, the processing of the signal (coding, decoding, modulation, demodulation and others) also differs on the transmitter side and the receiver side. Thus, if there are a large number of MCSs, the number of modification time of the signal processing schemes and the computational workload may also be increased. This is not desirable from the point of view of simplification of signal processing (particularly for simple communication terminals). The fifth embodiment of the present invention can face the aforementioned problem. Figure 32 is a block diagram illustrating a transmitter according to this embodiment. This transmitter is the same as the transmitter described above in conjunction with Figure 7, except that a shared data channel processing unit 760 in FIG. 32 includes a power control unit 768. Although some components for adjusting the transmission power for the common control channels and the shared control channels can be provided, these components do not refer to the present invention directly and thus are not illustrated. Note that the channel coding rate, the modulation scheme and the transmission power are kept constant for the common control channels. Also for the shared control channels, the channel coding rate, the modulation scheme and the transmission power are kept constant in general. The transmission power for the shared control channels can be controlled according to the control of open-circuit or closed-circuit transmission power, or based on the reception quality (CQI information) of the downlink pilot channels reported within of mobile stations. The power control unit 768 adjusts the transmit power for the data channels based on the power control information supplied from the packet programming unit 761. In this embodiment, the combination of a modulation scheme and a coding scheme for the data channels is adjusted under the control of AMC if necessary, in addition, the transmission energy for the data channels is also controlled. The energy control information includes the information to specify the transmission power of the shared data channels for each resource block (frequency block). The energy control information is determined by the packet programming unit 761. The energy control information may be derived based on a predetermined correspondence between the modulation schemes (or MCSs), and the transmission energy levels. Alternatively, the energy control information can be found without the use of such predetermined correspondence. The energy control information can be updated for each subframe (or TTI) or it can be more or less frequently updated. Figure 33 shows an exemplary correspondence available for the case where the energy control information is derived based on a predefined correspondence. In the illustration, the transmission energy Pl is used in the case of the modulation scheme that is QPSK. The transmission energy P2 is used in the case of the modulation scheme that is 16QAM. The transmission energy P3 is used in the case of the modulation scheme that is 64QAM. There may be some or no relationship between the transmission energy levels Pl, P2 and P3. For example, there may or may not exist a certain ratio of proportion such as "P2 = 2P1 and P3 = 3P1". Of course, the data modulation schemes and / or the transmission energy levels are not limited to the three previous types, and may have more or fewer types. In addition, the modulation scheme and the transmission energy may or may not have a correspondence one or one, one with the other. For example, the same transmission power Pl can be used for QPSK and 16QAM. Figure 34 shows an exemplary correspondence between the MCSs and the transmission energy levels. The correspondence is not limited to the illustrations in Figures 33 and 34, and any other correspondence may be predefined. It is sufficient that the transmission energy can be derived from the modulation schemes and others. Figures 35A and 35B show exemplary transmit power for individual resource blocks. In Figure 35A, the same level of transmission energy is established for all resource blocks, which corresponds to the case of the transmission energy under the conventional AMC control. Figure 35B illustrates an exemplary case where the AMC control as well as the transmission power level is adjusted for each resource block. Since not only the MCSs but also the transmission energy can be adaptively changed, the performance can be further improved compared to the case with the use only of the AMC control. Figure 36 schematically shows an exemplary relationship between the achievable performances under the predefined MCSs and the signal-to-noise ratios (SNRS). Suppose that MCS1 has a lower bit rate than MCS2 and MCS2 in turn has a bit rate lower than MCS3. Let the maximum achievable yields under MCS1, MCS2 and MCS3 be Tphl, Tph2 and Tph3 respectively. Also suppose that SNR under a certain level of transmission energy is equal to the value "E" in the illustration. In this case, the achievable performance under MCS1 is approximately Tphl, while the performance greater than Tphl may be achievable under MCS2. However, suppose that MCS2 is not provided in the system and only MCS1 and MCS3 are provided in the system. In this case, according to the conventional AMC control, when the SNR is equal to E, only MCS1 can be adopted in the system. On the other hand, according to this modality, a greater transmission energy is reached. For example, it is possible to increase the SNR from E to F. Once the SRN equals F, MCS3 together with MCS1 becomes available. By using MCS3, higher performance is achieved. In other words, according to this modality, even if only the MCS1 and the MCS3 are provided in a system between the three types of MCSs, ie MCS1, MCS2 and MCS3, a higher performance is achieved. In other words, it is possible to use variable transmission power to reduce the types of MCSs while maintaining high performance. As stated above, the level of transmission energy can be derived based on a predefined correspondence between the modulation schemes and others, and the transmission energy levels. Alternatively, this can be found without the use of such predefined correspondence. In the first, the energy information indicating the predefined correspondence is stored as common information between a base station and a mobile station in respective memories. The mobile station can determine the transmission energy for an MCS reported from the base station, with reference to the correspondence. In this case, the base station does not have to transmit the information indicating the transmission energy via the shared or other control channels. The predefined correspondence can be reported to the mobile