KR20070107614A - Method for transmitting and receiving downlink scheduling information in ofdma system - Google Patents

Abstract

A method for transmitting/receiving downlink scheduling information in an OFDMA(Orthogonal Frequency Division Multiple Access) system is provided to reduce the quantity of scheduling information by using a resource block having a minimum resource block index, a maximum resource block index, or a channel with a high quality. A method for transmitting/receiving downlink scheduling information in an OFDMA system includes the steps for allocating at least one of resource blocks comprising downlink resources of the OFDMA system, to each terminal(S200); selecting the resource block for each terminal on the basis of the size of indexes of each allocated resource block(S210); generating scheduling information including terminal resource allocation information and terminal discrimination information, for each terminal(S220); and transmitting the scheduling information of the terminal to each terminal by using the selected resource block(S234).

Description

Method for transmitting and receiving downlink scheduling information in orthogonal frequency division multiple access system {Method for transmitting and receiving downlink scheduling information in OFDMA system}

1 illustrates a structure of a physical resource of an orthogonal frequency division multiplexing (OFDM) system.

2 is a flowchart of a method for transmitting downlink scheduling information in an OFDMA system according to an embodiment of the present invention.

3 is a flowchart illustrating a method for receiving downlink scheduling information in an OFDMA system according to an embodiment of the present invention.

4 illustrates scheduling information and arrangement of the scheduling information according to an embodiment of the present invention.

5 shows scheduling information and arrangement of the scheduling information according to another embodiment of the present invention.

6 illustrates a flowchart of a method for transmitting downlink scheduling information in an OFDMA system according to another embodiment of the present invention.

7 is a flowchart of a method for receiving downlink scheduling information in an OFDMA system according to another embodiment of the present invention.

8 to 10 illustrate arrangement of second scheduling information and the second scheduling information according to an embodiment of the present invention.

11 illustrates a configuration of scheduling information in each terminal according to an embodiment of the present invention.

12 is a block diagram illustrating a configuration of an apparatus for transmitting downlink scheduling information in an OFDMA system according to an embodiment of the present invention.

13 is a block diagram illustrating a configuration of an apparatus for receiving downlink scheduling information in an OFDMA system according to an embodiment of the present invention.

The present invention relates to downlink control information transmission in an OFDMA system, and more particularly, to a method and apparatus for a base station to efficiently transmit downlink scheduling information in an OFDMA system and a terminal to receive the downlink scheduling information. will be.

1 illustrates a structure of a physical resource of an orthogonal frequency division multiplexing (OFDM) system.

The unit resource used for transmission and reception in the OFDMA system is a subcarrier, and as shown in FIG. 1, each subcarrier may be represented by a coordinate of time / frequency resource space. In particular, the OFDMA system allocates resources to the UE in units of resource blocks by setting a resource block composed of a predetermined number of subcarriers for convenience of resource management.

Referring to FIG. 1, one subframe has N OFDM symbol lengths on a time axis, and all resources in the subframe are composed of N _PRB resource blocks in total. Each resource block is composed of M subcarriers on the frequency axis and N OFDM symbols on the time axis.

Resource allocation for each terminal of the base station is performed in units of resource blocks. In order for the base station to transmit data through the downlink to the terminal, the base station should inform the terminal of control information such as physical resource allocation information and data transmission format. The base station transmits the above-described control information through a separate control channel, and the terminal uses the control information transmitted through the control channel to determine the location of the physical resource allocated to the base station and obtain information necessary for demodulation of the data. Through this process, data can be demodulated. The present invention provides a method for efficiently configuring and transmitting downlink scheduling information when an eNB allocates radio resources to a UE through downlink and transmits data.

The downlink scheduling information includes identification information for terminal identification, resource allocation information, additionally necessary additional control information, and an Error Correction Code bit for detecting a reception error of the aforementioned information. Here, the error correction code may be a cyclic redundancy check code.

If the amount of control information such as the above-mentioned scheduling information is excessively large, the amount of resources used for data transmission decreases and the data rate decreases. Therefore, there is a need for a method of maximizing a data rate by transmitting minimum control information. In addition, in minimizing control information, it should not impair the efficiency of system operation.

One conventional method of transmitting resource allocation information is a bitmap based transmission scheme. That is, in order to express resource allocation information, a bitmap scheme is used. When each resource block is allocated to the terminal, the bit value corresponding to the resource block is set to '1', otherwise, the bit value corresponding to the resource block is set to '0', so that the resource allocation information is in the form of a bitmap. (Or, if the terminal is allocated to the terminal, the bit value corresponding to the resource block may be set to '0', otherwise the bit value corresponding to the resource block may be set to '1'.)

For example, if all resources in a subframe consist of a total of N resource blocks, N-bit bitmaps are used for each UE for resource allocation information. That is, since the bitmap is used for each terminal, when the number of resource allocation terminals is M, the size of the total bitmap information used for providing the resource allocation information for the M terminals in the aforementioned OFDMA system is MxN bits. .

Another conventional method of transmitting resource allocation information is to place control information of a terminal allocated with the resource block in each resource block. In the present specification, this method is referred to as 'same location control information transmission scheme' for convenience. For example, when UE A is allocated the third and fifth resource blocks among N resource blocks, the base station controls UE A with respect to predetermined downlink resources belonging to each of the third and fifth resource blocks. To locate information. Here, the control information of the terminal A located with respect to the predetermined downlink resources may include a terminal identifier of the terminal A. The terminal A can know the resource block allocated from the position where the control information is placed even without the separate resource allocation information such as the bitmap.

In the above-described bitmap-based transmission scheme, there is no particular limitation in allocating a plurality of resource blocks, such as limiting the degree of freedom of resource allocation. However, when the number of resource blocks is large, the size of the bitmap increases, and when the number of terminals allocated to resources is large, there is a problem that the amount of control information indicating the resource allocation increases.

On the other hand, the same location control information transmission method described above has an advantage that resource allocation information is not required at all. However, in the case of allocating resource blocks that do not neighbor the same terminal, the amount of control information increases because the terminal identifier of the same terminal must be disposed and transmitted for each allocated resource block. In addition, when there is a restriction that allocates only resource blocks that are adjacent to each other, control information can be reduced, but the limitation of assigning only resource blocks that are adjacent to each other reduces the degree of scheduling freedom, thereby reducing the data transmission rate of the entire system. There is this.

Accordingly, there is a need for a method of efficiently configuring and transmitting / receiving scheduling information such as resource allocation information without limiting allocation of only neighboring resource blocks.

An object of the present invention is to provide a method for transmitting / receiving downlink scheduling information in an OFDMA system capable of reducing the amount of downlink resources used for transmitting scheduling information without reducing the degree of scheduling freedom.

