JP4373426B2 - Transmitting apparatus and transmitting method - Google Patents

Description

  The present invention relates to a technical field of wireless communication, and more particularly to a base station, a communication terminal, a transmission method, and a reception method used in a communication system in which frequency scheduling and multicarrier transmission are performed.

  In this type of technical field, it is becoming increasingly important to realize broadband wireless access that efficiently performs high-speed and large-capacity communication. Especially in the downlink channel, the multi-carrier method-more specifically, the Orthogonal Frequency Division Multiplexing (OFDM) method-is promising from the viewpoint of performing high-speed and large-capacity communication while effectively suppressing multipath fading. Is being viewed. And it is also proposed to perform frequency scheduling in the next-generation system from the viewpoint of improving the frequency utilization efficiency and improving the throughput.

As shown in FIG. 1, the frequency band that can be used in the system is divided into a plurality of resource blocks (divided into three in the illustrated example), and each resource block includes one or more subcarriers. A resource block is also called a frequency chunk. One or more resource blocks are allocated to the terminal. In frequency scheduling, a resource block is preferentially allocated to a terminal with good channel state according to the received signal quality or channel state information (CQI: Channel Quality Indicator) for each resource block of the downlink pilot channel reported from the terminal. Therefore, it is intended to improve the transmission efficiency or throughput of the entire system. When frequency scheduling is performed, it is necessary to notify the terminal of the contents of scheduling, and this notification is performed by a control channel (which may be referred to as an L1 / L2 control signaling channel or an accompanying control channel). Furthermore, using this control channel, the modulation scheme (eg, QPSK, 16QAM, 64QAM, etc.) used in the scheduled resource block, channel coding information (eg, channel coding rate, etc.), and hybrid automatic retransmission request ( HARQ: Hybrid Auto Repeat ReQuest) will also be sent. A technique for dividing a frequency band into a plurality of resource blocks and changing the modulation scheme for each resource block is described in Non-Patent Document 1, for example.
P.Chow, J.Cioffi, J. Bingham, “A Practical Discrete Multitone Transceiver Loading Algorithm for Data Transmission over Spectrally Shaped Channel”, IEEE Trans.Commun.vol.43, No.2 / 3/4, February / March / April 1995

  On the other hand, in the next generation wireless access scheme in the future, a wide variety of frequency bands may be prepared, and the terminal may be required to be able to use various bands depending on the location or depending on the application. In this case, the frequency bandwidth that can be received by the terminal can be prepared in various wide and narrow frequency bands depending on the application and price. Also in this case, if frequency scheduling is appropriately performed, it is possible to expect improvement in frequency utilization efficiency and throughput. However, since it is assumed that the frequency band that can be used in the existing communication system is a fixed band, all combinations are allowed when various frequency bands are prepared on the base station side and terminal side. In addition, a specific method for appropriately notifying the contents of scheduling to the terminal or the user has not been established yet.

  On the other hand, if a specific resource block common to all terminals is fixedly allocated for the control channel, the channel state of the terminal is generally different for each resource block, so that depending on the terminal, the control channel is good. May not be received. If the control channel is distributed to all resource blocks, any terminal may be able to receive the control channel with a certain level of reception quality, but it is difficult to expect a higher reception quality. Therefore, it is desired to transmit the control channel to the terminal with higher quality.

  In addition, when adaptive modulation and coding (AMC) control is performed in which the modulation scheme and channel coding rate are adaptively changed, the number of symbols required to transmit the control channel is determined for each terminal. Different. This is because the amount of information transmitted per symbol differs depending on the combination of AMC. In a future system, it is also considered to transmit and receive different signals with a plurality of antennas respectively prepared on the transmission side and the reception side. In this case, the aforementioned control information such as scheduling information may be required for each signal communicated by each antenna. Therefore, in this case, the number of symbols necessary for transmitting the control channel is not only different for each terminal, but may be different depending on the number of antennas used for the terminal. When the amount of information to be transmitted on the control channel differs from terminal to terminal, it is necessary to use a variable format that can flexibly cope with fluctuations in the amount of control information in order to use resources efficiently. There is a concern that the signal processing burden on the reception side and the reception side will increase. Conversely, when the format is fixed, it is necessary to secure a dedicated field for the control channel according to the maximum amount of information. However, in this case, even if a field dedicated to the control channel is vacant, that part of the resource is not used for data transmission, which is contrary to a request for effective use of the resource. Therefore, it is desired to transmit the control channel simply and efficiently.

  The present invention has been made to address at least one of the above-described problems. The problem is that the frequency band allocated to the communication system is divided into a plurality of frequency blocks, and each of the frequency blocks is one or more. In order to efficiently transmit a control channel to various terminals having different communicable bandwidths in a communication system in which a terminal performs communication using one or more frequency blocks. It is to provide a base station, a communication terminal, a transmission method, and a reception method.

  According to one aspect of the invention, a transmission device is used. The transmitter is
  A frequency scheduling unit in which a frequency band given to the communication system includes a plurality of frequency blocks, each frequency block includes a plurality of resource blocks, and allocates at least one resource block to each communication terminal;
  A first generation unit that generates a data channel for a communication terminal to which at least one resource block is allocated in the frequency scheduling unit;
  A second generation unit that generates a specific control channel for each communication terminal assigned at least one resource block in the frequency scheduling unit;
  A third generation unit that generates an unspecified control channel common to communication terminals to which at least one resource block is allocated in the frequency scheduling unit;
  A fourth generation unit for generating a broadcast channel including broadcast information for notifying a communication terminal;
  Among the plurality of frequency blocks included in the frequency band given to the communication system, the broadcast channel generated in the fourth generation unit is arranged in the frequency block including the center frequency, and the frequency band given to the communication system The unspecified control channel generated by the third generation unit, at least one specific control channel generated by the second generation unit, and at least one generated by the first generation unit over a plurality of frequency blocks included in A multiplexing unit for arranging the data channels of
  A transmission unit for transmitting the output signal of the multiplexing unit,
  The number of symbols for the portion including at least one specific control channel generated in the second generation unit is variable,
  The non-specific control channel generated in the third generation unit includes information on the number of symbols in a portion including at least one specific control channel generated in the second generation unit. is there.

