KR20060117864A - Method and apparatus for indexing physical channel in ofdma system - Google Patents

Abstract

A method and an apparatus for indexing physical channels in an OFDMA system are provided to make the physical channels, having different lengths, configured and indexed in a tree structure. A method for indexing physical channels in an OFDMA(Orthogonal Frequency Division Multiple Access) system comprises the steps of: dividing the total number of sub-carriers within a TTI(Transmission Time Interval)(303) into N groups; classifying resources corresponding to a kth group into a set of sub-carriers indicated by a predetermined value within a TTI; and indexing a physical channel as an order pair(N, k). A tree structure is formed between physical channels indexed by the order pair(N, k).

Description

Method and device for configuring physical channel index in orthogonal frequency division multiple access system TECHNICAL FIELD

1 is a graph illustrating an example of resources in time and frequency domain in an OFDM-based wireless communication system

2 is a graph illustrating an example in which a plurality of physical channels are indexed in a general OFDM-based wireless communication system.

3 is a graph illustrating an example in which a plurality of physical channels are indexed according to an embodiment of the present invention.

4 is a diagram illustrating an example in which a plurality of physical channels are indexed in a tree structure according to an embodiment of the present invention.

5 is a diagram illustrating the tree structure of FIG. 4 in a hierarchical representation according to a preferred embodiment of the present invention.

FIG. 6 illustrates an example of TFDCH used by each physical channel when a plurality of physical channels having different lengths are multiplexed within one TTI according to an exemplary embodiment of the present invention.

7 is a diagram illustrating a transceiver of an OFDM system performing index configuration of a physical channel according to an embodiment of the present invention.

8 is a graph illustrating an example of indexing of DRCH (N, k) according to a preferred embodiment of the present invention.

9 shows DRCH (8, 0) and DRCH (8, 4) when the sequence S is {0, 1, 2, 3, 4, 5, 6, 7} according to a preferred embodiment of the present invention. A graph representing justice

10 is a diagram illustrating the tree structure of FIG. 9 in a hierarchical representation according to a preferred embodiment of the present invention.

FIG. 11 illustrates an example of DRCHs allocated to respective physical channels when various physical channels are multiplexed within one TTI according to an exemplary embodiment of the present invention.

12 is a graph illustrating an example of indexing LRCH (N, k) according to a preferred embodiment of the present invention.

13 is a diagram illustrating the tree structure of FIG. 12 in a hierarchical representation according to a preferred embodiment of the present invention.

The present invention relates to a wireless communication system based on orthogonal frequency division multiplexing, and more particularly, to a method and apparatus for indexing a physical channel in a wireless communication system based on orthogonal frequency division multiplexing.

Recently, orthogonal frequency division multiplexing (hereinafter referred to as "OFDM") has been actively studied and utilized in wireless communication systems. The OFDM method is a method of transmitting data using a multi-carrier, and a plurality of sub-carriers having mutually orthogonality by converting symbol strings serially input in parallel. That is, it is a type of Multi Carrier Modulation (MCM) that modulates and transmits a plurality of subcarrier channels.

The OFDM method can be widely applied to digital transmission technologies such as digital audio broadcasting (DAB), digital television, and wireless local area network (WLAN), and is strong in multipath fading. It is possible to provide an efficient platform for high-speed data transmission.

An exemplary multiple access system based on the OFDM scheme is an OFDMA system. The OFDMA divides a frequency domain into subchannels consisting of a plurality of subcarriers, divides the time domain into a plurality of time slots, and allocates subchannels for each user to perform resource allocation considering both time and frequency domains. It is a multiple access method that can accommodate multiple users as frequency resources.

1 is a graph illustrating an example of resources in time and frequency domain in an OFDM-based wireless communication system.

Referring to FIG. 1, the horizontal axis represents time and the vertical axis represents frequency. In a typical OFDM system, since one modulation symbol (QPSK or 16 QAM) is transmitted through one subcarrier 101, the subcarriers are basic resources. That is, one rectangle (one subcarrier in a specific OFDM symbol) shown in FIG. 1 represents a resource in a time and frequency domain.

In general, one OFDM symbol 102 is composed of a plurality of subcarriers. It is assumed that the subcarriers shown in FIG. 1 actually represent subcarriers used for data transmission, and Guard subcarriers shown in a general OFDM system are not shown. In addition, in the general OFDM system, a plurality of OFDM symbols are grouped together as shown by reference numeral 103 to form a basic unit of packet data transmission. In this way, a basic unit of packet data transmission composed of a plurality of OFDM symbols is referred to as a transmission time interval (hereinafter referred to as "TTI").

Here, one small rectangle shown in FIG. 1 is called a time-frequency bin. Thus, one TTI 103 is composed of a plurality of time-frequency bins. The physical channel is a channel for transmitting different types of information such as a paging channel, a packet data channel, a packet data control channel, and a reverse scheduling channel required in a conventional mobile communication system.