station by means of a common control channel such as broadcast information. Alternatively, the correspondence can be reported to the mobile station as the layer 3 information at the time of call establishment or it can be written in ROM as system-specific information. On the other hand, without such a predefined correspondence, when individual resource blocks are assigned to the users, the base station can derive the transmission energy individually to thus facilitate the best performance. Since the MCS as well as the transmission energy are optimized, this method is particularly advantageous to improve the achievable performance. Note that the information to indicate which block of resource has been used for the transmission via a data channel at what level of the transmission power has to be reported to the mobile stations via the shared control channels. Also, if the predefined correspondence is not used, the base station does not have to report the transmit power to the mobile stations via the shared control channels. For example, mobile stations can measure the quality of reception of the individual resource blocks allocated for themselves, and can estimate the transmission power. Therefore, the frequency of how often allocation status of resource blocks is reported (information indicating which resource blocks are allocated for which users) to mobile stations can be reported for each subframe (TTI) or less frequently. More generally, the respective frequency of reporting to the mobile stations may not be the same for all or a portion of the allocation state of the resource block, the MCS number and the transmission power. A shared control channel can be used for the report. Figure 37 schematically shows an exemplary allocation of resource blocks. In the illustration, shaded resource areas are assigned to certain users. In the illustrated example, the condition or allocation status of the resource blocks is reported to the mobile stations every three subframes (resource assignment report) and the assignment is modified if necessary. In other words, the allocation status of the resource block is invariably maintained during the three subframes. Although a block of resources is allocated for a user with a better channel condition, there is no guarantee that the good channel condition will be maintained throughout the resource blocks during the three subframes. In some cases, the channel condition may change to a worse condition. In the illustration, resource blocks marked "X" indicate that their channel condition has become worse. Resource blocks marked "X" should not be used as data channels for transmission. In this mode, the transmission energy for these resource blocks can be adjusted to be zero, to prevent resource blocks from being used. In this way, even if the allocation of the resource blocks is infrequently updated, unnecessary transmission of data can be avoided by adjusting the transmission energy for resource blocks with poor channel condition to be zero. Adjustment of the transmission energy to zero if necessary, is also advantageous for mobile stations in conjunction with the efficient use of communication resources. This is explained in detail with reference to Figures 38A-38B and 39A-39B. Figure 38A schematically shows an exemplary case where some data is transmitted to the same transmission power in all eight resource blocks allocated for certain users. This corresponds to the case of the conventional AMC control and is the same as Figure 35A. Figure 38B shows an exemplary case where the transmission energy for resource blocks RB3 and RB5 is set to be zero. In this case, it is desirable for a base station to raise the transmission energy associated with the resource blocks, different from resource blocks RB3 and RB5, as well as to keep the total amount of transmission energy as constant as possible. This is why the level of total transmission energy in the base station should be kept as constant as possible from the standpoint of stable operation of an energy amplifier. As a result, the transmission energy is high from Pl to Pl '. From the point of view of mobile stations, it can be expected that the reception quality associated with the resource blocks other than RB3 and RB5 will be improved. Figures 39A and 39B show respective cases before and after the transmission energy for resource blocks RB3 and RB5 that are set to zero. In the illustration, the transmission energy is controlled as in the case of Figure 35B. As illustrated in Figure 39B, the transmission energy is high for each resource block. The information that indicates for which block of resources the transmission energy is adjusted to be zero, can be reported to the mobile stations via any shared control channels different from the shared control channels indicating the allocation status of the resource block. However, it is likely that such shared control channels are not necessarily provided. For example, mobile stations may try to receive all resource blocks assigned to themselves, and can ignore the signals for resource blocks with less than a predefined reception quality (in the previous example, RB3 and RB5). When the information indicating for which resource block the transmission power is equal to zero, is reported to a mobile station, the mobile station can measure the quality of the reception associated with each resource block with high precision based on the information reported, the total transmission energy and the reception energy for the mobile station. The preferred embodiments of the present invention have been described above. However, the present invention is not limited to these embodiments, and various modifications and variations may be made, within the scope and spirit of the present invention. For convenience, the present invention has been described with reference to the different modalities. However, the distinction of modalities is not essential to the present invention, and one or more modalities may be used, if necessary. This international patent application is based on the Japanese Priority Application No. 2005-106908 filed on April 1, 2005, the complete contents of which are incorporated by reference herein. This international patent application is based on Japanese Priority Application No. 2005-9299 filed on January 17, 2006, the complete contents of which are incorporated by reference herein. This international patent application is based on Japanese Priority Application No. 2005-31750 filed on February 8, 2006, the entire contents of which are incorporated by reference herein. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention is that which is clear from the present description of the invention.