  Also according to one aspect of the invention, a transmission method is used. The transmission method is
  A frequency band given to the communication system includes a plurality of frequency blocks, each frequency block includes a plurality of resource blocks, and assigns at least one resource block to each communication terminal;
  Generating a data channel for a communication terminal assigned with at least one resource block;
  Generating a specific control channel for each communication terminal assigned with at least one resource block;
  Generating an unspecified control channel common to communication terminals assigned with at least one resource block;
  Generating a broadcast channel including broadcast information for notifying a communication terminal;
  Among the plurality of frequency blocks included in the frequency band given to the communication system, the broadcast channel is arranged in the frequency block including the center frequency, and the plurality of frequency blocks included in the frequency band given to the communication system A non-specific control channel, at least one specific control channel, and at least one data channel,
  Transmitting an output signal from the placing step,
  The number of symbols for the portion including at least one specific control channel generated in the step of generating the specific control channel is variable,
  The unspecified control channel generated in the step of generating the unspecified control channel includes information on the number of symbols in a portion including at least one specific control channel generated in the second generation unit. This is the transmission method.

  According to an embodiment of the present invention, in a communication system including a plurality of resource blocks each including one or more subcarriers, each of a plurality of frequency blocks constituting a system frequency band, various communication terminals having different communicable bandwidths. In addition, the control channel can be transmitted efficiently.

  In one embodiment of the present invention, frequency scheduling is performed for each frequency block, and a control channel for notifying scheduling information is created for each frequency block according to the minimum bandwidth. As a result, the control channel can be efficiently transmitted to various communication terminals having different communicable bandwidths.

  The control channel created for each frequency block may be frequency multiplexed according to a predetermined hopping pattern. Thereby, it is possible to achieve uniform communication quality between communication terminals and between frequency blocks.

  The broadcast channel may be transmitted in a band including the center frequency of the frequency band given to the communication system and having a bandwidth corresponding to one frequency block. As a result, any communication terminal that intends to access the communication system can easily connect to the communication system by receiving a signal having the minimum bandwidth near the center frequency.

  The paging channel is also transmitted in a band including the center frequency of the frequency band given to the communication system and having a bandwidth corresponding to one frequency block. This is preferable from the viewpoint of reducing the number of frequency tunings as much as possible because the reception band at the time of standby and the band for cell search can be matched.

  From the viewpoint of uniformly using the entire frequency band, a paging channel for calling the communication terminal may be transmitted using the frequency block assigned to the communication terminal.

  In one aspect of the present invention, the control channel is divided into an unspecified control channel that is decoded by an unspecified communication terminal and a specific control channel that is decoded by a specific communication terminal to which one or more resource blocks are allocated, They may be encoded and modulated separately. The control channel is time-multiplexed with the non-specific control channel and the specific control channel according to the scheduling information, and is transmitted in a multi-carrier scheme. Thereby, even if the amount of control information differs for each communication terminal, it is possible to efficiently transmit the control channel in a fixed format without wasting resources.

  The non-specific control channel may be mapped so as to be distributed over the entire frequency block, and the specific control channel related to a specific communication terminal may be mapped only to the resource block assigned to the specific communication terminal. The quality of the specific control channel can be improved while ensuring the quality of the non-specific control channel to a certain level or more over all users. This is because the specific control channel is mapped to a resource block having a good channel state for each specific communication terminal.

  The downlink pilot channel may also be mapped so as to be distributed over a plurality of resource blocks allocated to a plurality of communication terminals. By mapping the pilot channel over a wide band, the channel estimation accuracy and the like can be improved.

  FIG. 2 shows the frequency band used in one embodiment of the present invention. For convenience of explanation, specific numerical values are used, but the numerical values are merely examples, and various numerical values may be used. As an example, the frequency band (total transmission band) given to the communication system has a bandwidth of 20 MHz. The entire transmission band includes four frequency blocks 1 to 4, and each frequency block includes a plurality of resource blocks including one or more subcarriers. In the illustrated example, a state in which a large number of subcarriers are included in each frequency block is schematically illustrated. In this embodiment, four types of bandwidths of 5 MHz, 10 MHz, 15 MHz, and 20 MHz are prepared as communication bandwidths, and the terminal uses one or more frequency blocks and any one of the four bandwidths. Communicate with. A terminal that communicates within a communication system may be able to communicate in any of the four bands, or may be able to communicate only in any bandwidth. However, it is necessary to be able to communicate in a band of at least 5 MHz.

  In this embodiment, the control channel (L1 / L2 control signaling channel or low layer control channel) for notifying the terminal of the scheduling content of the data channel (shared data channel) is configured with a minimum bandwidth (5 MHz), and the control channel Are prepared independently for each frequency block. For example, when a terminal that performs communication in a bandwidth of 5 MHz performs communication in the frequency block 1, it can receive the control channel prepared in the frequency block 1 and obtain the contents of scheduling. Which frequency block the terminal can communicate with may be notified in advance using a broadcast channel, for example. Moreover, the frequency block to be used may be changed after the start of communication. When a terminal that communicates with a bandwidth of 10 MHz communicates with frequency blocks 1 and 2, the terminal uses two adjacent frequency blocks, and both control channels prepared in frequency blocks 1 and 2 are used. The content of the scheduling over the range of 10 MHz can be obtained. A terminal that performs communication with a bandwidth of 15 MHz uses three adjacent frequency blocks. When communication is performed using frequency blocks 1, 2, and 3, the terminals are all prepared in frequency blocks 1, 2, and 3. And control content over a 15 MHz range can be obtained. A terminal that performs communication with a bandwidth of 20 MHz can receive all the control channels prepared in all frequency blocks, and obtain scheduling contents over a range of 20 MHz.

  In the figure, four discrete blocks are shown in the frequency block for the control channel, and this shows how the control channel is distributed and mapped to a plurality of resource blocks in the frequency block. A specific mapping example of the control channel will be described later.

  FIG. 3A shows a partial block diagram of a base station according to one embodiment of the present invention. 3A shows a frequency block allocation control unit 31, a frequency scheduling unit 32, a control signaling channel generation unit 33-1 and a data channel generation unit 34-1 in the frequency block 1,. . . Control signaling channel generation unit 33-M and data channel generation unit 34-M in frequency block M, broadcast channel (or paging channel) generation unit 35, first multiplexing unit 1-1 related to frequency block 1,. . . The first multiplexing unit 1-M, the second multiplexing unit 37, the third multiplexing unit 38, the other channel generation unit 39, the inverse fast Fourier transform unit 40 (IFFT), and the cyclic prefix (CP) addition unit 41 related to the frequency block M are provided. It is drawn.