On the other hand, in a typical OFDM system, the one TTI 103 is generally composed of a plurality of physical channels. For example, in one TTI 103, some resources (time-frequency bins) in the time and frequency domains are used for the paging channel, and some resources are common control channels for providing system information and the like. Hereinafter referred to as "CCCH". In addition, some resources are used as a packet data channel (PDCH) for transmitting user data, and some resources are packet data control for transmitting control information for demodulation of the packet data channel. Sometimes used as a channel (Packet Data Control Channel, called "PDCCH"). Although not mentioned here, other physical channels may exist depending on the purpose.

In addition, resources in the time and frequency domain required for the plurality of physical channels are generally different. For example, when a resource in the time and frequency domain included in the one TTI is composed of 5,000 time-frequency bins (that is, the number of subcarriers used for data transmission in one OFDM symbol is 500, and such OFDM symbol Assuming that 10 of them are configured to form a TTI), the number of subcarriers used for the paging channel is 100, the number of subcarriers used for the common control channel is 500, and the number of subcarriers used for transmitting user data. The number is 4000, and the number of subcarriers used to transmit packet data control channels is 400.

As described above, the conventional OFDM-based wireless communication system has a resource that takes a two-dimensional form in the time and frequency domain, and each physical channel is composed of a plurality of physical channels that require different amounts of resources. It shall be possible to efficiently define and indicate between the transceivers what resources are used for the time-frequency bins. For example, when 5000 subcarriers exist in one TTI as described above, the transmitter can receive information such as 1 to 100 times assigned to the paging channel, 101 to 600 assigned to the common channel, etc. to the receiver. It should be. To this end, there is a general method of indicating each subcarrier, such as a few subcarriers in a few OFDM symbols, when indicating one physical channel, but this is very inefficient. This is because such a method requires too much information to inform which physical carrier is used for which physical channel.

In other words, in a general OFDM-based wireless communication system, when a plurality of packet data channels each forming one physical channel are multiplexed as described above, a channel number is used as an indicator for each packet data channel. Through this, it is prescribed that which subcarriers of which OFDM symbols are used between data transceivers for which user's data channels.

2 is a graph illustrating an example in which a plurality of physical channels are indexed in a typical OFDM based wireless communication system.

Referring to FIG. 2, the horizontal axis of the illustrated graph represents time as shown in FIG. 1, and the vertical axis represents frequency. One OFDM symbol 202 is composed of a plurality of subcarriers, and one TTI 203 is composed of a plurality of physical channels. Each physical channel may be referred to as one time frequency diversity channel (hereinafter referred to as "TFDCH") 204, 205, and 206. This is because one TFDCH is composed of a plurality of subcarriers scattered in a time and frequency domain in one TTI as shown in FIG. 2. As shown in FIG. 2, it is defined which subcarriers are configured in one TFDCH within a specific TTI, and resource usage information may be defined between transceivers through a corresponding channel number.

However, the prior art as described above is a subcarrier used by each physical channel when all physical channels have the same channel length (where the channel length represents the number of subcarriers used for one physical channel within one TTI). Although appropriately used to indicate information, when a plurality of physical channels have different channel lengths, it is difficult to index or indicate resource information used for each physical channel.

Accordingly, an object of the present invention is to effectively indicate the resources of the time and frequency domain used for each physical channel when various physical channels having various channel lengths are mixed and used in the OFDM-based wireless communication system as described above. The present invention provides a method and apparatus.

Another object of the present invention is to provide an efficient definition method and apparatus for resource allocation units for two-dimensional resources in time and frequency domain in an OFDM-based wireless communication system.

Another object of the present invention is to provide an efficient resource allocation method and apparatus for two-dimensional resources in the time and frequency domain in an OFDM-based wireless communication system.

In order to achieve the above object, in the method of the present invention, in an orthogonal frequency division multiple access system, one orthogonal frequency division multiple symbol consists of a plurality of subcarriers, and one transmission time interval. In the index configuration method of the physical channel consisting of the plurality of orthogonal frequency division multiple symbols, k is the kth when dividing the total number of subcarriers (the total number of resources in time and frequency domain) into N groups in the one TTI A resource corresponding to a group is classified into a set of subcarriers indicated by a predetermined value in one TTI, and indexed into an ordered pair (N, k).

