KR101061131B1 - Signal transmission method in wireless communication system and apparatus therefor - Google Patents

Abstract

The present invention relates to a wireless communication system. Specifically, the present invention provides a method for transmitting data by a base station in a wireless communication system, comprising: grouping a plurality of subcarriers in a first Orthogonal Frequency Division Multiplexing (OFDM) symbol in a distributed resource by a predetermined number; Distributing a plurality of subcarrier groups according to the first permutation pattern; Transmitting data on a distributed subcarrier group in a first OFDM symbol; Grouping a plurality of subcarriers in a second OFDM symbol by a predetermined number in the distributed resource; Distributing a plurality of subcarrier groups according to a second permutation pattern; And transmitting data through a distributed subcarrier group in a second OFDM symbol.

Description

Method for transmitting signal in wireless communication system and apparatus therefor {METHOD OF TRANSMITTING SIGNALS AND AN APPRATUS THEREFORE}

The present invention relates to a wireless communication system. Specifically, the present invention relates to a signal transmission method and apparatus therefor in a wireless communication system.

1 illustrates a wireless communication system. Referring to FIG. 1, the wireless communication system 100 includes a plurality of base stations 110 and a plurality of terminals 120. The wireless communication system 100 may include a homogeneous network or a heterogeneous network. Here, the heterogeneous network refers to a network in which different network entities coexist such as a macro cell, a femto cell, a pico cell, a repeater, and the like. A base station is generally a fixed station that communicates with a terminal, and each base station 110a, 110b, and 110c provides services to specific geographic regions 102a, 102b, and 102c. In order to improve system performance, the particular area may be divided into a plurality of smaller areas 104a, 104b and 104c. Each smaller area may be referred to as a cell, sector or segment. In the case of an IEEE 802.16 system, a cell identifier (Cell ID; Cell_ID or IDCell) is assigned based on the entire system. On the other hand, the sector or segment identifier is given based on a specific area where each base station provides a service and has a value of 0 to 2. The terminal 120 is generally distributed in a wireless communication system and can be fixed or mobile. Each terminal may communicate with one or more base stations via uplink (UL) and downlink (DL) at any instant. The base station and the terminal are frequency division multiple access (FDMA), time division multiple access (TDMA), code division multiple access (CDMA), single carrier-FDMA (SC-FDMA), multi carrier-FDMA (MC-FDMA), and OFDMA ( Communication may be performed using Orthogonal Frequency Division Multiple Access) or a combination thereof. In the present specification, uplink refers to a communication link from a terminal to a base station, and downlink refers to a communication link from a base station to a terminal.

2 illustrates a channel change in frequency in a wireless communication system.

Referring to FIG. 2, when the system band is larger than the coherence bandwidth, the channel may show a sudden change in the system band. In this case, a frequency diversity gain can be obtained by widely distributing a signal to be transmitted within the entire or partial bandwidth on the frequency axis. For example, if an appropriate permutation is applied in the process of extracting a frequency resource for transmitting a signal, the transmitted signal may be mixed and spread within a corresponding bandwidth. Therefore, there is a continuous need for a permutation method for effectively distributing transmission signals within a corresponding bandwidth.

The present invention has been made to solve the problems of the prior art as described above, an object of the present invention to provide a signal transmission method and apparatus for the same in a wireless communication system.

Another object of the present invention is to provide a permutation method and apparatus therefor capable of increasing diversity gain in transmitting a signal.

Technical problems to be achieved in the present invention are not limited to the above-mentioned technical problems, and other technical problems not mentioned above will be clearly understood by those skilled in the art from the following description. Could be.

In one aspect of the present invention, a method for transmitting data by a base station in a wireless communication system, the method comprising: grouping a plurality of subcarriers in a first Orthogonal Frequency Division Multiplexing (OFDM) symbol within a distributed resource by a predetermined number; Distributing a plurality of subcarrier groups according to the first permutation pattern; Transmitting data on a distributed subcarrier group in a first OFDM symbol; Grouping a plurality of subcarriers in a second OFDM symbol by a predetermined number in the distributed resource; Distributing a plurality of subcarrier groups according to a second permutation pattern; And transmitting data through a distributed subcarrier group in a second OFDM symbol.

In another aspect of the present invention, an RF module configured to transmit a signal through a distributed resource to the terminal; And a processor configured to generate the signal, wherein the processor groups the plurality of subcarriers in a first Orthogonal Frequency Division Multiplexing (OFDM) symbol within the distributed resource by a predetermined number; Distributing a plurality of subcarrier groups according to the first permutation pattern; Transmitting data on a distributed subcarrier group in the first OFDM symbol; Grouping a plurality of subcarriers in a second OFDM symbol by a predetermined number in the distributed resource; Distributing a plurality of subcarrier groups according to a second permutation pattern; And transmitting data through a distributed subcarrier group in the second OFDM symbol.

In another aspect of the present invention, a method for processing data by a terminal in a wireless communication system, the method comprising: receiving a signal from a base station through a distributed resource; Grouping a plurality of subcarriers in a first Orthogonal Frequency Division Multiplexing (OFDM) symbol by a predetermined number in the distributed resource; Despreading a plurality of subcarrier groups according to the first permutation pattern; Decoding the data obtained through the group of subcarriers subcarriers in the first OFDM symbol; Grouping a plurality of subcarriers in a second OFDM symbol by a predetermined number in the distributed resource; Despreading a plurality of subcarrier groups according to a second permutation pattern; And decoding the data obtained through the despread subcarrier group in the second OFDM symbol.