In order to achieve the above technical problem, a method for transmitting downlink scheduling information in an OFDMA system according to the present invention is provided, and among at least one resource block composed of downlink resources of an OFDMA system, at least one resource block is allocated to each terminal. Allocation step; Selecting, for each terminal, a resource block from the allocated resource blocks based on the resource block index size of each resource block; Generating, for each terminal, scheduling information including resource allocation information of the terminal and identification information for identifying the terminal; And transmitting, to each terminal, the scheduling information of the terminal by using the selected resource block.

Preferably, the selecting step, characterized in that for selecting the resource block having a minimum resource block index among the resource blocks allocated to the terminal.

Preferably, the resource allocation information, characterized in that it comprises information indicating whether resource blocks having a resource block index larger than the resource block index of the selected resource block is allocated to the terminal.

Preferably, the resource allocation information is characterized in that the bitmap consisting of a binary value indicating whether each resource block having a resource block index larger than the resource block index of the selected resource block is allocated to the terminal.

Preferably, the selecting step, characterized in that for selecting the resource block having the maximum resource block index among the resource blocks allocated to the terminal.

Preferably, the resource allocation information is characterized in that information indicating whether resource blocks having a resource block index smaller than the resource block index of the selected resource block is allocated to the terminal.

Preferably, the resource allocation information is characterized in that the bitmap consisting of a binary value indicating whether each resource block having a resource block index smaller than the resource block index of the selected resource block is allocated to the terminal.

The scheduling information may further include a cyclic redundancy check (CRC) bit.

Preferably, the identification information is characterized in that the terminal identifier.

Preferably, the identification information is characterized in that the CRC bit generated to identify the terminal.

Preferably, the scheduling information, characterized in that it further comprises a transport format (transport format).

Preferably, the transmission format includes information on a modulation scheme, multi-antenna related information, and payload size.

Preferably, the transmitting step, the channel coding step of channel coding the scheduling information of the terminal; And a resource block transmission step of transmitting the channel-encoded scheduling information using the selected resource block.

Preferably, the channel encoding step is characterized by performing a separate encoding method for channel encoding the scheduling information for each terminal.

Preferably, each resource block is characterized by consisting of at least one downlink resource belonging to a time and a predetermined frequency band according to a predetermined number of OFDM symbols.

Preferably, each resource block is characterized by consisting of a plurality of downlink resources continuous in time or frequency according to the centralized resource allocation scheme.

Preferably, each resource block is characterized by consisting of a plurality of downlink resources, without being bound to continuity in time and frequency, according to a distributed resource allocation scheme.

In addition, in order to achieve the above technical problem, among the resource blocks consisting of downlink resources of the OFDMA system, allocating at least one resource block to each terminal; Selecting, for each terminal, resource blocks based on channel quality of each resource block among the allocated resource blocks; Generating, for each terminal, scheduling information including resource allocation information of the terminal and identification information for identifying the terminal; And transmitting, to each terminal, a scheduling step of transmitting scheduling information of the terminal by using a selected resource block.

Preferably, the selecting step, characterized in that for selecting the resource block having the highest quality among the resource blocks allocated to the terminal.

Preferably, the resource allocation information is characterized in that the information indicating whether the remaining resource blocks other than the selected resource block among the resource blocks are allocated to the terminal.

Preferably, the resource allocation information, characterized in that the bitmap consisting of a binary value indicating whether each of the remaining resource blocks are allocated to the terminal.

The scheduling information may further include a cyclic redundancy check (CRC) bit.

Preferably, the identification information is characterized in that the terminal identifier.

Preferably, the identification information is characterized in that the CRC bit generated to identify the terminal.

Preferably, the scheduling information, characterized in that it further comprises a transport format (transport format).

Preferably, the transmission format includes information on a modulation scheme, multi-antenna related information, and payload size.

Preferably, the transmitting step, the channel coding step of channel coding the scheduling information of the terminal; And a resource block transmission step of transmitting the channel-encoded scheduling information using the selected resource block.

Preferably, the channel encoding step is characterized by performing a separate encoding method for channel encoding the scheduling information for each terminal.

Preferably, each resource block is characterized by consisting of at least one downlink resource belonging to a time and a predetermined frequency band according to a predetermined number of OFDM symbols.

Preferably, each resource block is characterized by consisting of a plurality of downlink resources continuous in time or frequency according to the centralized resource allocation scheme.

Preferably, each resource block is characterized by consisting of a plurality of downlink resources, without being bound to continuity in time and frequency, according to a distributed resource allocation scheme.

Hereinafter, a method and an apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

As described above, the unit resource used for transmitting and receiving in the OFDMA system is a subcarrier (subcarrier), each subcarrier may be represented by the coordinates of the time / frequency resource space, in particular, the OFDMA system, for convenience of resource management, A resource block composed of a predetermined number of subcarriers is set. The resource block may be classified into a physical resource block and a virtual resource block, but the present invention may be applied regardless of such division. Therefore, in the following description, a resource block includes both a physical resource block and a virtual resource block within a range that is not contrary to the meaning.

Types of resource blocks are classified into sizes and types. The size means the total number of time / frequency resources constituting the resource block, and the type means a form in which time / frequency resources constituting the resource block are distributed in the time / frequency resource space. The present invention considers two types, localized resource blocks and distributed or scattered resource blocks. Unit resources constituting the centralized resource block are concatenated with each other in the time / frequency resource space. On the other hand, the unit resources constituting the distributed resource block are located at a distance in the time / frequency resource space.

The centralized resource block scheme is physically taken in the form of a block in the time / frequency resource space, and thus may be easier than the distributed resource block in order to understand the present invention. It will be described the present invention by using. However, if both the base station and the terminal share information on which downlink resources each resource block is made up of each downlink resource, distributed as well as the centralized resource block scheme only by transmitting the index or identifier for each resource block It can be easily understood by those skilled in the art that the type resource block method can be easily applied to the present invention.

Information included in the downlink scheduling information transmitted through the present invention includes identification information for identifying a terminal, resource allocation information, additional control information, an error detection code, and the like. Identification information for identifying a terminal may include a terminal identifier, but a CRC bit according to a CRC code, which is a kind of error detection code, may replace the terminal identifier. That is, the identification information may be represented by using a terminal-specific CRC bit so that the CRC bit may replace the terminal identifier. The resource allocation information indicates the location information of the resource block allocated to the terminal, which will be described later. The additional control information includes transport format information and HARQ (Hybrid Automatic Repeat Request) related information. Examples of the transmission format information may include modulation scheme information, multi-antenna related information, payload size information, and the like.

Meanwhile, the scheduling information includes channel coding using forward error correction (FEC) codes, such as convolutiona code, turbo code, and low density parity check (LDPC) code. It may be transmitted to each terminal in the form.