In the transmission apparatus according to the embodiment of the present invention, in the orthogonal frequency division multiple access system, one orthogonal frequency division multiple symbol consists of a plurality of subcarriers, and one transmission time interval corresponds to the plurality of transmission carriers. An apparatus for indexing and transmitting a physical channel consisting of orthogonal frequency division multiple symbols, wherein the total number of subcarriers (the total number of resources in time and frequency domain) in the one TTI is divided into N groups in the k-th group. A transmission control unit for classifying a corresponding resource into a set of subcarriers indicated by a predetermined value in one TTI, and controlling multiplexing in the one TTI for a physical channel indexed with an ordered pair (N, k); A physical channel index construction unit constituting index information of the physical channel under control of the transmission control unit, and under the control of the transmission control unit And an OFDM transmitter configured to multiplex index information and traffic channels of a physical channel and configure a frame to be transmitted to a receiver.

In addition, in a receiving apparatus according to an embodiment of the present invention, in an orthogonal frequency division multiple access system, one orthogonal frequency division multiple symbol consists of a plurality of subcarriers, and one transmission time interval corresponds to the plurality of subcarriers. A device for receiving a physical channel consisting of orthogonal frequency division multiple symbols of the physical channel and index information of the physical channel, the apparatus comprising: receiving a frame transmitted from a transmitter, and receiving the index information and traffic from the received frame under control of a receiving controller An OFDM receiver for demultiplexing channels, a physical channel index analyzer for analyzing the index information of the received physical channel under control of the reception controller, and the total number of subcarriers in the one TTI (in time and frequency domain) When dividing the total number of resources) into N groups, resources corresponding to the kth group are included in one TTI. The classification of a set of sub-carriers is indicated by a predetermined value, characterized in that it comprises a reception control unit for controlling the demultiplexed from within said one TTI with respect to the physical channel index in ordered pairs (N, k).

In the system according to the embodiment of the present invention, in the orthogonal frequency division multiple access system, one orthogonal frequency division multiple symbol consists of a plurality of subcarriers, and one transmission time interval corresponds to the plurality of orthogonal numbers. In a system for indexing and transmitting and receiving a physical channel consisting of frequency division multiple symbols, the total number of subcarriers (the total number of resources in time and frequency domain) in one TTI is divided into N groups in the k-th group. A base station including a transmitter capable of classifying a corresponding resource into a set of subcarriers indicated by a predetermined value within one TTI, and transmitting a physical channel indexed into an ordered pair (N, k); And a receiver including a receiver capable of receiving a physical channel indexed by the ordered pair (N, k). .

Hereinafter, with reference to the accompanying drawings will be described in detail the operating principle of the preferred embodiment of the present invention. Like reference numerals refer to the same elements as shown in the drawings, even though they may be shown on different drawings, and in the following description, detailed descriptions of related well-known functions or constructions are unnecessary. If it is determined that it can be blurred, the detailed description thereof will be omitted. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

The indexing method of the TFDCH proposed in the present invention defines time and frequency resources (ie, a plurality of subcarriers) included in one TTI as a "kth group when divided into N groups" and an ordered pair (N, k ) Is used to identify each physical channel.

In addition, when physical channels of different channel lengths exist within one TTI, the ordered pairs (N, k) may have a tree structure in order to identify each physical channel as described above. This can indicate the time and frequency resources used more efficiently.

As described above, what is the meaning of "k-th group divided into N groups", which is a characteristic of the physical channel indexing method proposed in the present invention, and how to have a tree structure will be described in detail as follows. Same as

Assume that one TTI consists of 10 OFDM symbols and one OFDM symbol consists of 500 subcarriers. This consequently means that there are 5000 time and frequency domain resources within one TTI. In this case, the method of defining the index of the physical channel by the method of ordered pairs (N, k) together with the tree structure is as follows.

As described above, the expression "indicating the physical channel by the method of (N, k)" refers to "the k-th group when the resource of the entire time and frequency domain is divided into N groups". This can be summarized as (1) to (4) as follows.

(1) A total of 5000 resources in time and frequency domain may be configured as one physical channel. In this case, the number of possible physical channels is '1', which is TFDCH (1, 0) according to the above-described physical channel indexing method.

(2) A total of 5000 time and frequency domain resources can be configured with two physical channels. In this case, the number of possible physical channels is '2', and TFDCH (2, 0) and TFDCH (2, 1) may exist according to the above-described physical channel indexing method.

(3) A total of 5,000 time and frequency domain resources can be composed of three physical channels. In this case, the number of possible physical channels is '3', and there may be TFDCH (3, 0), TFDCH (3, 1) and TFDCH (3, 2) according to the above-described physical channel indexing method.

(4) When the process of (1) to (3) is algebraically generalized through inductive inference, it can be defined as TFDCH (N, k).

In other words, there are various methods for organizing resources in time and frequency domain into N physical channels, which is represented by the following mathematical equation utilizing a modulo operation (which is represented by a symbol such as "%"). Equation 1 can be defined mathematically.