  The frequency block allocation control unit 31 confirms the frequency block used by the terminal based on the information on the maximum communicable bandwidth reported from the terminal (which may be a mobile terminal or a fixed terminal). The frequency block allocation control unit 31 manages the correspondence between individual terminals and frequency blocks, and notifies the frequency scheduling unit 32 of the contents. As to which frequency block a terminal that can communicate with a certain bandwidth may communicate with may be broadcast in advance on a broadcast channel. For example, the broadcast channel may allow a user communicating with a bandwidth of 5 MHz to use any one of the frequency blocks 1, 2, 3, and 4 or use any of them. May be limited. Moreover, use of a combination of two adjacent frequency blocks such as frequency blocks (1, 2), (2, 3) or (3,4) is permitted for a user communicating with a bandwidth of 10 MHz. . Use of all of these may be permitted, or use may be limited to any combination. A user communicating with a bandwidth of 15 MHz is allowed to use a combination of three adjacent frequency blocks such as frequency block (1, 2, 3) or (2, 3, 4). Use of both may be permitted, or use may be restricted to one combination. All frequency blocks are used for users communicating in a 20 MHz bandwidth. The usable frequency block may be changed after the start of communication according to a predetermined frequency hopping pattern.

  The frequency scheduling unit 32 performs frequency scheduling in each of the plurality of frequency blocks. In the frequency scheduling within one frequency block, scheduling information is determined so that resource blocks are preferentially allocated to terminals having good channel conditions based on channel state information CQI for each resource block reported from the terminals.

  The control signaling channel generation unit 33-1 in the frequency block 1 configures a control signaling channel for notifying the terminal of scheduling information in the frequency block 1 using only resource blocks in the frequency block 1. Similarly, other frequency blocks use only resource blocks in the frequency block to configure a control signaling channel for notifying the terminal of scheduling information in the frequency block.

  The data channel generation unit 34-1 in the frequency block 1 generates a data channel to be transmitted using one or more resource blocks in the frequency block 1. Since the frequency block 1 may be shared by one or more terminals (users), N data channel generators 1-1 to N are prepared in the illustrated example. Similarly, for other frequency blocks, data channels of terminals sharing the frequency block are generated.

  The first multiplexing unit 1-1 related to the frequency block 1 multiplexes signals related to the frequency block 1. This multiplexing includes at least frequency multiplexing. How the control signaling channel and the data channel are multiplexed will be described later. The other first multiplexing unit 1-x similarly multiplexes the control signaling channel and data channel transmitted in the frequency block x.

  The second multiplexing unit 37 performs an operation of changing the positional relationship on the frequency axis of various multiplexing units 1-x (x = 1,..., M) according to a predetermined hopping pattern. This will be described in the second embodiment.

  The broadcast channel (or paging channel) generation unit 35 generates broadcast information for notifying a subordinate terminal such as station data. Information indicating the relationship between the maximum frequency band in which a terminal can communicate and the frequency block that can be used by the terminal may be included in the control information. When the usable frequency block is changed variously, information specifying a hopping pattern indicating how the frequency block changes may be included in the broadcast information. Note that the paging channel may be transmitted in the same band as the broadcast channel, or may be transmitted in a frequency block used in each terminal.

  The other channel generation unit 39 generates a channel other than the control signaling channel and the data channel. For example, the other channel generation unit 39 generates a pilot channel.

  The third multiplexing unit 38 multiplexes the control signaling channel and data channel of each frequency block and the broadcast channel and / or other channels as necessary.

  The inverse fast Fourier transform unit 40 performs inverse fast Fourier transform on the signal output from the third multiplexing unit 38 and performs OFDM modulation.

  A cyclic prefix (CP) adding unit 41 adds a guard interval to the OFDM-modulated symbol, and generates a transmission symbol. The transmission symbol may be created, for example, by adding a series of data at the end (or the beginning) of the OFDM symbol to the beginning (or the end).

  FIG. 3B shows elements following the CP adding unit 41 in FIG. 3A. As shown in the figure, the symbol with the guard interval added is subjected to processing such as digital-analog conversion, frequency conversion, and band limitation in an RF transmission circuit, and is amplified to an appropriate power by a power amplifier. Sent through.

  Although not essential to the present invention, in this embodiment, antenna diversity reception by two antennas is performed during reception. Uplink signals received by the two antennas are input to the uplink signal receiver.

  FIG. 4A shows signal processing elements for one frequency block (xth frequency block). x is an integer of 1 or more and M or less. In general, a control signaling channel generation unit 33-x and a data channel generation unit 34-x, a multiplexing unit 43-A, B, and a multiplexing unit 1-x related to the frequency block x are illustrated. The control signaling channel generator 33-x includes an unspecific control channel generator 41 and one or more specific control channel generators 42-A, B,. . . Have

  The unspecified control channel generation unit 41 is a channel in a portion of an unspecified control channel (which may be referred to as unspecified control information) that all terminals using the frequency block of the control signaling channel must decode and demodulate. Encoding and multilevel modulation are performed and output.

  Specific control channel generators 42-A, B,. . . Is a channel code in a part of a specific control channel (which may be referred to as specific control information) that must be decoded and demodulated by a terminal to which one or more resource blocks are allocated in the frequency block. And multi-level modulation and output it.

  Data channel generators x-A, B,. . . Are the individual terminals A, B,. . . Channel coding and multi-level modulation are performed for the data channel to which it is addressed. Information regarding this channel coding and multi-level modulation is included in the specific control channel.

  Multiplexers 43-A, B,. . . Associates a specific control channel and a data channel with a resource block for each terminal to which the resource block is assigned.

  As described above, the coding (and modulation) for the unspecified control channel is performed by the unspecified control channel generating unit 41, and the coding (and modulation) for the specified control channel is performed by the specified control channel generating units 42-A and B. ,. . . Done individually. Therefore, in this embodiment, as conceptually shown in FIG. 6, the unspecified control channel includes information for all the users to which the frequency block x is assigned, and these are collectively included in the error correction coding target. Become.

  In another embodiment, the unspecified control channel may also be error correction coded for each user. In this case, each user cannot uniquely identify which of the individual error correction coded blocks contains the information of the own station, so it is necessary to decode all the blocks. In this alternative embodiment, since the encoding process is closed for each user, addition and change of users are relatively easy. Each user needs to decode and demodulate the unspecified control channel for all the users.

  On the other hand, the specific control channel includes only information related to users to which resource blocks are actually allocated, and is error-correction coded for each user. The user to whom the resource block is assigned can be determined by decoding and demodulating the unspecified control channel. Therefore, it is not necessary for everyone to decode the specific control channel, and only the user to whom the resource block is assigned needs to decode it. Note that the channel coding rate and the modulation scheme for the specific control channel are appropriately changed during communication, but the channel coding rate and the modulation scheme for the non-specific control channel may be fixed. However, it is desirable to perform transmission power control (TPC) to ensure a certain level of signal quality. The specific control channel is transmitted with a good resource block after being subjected to error correction coding. Therefore, the amount of downlink data may be reduced to a certain degree by performing puncturing.