Channel coding schemes for control information such as scheduling information may include a separate coding scheme and a group or joint coding scheme. In the individual encoding method, after all control information is separated for each terminal, channel coding is independently applied to the control information of each terminal. On the other hand, the coding scheme for each group is a method of classifying the terminals into several groups, and grouping the control information corresponding to each group and applying channel coding.

Individual coding schemes have the advantage of being able to suitably control the transmission power of control information for each terminal. In general, since the channel environment is different for each terminal, it is effective to use an appropriate transmission power for each terminal by performing an individual encoding scheme. On the other hand, the coding method for each group collects control information of various terminals and applies channel coding for each group, so that the coding block is large and the coding gain is increased.

In relation to the above-described channel coding scheme, the present invention provides Embodiment A, which performs channel coding on scheduling information by using an individual coding scheme, and separates scheduling information into first scheduling information and second scheduling information, and thus, the first scheduling information. For example, the present invention includes Embodiment B, which applies a coding scheme according to a group and applies an individual coding scheme to the second scheduling information.

2 is a flowchart of a method for transmitting downlink scheduling information in an OFDMA system according to an embodiment of the present invention. That is, FIG. 2 is a flowchart for explaining Embodiment A described above.

Referring to FIG. 2, in step S200, the base station allocates at least one resource block to each terminal among resource blocks configured as downlink resources of the OFDMA system. Here, each resource block includes a time according to a predetermined number of OFDM symbols and at least one downlink resource belonging to a predetermined frequency band.

Here, as a method of configuring a resource block with downlink resources, there are a centralized resource allocation method and a distributed resource allocation method as described above. According to the centralized resource allocation scheme, each resource block includes a plurality of downlink resources contiguous in time or frequency. According to the distributed resource allocation scheme, each resource block is composed of a plurality of downlink resources without being bound to continuity in time and frequency, and is generally made up of downlink resources distributed in time and frequency.

In step S210, the base station selects a resource block from the allocated resource blocks based on the index size or channel quality of each resource block for each terminal.

The case of selecting based on the index size of each resource block will be described in more detail. Each resource block included in one subframe has an index numbered sequentially according to a promised method. However, the numbering of resource blocks does not necessarily need to be sequential on the frequency axis. This is because each resource block is numbered according to a predetermined rule and the numbering information of the resource block is shared between the base station and the terminal, so that the location of the resource block indicated by the number is sufficient.

In step S210, when several resource blocks are allocated to one terminal, when selecting one of the resource blocks to be used for transmission of scheduling information, the resource block is selected based on the size of the index.

Here, an example of a method of selecting an resource block based on the index size of the resource block may include selecting a resource block having a minimum resource block index among the resource blocks allocated to the terminal. This is called Example A-1 for convenience. Example A-1 will be described in more detail with reference to FIG. 4.

In addition, another example of a method of selecting a resource block based on an index size of the resource block may include selecting a resource block having a maximum resource block index among resource blocks allocated to the terminal. This is called Example A-2 for convenience.

In addition, another example of a method of selecting a resource block based on the channel quality of the resource block may be to select the resource block having the highest channel quality among the resource blocks allocated to the terminal. This is called Example A-3 for convenience. Example A-3 will be described in more detail with reference to FIG. 5.

In step S220, the base station generates, for each terminal, scheduling information including resource allocation information of the terminal and identification information for identifying the terminal. Preferably, the resource allocation information is information indicating whether, among the resource blocks, resource blocks larger than or smaller than the index of the selected resource block or the selected resource block except the selected resource block are allocated to the terminal. Also, preferably, such resource allocation information may be represented by the above-described bitmap method.

Preferably, the scheduling information further includes a transport format. Here, examples of the information included in the transmission format may include information on a modulation scheme, multiple antenna related information, and payload size.

Preferably, the scheduling information further includes a Cyclic Redundancy Check (CRC) bit.

The identification information will generally be in the form of a terminal identifier, but if the above-described CRC bit is generated to identify the terminal, there is no need to transmit the terminal identifier.

In step S230, the base station transmits scheduling information of the terminal to each terminal using the selected resource block. Referring to FIG. 2, step S230 includes a channel encoding step S232 and a resource block transmission step S234.

In step S232, the base station channel-codes the scheduling information of each terminal. In this case, the channel encoding scheme uses an individual encoding scheme for channel encoding scheduling information for each terminal.

In step S234, the base station transmits the channel-encoded scheduling information using the selected resource block. Specifically, the base station transmits the channel-encoded scheduling information by using downlink resources located at a specific position among downlink resources belonging to the selected resource block, and uses the remaining downlink resources for transmission of downlink traffic data. . If the specific location on which the scheduling information is loaded is also known to the terminals, each terminal performs demodulation on the downlink resources of the specific location of each resource block to check whether there is scheduling information for itself.

3 is a flowchart illustrating a method for receiving downlink scheduling information in an OFDMA system according to an embodiment of the present invention. That is, FIG. 3 is a flowchart illustrating a method of receiving downlink scheduling information corresponding to the embodiment of FIG. 2.

Referring to FIG. 3, in step S300, a resource block including scheduling information including resource allocation information of the terminal and identification information for identifying the terminal, is received from the received OFDM symbols including a plurality of resource blocks by the terminal. Is detected based on the index size of each resource block or channel quality.

This is to perform demodulation on a resource at a specific position of every resource block to detect an resource block having its own scheduling information. Preferably, when the scheduling information is transmitted by selecting a resource block having the smallest resource block index in the transmission system, the index is detected in the order of receiving blocks having the smallest index from the largest receiving block, and resource blocks having the largest resource block index. When the scheduling information is selected and transmitted, it can be detected in the reverse order from the receiving block having the large index to the receiving block having the smallest index.

In the case of detection based on channel quality, the remaining resource blocks except for the best channel quality resource block may be sequentially detected.

An example of a method of determining whether the terminal is an RB including its own scheduling information may include a method of determining that the terminal is an RB including scheduling information of the terminal when the demodulation result includes identification information of the terminal. Here, examples of the identification information may include a terminal identifier and a CRC bit generated to identify the terminal.

On the other hand, if the base station performs channel coding to transmit the scheduling information, the terminal performs a channel decoding on the demodulated result to detect the resource block having its own scheduling information.

In step S310, the terminal detects its own scheduling information from the detected resource block. Thereafter, the terminal demodulates the resources of the resource block according to the resource allocation information included in the detected scheduling information and the remaining resources of the detected resource block. In particular, if the scheduling information includes a transmission format, the terminal performs demodulation or the like based on the transmission format.

4 illustrates scheduling information and arrangement of the scheduling information according to an embodiment of the present invention. That is, FIG. 4 illustrates the arrangement of scheduling information used in the embodiments of FIGS. 2 and 3 and scheduling information using the minimum resource block index (Example A-1).