In another aspect of the present invention, there is provided an RF module, comprising: an RF module configured to receive a signal via a distributed resource from a base station; And a processor configured to process the received signal, wherein the processor groups a plurality of subcarriers in a first Orthogonal Frequency Division Multiplexing (OFDM) symbol within the distributed resource by a predetermined number; Despreading a plurality of subcarrier groups according to the first permutation pattern; Decoding the data obtained through the group of subcarriers subcarriers in the first OFDM symbol; Grouping a plurality of subcarriers in a second OFDM symbol by a predetermined number in the distributed resource; Despreading a plurality of subcarrier groups according to a second permutation pattern; And decoding the data obtained through the despread subcarrier group in the second OFDM symbol.

Herein, the distributed resource may include one or more distributed resource units (DRUs).

Here, the plurality of subcarrier groups in each OFDM symbol may be configured from the remaining subcarriers except for the pilot subcarriers.

Here, the second permutation pattern may be transformed from the first permutation pattern using the OFDMA symbol index. In this case, the OFDMA symbol index may be used as a cyclic shift value or a masking value for the first permutation pattern.

Here, the first and second permutation patterns may be obtained using at least one of time variant intra-row permutation and time variant intra-column permutation.

Here, the first and second permutation patterns can be obtained using a permutation sequence according to the following equation:

Equation

g ( PermSeq (), s, m, l) = { PermSeq ({f (m, s) + s + l} mod { L _{DRU , FPi} }) + DL _ Permbase } mod { L _{DRU , FPi} }

Here, PermSeq () represents the basic permutation sequence of length L _{DRU , FPi} , L _{DRU, FPi} represents the number of DRUs included in the i -th frequency partition, and s is a logical DRU (LDRU). represents the index, l is and represents the OFDMA symbol index, DL _ PermBase represents an integer of 0 or more, mod denotes a (modulo) modulo operation.

According to the embodiments of the present invention, the following effects are obtained.

First, a method of transmitting a signal in a wireless communication system and an apparatus therefor may be provided.

Second, it is possible to provide a permutation method and apparatus therefor that can increase diversity gain in transmitting a signal.

The effects obtainable in the present invention are not limited to the above-mentioned effects, and other effects not mentioned above may be clearly understood by those skilled in the art from the following description. will be.

The construction, operation and other features of the present invention will be readily understood by the preferred embodiments of the present invention described with reference to the accompanying drawings. The embodiments described below are examples in which the technical features of the present invention are applied to a system using a plurality of orthogonal subcarriers. For convenience, the present invention is described using an IEEE 802.16 system, but this is exemplified, and the present invention can be applied to various wireless communication systems including a 3rd Generation Partnership Project (3GPP) system.

3 illustrates a block diagram of a transmitter and a receiver for OFDMA and SC-FDMA. In uplink, a transmitter may be part of a terminal and a receiver may be part of a base station. In downlink, a transmitter may be part of a base station and a receiver may be part of a terminal.

Referring to FIG. 3, an OFDMA transmitter includes a serial to parallel converter (202), a sub-carrier mapping module (206), an M-point inverse discrete fourier transform (IDFT) module, and the like. 208, a cyclic prefix (CP) addition module 210, a parallel to serial converter (212), and a Radio Frequency (RF) / Digital to Analog Converter (DAC) module 214. .

Signal processing in the OFDMA transmitter is as follows. First, a bit stream is modulated into a data symbol sequence. The bit stream may be obtained by performing various signal processing such as channel encoding, interleaving, scrambling, etc. on the data block received from the medium access control (MAC) layer. The bit stream is sometimes referred to as a codeword and is equivalent to a block of data received from the MAC layer. The data block received from the MAC layer is also called a transport block. The modulation scheme may include, but is not limited to, Binary Phase Shift Keying (BPSK), Quadrature Phase Shift Keying (QPSK), and Quadrature Amplitude Modulation (n-QAM). Thereafter, the serial data symbol sequences are converted N by N in parallel (202). The N data symbols are mapped to the allocated N subcarriers among the total M subcarriers, and the remaining M-N carriers are padded with zeros (206). Data symbols mapped to the frequency domain are converted to time domain sequences through M-point IDFT processing (208). Thereafter, in order to reduce Inter-Symbol Interference (ISI) and Inter-Carrier Interference (ICI), an OFDMA symbol is generated by adding a cyclic prefix to the time-domain sequence. The generated OFDMA symbols are converted 212 in parallel to serial. Thereafter, the OFDMA symbol is transmitted to the receiver through the process of digital-to-analog conversion, frequency upconversion, etc. (214). The other user is allocated available subcarriers among the remaining M-N subcarriers. On the other hand, the OFDMA receiver includes an RF / ADC (Analog to Digital Converter) module 216, a serial / parallel converter 218, a remove CP module 220, and an M-point Discrete Fourier Transform (DFT) module ( 224, subcarrier demapping / equalization module 226, parallel / serial converter 228, and detection module 230. The signal processing of the OFDMA receiver consists of the inverse of the OFDMA transmitter.

Meanwhile, the SC-FDMA transmitter further includes an N-point DFT module 204 before the subcarrier mapping module 206 as compared to the OFDMA transmitter. SC-FDMA transmitter can significantly reduce the peak-to-average power ratio (PAPR) of the transmission signal compared to the OFDMA scheme by spreading a plurality of data in the frequency domain through the DFT prior to IDFT processing. The SC-FDMA receiver further includes an N-point IDFT module 228 after the subcarrier demapping module 226 as compared to the OFDMA receiver. The signal processing of the SC-FDMA receiver consists of the inverse of the SC-FDMA transmitter.

The module illustrated in FIG. 3 is for illustrative purposes, and the transmitter and / or receiver may further include necessary modules, some modules / functions may be omitted, or may be separated into different modules, and two or more modules may be one module. It can be integrated into.