Claims (26)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property: 1. A transmitter for assigning a data channel for a communication opponent with a better channel condition, with the use of one or more blocks of communication. frequency including one or more carrier frequencies, characterized in that it comprises: a communication opponent's selection unit, which evaluates the condition of the channel for each of the frequency blocks for each of the multiple communication opponents and the selection of one or more communication opponents from the multiple opponents of communication; a unit for determining the modulation scheme, which determines at least one modulation scheme depending on the evaluated channel condition; a control channel generation unit, which generates a control channel indicating the determined modulation scheme and one or more frequency blocks available for the selected communication opponents to receive a data channel; and a channel transmission unit that provides the selected communication opponents with the control channel and the modulated data channel according to the modulation scheme.
2. 2. The transmitter according to claim 1, characterized in that: the modulation scheme determining unit determines a channel coding rate depending on the condition of the channel for each of the frequency blocks; the channel transmission unit transmits the data including the data channel, the data channel is modulated according to the modulation scheme and encoded with the channel coding rate.
3. 3. The transmitter according to claim 2, characterized in that the channel coding rate is adjusted to be a uniform value over the multiple frequency blocks.
4. 4. The transmitter according to any of claims 1 to 3, characterized in that the modulation scheme is determined for each of the frequency blocks.
5. 5. The transmitter according to any of claims 1 to 3, characterized in that the modulation scheme is determined uniformly on the multiple frequency blocks.
6. The transmitter according to any of claims 1 to 3, characterized in that the modulation scheme is determined uniformly on the multiple subcarriers distributed on a frequency axis.
7. The transmitter according to claim 1, characterized in that it further comprises: a unit for receiving the retransmission request, which receives a retransmission request for the data coming from one of the communication opponents, the channel transmission unit , in response to the retransmission request, retransmits the data.
8. The transmitter according to claim 7, characterized in that the transmission of the data in response to the retransmission request is conducted for each of the frequency blocks.
9. The transmitter according to claim 1, characterized in that it further comprises: an error correction coding unit that performs error correction coding on the control channel.
10. The transmitter according to claim 9, characterized in that the error correction coding unit performs the error correction coding on the control channel, for each of the frequency blocks.
11. The transmitter according to claim 1, characterized in that the data transmitted by the channel transmission unit includes an error detection code for the control channel.
12. The transmitter according to any of claims 1 to 3, characterized in that it further comprises: a division unit that divides a data sequence to be transmitted in multiple sequences, the transmission unit of the modulation scheme determines at least one modulation scheme for each of the multiple divided sequences.
13. The transmitter according to claim 12, characterized in that the unit for determining the modulation scheme determines the modulation scheme for each of the frequency blocks for each of the multiple divided sequences.
14. The transmitter according to claim 12, characterized in that the unit determining the modulation scheme determines a uniform modulation scheme on the plurality of frequency blocks, for each of the multiple divided sequences.
15. The transmitter according to claim 12, characterized in that the unit determining the modulation scheme determines a uniform modulation scheme on the multiple divided sequences.
16. The transmitter according to claim 12, characterized in that the unit for determining the modulation scheme determines a uniform modulation scheme on the multiple subcarriers distributed on a frequency axis for each of the multiple divided sequences.
17. The transmitter according to claim 12, characterized in that the modulation scheme determining unit further determines a channel coding rate for each of the multiple divided sequences.
18. The transmitter according to claim 12, characterized in that the unit determining the modulation scheme determines a uniform channel coding rate over the plurality of divided sequences.
19. 19. The transmitter according to claim 12, characterized in that the modulation scheme determining unit determines a channel coding rate applied to the data sequence to be divided.
20. 20. The transmitter according to claim 12, characterized in that the division unit divides the data sequence depending on a number of multiple transmit antennas.
21. The transmitter according to claim 12, characterized in that the division unit divides the data sequence to be transmitted in a greater number of sequences than a number of transmission antennas.
22. 22. The transmitter according to claim 4, characterized in that the modulation scheme determining unit determines the transmission energy for the data channel for each of the frequency blocks.
23. 23. The transmitter according to claim 22, characterized in that it further comprises: a storage unit that stores a predefined correspondence between the modulation schemes for the data channel and the transmission energy levels.
24. The transmitter according to claim 22, characterized in that the control channel includes the information indicating the transmit power of the data channel.
25. 25. The transmitter according to claim 22, characterized in that the control channel indicates that the transmission energy for at least one frequency block is equal to zero, is transmitted to the selected communication opponents to a transmission synchronization for the control channel, different from a control channel indicator of frequency block assignment for communication opponents.
26. 26. A method for transmitting to a communication opponent with a better channel condition, with the use of one or more frequency blocks, including one or more carrier frequencies; characterized in that it comprises the steps of: evaluating the condition of the channel for each of the frequency blocks for each of the multiple communication opponents; selecting one or more of the communication opponents of the plurality of communication opponents; determine at least one modulation scheme depending on the evaluated channel condition; generating a control channel indicating the determined modulation scheme and one or more of the frequency blocks available to the selected communication opponents, to receive data; and the provision of selected communication opponents with the control channel and a modulated data channel according to the modulation scheme.