Assume that the resource space considered for resource allocation is composed of a total of N _PRB resource blocks. First, a total of N _PRB resource blocks are numbered. In FIG. 4, for convenience, the sequential numbers of 1, 2, 3, ..., N _PRBs are allocated to resource blocks from left to right, but the numbering of resource blocks does not necessarily need to be sequential on the frequency axis. This is because each resource block is numbered according to a predetermined rule and the numbering information of the resource block is shared between the base station and the terminal, so that the physical location of the resource block indicated by the number is sufficient.

Referring to FIG. 4, Example A-1 will be described. The location information of the resource block included in the scheduling information according to the embodiment A-1 is the location information of the resource block having the minimum resource block index among the resource blocks allocated to each terminal. In addition, the resource allocation information according to the embodiment A-1 indicates whether resource blocks having a resource block index larger than the minimum resource block index are allocated to the terminal, which can be represented by a bitmap.

4 illustrates a location and a bitmap of scheduling information in a band having 12 resource blocks. In the case of FIG. 4, since UE 3 is allocated resource blocks 4, 5, 6, 8, and 9, the resource block having the smallest resource block index is resource block 4. Therefore, the scheduling information for the terminal 3 is located in a specific resource in resource block 4. The scheduling information for the terminal 3 includes a bitmap 11011000 consisting of 8 bits. Each bit of the bitmap corresponds to one or more resource blocks (index 5 to index 12) having an index greater than 4 to indicate whether each resource block is allocated.

That is, the 8-bit bitmap for the terminal 3 indicates whether the terminal 3 is allocated from the index 5 to the index 12. In the embodiment of FIG. 4, the bitmap stored at index 4 indicates that a resource block corresponding to indexes 5, 6, 8, and 9 except 4 is allocated to UE3.

In the bitmap according to the embodiment of FIG. 4, an allocated resource block is marked with '1' and an unallocated resource block is marked with '0'. In general, when the total number of resource blocks constituting the resource is N, if the order of the resource block having the smallest order among the T resource blocks allocated by a terminal is T, the scheduling information of the terminal is a resource of the order T The bitmap located in the block and representing resource allocation consists of (NT) bits. Each bit of the bitmap corresponds one-to-one to resource blocks whose sequence is greater than T. That is, each bit of the bitmap sequentially corresponds one-to-one with respect to the resource block whose order is (T + 1) to the resource block whose order is the last order N.

For example, in the embodiment of Fig. 4, the total number of resource blocks N = 12, the sequence number T = 4 scheduling information is located in the resource block (NT) = (12-4) = 8-bit bitmap is formed It will be.

Although not shown, arrangement of scheduling information using the largest resource block index (Example A-2) may be easily implemented by those skilled in the art.

4, since the terminal 2 is allocated resource blocks 3 and 7, the resource block having the largest resource block index is resource block 7. Therefore, the scheduling information for the terminal 2 is located in a specific resource in resource block 7. The scheduling information for the terminal 2 includes a bitmap consisting of 6 bits. Each bit of the bitmap corresponds to one or more other resource blocks (index 1 to index 6) having an index smaller than 7 to indicate whether each resource block is allocated.

In the bitmap according to the embodiment of FIG. 4, an allocated resource block is marked with '1' and an unallocated resource block is marked with '0'. In general, when the total number of resource blocks constituting the resource is N, if the sequence number of the resource block having the largest sequence number among S resource blocks allocated by a terminal is T, the scheduling information of the terminal is the resource number T The bitmap located in the block and representing resource allocation consists of (T-1) bits. Each bit of the bitmap corresponds one-to-one to resource blocks whose sequence is greater than T. That is, each bit of the bitmap sequentially corresponds one-to-one with respect to a resource block having a sequence number 1 to a resource block having a (T-1) order.

For example, in the above embodiment, the total number of resource blocks N = 12, the sequence number T = 7 scheduling information is located in the resource block (T-1) = (7-1) = 6-bit bitmap is formed It will be.

5 illustrates scheduling information and arrangement of the scheduling information according to an embodiment of the present invention. That is, FIG. 4 illustrates the arrangement of scheduling information used in the embodiments of FIGS. 2 and 3 and scheduling information using the highest channel quality (Example A-3).

As above, the resource space considered for resource allocation is composed of a total of N _PRB resource blocks. First, a total of N _PRB resource blocks are numbered. In FIG. 5, for convenience, the sequential numbers of 1, 2, 3, ..., N _PRBs are allocated to resource blocks from left to right, but the numbering of resource blocks is not necessarily sequential on the frequency axis. This is because each resource block is numbered according to a predetermined rule and the numbering information of the resource block is shared between the base station and the terminal, so that the physical location of the resource block indicated by the number is sufficient.

Referring to FIG. 5, Example A-3 will be described. The location information of the resource block included in the scheduling information according to the embodiment A-3 is the location information of the resource block having the highest channel quality among the resource blocks allocated to each terminal. In addition, the resource allocation information according to the embodiment A-3 indicates whether resource blocks other than the resource block having the highest channel quality are allocated to the terminal, which can be represented by a bitmap.

5 illustrates a location and a bitmap of scheduling information in a band having 12 resource blocks. In the case of FIG. 5, UE 3 is allocated resource blocks 4, 5, 6, 8, and 9. Herein, it is assumed that the resource block having the highest channel quality is resource block 5, and the scheduling information for UE 3 is located in a specific resource in resource block 5. Here, unlike the embodiments A-1 and A-2 using the index, the scheduling information always includes a bitmap consisting of allocated resource blocks-corresponding to the number of 1-where (12-1) = 11-bits. do. Each bit of the bitmap corresponds to one-to-one resource block other than number 5 to indicate whether each resource block is allocated.

In the bitmap according to the embodiment of FIG. 5, an allocated resource block is marked with '1' and an unallocated resource block is marked with '0'. In general, when the total number of resource blocks constituting the resource is N, the scheduling information of the terminal is located in the resource block having the highest channel quality, and the bitmap indicating resource allocation is composed of (N-1) bits. Each bit of the bitmap corresponds one-to-one to resource blocks except for the resource block having the highest channel quality for each terminal.

4 illustrates the configuration of scheduling information in each terminal according to an embodiment of the present invention.

4 specifically illustrates an example in which 12 resource blocks are allocated to 6 terminals. According to this embodiment, the number of resource blocks allocated to each terminal and the location of scheduling information are shown in Table 1. That is, the scheduling information is sent to the resource block having the minimum resource block index among the resource blocks allocated by each terminal.

Terminal Resource block number allocated Resource block number where scheduling information is located Bitmap size (bits) UE1 1, 2 One 11 UE2 3, 7 3 9 UE3 4, 5, 6, 8, 9 4 8 UE4 10 10 2 UE5 11 11 One UE6 12 12 0

Referring to Table 1, UE, UE2, UE3, UE4, UE5, UE1, UE2, UE3, UE5, respectively, are located at positions of resource blocks 1, 3, 4, 10, 11, and 12 having the smallest index numbers among the allocated resource blocks in the example of FIG. It can be seen that scheduling information of UE6 is carried. The portion where no scheduling information is carried may be used for data transmission.