4 illustrates a radio frame structure of an IEEE 802.16m system. The radio frame structure may be applied to a frequency division duplex (FDD), a half frequency division duplex (H-FDD), a time division duplex (TDD), and the like.

Referring to FIG. 4, the radio frame structure includes a 20 ms superframe SU0-SU3 supporting a 5 MHz, 8.75 MHz, 10 MHz or 20 MHz bandwidth. The superframe includes four 5ms frames (F0-F3) having the same size and starts with a Superframe Header (SFH). The superframe header carries essential system parameters and system configuration information. The superframe header may be located within the first subframe. The superframe header may be classified into primary-SFH (P-SFH) and secondary-SFH (S-SFH). P-SFH is transmitted every superframe. S-SFH may be transmitted every superframe. The superframe header may include a broadcast channel.

The frame includes eight subframes SF0-SF7. Subframes are allocated for downlink or uplink transmission. The subframe includes a plurality of OFDM symbols in the time domain and includes a plurality of subcarriers in the frequency domain. The OFDM symbol may be called an OFDMA symbol, an SC-FDMA symbol, or the like according to a multiple access scheme. The number of OFDM symbols included in the subframe may be variously changed according to the channel bandwidth and the length of the CP. A type of a subframe may be defined according to the number of OFDM symbols included in the subframe. For example, the type-1 subframe may be defined to include 6 OFDM symbols, the type-2 subframe includes 7 OFDM symbols, the type-3 subframe includes 5 OFDM symbols, and the type-4 subframe includes 9 OFDM symbols. have. One frame may include all subframes of the same type or different subframes.

The OFDM symbol includes a plurality of subcarriers, and the number of subcarriers is determined according to the fast fourier transform (FFT) size. The types of subcarriers may be divided into data subcarriers for data transmission, pilot subcarriers for channel measurement, null subcarriers for guard bands, and DC components. Parameters that characterize an OFDM symbol are BW, N _used , n, G, and the like. BW is the nominal channel bandwidth. N _used is the number of subcarriers _used for signal transmission. n is a sampling factor and, together with BW and N _used , determines subcarrier spacing and useful symbol time. G is the ratio of CP time to useful time.

Table 1 shows an example of OFDMA parameters.

The subframe includes a plurality of physical resource units (PRUs) in the frequency domain. The PRU is a basic unit for resource allocation and is composed of a plurality of consecutive OFDM symbols in the time domain and a plurality of consecutive subcarriers in the frequency domain. For example, the number of OFDM symbols in the PRU may be the same as the number of OFDM symbols included in the subframe. Thus, the number of OFDM symbols in the PRU may be determined according to the type of subframe. Meanwhile, the number of subcarriers in the PRU may be 18. In this case, the PRU may consist of 6 OFDM symbols x 18 subcarriers. The PRU may be referred to as a distributed resource unit (DRU) or a continuous resource unit (CRU) according to a resource allocation scheme.

The above structure is merely an example. Accordingly, the length of the superframe, the number of frames included in the superframe, the number of subframes included in the frame, the number of OFDMA symbols included in the subframe, the parameters of the OFDMA symbols, and the like may be variously changed. For example, the number of subframes included in the frame may be variously changed according to a channel bandwidth and a length of a cyclic prepix (CP).

5 shows the structure of a superframe according to the duplex mode in the IEEE 802.16m system. This embodiment assumes an IEEE 802.16m only mode.

Referring to FIG. 5, in the FDD mode, since downlink transmission and uplink transmission are divided by frequency, a frame includes only one of a downlink subframe (D) and an uplink subframe (U). In the FDD mode, an idle time may exist at the end of every frame. On the other hand, since the downlink transmission and the uplink transmission in the TDD mode are separated by time, the subframes in the frame are divided into a downlink subframe (D) and an uplink subframe (U). There is a downtime called TTG (Transmit / receive Transition Gap) during the change from downlink to uplink, and there is a downtime called RTG (Receive / transmit Transition Gap) during the change from uplink to downlink. do. In the IEEE 802.16m system, the downlink synchronization channel includes a main synchronization channel and a floating channel, and is composed of a primary advanced preamble (PA-preamble) and a secondary advanced preamble (SA-preamble), respectively. The PA-preamble is used to obtain information such as time / frequency synchronization and partial cell identifiers, system information, and the like. The SA-preamble is used to obtain the final physical cell identifier, and may also be used for the purpose of measuring Received Signal Strength Indication (RSSI).

6 shows an example of a physical structure of a subframe in the IEEE 802.16m system.

Referring to FIG. 6, a subframe may be divided into at least one frequency partition (FP). 6 illustrates that a subframe is divided into two frequency partitions, but the number of frequency partitions is not limited thereto. Frequency division may be used for purposes such as Fractional Frequency Reuse (FFR).

Each frequency partition includes one or more PRUs. Distributed frequency allocation and / or contiguous resource allocation may be applied to each frequency partition. Logical Resource Unit (LRU) is a basic logical unit for distributed resource allocation and continuous resource allocation. The Logical Distributed Resource Unit (LDRU) includes a plurality of subcarriers Sc distributed in a frequency band. The size of the LDRU is equal to the size of the PRU. LDRU is also referred to as Distributed LRU (DLRU). The Logical Contiguous Resource Unit (LCRU) includes a contiguous subcarrier Sc. The size of the LCRU is equal to the size of the PRU. LCRU is also referred to as Contiguous LRU (CLRU).

7 illustrates a block diagram for a transmission chain in an IEEE 8002.16m system.