Set of subcarriers indexed with TFDCH (N, k) = n

Where n satisfies n% N = (k + L + B)% N, where L is the position of the OFDM symbol in the TTI, B is the base station index, N is the number of physical channels to be configured, k (= 0, ..., N-1) indicate the TFDCH identifier. In addition, n corresponds to a subcarrier index in one OFDM symbol. That is, according to Equation 1, TFDCH (N, k) is a set of subcarriers n satisfying Equation 1 within one TTI. An example of FIG. 3 will be described in order to help the understanding of Equation 1 above.

3 is a graph illustrating an example in which a plurality of physical channels are indexed according to an exemplary embodiment of the present invention.

Referring to FIG. 3, the horizontal axis of the illustrated graph represents time as shown in FIG. 1, and the vertical axis represents frequency. One TTI 303 is composed of eight OFDM symbols, and each OFDM symbol 302 is composed of 32 subcarriers. According to the index definition of the physical channel proposed by the present invention, resources in the time and frequency domain are divided into four physical channels (N = 4), the base station index is' 0 '(B = 0), and the TFDCH index is' In the case of 0 '(k = 0), subcarriers constituting the TFDCH (4, 0) of the reference numeral 301 are shown.

That is, eight OFDM symbols exist in one TTI, and each OFDM symbol has L = 0,... , L = 7 is indexed. Each OFDM symbol consists of 32 subcarriers, each subcarrier having n = 0,... , n = 31 is indexed. In FIG. 3, subcarriers satisfying Equation 1 are indicated by hatching slanted from the upper right to the lower left. These subcarriers gather to form the TFDCH (4, 0) of the reference numeral 301. Equation (1) shows one of various mathematical definitions that represent a case in which a TFDCH of a specific length is simply configured through a modulo operation, but according to another purpose, TFDCHs having various lengths may be used using other equations. There may also be definitions that can be configured. In addition, how the different TFDCHs configured as described above can be indexed into a tree structure according to the present invention will be described with reference to FIG. 4.

4 is a diagram illustrating an example in which a plurality of physical channels are indexed in a tree structure according to an embodiment of the present invention.

Referring to FIG. 4, one TTI 403 is composed of eight OFDM symbols, and each OFDM symbol is composed of 32 subcarriers. According to the index definition of the physical channel proposed by the present invention, resources in the time and frequency domain are divided into eight physical channels (N = 8), the base station index is' 0 '(B = 0), and the TFDCH index is' In the case of '0' and '4' (k = 0, 4), the subcarriers constituting the TFDCH (8, 0) of the reference numeral 401 and the TFDCH (8, 4) of the reference numeral 402 are shown with different hatchings. . The TFDCH (8, 0) of reference numeral 401 is indicated by a hatching inclined from the upper left to the lower right, and the TFDCH (8, 4) of the reference symbol 402 is indicated by a hatching inclined from the upper left to the lower right. .

In addition, there are eight OFDM symbols in one TTI 403 and each OFDM symbol has L = 0,... , L = 7 is indexed. In FIG. 4, each OFDM symbol 402 is composed of 32 subcarriers, and each subcarrier is n = 0,... , n = 31 is indexed.

4, the TFDCH (8, 0) shown in FIG. 4 and the TFDCH (8, 4) are equal to the TFDCH (4, 0) shown in FIG. In other words, it means that TFDCH (8, 0) and TFDCH (8, 4) are derived from TFDCH (4, 0). This feature is a key element in the physical channel indexing method proposed by the present invention. Such features are more generally shown in FIG. 5.

5 is a diagram illustrating the tree structure of FIG. 4 in a hierarchical representation according to a preferred embodiment of the present invention.

Referring to FIG. 5, when resources in the time and frequency domain within one TTI are divided into one physical channel, one TFDCH, that is, TFDCH (1, 0) may be present. In addition, if resources in the time and frequency domain within one TTI are divided into two physical channels, TFDCH (2, 0) and TFDCH (2, 1) may exist, and conversely, TFDCH (2, 0) and When TFDCH (2, 1) is combined, it becomes TFDCH (1, 0). In the same manner as above, TFDCH (4, 0) and TFDCH (4, 2) can be derived from TFDCH (2, 0). Further, TFDCH (8, 0) and TFDCH (8, 4) can be derived from TFDCH (4, 0), and so on.

As described above, a resource used in a specific physical channel in a transmission / reception period by configuring a resource in a time and frequency domain in a TTI with TFDCH having various lengths and indexing only a node value, that is, an (N, k) value. It is easier to exchange information. Looking at the example through FIG. 6 as follows.

FIG. 6 illustrates an example of a TFDCH used by each physical channel when a plurality of physical channels having different lengths are multiplexed within one TTI according to an exemplary embodiment of the present invention.