The size of the bitmap for each terminal is variable depending on the index number of the resource block carrying the scheduling information. If the minimum index number of the allocated resource block is 1, the size of the bitmap is the largest 11 bits. The larger the minimum index number is, the smaller the size of the bitmap is. Therefore, when the minimum index number is 12, the size of the bitmap is 0 bits. Each bit of the bitmap corresponds one-to-one with resource blocks having an index larger than that of the resource block in which the scheduling information exists.

In the same manner, referring to FIG. 4, Example A-2 will be described. The location information of the resource block included in the scheduling information according to the embodiment A-2 is the location information of the resource block having the largest resource block index among the resource blocks allocated to each terminal. In addition, the resource allocation information according to the embodiment A-2 indicates whether resource blocks having a resource block index smaller than the maximum resource block index are allocated to the terminal, which can be represented by a bitmap.

Below, the number of resource blocks allocated to each terminal and the location of scheduling information according to embodiment A-2 are expressed through Table 2.

Terminal Resource block number allocated Resource block number where scheduling information is located Bitmap size (bits) Bitmap Configuration UE1 1, 2 2 One One UE2 3, 7 7 6 001000 UE3 4, 5, 6, 8, 9 9 8 00011101 UE4 10 10 9 000000000 UE5 11 11 10 0000000000 UE6 12 12 11 000000000000

At the far right, a bitmap configuration according to Example A-2 was added.

FIG. 5 exemplarily illustrates a case in which a resource block having the highest channel quality is selected in selecting a resource block for loading scheduling information when allocating 12 resource blocks to five terminals. According to this embodiment, the number of resource blocks allocated to each terminal and the location of scheduling information are shown in Table 3. That is, the scheduling information is sent to the resource block having the minimum resource block index among the resource blocks allocated by each terminal.

Terminal Resource block number allocated Resource block number where scheduling information is located Bitmap size (bits) UE1 1, 2 2 11 UE2 3, 7 7 11 UE3 4, 5, 6, 8, 9 5 11 UE4 10 10 11 UE5 11, 12 12 11

Referring to Table 3, the UEs 1, 3, 4, 10, 11, and 12 of the resource blocks having the smallest index number among the allocated resource blocks in the example of FIG. 5, respectively, UE UE1, UE2, UE3, UE4, UE5, It can be seen that scheduling information of UE6 is carried. The portion where no scheduling information is carried may be used for data transmission.

The size of the bitmap for each terminal is always constant. That is, the number of allocated resource blocks is -1. Each bit of the bitmap corresponds one-to-one with resource blocks other than the resource block in which the scheduling information exists.

The resource allocation information configuration and transmission method described above can be applied in various forms. For example, the above-described resource allocation information configuration and transmission method may be applied to a total frequency band operated by an OFDMA system. The total frequency band may be divided into a plurality of subbands, and independent resource allocation may be performed on a subband basis. You can also do it. In this case, the above-described method may be applied independently for each subband.

In the above, the case where the individual channel coding scheme is applied to the terminal control information has been described. Hereinafter, a case in which the group channel coding method is applied will be described.

6 is a flowchart of a method for transmitting downlink scheduling information in an OFDMA system according to another embodiment of the present invention. That is, FIG. 6 is a flowchart for describing Embodiment B of channel coding scheduling information using the group channel coding scheme described above.

Referring to FIG. 6, in step S600, the base station allocates at least one resource block to each terminal among resource blocks configured of downlink resources of the OFDMA system.

In step S610, the base station selects, for each terminal, from among the allocated resource blocks according to a predetermined condition. Here, examples of the resource block selection method may include selecting a resource block having a minimum resource block index among resource blocks allocated to the terminal, selecting a maximum resource block index among resource blocks allocated to the terminal, and A method of selecting a resource block of the highest quality among the resource blocks allocated to the terminal may be mentioned. Examples according to this selection method are referred to herein as Examples B-1, B-2, and B-3 for convenience.

In step S620, the base station generates first scheduling information including identification information for identifying each terminal and location information of a resource block selected for each terminal, and for each terminal, resource allocation of the terminal Generate second scheduling information including the information.

Preferably, the second scheduling information includes additional control information. The additional control information includes a transport format. Here, examples of the information included in the transmission format may include information on a modulation scheme, multiple antenna related information, and payload size.

Advantageously, said second scheduling information further comprises a cyclic redundancy check (CRC) bit.

The identification information will generally be in the form of a terminal identifier, but if the above-described CRC bit is generated to identify the terminal, there is no need to transmit the terminal identifier.

According to embodiment B-1, the resource allocation information is information indicating whether resource blocks having an resource block index larger than that of the selected resource block are allocated to the terminal. According to embodiment B-2, the resource allocation information is information indicating whether resource blocks having an resource block index smaller than that of the selected resource block are allocated to the terminal. According to embodiment B-3, the resource allocation information is information indicating whether resource blocks other than the selected resource block are allocated to the terminal. Also preferably, such resource allocation information may be represented by the above-described bitmap method.

In step S630, the base station transmits the first scheduling information using a predetermined downlink resource, and for each terminal, transmits the second scheduling information of the terminal using the selected resource block. Herein, the base station and the terminal share a rule about a resource location where the second scheduling information may exist in every resource block, and likewise, the location of the predetermined downlink resource used for the transmission of the first scheduling information is shared with the base station. If the terminal is shared, the terminal subsequently demodulates the predetermined downlink resource to detect the resource block in which the second scheduling information is located, and demodulates the resource position according to the rule defined in the detected resource block. To detect the second scheduling information.

Step S630 includes a channel encoding step S632 and a resource block transmission step S634.

In step S632, the base station performs channel encoding for channel encoding the first scheduling information and the second scheduling information. Preferably, the base station performs a group-by-group encoding method for group-coding the first scheduling information of all terminals, and performs an individual encoding method for channel-coding the second scheduling information for each terminal.

In step S634, the base station transmits the channel-encoded first scheduling information by using a predetermined downlink resource, and for each terminal, the channel-encoded second scheduling information of the terminal by using the selected resource block. send.

7 illustrates a flowchart of a method for receiving downlink scheduling information in an OFDMA system according to another embodiment of the present invention. That is, FIG. 7 is a flowchart illustrating a method of receiving downlink scheduling information corresponding to the embodiment of FIG. 6.

Referring to FIG. 7, in step S700, the terminal detects first scheduling information from received OFDM symbols including a plurality of resource blocks, each of which includes at least one downlink resource. The location of the downlink resource where the first scheduling information is located is to obtain the first scheduling information by demodulating the downlink resource in a state in which the terminal is previously known.