  FIG. 5A shows an example of the types and information items of the downlink control signaling channel. The downlink control signaling channel includes a broadcast channel (BCH), a dedicated L3 signaling channel (upper layer control channel), and an L1 / L2 control channel (lower layer control channel). The L1 / L2 control channel may include not only information for downlink data transmission but also information for uplink data transmission. The L1 / L2 control channel may include the transmission format of the L1 / L2 control channel (data modulation scheme, channel coding rate, number of simultaneously allocated users, etc.). The information items transmitted in each channel will be outlined below.

(Broadcast channel)
The broadcast channel is used to notify a communication terminal (which may be a mobile terminal or a fixed terminal or may be referred to as a user apparatus) of information that does not change in a cell or information that changes at a low speed. For example, information that may change at a cycle of about 1000 ms (1 second) may be notified as broadcast information. The broadcast information may include the transmission format of the downlink L1 / L2 control channel, the maximum number of simultaneously allocated users, resource block arrangement information, and MIMO scheme information.

  The transmission format is specified by the data modulation scheme and the channel coding rate. The data size may be notified instead of the channel coding rate. This is because the channel coding rate can be uniquely derived from the data modulation scheme and data size. This transmission format may be notified in the L1 / L2 control channel (part 0) described later.

  The maximum number of simultaneously allocated users represents the maximum number that can be multiplexed using one or more of FDM, CDM, and TDM in 1 TTI. This number may be the same for the uplink channel and the downlink channel, or may be different.

  The resource block arrangement information is information for specifying the frequency block and the position on the time axis of the resource block used in the cell. In this embodiment, two types of frequency division multiplexing (FDM) systems, a localized FDM system and a distributed FDM system, can be used. In the localized FDM scheme, a continuous band is preferentially allocated to users in a channel state that is locally good on the frequency axis. This method is advantageous for communication of users with low mobility, high-quality and large-capacity data transmission, and the like. In the distributed FDM system, a downlink signal is created so as to have a plurality of frequency components intermittently over a wide band. This method is advantageous for communication of users with high mobility, data transmission of periodic and small data size such as voice packet (VoIP), and the like. Regardless of which method is used, the frequency resource is allocated according to information specifying a continuous band or a plurality of discrete frequency components.

  As shown in the upper part of FIG. 5B, for example, when the resource is specified as “No. 4” in the localized FDM method, the resource of physical resource block number 4 is used. In the distributed FDM system as shown in the lower side of FIG. 5B, when a resource is specified by “No. 4”, two left halves of physical resource blocks 2 and 8 are used. In the illustrated example, one physical resource block is divided into two. The numbering and the number of divisions in the distributed FDM method may be different for each cell. For this reason, the resource block arrangement information is notified to the communication terminals in the cell through the broadcast channel.

  MIMO system information includes single user mimo (SU-MIMO) or multi user mimo (MU-MIMO: Multi-User MIMO) when multiple antennas are prepared in the base station. Which of the schemes is performed is indicated. The SU-MIMO method is a method for communicating with one communication terminal having a plurality of antennas, and the MU-MIMO method is a method for performing communication simultaneously with a plurality of communication terminals having one antenna.

(Dedicated L3 signaling channel)
The dedicated L3 signaling channel is also used to notify the communication terminal of information that changes at a low speed such as a period of 1000 ms. The broadcast channel is notified to all communication terminals in the cell, but the dedicated L3 signaling channel is notified only to a specific communication terminal. The dedicated L3 signaling channel includes the FDM type and persistent scheduling information. The dedicated L3 signaling channel may be classified as a specific control channel.

  The type of the FDM system indicates whether the specified individual communication terminal is multiplexed by the localized FDM system or the distributed FDM system.

  The persistent scheduling information specifies the transmission format (data modulation scheme and channel coding rate) of the uplink or downlink data channel, the resource block to be used, etc. when persistent scheduling is performed.

(L1 / L2 control channel)
The downlink L1 / L2 control channel may include not only information related to downlink data transmission but also information related to uplink data transmission. Furthermore, an information bit (part 0) indicating the transmission format of the L1 / L2 control channel may be included. Information related to downlink data transmission can be classified into three types, part 1, part 2a and part 2b as follows. Part 1 and part 2a can be classified as non-specific control channels, and part 2b can be classified as specific control channels.

(Part 0)
Part 0 includes the transmission format of the L1 / L2 control channel (modulation scheme and channel coding rate, the number of simultaneously allocated users or the total number of control bits). In the case where the information notified by the broadcast channel is used as the transmission format of the L1 / L2 control channel, part 0 includes the number of simultaneously allocated users (or the total number of control bits).

  The number of symbols required for the L1 / L2 control channel depends on the number of simultaneously multiplexed users and the reception quality of the users to be multiplexed. As shown in the left side of FIG. 5C, typically, the number of symbols of the L1 / L2 control channel is made sufficiently large. When changing the number of symbols, control can be performed with a period of about 1000 ms (1 second), for example, according to the transmission format of the L1 / L2 control channel notified by the broadcast channel. However, if the number of simultaneously multiplexed users is small as shown on the right side of FIG. 5C, the number of symbols required for the control channel is reduced. Therefore, when the number of simultaneously multiplexed users and the reception quality of the users to be multiplexed change in a short period, there may be waste in the L1 / L2 control channel that is secured sufficiently large.

  In order to reduce the waste of the L1 / L2 control channel, the modulation scheme, the channel coding rate, and the number of simultaneously allocated users (or the total number of control bits) may be notified in the L1 / L2 control channel. By notifying the modulation scheme and channel coding rate in the L1 / L2 control channel, it becomes possible to change the modulation scheme and channel coding rate in a shorter cycle than the notification by the broadcast channel.

(Part 1)
Part 1 includes a paging indicator (PI). Each communication terminal demodulates the paging indicator, thereby confirming whether or not a call is made to the terminal itself.

(Part 2a)
Part 2a includes resource allocation information, allocation time length, and MIMO information of the downlink data channel.

  The resource allocation information of the downlink data channel specifies a resource block including the downlink data channel. Various methods known in the art can be used for specifying the resource block. For example, a bitmap method, a tree branch number method, or the like may be used.