Referring to FIG. 6, TFDCH (4, 0), TFDCH (4, 1), and TFDCH (4, 2) are used as PDCHs for users A, B, and C, respectively. In addition, two length 8 channel TFDCH (8, 3) and TFDCH (8, 7) derived from TFDCH (4, 3) are used as CCCH and PDCCH, respectively.

7 is a diagram illustrating a transceiver of an OFDM system for performing an index configuration of a physical channel according to an embodiment of the present invention.

Referring to FIG. 7, an apparatus 700 for transmitting an OFDM system performing a physical channel indexing method includes a transmission controller 701, a physical channel index configuration unit 703, a traffic transmitter 705, and an OFDM transmitter 707. do.

The transmission control unit 701 controls the multiplexing of a plurality of physical channels having different lengths in one TTI according to the definition constituting the index of the physical channel proposed in the present invention. The physical channel index construction unit 703 configures index information of the physical channel under the control of the transmission control unit 701. The traffic transmitter 705 stores the traffic transmitted from another block or higher node in the device in an internal buffer. The OFDM transmitter 707 configures a frame to be transmitted to the receiver 710 by multiplexing the index information, the traffic channel, etc. of the physical channel under the control of the transmission controller 701. Here, a component block not directly related to the present invention, such as an Inverse Fast Fourier Transform, is not shown.

In addition, the receiver 710 of the OFDM system that performs the physical channel indexing method includes an OFDM receiver 711, a physical channel index analyzer 713, a reception controller 715, and a traffic receiver 717.

The OFDM receiver 711 receives the frame transmitted from the transmitter 700 and performs demultiplexing from the received frame under the control of the reception controller 715. The physical channel index analyzer 713 analyzes index information of the received physical channel under the control of the reception controller 715. The reception control unit 715 controls the demultiplexing of a plurality of physical channels having different lengths from one TTI according to the definition constituting the index of the physical channel proposed by the present invention. The traffic receiver 717 has a buffer in itself to store the traffic data transmitted from the OFDM receiver 715. Here, like the transmitting apparatus 700, a configuration block not directly related to the present invention is not shown.

In addition, another embodiment of the resource allocation unit definition and indication and the allocation method proposed in the present invention can be summarized as follows.

Two different resource allocation unit definition and indication methods are used for two-dimensional resources in one TTI, that is, a plurality of time-frequency bins. In the above two different methods, a distributed resources channel (DRCH) method for configuring and indicating a channel by combining resources separated from each other with a specific rule among two-dimensional resources in one TTI and two-dimensional in one TTI There is a Localized Resources Channel (LRCH) method of forming a channel by combining adjacent resources among resources and indicating the same. The resource allocation unit defined by the LRCH and DRCH method is indicated as DRCH (N, k) or LRCH (N, k), and resource allocation for each physical channel is performed by the DRCH (N, k) or LRCH ( N, k) by assigning N and k values. First, a detailed description of DRCH (N, k) will be described with reference to FIGS. 8 and 9.

8 is a graph illustrating an example of indexing of DRCH (N, k) according to a preferred embodiment of the present invention. Here, the DRCH (N, k) is a k-th group (each group corresponds to a channel, when the time and frequency resources in the TTI is divided into N groups having a distributed or scattered shape, each referred to as "DRCH". Resource).

Referring to FIG. 8, there are eight OFDM symbols in one TTI 804. Each OFDM symbol is indicated from L = 0 to L = 7. The one OFDM symbol 803 is composed of 32 subcarriers. 32 subcarriers included in one OFDM symbol are indicated by n = 0 and n = 31. In FIG. 8, a resource corresponding to DRCH (8, 0) where N = 8 and k = 0 is indicated by reference numeral 801, and a resource corresponding to DRCH (8, 4) is indicated by reference numeral 802. How to configure the resource of the DRCH (8, 0) is as follows.

32 subcarriers in each OFDM symbol are divided into N groups (8 in FIG. 8). The subcarriers included in each group are characterized by having the same distance. That is, subcarriers belonging to 'group 0' are subcarriers corresponding to n = {0, 8, 16, 24}, and subcarriers belonging to 'group 1' are subcarriers corresponding to n = {1, 9, 17, 25}. Subcarriers belonging to 'group 2' are n = {2, 10, 18, 26} subcarriers and subcarriers belonging to 'group 3' are n = {3, 11, 19, 27} Subcarriers belonging to 'group 4' are n = {4, 12, 20, 28} subcarriers, and subcarriers belonging to 'group 5' are n = {5, 13, 21, 29}. Subcarriers belonging to 'group 6' are n = {6, 14, 22, 30} and subcarriers belonging to 'group 7' are subcarriers corresponding to n = {7, 15, 23, 31}. admit. As described above, when N = 8, the subcarriers included in each group in each OFDM symbol have the same distance in the frequency domain. Finally, resources in the frequency and time domain corresponding to DRCH (8, 0) are defined by the sequence S unique to each base station. The sequence S has the same number of elements as the number of OFDM symbols included in one TTI.