Referring to FIG. 7, a medium access control (MAC) block 702 configures MAC data from higher layer data. The size of the MAC data is scheduled in units of transmission time interval (TTI). MAC data may also be referred to as a transport block and correspond to a codeword in a later process. Forward Error Correction (FEC) block 704 performs channel coding on the MAC data. Channel coding may be performed using Turbo Coding (TC), Convolutional Turbo Coding (CTC), Low Density Parity Check (LDPC), and the like, but the present invention is not limited thereto. The coded data may be referred to as codewords or coded packet data. Mod (Modulation) block 706 modulates the coded data. Data modulation may be performed using modulation techniques such as Phase Shift Keying (n-PSK) and Quadrature Amplitude Modulation (n-QAM) (n: integer), but the present invention is not limited thereto. LRU assignment block 708 divides the modulated symbols into segments of LRU size, and then assigns each segment to an LRU. Mapping block 710 maps the LRUs to data bursts. Data bursts are assigned to PRUs in the physical frequency domain. Accordingly, the mapping block 710 performs a function of mapping the modulated data to the subcarriers according to the mapping relationship between the LRU and the PRU. The IFFT / CP block 710 converts a frequency domain signal into an inverse Fourier transform to a time domain signal, and adds a cyclic prefix to the time domain signal to generate an OFDMA symbol.

8 illustrates a process of mapping a resource unit.

Referring to FIG. 8, outer permutation may be performed on a physical frequency resource. External permutation is applied in at least one PRU unit. External permutation may be performed in units of N1 or N2 PRUs (N1> N2), and N1 and N2 may vary according to bandwidth. However, N1 needs to be an integer multiple of N2 for efficient external permutation. External permutation is divided into subband subband (SB) PRU (hereinafter referred to as PRU _SB ) and miniband (MB) PRU (hereinafter referred to as PRU _MB ) such as subband division and miniband permutation. It may mean a process of performing permutation of a PRU unit for the band PRU. The PRU _SB is the PRU to be allocated to the subbands, and the PRU _MB is the PRU to be allocated to the minibands. In the above process, N1 represents the number of PRUs included in the subband, and N2 represents the number of PRUs included in the miniband.

Next, distribute the rearranged PRU into frequency partitions. Each frequency segment is divided into a Logical CRU (LCRU) and a Logical DRU (LDRU). Sector Specific Permutation can be supported, and direct mapping of resources can be supported for consecutive resources. The size of distributed / continuous resources can be set flexibly per sector.

Next, contiguous and distributed groups are mapped to LRUs. Inner permutation (or subcarrier permutation), defined for distributed resource allocation, allows subcarriers to spread within the entire distributed resource. There is no internal permutation of consecutive resource allocations. PRUs are directly mapped to contiguous resource units within each frequency partition.

Meanwhile, a partial frequency reuse (FFR) technique may be used. The FFR technique is a technique of dividing an entire frequency band into a plurality of frequency partitions (FPs) and allocating a frequency partition to each cell. Different frequency partitions may be allocated between adjacent cells through the FFR scheme, and the same frequency partition may be allocated between distant cells. Therefore, interference between cells can be reduced, and performance of a cell edge terminal can be improved.

9 illustrates a subchannelization process. There are some things to consider for subchannelization. For example, performance of DRUs and CRUs, signaling overhead for resource allocation, channel quality indicator (CQI) feedback overhead, flexibility of the ratio between distributed and contiguous resources, scaling according to bandwidth (BW) Ease of use, ease of resource allocation order design, and ease of FFR setting are factors to be considered for subchannelization. For convenience of description, the total frequency band is 10 MHz, the total number of PRUs is 48, N ₁ = 4, the number of subbands having a granularity of N ₁ (N _N1 ) is 6, and N ₂ = 1 illustrates a case where the number N _N2 of minibands having a granularity of N ₂ is 24.

Referring to FIG. 9, the PRU in the physical region is divided into subband PRUs or miniband PRUs, which are logical regions, through external permutation of the N1 granularity, and the permutation is divided into N2 granularities for the miniband PRU. It is performed (S900).

The subband PRU or miniband PRU is distributed to each frequency partition, and permutation is performed to distinguish continuous resources L and distributed resources D in each frequency partition (S910). The process of distributing the subband PRU or the miniband PRU to each frequency partition may be performed by being included in the external permutation process of step S900 or may be performed independently. When performed independently, it may be performed based on frequency partition information broadcast through SFH or based on a separate distribution rule. Inner permutation is additionally performed to obtain diversity gain for distributed resources (S920).

10A and 10C illustrate an example of performing permutation using block interleaving. Block interleaving includes row-wise index writing, intra-row permutation, intra-column permutation, and column-wise index reading It may include. The order of each step may be changed freely by way of example. Hereinafter, a case of block interleaving of resource indexes 0 to 40 will be described with reference to the drawings. Each resource index indicates a base resource to be interleaved, and each base resource may be adjacent to each other in the frequency domain.

10A shows a result of recording resource indices 0 to 40 in a row-direction in an interleaving matrix. This embodiment has illustrated an 8x5 interleaving matrix, but the invention is not so limited. After row-direction writing, intra-row permutation may be applied to the interleaving matrix. In-row permutation may be performed using a permutation pattern shared between the transmitting and receiving end. 10B (a) shows an example of an intra-row permutation pattern shown in matrix form. As another example, intra-row permutation may be performed using a basic permutation sequence of length 5. In this embodiment, the basic permutation sequence is illustrated as [0, 3, 1, 4, 2]. 10B (a) shows the results of the intra-row permutation. In-row permutation shows that the resource indexes are shuffled within the row.