  The allocated time length indicates how long the downlink data channel is continuously transmitted. The resource allocation contents change most frequently every TTI, but from the viewpoint of reducing overhead, the data channel may be transmitted with the same resource allocation contents over a plurality of TTIs.

  The MIMO information specifies the number of antennas, the number of streams, and the like when the MIMO scheme is used for communication. The number of streams may be called the number of information sequences.

  In addition, although it is not essential that the part 2a includes user identification information, it may be included in whole or in part.

(Part 2b)
Part 2b includes precoding information, a downlink data channel transmission format, hybrid retransmission control (HARQ) information, and CRC information when the MIMO scheme is used.

  The precoding information when the MIMO scheme is used specifies a weighting factor applied to each of a plurality of antennas. The directivity of the communication signal is adjusted by adjusting the weighting coefficient applied to each antenna.

  The transmission format of the downlink data channel is specified by the data modulation scheme and the channel coding rate. Instead of the channel coding rate, the data size or the payload size may be notified. This is because the channel coding rate can be uniquely derived from the data modulation scheme and data size.

  Hybrid retransmission control (HARQ: Hybrid Automatic Repeat ReQuest) information includes information necessary for downlink packet retransmission control. Specifically, the retransmission control information includes a process number, redundant version information indicating a packet combining method, and a new and old indicator (New Data Indicator) for distinguishing whether the packet is a new packet or a retransmission packet.

  CRC information indicates a CRC detection bit in which user identification information (UE-ID) is convoluted when the cyclic redundancy check method is used for error detection.

  Information related to uplink data transmission can be classified into four types of part 1 to part 4 as follows. In principle, these pieces of information may be classified into unspecified control channels, but may be transmitted as specific control channels to communication terminals to which resources are allocated for downlink data channels.

(Part 1)
Part 1 includes acknowledgment information for past uplink data channels. Acknowledgment information includes an acknowledgment (ACK) indicating that there was no error in the packet, or if it was within the allowable range, or a negative response (NACK) indicating that the packet had an error exceeding the allowable range. ).

(Part 2)
Part 2 includes resource allocation information for a future uplink data channel, a transmission format of the uplink data channel, transmission power information, and CRC information.

  The resource allocation information specifies resource blocks that can be used for uplink data channel transmission. Various methods known in the art can be used for specifying the resource block. For example, a bitmap method, a tree branch number method, or the like may be used.

  The transmission format of the uplink data channel is specified by the data modulation scheme and the channel coding rate. Instead of the channel coding rate, the data size or the payload size may be notified. This is because the channel coding rate can be uniquely derived from the data modulation scheme and data size.

  The transmission power information indicates how much power the uplink data channel should be transmitted.

  CRC information indicates a CRC detection bit in which user identification information (UE-ID) is convoluted when the cyclic redundancy check method is used for error detection. In the response signal (downlink L1 / L2 control channel) for the random access channel (RACH), the random ID of the RACH preamble may be used as the UE-ID.

(Part 3)
Part 3 includes transmission timing control bits. This is a control bit for synchronizing the communication terminals in the cell.

(Part 4)
Part 4 includes transmission power information relating to the transmission power of the communication terminal, and this information indicates how much power a communication terminal that has not been allocated for uplink data channel transmission reports, for example, CQI of the downlink channel. Indicates whether the uplink control channel should be transmitted.

  FIG. 4B shows signal processing elements related to one frequency block, similar to FIG. 4A, but looks different from FIG. 4A in that each control information is clearly specified. The same reference numerals in FIGS. 4A and 4B indicate the same elements. In the figure, “mapping within a resource block” indicates that mapping is limited to one or more resource blocks assigned to a specific communication terminal. “Outside resource block mapping” indicates mapping across the entire frequency block including a large number of resource blocks. Part 0 in the L1 / L2 control channel is transmitted throughout the frequency block as an unspecified control channel. Information related to uplink data transmission (parts 1 to 4) in the L1 / L2 control channel is the resource as a specific control channel if a resource is allocated for the downlink data channel, and unspecified control otherwise. It is transmitted as a channel over the entire frequency block.

  FIG. 7A shows an example of data channel and control channel mapping. The illustrated mapping example relates to one frequency block and one subframe, and generally corresponds to the output content of the first multiplexing unit 1-x (however, the pilot channel and the like are multiplexed by the third multiplexing unit 38). .) One subframe may correspond to, for example, one transmission time interval (TTI) or may correspond to a plurality of TTIs. In the illustrated example, seven resource blocks RB1 to RB7 are included in the frequency block. These seven resource blocks are allocated to terminals having good channel states by the frequency scheduling unit 32 in FIG. 3A.

  In general, unspecified control channels, pilot channels, and data channels are time-multiplexed. Unspecified control channels (including part 0 in the L1 / L2 control channel) are distributed and mapped over the entire frequency block. That is, the unspecified control channel is distributed over the entire band occupied by the seven resource blocks. In the illustrated example, the non-specific control channel (including part 0 in the L1 / L2 control channel) and other control channels (excluding the specific control channel) are frequency-multiplexed. Other channels may include, for example, a synchronization channel. In particular, since part 0 in the L1 / L2 control channel needs to have a short delay time, it is preferably multiplexed with the first OFDM symbol. In the illustrated example, the unspecified control channel and the other control channels are frequency-multiplexed so that each has a plurality of frequency components arranged at some interval. Such a multiplexing scheme is called a distributed frequency division multiplexing (distributed FDM) scheme. The distributed FDM system is advantageous in that a frequency diversity effect can be obtained. The intervals between the frequency components may all be the same or different. In any case, it is necessary that the unspecified control channel is distributed over the entire area of one frequency block. Furthermore, it is also possible to apply the CDM method as an alternative method. The CDM method has an advantage that the frequency diversity effect is further increased, but also has a disadvantage that the reception quality is deteriorated due to the loss of orthogonality.

  In the illustrated example, pilot channels and the like are also mapped over the entire frequency block. From the viewpoint of accurately performing channel estimation and the like for various frequency components, it is desirable that the pilot channel is mapped over a wide range as illustrated.

  In the illustrated example, resource blocks RB1, RB2, and RB4 are assigned to user 1 (UE1), resource blocks RB3, RB5, and RB6 are assigned to user 2 (UE2), and resource block RB7 is assigned to user 3 (UE3). . As described above, such allocation information is included in the unspecified control channel. Furthermore, a specific control channel for user 1 is mapped to the head of resource block RB1 among the resource blocks allocated to user 1. A specific control channel related to user 2 is mapped to the head of resource block RB3 among the resource blocks allocated to user 2. A specific control channel related to the user 3 is mapped to the head of the resource block RB7 assigned to the user 3. In the figure, it should be noted that the sizes occupied by the specific control channels of the users 1, 2 and 3 are drawn unevenly. This represents that the amount of information of a specific control channel may differ depending on the user. The specific control channel is mapped locally only to the resource block allocated to the data channel. In this regard, unlike distributed FDM that is distributed and mapped across various resource blocks, such a mapping scheme is also called localized frequency division multiplexing (localized FDM).