According to the graph of FIG. 8, the sequence corresponds to the case where S = {0, 3, 1, 7, 2, 6, 4, 5}. The sequence is an index indicating a group in each OFDM symbol. In other words, in a base station defined as S = {0, 3, 1, 7, 2, 6, 4, 5}, the resource in the frequency and time domain corresponding to DRCH (8, 0) is the first in the corresponding TTI. Group 0 of the OFDM symbol, Group 3 of the second OFDM symbol, Group 1 of the third OFDM symbol, Group 7 of the fourth OFDM symbol 7, Group 2 of the fifth OFDM symbol 2, Group 6 of the sixth OFDM symbol, Seventh OFDM symbol A resource included in DRCH (8, 0) is defined by gathering all subcarriers included in group 4 of group 4 and group 5 of the eighth OFDM symbol.

More generally, the resource in the frequency and time domain corresponding to DRCH (8, k) in the base station defined as S = {0, 3, 1, 7, 2, 6, 4, 5} {(0 + k)% N, (3 + k)% N, (1 + k), (7 + k)% N, (2 + k)% N, (6 + k) in each OFDM symbol in the TTI Subcarriers corresponding to a group represented by% N, (4 + k)% N, and (5 + k)% N}.

Therefore, the resources in the frequency and time domain corresponding to the DRCH (8, 4) in FIG. 8 is {4% 8, 7% 8, 5% 8, 11% 8, 6% 8, 10 in each OFDM symbol in the TTI. % 8, 8% 8, 9% 8}, i.e., {4, 7, 5, 3, 6, 2, 0, 1} may be formed by gathering subcarriers included in the corresponding group.

9 shows DRCH (8, 0) and DRCH (8, 4) when the sequence S is {0, 1, 2, 3, 4, 5, 6, 7} according to a preferred embodiment of the present invention. Graph showing definition.

Referring to FIG. 9, the resource allocation method may be performed by allocating an ordered pair (N, k) together with the DRCH. As described above, when the order pair (N, k) values indicate each physical channel, the order pair (N, k) values may have a tree structure. As a result, it is possible to indicate time and frequency resources used more efficiently when physical channels of different channel lengths exist within one TTI.

The following describes how DRCHs can be indexed in a tree structure. The embodiment of FIG. 8 is used for the above description. Referring to FIG. 8, eight OFDM symbols exist in one TTI 904, and each OFDM symbol 903 has L = 0,... , L = 7 is indexed.

4, each OFDM symbol is composed of 32 subcarriers, and each subcarrier is n = 0,... , n = 31 is indexed. As described with reference to FIG. 4, subcarriers corresponding to DRCH (8, 0) (reference numeral 901) and DRCH (8, 4) (reference symbol 902) are combined to correspond to DRCH (4, 0). That is, when S = {0, 3, 1, 7, 2, 6, 4, 5} by the above-described method, a process of configuring DRCH (4, 0) is as follows.

Since N = 4, the subcarriers in one OFDM symbol are divided into four groups consisting of subcarriers having the same distance, and each group is indexed as 0, 1, 2, and 3. In addition, when each element of S is modulated by 4 (= N), {0, 3, 1, 3, 2, 2, 0, 1} becomes DR0 (4). , 0). Subcarriers corresponding to the DRCH (4, 0) configured in the above manner are the same as the sum of the resources of the DRCH (8, 0) indicated by 901 and the DRCH (8, 4) indicated by 902 in FIG. Will be the same. In other words, DRCH (8, 0) and DRCH (8, 4) are derived from DRCH (4, 0). An example of the tree structure as described above is shown in FIG.

FIG. 10 is a diagram illustrating the tree structure of FIG. 9 in a hierarchical representation according to an embodiment of the present invention. FIG.

Referring to FIG. 10, dividing resources in time and frequency domains within one TTI into one physical channel may indicate that one DRCH, that is, DRCH (1, 0) may exist. In addition, when resources in the time and frequency domain in one TTI are divided into three physical channels, DRCH (3, 0), DRCH (3, 1), and DRCH (3, 2) exist, and the DRCH ( When 3, 0), DRCH (3, 1) and DRCH (3, 2) are combined, it becomes DRCH (1, 0). In the same way, DRCH (6, 0) and DRCH (6, 3) can be derived from DRCH (3, 0). The following also develops in the same manner.

As described above, the resource in the time and frequency domain in the TTI is composed of DRCHs having various lengths, and only the node value, that is, the (N, k) value is indexed so that the resource information used for a specific physical channel between the transceivers It becomes easy to exchange. An example thereof is as follows.