In step S710, the terminal is based on the location information of the resource block containing the identification information and the second scheduling information for identifying the terminal included in the first scheduling information, the resource block containing the second scheduling information. Is detected.

That is, since the first scheduling information includes the terminal identifier of each terminal and the location information of the resource block in which the second scheduling information of each terminal exists, the terminal selects the resource block in which its second scheduling information exists. Can be detected.

In step S720, the terminal demodulates a resource of a predetermined position of the detected resource block to detect the second scheduling information. Thereafter, the terminal demodulates the resources of the resource block according to the resource allocation information included in the detected second scheduling information and the remaining resources of the detected resource block. In particular, if the second scheduling information includes a transport format, the terminal performs demodulation or the like based on the transport format.

Meanwhile, if the base station performs channel coding on the first scheduling information and the second scheduling information and transmits the channel information, the terminal performs channel decoding on the result demodulated in step S700 to detect the resource block having its second scheduling information. Similarly, the second scheduling information is detected by performing channel decoding on the result demodulated in step S720.

8 to 10 illustrate arrangement of second scheduling information and the second scheduling information according to an embodiment of the present invention. That is, FIGS. 8, 9 and 10 illustrate the arrangement of the second scheduling information and the second scheduling information used in the embodiments B-1, B-2 and B-3.

The first scheduling information includes a terminal identifier of each terminal belonging to a group corresponding to the first scheduling information, and location information of a resource block in which second scheduling information of each terminal exists. Here, an example of the location information of the resource block may be a number or index of the resource block. As described above, the second scheduling information includes resource allocation information and additional control information of the terminal.

Referring to FIG. 8, Example B-1 will be described below. The location information of the resource block included in the first scheduling information according to the embodiment B-1 is the location information of the resource block having the smallest resource block index among the resource blocks allocated to each terminal. In addition, the resource allocation information according to the embodiment B-1 indicates whether resource blocks having a resource block index larger than the minimum resource block index are allocated to the terminal, which can be expressed as a bitmap.

8 illustrates a location and a bitmap of second scheduling information in a band having 12 resource blocks. In the case of FIG. 8, since UE A is allocated resource blocks 3, 6, 7, 10, the resource block having the smallest resource block index is resource block 3. Therefore, the second scheduling information for the terminal A is located in a specific resource in resource block # 3. The second scheduling information for the terminal A includes a bitmap consisting of 9 bits. Each bit of the bitmap corresponds one-to-one to other resource blocks having an index greater than 3, indicating whether each resource block is allocated.

In the bitmap according to the embodiment of FIG. 8, an allocated resource block is marked with '1' and an unallocated resource block is marked with '0'.

In general, when the total number of resource blocks constituting the resource block set is N, if the order of the resource block having the highest quality among the S resource blocks allocated to a terminal is T, the second control information of the terminal is sequentially A bitmap located in this T resource block and indicating resource allocation is composed of (N-1) bits. Each bit of the bitmap corresponds one-to-one to (N-1) resource blocks except for a resource block of sequence T.

Referring to FIG. 9, Example B-2 will be described. The location information of the resource block included in the first scheduling information according to the embodiment B-2 is the location information of the resource block having the largest resource block index among the resource blocks allocated to each terminal. In addition, the resource allocation information according to the embodiment B-2 indicates whether resource blocks having a resource block index smaller than the maximum resource block index are allocated to the terminal, which can be represented by a bitmap.

9 illustrates a location and a bitmap of second scheduling information in a band having 12 resource blocks. In the case of FIG. 9, since UE A is allocated resource blocks 3, 6, 7, 10, the resource block having the largest resource block index is resource block 10. Therefore, the second scheduling information for the terminal A is located in a specific resource in resource block # 10. The second scheduling information for the terminal A includes a bitmap consisting of 9 bits. Each bit of the bitmap corresponds to one-to-one corresponding to other resource blocks having an index smaller than 10, indicating whether each resource block is allocated.

In the bitmap according to the embodiment of FIG. 9, an allocated resource block is indicated by '1' and an unallocated resource block is indicated by '0'.

In general, when the total number of resource blocks constituting the resource is N, if the sequence number of the resource block having the largest sequence number among the S resource blocks allocated to a terminal is T, the second scheduling information of the terminal has a sequence number A bitmap located in a resource block of T and indicating resource allocation consists of (T-1) bits. Each bit of the bitmap corresponds one-to-one to resource blocks whose sequence is less than T.

Referring to FIG. 10, Example B-3 will be described below. The location information of the resource block included in the first scheduling information according to the embodiment B-3 is the location information of the resource block having the highest quality among the resource blocks allocated to each terminal. In addition, the resource allocation information according to the embodiment B-3 indicates whether to allocate the remaining resource blocks except for the resource block indicated by the first scheduling information, which can be expressed as a bitmap.

In detail, FIG. 10 illustrates a location and a bitmap of second scheduling information in a band having 12 resource blocks. In the case of FIG. 10, UE A is allocated resource blocks 3, 6, 7, and 10 and resource block 6 is the best quality resource block. Therefore, the first scheduling information includes the terminal identifier of the terminal A and the location information of resource block 6 corresponding to the terminal identifier of the terminal A. The second control information for the terminal A is located in a specific resource in resource block six. The second scheduling information for the terminal A includes a bitmap of 11 bits. Each bit of the bitmap corresponds one-to-one to the remaining resource blocks except resource block 6 to indicate whether each resource block is allocated to the terminal A. FIG.

In the bitmap according to the exemplary embodiment of FIG. 10, an allocated block is marked as '1', and a block which is not allocated is marked as '0'.

In general, when the total number of resource blocks constituting the resource block set is N, if the order of the resource block having the highest quality among the S resource blocks allocated to a terminal is T, the second control information of the terminal is A bitmap located in a resource block having a sequence number T and indicating resource allocation consists of (N-1) bits. Each bit of the bitmap corresponds one-to-one to (N-1) resource blocks except for a resource block of sequence T.

11 illustrates a configuration of scheduling information in each terminal according to another embodiment of the present invention. That is, FIG. 11 illustrates the arrangement of scheduling information and scheduling information used in the embodiment of FIGS. 8 to 10.

Referring to FIG. 11, the configuration of control information when channel coding is applied in the same resource allocation situation as in FIG. 4 is shown. Since the resource space considered for resource allocation is composed of 12 resource blocks, the group scheduling information is composed of 12 information paragraphs. The size of the entire group scheduling information is fixed regardless of the total number of terminals receiving the actual resource allocation.

In the example of FIG. 11, since resource blocks 1 and 2 are allocated to UE 1, the ID of UE 1 is carried in information paragraphs 1 and 2. In the case of UE 3, since resource blocks 4, 5, 6, 8, and 9 are allocated, the information paragraphs 4, 5, 6, 8, and 9 have an ID of UE 3. In this way, each terminal can determine the location of the information block allocated to it by identifying the location of the information paragraph in which its identification information is located. Since the size of the entire control information is fixed, the terminal does not need to repeatedly demodulate in consideration of various sizes.