  FIG. 7B shows another example of mapping of unspecified control channels. The specific control channel of user 1 (UE1) is mapped to only one resource block RB1 in FIG. 7A, but over the entire resource blocks RB1, RB2, and RB4 (entire resource blocks assigned to user 1) in FIG. 7B. The distributed FDM method is discretely distributed and mapped. Also, the specific control channel for user 2 (UE2) is also mapped over the entire resource blocks RB3, RB5, RB6, unlike the case shown in FIG. 7A. User 2's specific control channel and shared data channel are time-division multiplexed. As described above, the specific control channel and the shared data channel of each user are time-division multiplexed (TDM) and / or frequency division multiplexed among all or a part of one or more resource blocks allocated to each user. Multiplexing may be performed in a system (including localized FDM system and distributed FDM system). By mapping the specific control channel over two or more resource blocks, the frequency diversity effect can be expected for the specific control channel, and the signal quality of the specific control channel can be further improved.

  Next, a specific format of part 0 in the L1 / L2 control channel will be described.

  FIG. 7C shows an example of the format of the L1 / L2 control channel when the number of symbols (or the number of simultaneously allocated users) of the L1 / L2 control channel is notified in part 0. When the communication terminal uses the modulation scheme and coding rate (MCS) notified by the broadcast channel, the number of symbols required for the L1 / L2 control channel varies depending on the number of simultaneously allocated users. In order to identify this, a control bit (2 bits in FIG. 7C) is provided as part 0 information of the L1 / L2 control channel. For example, by notifying the control bit of 00 as part 0 information, it is possible to know that the number of symbols of the L1 / L2 control channel is 100 by decoding this control bit at the communication terminal. 7C corresponds to part 0, and the variable control channel corresponds to an unspecified control channel (part 1 and part 2a in the case of downlink). In FIG. 7C, MCS is reported on the broadcast channel, but MCS may be reported on the L3 signaling channel.

  FIG. 7D is an example showing the format of the L1 / L2 control channel when the number of simultaneously allocated users of each MCS is notified in part 0. When an appropriate MCS is used according to the reception quality of the communication terminal from among predetermined types of MCS, the number of symbols required for the L1 / L2 control channel changes according to the reception quality of the communication terminal. In order to identify this, a control bit (8 bits in FIG. 7D) is provided as part 0 information of the L1 / L2 control channel. FIG. 7D shows a case where there are four types of MCSs as an example, and the maximum value of the number of simultaneously allocated users in each MCS is three. Since the number of simultaneously allocated users is 0 to 3, this information can be represented by 2 bits (00 = 0 user, 01 = 1 user, 10 = 2 user, 11 = 3 user). Since 2 bits are required for each MCS, part 0 in this case is 8 bits. For example, by notifying the control bit of 01100001 as part 0 information, the communication terminal can know the control information (part 2a in the case of downlink) according to its reception quality based on this control bit.

  FIG. 7E is an example showing mapping of information bits (part 0) in the L1 / L2 control channel in the case of a three-sector configuration. In the case of a three-sector configuration, three types of patterns are prepared for transmitting information bits (part 0) indicating the transmission format of the L1 / L2 control channel so that the patterns do not overlap in the frequency domain. It may be assigned to each sector. By selecting patterns so that transmission patterns in adjacent sectors (or cells) are different from each other, the effect of interference coordination can be obtained.

  FIG. 7F shows examples of various multiplexing methods. In the above example, various unspecified control channels are multiplexed using the distributed FDM method, but various appropriate multiplexing methods such as code division multiplexing (CDM) and time division multiplexing (TDM) are used. Also good. FIG. 7F (1) shows a state in which multiplexing is performed by the distributed FDM method. By using numbers 1, 2, 3, and 4 that specify a plurality of discrete frequency components, the signals of each user can be appropriately orthogonalized. However, it does not have to be regular as in this example. Further, by using different rules between adjacent cells, the amount of interference when performing transmission power control can be randomized. FIG. 7F (2) shows how multiplexing is performed by the code division multiplexing (CDM) method. By using the codes 1, 2, 3, and 4, the signals of each user can be appropriately orthogonalized. FIG. 7F (3) shows a state in which the user multiplexing number is changed to 3 in the distributed FDM system. By redefining the numbers 1, 2, and 3 that specify a plurality of discrete frequency components, the signals of each user can be appropriately orthogonalized. When the number of simultaneously allocated users is less than the maximum number, the base station may increase the transmission power of the downlink control channel as shown in FIG. 7F (4). A hybrid of CDM and FDM is also applicable.

  FIG. 8A shows a partial block diagram of a mobile terminal used in one embodiment of the present invention. 8A shows a carrier frequency tuning unit 81, a filtering unit 82, a cyclic prefix (CP) removing unit 83, a fast Fourier transform unit (FFT) 84, a CQI measuring unit 85, a broadcast channel (or paging channel) decoding unit 86, A specific control channel (part 0) decoding unit 87-0, an unspecific control channel decoding unit 87, a specific control channel decoding unit 88, and a data channel decoding unit 89 are depicted.

  The carrier frequency tuning unit 81 appropriately adjusts the center frequency of the reception band so that the signal of the frequency block assigned to the terminal can be received.

  The filtering unit 82 filters the received signal.

  The cyclic prefix removing unit 83 removes the guard interval from the received signal and extracts the effective symbol portion from the received symbol.

  A fast Fourier transform unit (FFT) 84 performs fast Fourier transform on information included in the effective symbol and performs OFDM demodulation.

  CQI measuring section 85 measures the received power level of the pilot channel included in the received signal, and feeds back the measurement result to the base station as channel state information CQI. CQI is performed for every resource block in the frequency block, and they are all reported to the base station.

  The broadcast channel (or paging channel) decoding unit 86 decodes the broadcast channel. If a paging channel is included, it is also decoded.

  The unspecified control channel (part 0) decoding unit 87-0 decodes the information of part 0 in the L1 / L2 control channel. This part 0 makes it possible to recognize the transmission format of the unspecified control channel.