FIG. 11 is a diagram illustrating an example of DRCHs allocated to respective physical channels when various physical channels are multiplexed within one TTI according to an exemplary embodiment of the present invention.

Referring to FIG. 11, DRCH (6, 0), DRCH (6, 3), DRCH (6, 1), DRCH (6, 4) are respectively a packet data channel (PDCH) 0, a packet data channel 1, packet data channel 2 and packet data channel 3. In addition, DRCH (12, 2) is assigned to a Packet Data Control Channel (PDCCH), DRCH (12, 5) is assigned to a Common Control Channel (CCCH). The resource for each physical channel may be defined by allocating N and k values in the DRCH (N, k) through the above-described resource allocation unit definition method and indication method. A detailed description of LRCH (N, k), which is another resource allocation unit definition method proposed by the present invention, will be described with reference to FIG. 12.

12 is a graph showing an example of indexing LRCH (N, k) according to a preferred embodiment of the present invention.

Here, LRCH (N, k) refers to a resource corresponding to the k-th group when the time and frequency resources in the TTI are divided into N groups having localized shapes.

Referring to FIG. 12, there are eight OFDM symbols in one TTI 1206. Each OFDM symbol is indicated from L = 0 to L = 7. The one OFDM symbol 1205 consists of 32 subcarriers. 32 subcarriers included in the one OFDM symbol 1205 are indicated by n = 0 and n = 31. In FIG. 12, a resource corresponding to LRCH (4, 0) where N = 4 and k = 0 is indicated by reference numeral 1201. 64 subcarriers corresponding to n = 0 to 7 included in eight OFDM symbols in one TTI constitute LRCH (4, 0) (denoted by reference numeral 1201). 64 subcarriers corresponding to n = 8 to 15 included in 8 OFDM symbols in the one TTI constitute LRCH (4, 1) (denoted by reference numeral 1202). 64 subcarriers corresponding to n = 16 to 23 included in the 8 OFDM symbols in the one TTI configure the LRCH (4, 2). 64 subcarriers corresponding to n = 24 to 31 included in 8 OFDM symbols in the one TTI constitute LRCH (4, 3). When LRCH (2, 0) is configured in the same manner as described above, the resource corresponding to LRCH (2, 0) is the same as the sum of the resources corresponding to LRCH (4, 0) and LRCH (4, 1). do.

The characteristics of the tree structure described above are similar to those of the DRCH described with reference to FIG. 11, and an example thereof is shown in FIG. 12. In addition, the LRCH (N, k) can be divided into several groups in time, such as LRCH (N, k, m). Here m is a time division index and becomes an OFDM symbol index within one TTI. In FIG. 12, a part denoted by reference numeral 1203 represents resources corresponding to LRCH (4, 2, 0), which indicates a resource corresponding to the first OFDM symbol among eight OFDM symbols in the TTI. In the same way, LRCH (4, 2, 1) represents a resource corresponding to the second OFDM symbol among the eight OFDM symbols in the TTI (denoted by reference numeral 1204). Therefore, combining LRCH (4, 2, 0) to LRCH (4, 2, 7) is characterized by the same as LRCH (4, 2). Such LRCH (N, k, m) may be used when multiple users are multiplexed on the LRCH (N, k).

13 is a diagram illustrating the tree structure of FIG. 12 in a hierarchical representation according to an embodiment of the present invention.

Referring to FIG. 13, when resources in the time and frequency domain within one TTI are divided into one physical channel, one LRCH, that is, LRCH (1, 0), may exist. In addition, if resources in the time and frequency domain within one TTI are divided into two physical channels, LRCH (2, 0) and LRCH (2, 1) may exist, and conversely, LRCH (2, 0) and When LRCH (2, 1) is combined, it becomes LRCH (1, 0). In the same manner as above, LRCH (4, 2) and LRCH (4, 3) can be derived from LRCH (2, 1). Also, LRCH (8, 6) and LRCH (8, 7) can be derived from LRCH (4, 3), and so on.

Although the present invention has been described in detail so far, it should be apparent that the embodiments mentioned in the process are only illustrative, and not restrictive, and the present invention is provided by the following claims. Within the scope not departing from the scope of the present invention, component changes to the extent that they can be equivalently substituted from the present invention will fall within the scope of the present invention.

In the present invention operating as described in detail above, the effects obtained by the representative ones of the disclosed inventions will be briefly described as follows.

The present invention facilitates what resources (two-dimensional resources) are used for each physical channel between transceivers by using a channel structure and indexing method having a tree structure in configuring physical channels having various lengths in an OFDM-based wireless communication system. It has a definite effect.

In addition, the present invention has an effect of enabling efficient scheduling and resource utilization by easily defining which subcarriers each physical channel is configured with.