After intra-row permutation, intra-column permutation may be applied to the interleaving matrix. In-row permutation may be performed using a permutation pattern shared between the transmit and receive ends. 10C (a) shows an example of an intra-column permutation pattern shown in matrix form. As another example, intra-row permutation may be performed using a permutation sequence of length 8. In this embodiment, the basic permutation sequence is illustrated as [0,5,2,7,4,1,6,3]. 10C (a) shows the results of the intra-row permutation performed. Intra-column permutation shows that the resource indexes are intermingled within the column. After intra-column permutation, the resource index recorded in the interleaving matrix is read in the column-direction. As a result, the original resource index [0,1,2,3,4,5,... , 40 is [0,25,11,36,22,8,... [38].

Block interleaving allows resources to be effectively mixed and distributed within a distributed resource domain. Therefore, a frequency diversity gain can be sufficiently obtained when a signal is transmitted using a predetermined resource to which block interleaving is applied. However, conventionally, since the permutation pattern for block interleaving was time independent, the output pattern of block interleaving was always the same. Therefore, according to the conventional block interleaving, frequency resources are effectively distributed in the corresponding domain, but relatively the same frequency resources continue to be adjacent in the time domain. The regular arrangement of resources in the time domain reduces the effects of interference randomization and thus degrades system performance.

Example: Resources Based on Time Parameters Permutation

11 is a flowchart illustrating a method of performing permutation in consideration of time and transmitting data using distributed resources according to an embodiment of the present invention.

Referring to FIG. 11, radio resources may be grouped into a plurality of permutation units for each time unit (S1110). The radio resource may include at least some bands within a system band. The permutation unit may include a subcarrier or a multiple of subcarriers in the frequency domain as a basic unit for interleaving. The time unit for permutation may include an OFDMA symbol or a multiple of an OFDMA symbol. The plurality of permutation units are newly indexed in each time unit (S1120). A plurality of newly numbered permutation units are interleaved according to the permutation pattern. In this case, the block interleaving method illustrated in FIG. 10 may be used. In addition, a permutation sequence for interleaving may be used. However, the permutation pattern for interleaving will vary depending on the time unit (S1130). For example, permutation based on a time parameter may be performed using at least one of a time variant intra-row permutation and a time varying intra-permutation. Accordingly, when data is transmitted using a plurality of frequency resources and a plurality of time resources, the transmitting end may disperse and mix resources for data transmission in a frequency domain in a form changed over time. Thereafter, the transmitting end may transmit data to the receiving end using the interleaved resources (S1140).

12 illustrates an example of performing permutation in consideration of time according to an embodiment of the present invention. Referring to FIG. 12, it can be seen that the block interleaving pattern is changed according to time t. This embodiment exemplifies a case of shifting three spaces downward by the time t in the process of performing intra-row permutation (see hatched portion). As another example, time t may affect in-row permutation or may affect both in-column and in-row permutation. Also, the time t can affect the permutation pattern in various ways, such as shifting, masking, and the like.

Hereinafter, a method of applying an embodiment of the present invention using an internal permutation applied to a downlink DRU will be described in detail.

FIG. 13 is a flowchart for performing internal permutation in consideration of time and transmitting data using distributed resources according to an embodiment of the present invention.

Referring to FIG. 13, data subcarriers in distributed resources may be grouped in pairs for each OFDMA symbol unit, and new indexes may be assigned to all data subcarrier pairs (S1410). The distributed resources may include one or more PRUs (ie, DRUs). The newly numbered data subcarrier pairs are interleaved according to the permutation pattern. In this case, the block interleaving method illustrated in FIG. 10 may be used. In addition, a permutation sequence for interleaving may be used. However, the permutation pattern is changed according to the OFDMA symbol (S1420). For example, the permutation based on the time parameter may be performed using at least one of time-varying in-row permutation and time-varying in-row permutation. Therefore, when transmitting data using one or more PRUs, the transmitting end may distribute and disperse resources for data transmission in a frequency domain in a form changed over time. Thereafter, the transmitting end may configure the downlink subchannel using the interleaved data subcarrier pair and the pilot subcarrier pair in its original position (S1420). The downlink subchannel corresponds to the LRU. Thereafter, the transmitting end may transmit data to the receiving end through the subchannel (S1440).

14 illustrates a process of dividing a downlink DRU into permutation units.

Referring to FIG. 14, one DRU includes 18 subcarriers (P _sc = 18) × 6 OFDMA symbols (N _sym = 6). In the DRU, a predetermined position / number of resource elements is used for transmitting pilots, and the remaining resource elements are used for transmitting data. This embodiment exemplifies that two consecutive subcarriers per OFDMA symbol are used for pilot transmission in a DRU. Meanwhile, the pilot subcarriers may be separated from each other. Internal permutation is performed together for one or more DRUs, and may be performed in units of subcarrier pairs. To this end, the DRU pairs the remaining subcarriers except for the pilot subcarriers in OFDMA symbol units and newly assigns an index. When each OFDMA symbol in the DRU includes two pilot subcarriers, the number (N _{pair , PRU} ) of data subcarrier pairs included in the OFDMA symbol is eight. Since the present embodiment assumes that the number of DRUs (N _DRUs ) is two, the total number of data subcarrier pairs (N _pair = N _{pair , PRU} × N _DRU ) is 16. Data subcarrier pairs are sequentially numbered 0-15.

Note that in downlink, internal permutation is performed only for the data subcarriers and not for the pilot subcarriers. Internal permutation may be performed using the block interleaving scheme illustrated in FIG. 10. In this case, the interleaving matrix may be an N _{pair, PRU} x N _DRU matrix. In the interleaving matrix, the row index m has a value of 0 to N _{pair and PRU} −1, and the column index n has a value of 0 to N _DRU −1.

Example  1: block Interleaving  Of distributed resources used Permutation

15A-15C illustrate an example of performing internal permutation when N _DRU = 5 according to an embodiment of the present invention. This embodiment exemplifies a case in which internal permutation is performed by using block interleaving illustrated in FIGS. 10A-10C, but internal permutation is performed in consideration of a time parameter (eg, OFMDA symbol index).