  The unspecified control channel decoding unit 87 decodes the unspecified control channel included in the received signal and extracts scheduling information. The scheduling information includes information indicating whether or not a resource block is allocated to the shared data channel addressed to the terminal, information indicating a resource block number when the resource block is allocated, and the like.

  The specific control channel decoding unit 88 decodes the specific control channel included in the received signal. The specific control channel includes data modulation, channel coding rate, and HARQ information regarding the shared data channel.

  The data channel decoding unit 89 decodes the shared data channel included in the received signal based on the information extracted from the specific control channel. An acknowledgment (ACK) or a negative acknowledgment (NACK) may be reported to the base station according to the decoding result.

  FIG. 8B shows a partial block diagram of the mobile terminal as in FIG. 8A, but it looks different from FIG. 8A in that individual control information is specifically shown. The same reference numerals in FIG. 8A and FIG. 8B indicate the same elements. In the figure, “in-resource block demapping” indicates that information mapped to one or more resource blocks allocated to a specific communication terminal is extracted. “Outside resource block demapping” indicates that information mapped over the entire frequency block including a large number of resource blocks is extracted.

  FIG. 8C shows elements associated with the receiver of FIG. 8A. Although not essential to the present invention, in this embodiment, antenna diversity reception by two antennas is performed during reception. The downlink signals received by the two antennas are respectively input to the RF receiving circuits (81, 82), the guard interval (cyclic prefix) is removed (83), and fast Fourier transformed (84). Signals received by the respective antennas are combined by an antenna diversity combining unit. The combined signal is supplied to each decoding unit in FIG. 8A or to the separation unit in FIG. 8B.

  FIG. 9 is a flowchart showing an operation example according to an embodiment of the present invention. As an example, it is assumed that a user having a mobile terminal UE1 that can communicate with a bandwidth of 10 MHz enters a cell or a sector that performs communication with a bandwidth of 20 MHz. It is assumed that the minimum frequency band of the communication system is 5 MHz, and the entire band is divided into four frequency blocks 1 to 4 as shown in FIG.

  In step S11, the terminal UE1 receives the broadcast channel from the base station, and confirms what frequency blocks the local station can use. The broadcast channel may be transmitted in a 5 MHz band including the center frequency of the entire 20 MHz band. In this way, any terminal having a different receivable bandwidth can easily receive the broadcast channel. The broadcast channel allows users communicating with a bandwidth of 10 MHz to use a combination of two adjacent frequency blocks such as frequency blocks (1, 2), (2, 3) or (3,4). To do. Use of all of these may be permitted, or use may be limited to any combination. As an example, it is assumed that use of the frequency blocks 2 and 3 is permitted.

  In step S12, the terminal UE1 receives the downlink pilot channel and measures the received signal quality regarding the frequency blocks 2 and 3. The measurement is performed for each of a number of resource blocks included in each frequency block, and all of them are reported to the base station as channel state information CQI.

  In step S21, the base station performs frequency scheduling for each frequency block based on the channel state information CQI reported from the terminal UE1 and other terminals. It is confirmed and managed by the frequency block allocation control unit (31 in FIG. 3A) that the data channel addressed to UE1 is transmitted from frequency block 2 or 3.

  In step S22, the base station creates a control signaling channel for each frequency block according to the scheduling information. The control signaling channel includes an unspecified control channel and a specified control channel.

  In step S23, the control channel and the shared data channel are transmitted from the base station for each frequency block according to the scheduling information.

  In step S13, the terminal UE1 receives signals transmitted in the frequency blocks 2 and 3.

  In step S14-0, the terminal UE1 recognizes the transmission format of the unspecified control channel from the part 0 of the control channel received in the frequency blocks 2 and 3.

  In step S14, the unspecified control channel is separated from the control channel received in the frequency block 2, is decoded, and scheduling information is extracted. Similarly, the unspecified control channel is separated from the control channel received by the frequency block 3, is decoded, and the scheduling information is extracted. Any scheduling information includes information indicating whether or not a resource block is allocated to the shared data channel addressed to the terminal UE1, information indicating a resource block number when the resource block is allocated, and the like. When no resource block is assigned to the shared data channel addressed to the own station, the terminal UE1 returns to the standby state and waits for reception of the control channel. If any resource block is allocated to the shared data channel addressed to the own station, the terminal UE1 separates the specific control channel included in the received signal in step S15 and decodes it. The specific control channel includes data modulation, channel coding rate, and HARQ information regarding the shared data channel.

  In step S16, the terminal UE1 decodes the shared data channel included in the received signal based on the information extracted from the specific control channel. An acknowledgment (ACK) or a negative acknowledgment (NACK) may be reported to the base station according to the decoding result. Thereafter, the same procedure is repeated.

  The unspecified control channel (including part 0) is information required by all users, and in order to decode the data channel based on this unspecified control channel, error detection (CRC) coding and channel are added to the unspecified control channel. Encoding is performed. In the second embodiment of the present invention, a specific example of this error detection coding and channel coding will be described. FIG. 4B is a diagram corresponding to a configuration in which L1 / L2 control information (part 0) and L1 / L2 control information (parts 2a and 2b) are separately channel-coded (channel coding / (Including diffusion / data modulation units 41 and 42-A). This alternative configuration is described below.

  FIG. 10A shows a case where part 0 and parts 2a and 2b are combined with error detection coding, and part 0 and parts 2a and 2b are separately channel coded. The communication terminals UE1 and UE2 detect an error by combining part 0 and parts 2a and 2b, and use the L1 / L2 control channel for the own communication terminal from among parts 2a and 2b based on part 0.

  Since the error detection (CRC) code of part 0 may be larger than the control bits of part 0, it is possible to reduce the error detection coding overhead in this case.

  FIG. 10B shows a case where part 0 and parts 2a and 2b are separately subjected to error detection coding, and part 0 and parts 2a and 2b are separately subjected to channel coding. Compared to the case of FIG. 10A, the overhead becomes larger, but there is an advantage that it is not necessary to perform the processes of parts 2 a and 2 b when the error detection of part 0 fails.

  FIG. 10C shows a case where part 0 and parts 2a and 2b are error-coded together and part 0 and parts 2a and 2b are channel-coded together. In this case, if the part 0 and the parts 2a and 2b are not decoded together, the information of the part 0 cannot be extracted, but there is an advantage that the efficiency of the channel coding rate is increased.

  Although FIGS. 10A to 10C describe error detection coding and channel coding of part 0 and parts 2a and 2b, the present invention can be similarly applied to unspecified control channels other than parts 2a and 2b.