12 is a diagram illustrating a configuration of an apparatus for transmitting downlink scheduling information in an OFDMA system according to an embodiment of the present invention.

Referring to FIG. 12, the apparatus for transmitting downlink scheduling information 1200 according to the present invention includes a resource block allocator 1210, a resource block selector 1220, a scheduling information generator 1230, and a transmitter 1240. Include.

In more detail, the resource block allocator 1210 allocates at least one resource block to each terminal among resource blocks configured of downlink resources of an orthogonal frequency division multiple access system.

The resource block selector 1220 selects, for each terminal, the resource block among the allocated resource blocks based on the resource block index size or the channel quality of each resource block.

Preferably, the resource block selector 1220 may select a resource block having a minimum resource block index among resource blocks allocated to the terminal. Preferably, the resource allocation information at this time may include information indicating whether resource blocks having a resource block index larger than that of the selected resource block are allocated to the terminal. For more detailed method of transmitting the scheduling information by selecting the resource block having the minimum resource block index, refer to the description of FIG. 2. In addition, refer to description of FIG. 4 and FIG. 8 for the example of the scheduling information and arrangement | positioning of the said scheduling information in this case.

Preferably, the resource block selector 1220 may select a resource block having the largest resource block index among resource blocks allocated to the terminal. Preferably, the resource allocation information at this time may include information indicating whether resource blocks having a resource block index larger than that of the selected resource block are allocated to the terminal. For a more detailed method of transmitting the scheduling information by selecting the resource block having the largest resource block index, refer to the description of FIG. 4. In addition, refer to description of FIG. 9 for the example of the scheduling information and arrangement | positioning of this scheduling information in this case.

Preferably, the resource block selector 1220 may select a resource block having the highest channel quality among resource blocks allocated to the terminal. Preferably, the resource allocation information at this time may include information indicating whether resource blocks other than the selected resource block are allocated to the terminal. For a more detailed method of transmitting the scheduling information by selecting the resource block having the highest channel quality, refer to the description of FIG. 5. In addition, refer to description of FIG. 10 for the example of the scheduling information and the arrangement | positioning of the said scheduling information in this case.

The scheduling information generator 1230 generates, for each terminal, scheduling information including resource allocation information of the terminal and identification information for identifying the terminal.

The transmitter 1240 transmits scheduling information of the corresponding terminal to each terminal using the selected resource block. Preferably, the transmitter 1240 includes a channel encoder 1242 for channel encoding the scheduling information of the terminal and a resource block transmitter 1244 for transmitting the channel encoded scheduling information using the selected resource block. can do..

13 is a diagram illustrating a configuration of an apparatus for receiving downlink scheduling information in an OFDMA system according to an embodiment of the present invention.

Referring to FIG. 13, the apparatus for receiving downlink scheduling information 1300 according to the present invention includes a first scheduling information detector 1320, a resource block detector 1330, and a second scheduling information detector 1330.

More specifically, the first scheduling information detector 1320 may determine a specific location of a predetermined resource block from received OFDM symbols including a plurality of resource blocks, each of which includes at least one downlink resource. In this case, the identification information for identifying each terminal and the second scheduling information of each terminal, wherein the second scheduling information of each terminal includes the resource information of each terminal, including the location information of the resource block Detect first scheduling information.

The resource block detector 1330 detects the resource block including the second scheduling information based on the location information of the second scheduling information included in the first scheduling information.

The second scheduling information detector 1340 detects the second scheduling information based on the detected resource block.

According to the embodiment B-1 described above, the second scheduling information is contained in a resource block having the smallest resource block index among the resource blocks allocated to the terminal, and the resource allocation information includes the second scheduling information. Information indicating whether resource blocks having an resource block index larger than that of an existing resource block are allocated to the terminal.

According to the embodiment B-2 described above, the second scheduling information is carried in a resource block having the largest resource block index among the resource blocks allocated to the terminal, and the resource allocation information is loaded with the second scheduling information. Information indicating whether resource blocks having an resource block index smaller than that of an existing resource block are allocated to the terminal.

According to the embodiment B-3 described above, the resource allocation information is information indicating whether the remaining resource blocks other than the selected resource block among the resource blocks are allocated to the terminal.

The resource allocation information configuration and transmission method described above can be applied in various forms. For example, the above-described resource allocation information configuration and transmission method may be applied to a total frequency band operated by an OFDMA system. The total frequency band may be divided into a plurality of subbands, and independent resource allocation may be performed in subband units. You can also do it. In this case, the above-described method may be applied independently for each subband.

On the other hand, the method proposed by the present invention can be applied to the case of allocating distributed resources to the terminal. Set the unit size and total number of distributed resource blocks to be used for data transmission in the resource space, and establish a relationship in which each distributed resource block is mapped to resources in the physical resource space. If not only the relationship between the resource block and the resource block index of the resource block but also the mapping relationship between the resource block and the physical resources is set in advance and the configuration information is shared between the terminal and the base station, the above-described centralized resource allocation scheme In addition, the present invention can be applied to a distributed resource allocation scheme. That is, when there are a total of N distributed resource blocks, the resource allocation information is configured in the same manner as described above after numbering. Even in this case, the scheduling information of the specific terminal is transmitted from the resource blocks allocated to the terminal by using the specific resource in the resource block having the smallest resource block index in the case of embodiment A-1, and the embodiment A-2 In case of, it transmits using a specific resource in the resource block having the largest resource block index. Similarly, in the case of the embodiment A-3, the specific resource in the resource block having the highest channel quality is transmitted. In addition, in the embodiment B, the scheduling information is transmitted by treating the indexes of the distributed resource blocks allocated to the terminal group as the indexes of the centralized resource blocks.

Meanwhile, according to Embodiment A, since the UE cannot know whether demodulation information is present in any resource block or not, it is assumed that the scheduling information exists and demodulation and decoding are performed for each resource block. In this case, it is not necessary to perform demodulation and decoding on the entire resource block, and it is sufficient to perform demodulation and decoding only on resources that may be occupied by the scheduling information.

The invention can also be embodied as computer readable code on a computer readable recording medium. Computer-readable recording media include all kinds of recording devices that store data that can be read by a computer system. Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disks, optical data storage devices, and the like, which are also implemented in the form of carrier waves (for example, transmission over the Internet). Include. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. In addition, functional programs, codes, and code segments for implementing the present invention can be easily inferred by programmers in the art to which the present invention belongs.

Such a method and apparatus of the present invention have been described with reference to the embodiments shown in the drawings for clarity, but these are merely exemplary, and various modifications and equivalent other embodiments are possible to those skilled in the art. Will understand. Therefore, the true technical protection scope of the present invention will be defined by the appended claims.