FIG. 15A illustrates a result of grouping all subcarriers constituting five DRUs into subcarrier pairs for each OFDMA symbol and newly assigning an index to all data subcarrier pairs. Since the number of data subcarrier pairs (N _{pair , PRU} ) is 8 in one DRU, a total of 40 data subcarrier pairs are generated (index: 0 to 39). Although FIG. 15A illustrates a pilot subcarrier pair as P, since internal permutation is applied only to the data subcarrier pair, the pilot subcarrier is not considered in a subsequent process.

15B illustrates a process of performing intra-row permutation for each OFDMA symbol. The permutation pattern used for in-row permutation is the same as illustrated in FIG. 10B. However, the permutation pattern according to the embodiment of the present invention may be changed in a predetermined manner from the basic permutation pattern according to the OFDMA symbol index. Here, it is assumed that the basic permutation pattern is a permutation pattern applied to the 0 th OFDMA symbol for convenience. As such, by performing time-varying in-row permutation, the result of the internal permutation can be varied over time. Specifically, in this embodiment, the permutation pattern used for each OFDMA symbol is generated by cyclically shifting the basic permutation pattern to the left by the OFDMA symbol index.

15C illustrates a process of performing intra-column permutation for each OFDMA symbol. The permutation pattern used for in-row permutation is the same as illustrated in FIG. 10C. This embodiment illustrates the same intra-column permutation pattern for each OFDMA symbol. That is, this embodiment assumes a case of performing time invariant intra-permutation. After performing intra-column permutation, the data subcarrier pair indices in the interleaving matrix are read in the column-direction and sequentially mapped to corresponding OFDMA symbols in the subchannel (or LRU). When the subchannel is formed, the position where the pilot subcarriers are mapped is fixed, and therefore, the data subcarrier pairs are mapped to avoid the pilot subcarriers.

The internal permutation described above illustrates the case where it is performed by a block interleaving method including a row-direction write step, a time-dependent intra-row permutation step, an intra-column permutation step, and a column-direction read step. However, this is by way of example and the present invention is not limited thereto. Although FIG. 15 illustrates a case in which time-varying internal permutation is performed using block interleaving, it is not limited to implementing time-varying internal permutation as an example. Hereinafter, various modified examples of performing time-varying internal permutation will be described in detail.

Example  2-1: Sequence  Of distributed resources used Permutation

Permutation for distributed resources may be performed by the rules described below without using block interleaving. For the m-th subcarrier pair in the s-th LRU in the t-th OFDMA symbol, the permutation index R [n, m, t] (that is, the index of the physical subcarrier pair) may be defined as Equation 1 below.

R [n, m, t] = s × N _DRU + P [(n + s) mod N _DRU ], where s = (f ₁ × m + f ₂ × n + t) mod N _{pair , PRU}

In the above equation, N _DRU represents the number of distributed resource units and mod represents a modulo operation. That is, A mod B represents the remainder of A divided by B. P [.] Also represents the base sequence of length N _DRUs for intra-row permutation. Each element of P [·] may have a value from 0 to N _DRU −1. In addition, N _{pair and PRU} indicate the number of data subcarrier pairs included in one resource unit.

Wherein, f ₁ is a positive integer of N _pair and cattle (prime) to each other. If not performing intra-row permutation, f ₁ may be set to one. In addition, f ₂ is a positive integer. When f ₂ is small with N _DRU , each column has a different intra-row permutation pattern. To use the same in-row permutation pattern, f ₂ can be set to zero. In addition, when the time parameter t is not used, the permutation sequence has a time-invariant characteristic. The above equation may be described as in Equation 2.

R [n, m, t] = s × N _DRU + P _s [n], where s = (f ₁ × m + f ₂ × n + t) mod N _{pair , PRU}

In the above formula, P _s [·] can be obtained by cyclically rotating the basic permutation sequence P [·] to the left.

Meanwhile, the basic permutation sequence P [·] may be generated by a random sequence generation algorithm. Although not limited thereto, a basic permutation sequence P [·] of length L may be generated to satisfy a condition defined in the following equation.

(P [i + 1]-P [i]) mod L = D or D + 1

The random sequence that satisfies the above condition is referred to as Almost Equidistance Permutation Sequence (AEPS), and the permutation sequence P [i] is distributed to have almost equal intervals D. Also, if the offset O is defined, the permutation sequence will start from the value of (0 mod L). Specifically, the basic permutation sequence P [·] satisfying the above condition may be defined as in Equation 4 below.

P [i] = {D × i + O + floor (i / W)} mod L, where i = 0, 1,... , L-1

Here, D represents a positive integer less than L, O represents an offset value for the permutation sequence, and W may be defined as W = L / GCD (L, D) as the window size. Here, GCD (L, D) represents the greatest common divisor of L and D.

As an example, an example of an AEPS sequence may be as follows.

L = 14, D = 6 and O = 0; P = {0,6,12,4,10,2,8,1,7,13,5,11,3,9}

L = 16, D = 4 and O = 3; P = {3,7,11,15,4,8,12,0,5,9,13,1,6,10,14,2}

L = 18, D = 7 and O = 6; P = {6,13,2,9,16,5,12,1,8,15,4,11,0,7,14,3,10,17}

A. Time-varying  In-row permutation ( time variant intra - row permutation )and Time-varying  In-column permutation ( intra-column permutation ) Permutation sequence  produce

Time-varying in-row permutation may also be applied to the permutation pattern generated according to Equation (2). In this case, the time parameter t can be used as the shift value or masking value of the intra-row permutation.