The figure for demonstrating frequency scheduling is shown. It is a figure which shows the frequency band used by one Example of this invention. The partial block diagram (the 1) of the base station by one Example of this invention is shown. The partial block diagram (the 2) of the base station by one Example of this invention is shown. It is a figure which shows the signal processing element regarding one frequency block. It is a figure which shows the signal processing element regarding one frequency block. It is a figure which shows the information item example of a control signaling channel. It is a figure which shows the localized FDM system and the distributed FDM system. It is a figure which shows the symbol number of the L1 / L2 control channel which changes according to the number of simultaneous multiplex users. It is a figure which shows the unit of error correction encoding. It is a figure which shows the example of mapping of a data channel and a control channel. It is a figure which shows the example of mapping of a data channel and a control channel. It is an example which shows the format of the L1 / L2 control channel when notifying the number of symbols of the L1 / L2 control channel in Part 0. It is an example which shows the format of the L1 / L2 control channel when notifying the number of simultaneously allocated users of each MCS in Part 0. It is an example which shows the mapping of the part 0 in the L1 / L2 control channel in the case of 3 sector structure. It is a figure which shows the example of a multiplexing system of an unspecified control channel. FIG. 2 shows a partial block diagram of a terminal according to an embodiment of the present invention. FIG. 2 shows a partial block diagram of a terminal according to an embodiment of the present invention. The block diagram regarding the receiving part of a terminal is shown. 6 is a flowchart illustrating an operation example according to an embodiment of the present invention. It is FIG. (The 1) which shows the error detection coding of a non-specific control channel, and channel coding. It is FIG. (The 2) which shows the error detection coding of a non-specific control channel, and channel coding. It is FIG. (The 3) which shows the error detection encoding of an unspecified control channel, and channel encoding.

Explanation of symbols

31 frequency block allocation control unit 32 frequency scheduling unit 33-x control signaling channel generation unit in frequency block x 34-x data channel generation unit in frequency block x 35 broadcast channel (or paging channel) generation unit 1-x frequency block first multiplexing unit 37 related to x 37 second multiplexing unit 38 third multiplexing unit 39 other channel generation unit 40 inverse fast Fourier transform unit 41 cyclic prefix addition unit 41 unspecified control channel generation unit 42 specific control channel generation unit 43 multiplexing unit 81 Carrier frequency tuning unit 82 Filtering unit 83 Cyclic prefix removal unit 84 Fast Fourier transform unit (FFT)
85 CQI measurement unit 86 Broadcast channel decoding unit 87-0 Unspecified control channel (part 0) decoding unit 87 Unspecified control channel decoding unit 88 Specific control channel decoding unit 89 Data channel decoding unit

Claims (14)

  A frequency scheduling unit in which a frequency band given to the communication system includes a plurality of frequency blocks, each frequency block includes a plurality of resource blocks, and allocates at least one resource block to each communication terminal;
  A first generation unit that generates a data channel for a communication terminal to which at least one resource block is allocated in the frequency scheduling unit;
  A second generation unit that generates a specific control channel for each communication terminal assigned at least one resource block in the frequency scheduling unit;
  A third generation unit that generates an unspecified control channel common to communication terminals to which at least one resource block is allocated in the frequency scheduling unit;
  A fourth generation unit for generating a broadcast channel including broadcast information for notifying a communication terminal;
  Among the plurality of frequency blocks included in the frequency band given to the communication system, the broadcast channel generated in the fourth generation unit is arranged in the frequency block including the center frequency, and the frequency band given to the communication system The unspecified control channel generated by the third generation unit, at least one specific control channel generated by the second generation unit, and at least one generated by the first generation unit over a plurality of frequency blocks included in A multiplexing unit for arranging the data channels of
  A transmission unit for transmitting the output signal of the multiplexing unit,
  The number of symbols for the portion including at least one specific control channel generated in the second generation unit is variable,
  The non-specific control channel generated in the third generation unit includes information on the number of symbols in a portion including at least one specific control channel generated in the second generation unit.   The transmission apparatus according to claim 1, wherein the specific control channel generated in the second generation unit includes information on a data modulation scheme.   The transmission apparatus according to claim 1, wherein the specific control channel generated in the second generation unit includes information related to an encoding scheme.   The transmission apparatus according to claim 1, wherein the specific control channel generated by the second generation unit includes information on hybrid retransmission control.   The transmission apparatus according to claim 1, wherein the specific control channel generated in the second generation unit includes precoding information when a MIMO scheme is used.   The multiplexing unit includes at least one data channel generated in the first generation unit with respect to an unspecified control channel generated in the third generation unit and at least one specific control channel generated in the second generation unit. 6. The transmission apparatus according to claim 1, wherein time multiplexing is performed.   The transmission apparatus according to claim 1, wherein the multiplexing unit arranges a paging channel in the same manner as the data channel.   A frequency band given to the communication system includes a plurality of frequency blocks, each frequency block includes a plurality of resource blocks, and assigns at least one resource block to each communication terminal;
  Generating a data channel for a communication terminal assigned with at least one resource block;
  Generating a specific control channel for each communication terminal assigned with at least one resource block;
  Generating an unspecified control channel common to communication terminals assigned with at least one resource block;
  Generating a broadcast channel including broadcast information for notifying a communication terminal;
  Among the plurality of frequency blocks included in the frequency band given to the communication system, the broadcast channel is arranged in the frequency block including the center frequency, and the plurality of frequency blocks included in the frequency band given to the communication system A non-specific control channel, at least one specific control channel, and at least one data channel,
  Transmitting an output signal from the placing step,
  The number of symbols for the portion including at least one specific control channel generated in the step of generating the specific control channel is variable,
  The unspecified control channel generated in the step of generating the unspecified control channel includes information on the number of symbols in a portion including at least one specific control channel generated in the second generation unit. How to send.   The transmission method according to claim 8, wherein the specific control channel generated in the step of generating the specific control channel includes information on a data modulation scheme.   9. The transmission method according to claim 8, wherein the specific control channel generated in the step of generating the specific control channel includes information related to an encoding scheme.   The transmission method according to claim 8, wherein the specific control channel generated in the step of generating the specific control channel includes information on hybrid retransmission control.   The transmission method according to claim 8, wherein the specific control channel generated in the step of generating the specific control channel includes precoding information when a MIMO scheme is used.   13. The transmission method according to claim 8, wherein in the arranging step, at least one data channel is time-multiplexed with respect to an unspecified control channel and at least one specific control channel.   The transmission method according to any one of claims 8 to 13, wherein in the arranging step, a paging channel is arranged similarly to the data channel.

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