According to the present invention, the amount of downlink resources used for transmission of scheduling information can be reduced without reducing the degree of scheduling freedom.

According to the present invention, the amount of scheduling information can be reduced as much as possible by using the minimum resource block index, the maximum resource block index, or the resource block having the highest channel quality for transmission of scheduling information.

In addition, according to the present invention, since all resource blocks do not need to be examined to confirm scheduling information, a false detection rate is relatively low.

Further, according to the present invention, efficient scheduling information transmission can be obtained by using a coding method for each group from the viewpoint of encoding gain and ease of detecting scheduling information.

Claims (31)

An allocating step of allocating at least one resource block to each terminal among resource blocks configured of downlink resources of an Orthogonal Frequency Division Multiple Access (OFDMA) system; Selecting, for each terminal, a resource block from the allocated resource blocks based on the resource block index size of each resource block; Generating, for each terminal, scheduling information including resource allocation information of the terminal and identification information for identifying the terminal; And And transmitting, to each terminal, the scheduling information of the terminal by using the selected resource block. The method of claim 1, wherein the selecting step, The downlink scheduling information transmission method of the OFDMA system, characterized in that for selecting the resource block having a minimum resource block index among the resource blocks allocated to the terminal. The method of claim 1, wherein the resource allocation information, And transmitting information indicating whether resource blocks having resource block indexes larger than the resource block indexes of the selected resource block have been allocated to the user equipment. The method of claim 3, wherein the resource allocation information, And a bitmap consisting of a binary value indicating whether each resource block having an resource block index larger than that of the selected resource block is allocated to the terminal. The method of claim 1, wherein the selecting step, The downlink scheduling information transmission method of the OFDMA system, characterized in that for selecting the resource block having the maximum resource block index among the resource blocks allocated to the terminal. The method of claim 1, wherein the resource allocation information, Downlink scheduling information transmission method in the OFDMA system, characterized in that information indicating whether or not resource blocks having an resource block index smaller than the resource block index of the selected resource block is allocated to the terminal. The method of claim 6, wherein the resource allocation information, And a bitmap comprising a binary value indicating whether each resource block having an resource block index smaller than the resource block index of the selected resource block is allocated to the terminal. The method of claim 1, wherein the scheduling information, The method for transmitting downlink scheduling information in an OFDMA system, further comprising a Cyclic Redundancy Check (CRC) bit. The method of claim 1, wherein the identification information, Downlink scheduling information transmission method in an OFDMA system, characterized in that the terminal identifier. The method of claim 1, wherein the identification information, Downlink scheduling information transmission method in an OFDMA system, characterized in that the CRC bit generated to identify the terminal. The method of claim 1, wherein the scheduling information, The method for transmitting downlink scheduling information in an OFDMA system, further comprising a transport format. The method of claim 11, wherein the transmission format, A method for transmitting downlink scheduling information in an OFDMA system, comprising information on a modulation scheme, multiple antenna related information, and payload size. The method of claim 1, wherein the transmitting step, A channel encoding step of channel encoding the scheduling information of the terminal; And And transmitting the channel-encoded scheduling information by using the selected resource block. The downlink scheduling information transmission method of the OFDMA system, characterized by the above-mentioned. The method of claim 13, wherein the channel encoding step, The method for transmitting downlink scheduling information in an OFDMA system, characterized in that for performing an individual coding scheme for channel coding the scheduling information for each terminal. The method of claim 1, wherein each resource block, A method for transmitting downlink scheduling information in an OFDMA system, characterized in that it comprises time according to a predetermined number of OFDM symbols and at least one downlink resource belonging to a predetermined frequency band. The method of claim 15, wherein each resource block, A method for transmitting downlink scheduling information in an OFDMA system, comprising a plurality of downlink resources consecutive in time or frequency according to a centralized resource allocation method. The method of claim 15, wherein each resource block, A method for transmitting downlink scheduling information in an OFDMA system according to a distributed resource allocation scheme, comprising a plurality of downlink resources without being bound to continuity in time and frequency. An allocating step of allocating at least one resource block to each terminal among resource blocks configured of downlink resources of an OFDMA system; Selecting, for each terminal, resource blocks based on channel quality of each resource block among the allocated resource blocks; Generating, for each terminal, scheduling information including resource allocation information of the terminal and identification information for identifying the terminal; And And transmitting, to each terminal, the scheduling information of the terminal by using the selected resource block. The method of claim 18, wherein the selecting step, Downlink scheduling information transmission method in an OFDMA system, characterized in that for selecting the resource block having the highest quality among the resource blocks allocated to the terminal. The method of claim 18, wherein the resource allocation information, The downlink scheduling information transmission method of the OFDMA system, characterized in that the information indicating whether the remaining resource blocks other than the selected resource block is allocated to the terminal. The method of claim 20, wherein the resource allocation information, The method according to claim 1, wherein each of the remaining resource blocks is a bitmap configured of a binary value indicating whether the remaining resource blocks are allocated to the terminal. The method of claim 18, wherein the scheduling information, The method for transmitting downlink scheduling information in an OFDMA system, further comprising a Cyclic Redundancy Check (CRC) bit. The method of claim 18, wherein the identification information, Downlink scheduling information transmission method in an OFDMA system, characterized in that the terminal identifier. The method of claim 18, wherein the identification information, Downlink scheduling information transmission method in an OFDMA system, characterized in that the CRC bit generated to identify the terminal. The method of claim 18, wherein the scheduling information, The method for transmitting downlink scheduling information in an OFDMA system, further comprising a transport format. The method of claim 25, wherein the transmission format, A method for transmitting downlink scheduling information in an OFDMA system, comprising information on a modulation scheme, multiple antenna related information, and payload size. The method of claim 18, wherein the transmitting step, A channel encoding step of channel encoding the scheduling information of the terminal; And And transmitting the channel-encoded scheduling information by using the selected resource block. The downlink scheduling information transmission method of the OFDMA system, characterized by the above-mentioned. The method of claim 27, wherein the channel encoding step, The method for transmitting downlink scheduling information in an OFDMA system, characterized in that for performing an individual coding scheme for channel coding the scheduling information for each terminal. The method of claim 18, wherein each resource block, A method for transmitting downlink scheduling information in an OFDMA system, characterized in that it comprises time according to a predetermined number of OFDM symbols and at least one downlink resource belonging to a predetermined frequency band. The method of claim 29, wherein each resource block, A method for transmitting downlink scheduling information in an OFDMA system, comprising a plurality of downlink resources consecutive in time or frequency according to a centralized resource allocation method. The method of claim 29, wherein each resource block, A method for transmitting downlink scheduling information in an OFDMA system according to a distributed resource allocation scheme, comprising a plurality of downlink resources without being bound to continuity in time and frequency.

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