In-row permutation using the time parameter as the shift value

R [n, m, t] = s × N _DRU + P _{(s + t)} [n]

Where s = (f ₁ × m + f ₂ × n + t) mod N _{pair , PRU}

In-row permutation using time parameters as masking values

R [n, m, t] = s × N _DRU + (P _s [n] + t) mod N _DRU

Where s = (f ₁ × m + f ₂ × n + t) mod N _{pair , PRU}

P _s [·] is obtained by rotating the basic permutation sequence P [·] left s times. In addition, using the permutation sequence P _time [] using the time parameter as the input index, P _time [t] instead of t may be used as a time shift value or a masking value in the above equations.

B. Cell-specific Time-varying ( cell - specific - time variant ) In-row Permutation  Cell-specific-time varying column-in Permutation  Used Permutation sequence  produce

Time-varying in-row permutation may also be applied to the permutation pattern generated according to Equation (2). In this case, the time parameter t may be used as a shift value or masking value of in-row permutation together with Coeff (Cell_ID), which is a cell-specific coefficient. Here, Coeff (·) represents a function that takes a Cell Identity (Cell_ID) as an argument.

In-row permutation using the time parameter as the shift value

R [n, m, t, Cell_ID] = s x N _DRU + P _{(s + Coeff ( Cell _ ID ) x t)} [n]

Where s = (f ₁ × m + f ₂ × n + Coeff (Cell_ID) × t) mod N _{pair , PRU}

In-row permutation using time parameters as masking values

R [n, m, t, Cell_ID] = s x N _DRU + (P _s [n] + Coeff (Cell_ID) x t) mod N _DRU

Where s = (f ₁ × m + f ₂ × n + Coeff (Cell_ID) × t) mod N _{pair , PRU}

C. Time-varying  In-row Permutation  Hour-unchanging time invariant A) heat- mine Permutation  Used Permutation sequence  produce

For time-invariant intra-permutation, the time parameter t is not used to calculate the s value. In this case, the time parameter t is used only for intra-row permutation.

In-row permutation using the time parameter as the shift value

R [n, m, t] = s × N _DRU + P _{(s + t)} [n]

Where s = (f ₁ × m + f ₂ × n) mod N _{pair , PRU}

In-row permutation using time parameters as masking values

R [n, m, t] = s × N _DRU + (P _s [n] + t) mod N _DRU

Where s = (f ₁ × m + f ₂ × n) mod N _{pair , PRU}

D. Cell-specific Time-varying  In-row Permutation  City-invariant heat-my Permutation  Used Permutation sequence  produce

For time-invariant intra-permutation, the time parameter t is not used to calculate the s value. In this case, the time parameter t is used only for in-row permutation with Coeff (Cell_ID), a cell-specific coefficient.

In-row permutation using the time parameter as the shift value

R [n, m, t, Cell_ID] = s x N _DRU + P _{(s + Coeff ( Cell _ ID ) x t)} [n]

Where s = (f ₁ × m + f ₂ × n) mod N _{pair , PRU}

In-row permutation using time parameters as masking values

R [n, m, t, Cell_ID] = s x N _DRU + (P _s [n] + Coeff (Cell_ID) x t) mod N _DRU

Where s = (f ₁ × m + f ₂ × n) mod N _{pair , PRU}

E. Cell-specific Shift /- Masking  And A time variable  In-row Permutation  City-invariant heat-my Permutation  Used Permutation sequence  produce

If the base sequence P [·] for intra-row permutation is a cell common permutation pattern, one may consider applying one or more shift or masking values based on the cell identifier to the intra-row permutation. .

In-row permutation using time and cell specific parameters as shift values

R [n, m, t, Cell_ID] = s × N _DRU + P _{(s + t + SM ( Cell _ ID ))} [n]

Where s = (f ₁ × m + f ₂ × n) mod N _{pair , PRU}

In-row permutation using time and cell specific parameters as masking values

R [n, m, t, Cell_ID] = s × N _DRU + (P _s [n] + t + SM (Cell_ID)) mod N _DRU

Where s = (f ₁ × m + f ₂ × n) mod N _{pair , PRU}

In the above formula, SM (Cell_ID) represents a cell-specific shift or masking value.

F. Cell-specific Shift /- Masking  And cell-specific- A time variable  In-row Permutation  City-invariant heat-my Permutation  Used Permutation sequence  produce

If the base sequence P [·] for intra-row permutation is a cell common permutation pattern, one may consider applying one or more shift or masking values based on the cell identifier to the intra-row permutation. have. In this case, the cell-specific shift / masking value and the cell-specific time parameter may be used together in the in-row permutation.

In-row permutation using time and cell specific parameters as shift values

R [n, m, t, Cell_ID] = s × N _DRU + P _{(s + Coeff ( Cell _ ID ) × t + SM ( Cell _ ID ))} [n]

Where s = (f ₁ × m + f ₂ × n) mod N _{pair , PRU}

In-row permutation using time and cell specific parameters as masking values

R [n, m, t, Cell_ID] = s × N _DRU + (P _s [n] + Coeff (Cell_ID) × t + SM (Cell_ID)) mod N _DRU

Where s = (f ₁ m + f ₂ × n) mod N _{pair , PRU}

16-18 illustrate results of time-varying permutation on distributed resources according to an embodiment of the present invention. 16 was performed using time-invariant intra-row permutation and time-varying column-permutation. 17 was performed using time varying intra-row permutation and time varying intra-permutation. 18 was performed using time varying intra-row permutation and time-invariant intra-permutation. This example was performed under the following conditions using equations (2) and (4).