Claims (13)

In an orthogonal frequency division multiple access system, one orthogonal frequency division multiple symbol consists of a plurality of subcarriers, and one transmission time interval constitutes an index structure of a physical channel composed of the plurality of orthogonal frequency division multiple symbols In the method, When the total number of subcarriers in the one TTI (the total number of resources in the time and frequency domain) is divided into N groups, the resources corresponding to the k th group are a set of subcarriers indicated by a predetermined value within one TTI. Classifying and indexing by ordered pair (N, k). The method of claim 1, And a tree structure is formed between the physical channels indexed by the ordered pair (N, k). In an orthogonal frequency division multiple access system, one orthogonal frequency division multiple symbol consists of a plurality of subcarriers, and one transmission time interval indexes a physical channel composed of the plurality of orthogonal frequency division multiple symbols. In the transmitting device, When the total number of subcarriers in the one TTI (the total number of resources in the time and frequency domain) is divided into N groups, the resources corresponding to the k th group are a set of subcarriers indicated by a predetermined value within one TTI. A transmission control section for classifying and controlling multiplexing within the one TTI for a physical channel indexed with an ordered pair (N, k), A physical channel index construction unit constituting index information of a physical channel under the control of the transmission control unit; And an OFDM transmitter configured to multiplex index information and traffic channels of a physical channel and configure a frame to be transmitted to a receiver under the control of the transmitter. The method of claim 3, And a tree structure is formed between the physical channels indexed by the ordered pairs (N, k). In an orthogonal frequency division multiple access system, one orthogonal frequency division multiple symbol consists of a plurality of subcarriers, and one transmission time interval includes a physical channel and the physical channel consisting of the plurality of orthogonal frequency division multiple symbols. An apparatus for receiving index information of An OFDM receiver which receives a frame transmitted from a transmitter, and demultiplexes the index information and the traffic channel from the received frame under the control of a reception controller; A physical channel index analyzer for analyzing the index information of the received physical channel under control of a reception controller; When the total number of subcarriers in the one TTI (the total number of resources in the time and frequency domain) is divided into N groups, the resources corresponding to the k th group are a set of subcarriers indicated by a predetermined value within one TTI. And a reception control section for classifying and controlling demultiplexing from within one TTI for a physical channel indexed into an ordered pair (N, k). The method of claim 5, And the tree structure is formed between the physical channels indexed by the ordered pairs (N, k). In an orthogonal frequency division multiple access system, one orthogonal frequency division multiple symbol consists of a plurality of subcarriers, and one transmission time interval indexes a physical channel composed of the plurality of orthogonal frequency division multiple symbols. In the system for transmitting and receiving When the total number of subcarriers in the one TTI (the total number of resources in the time and frequency domain) is divided into N groups, the resources corresponding to the k th group are a set of subcarriers indicated by a predetermined value within one TTI. A base station comprising a transmitter capable of classifying and transmitting physical channels indexed in ordered pairs (N, k), And a receiver including a receiver capable of receiving a physical channel indexed into the ordered pair (N, k) from a transmitter of the base station. The method of claim 7, wherein And a tree structure is formed between the physical channels indexed by the ordered pair (N, k). In an orthogonal frequency division multiple access system, one orthogonal frequency division multiplex (OFDM) symbol consists of a plurality of subcarriers, and one transmission time interval consists of the plurality of orthogonal frequency division multiple symbols. In the index construction method of, When the total number of subcarriers in the one TTI (the total number of resources in the time and frequency domain) is divided into N groups, the resources corresponding to the k th group are a set of subcarriers indicated by a predetermined value within one TTI. Sorted, indexed by ordered pair (N, k), The resource in the frequency and time domain corresponding to the ordered pair (N, k) is a sequence S = {S ₁ ,..., With the number of elements equal to the number L of symbols included in one TTI unique to each base station. , S _L }. The method of claim 9, The sequence S = {S ₁ ,... , The resource in the frequency and time domain corresponding to the ordered pair (N, k) indexed by S _L } is equal to {(S ₁ + k)% N,... In each OFDM symbol in the one TTI. , Subcarriers corresponding to the group represented by (S _L + k)% N}. The method of claim 9, And a tree structure is formed between the physical channels indexed by the ordered pair (N, k). In an orthogonal frequency division multiple access system, one orthogonal frequency division multiple symbol consists of a plurality of subcarriers, and one transmission time interval constitutes an index structure of a physical channel composed of the plurality of orthogonal frequency division multiple symbols In the method, When the time and frequency resources in the one TTI are divided into N groups having a localized shape, the resources corresponding to the k th group are indexed into ordered pairs (N, k), Wherein said group corresponding to said ordered pair (N, k) is further subdivided into m groups over time and indexed into ordered pair (N, k, m). The method of claim 12, And a tree structure is formed between the physical channels indexed by the ordered pair (N, k).

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