16: D = 3, L = 5, O = 0, N _pair = 8, N _DRU = 5, s = (5 × m + 7 × n + t) mod 8 and t = 0-5

Figure 17: D = 3, L = 5, O = 0, N _pair = 8, N _DRU = 5, s = (5 × m + 7 × n + t) mod 8 and t = 0-5

Figure 18: D = 3, L = 5, O = 0, N _pair = 8, N _DRU = 5, s = (5 × m + 7 × n) mod 8 and t = 0-5

16A, 17A, and 18A show a result of applying a time variant permutation sequence based on the original sequence and the OFDMA symbol index t. Each number in 16a, 17a, and 18a represents a data subcarrier pair index included in an OFDMA symbol. The data subcarrier pair index is given in consideration of the entire data subcarrier pair included in the plurality of DRUs. PRU grouping is a grouping of a plurality of logically adjacent data subcarrier pairs by the number of DRUs. 16B, 17B, and 18B, each number represents a group number and element index within each group. From the figure, it can be seen that distributed resources are distributed in different patterns over time.

Example  2-2: Sequence  Of distributed resources used Permutation

The symbols used in this embodiment are used the same as described above, unless otherwise defined. It should be noted, however, that some symbols have been defined to have different meanings from those described above for convenience. Some symbols are defined as follows.

Psc : Number of subcarriers of the l- th OFDMA symbol in the PRU

n _l : Number of pilot subcarriers of the l- th OFDMA symbol in the PRU

L _{SC , l} : Number of data subcarriers of the l- th OFDMA symbol in the PRU ( Psc - n _l )

L _{SP , l} : Number of data subcarrier pairs of l- th OFDMA symbol in PRU ( L _{SC , l} / 2)

PermSeq () : Permutation sequence for subcarriers (eg AEPS)

Permutation of distributed resources using a sequence may be performed as follows.

Step 1: allocates n _l pilot the l- th OFDMA symbol of each DRU. The data subcarriers of the DRU _FPi [ j ] in the l- th OFDMA symbol are represented by SC _{DRUj , l, FPi} (0 <= j < L _{DRU , FPi} ). Where SC _{DRUj , l, FPi} is It has a value from 0 to L _{SC , l} -1.

Step 2: sequentially number L _{DRUs , FPi} × L _{SCs , and l} data subcarriers included in the _DRUs from 0 to L _{DRUs , FPi} × L _{SCs , and} −1. Group a plurality of logically newly numbered contiguous data subcarriers into L _{DRU , FPi} × L _{SP , l} subcarrier pairs, and newly numbered from 0 to L _{DRU , FPi} × L _{SP , l} -1 for each subcarrier pair Tie. The newly numbered subcarrier pair in the l- th OFDMA symbol is referred to as RSP _{l , FPi} . RSP _{1 , FPi} may be defined as follows.

where,

는 내림 함수(floor)를 나타낸다.From here,

Represents a floor function.

Step 3: The subcarrier permutation equation is applied to RSP _{l and FPi} to form permuted subcarrier pairs (PSP) (0 to L _{DRU , FPi} × L _{SP , l} −1). Map PSP [ s x L _{SP , l} , ( s + 1 ) x L _{SP, l} -1] to the s -th distributed LRU ( s = 0, 1,... L _{DRU , FPi} -1). The subcarrier permutation equation may be defined as follows.

는 t-번째 서브프레임의 s-번째 분산 LRU에서 l-번째 OFDMA 심볼(0≤l< N _sym ) 내의 m-번째 부반송파(0≤m<L _{SP ,l} )를 나타낸다. 여기에서, t는 프레임을 기준으로 정의된 서브프레임 인덱스이다. s는 분산 LRU 인덱스(0≤s<L _{DRU , FPi} )를 나타낸다(0≤s<L _{DRU , FPi} ).From here,

Denotes the m-th subcarrier (0 ≦ m < L _{SP , l} ) in the l -th OFDMA symbol (0 ≦ l < N _sym ) in the s -th distributed LRU of the t-th subframe. Here, t is a subframe index defined based on the frame. s denotes a distributed LRU index (0 ≦ s < L _{DRU , FPi} ) (0 ≦ s < L _{DRU , FPi} ).

Where k is With the formula  Can be defined as:

k = L _{DRU , FPi} × f (m, s) + g ( PermSeq (), s, m, l, t),

k = { L _{DRU , FPi} × f (m, s) + g ( PermSeq (), s, m, l, t) + l × L _{SP , l} } mod { L _{SP , l} × L _{DRU , FPi} }, or

k = L _{DRU , FPi} × f (m, s) + {g ( PermSeq (), s, m, l, t) + l × L _{SP , l} + DL _ PermBase } mod { L _{DRU , FPi} }

Here, f (m, s) is a function having a value of [0, L _{SP , l} -1]. g ( PermSeq (), s, n, t) represents the permutation sequence of length L _{DRU , FPi} −1. As an example, g ( PermSeq (), s, n, t) may be a permutation sequence having a value of [0, L _{DRU , FPi} −1]. That is, each element of g ( PermSeq (), s, n, t) may have a value of any one of [0, L _{DRU , FPi} −1]. PermSeq () represents a basic permutation sequence of length L _{DRU , FPi} . For example, it may be a permutation sequence having a value of [0, L _{DRU , FPi} −1] of PermSeq () . That is, each element of PermSeq () may have a value of any one of [0, L _{DRU , FPi} −1]. PermSeq () can be obtained using a known random sequence generation method. For example, PermSeq () may be obtained using an AEPS sequence generation method. DL _ PermBase represents an integer of 0 or more, and can be replaced with the values associated with the Cell_ID or Cell_ID.

f (m, s) The With the formula  Can be defined as:

f (m, s) = ( f ₁ × m + f ₂ × s) mod L _{SP , l,}

f (m, s) = (5m + 7s) mod L _{SP , l} ,

f (m, s) = (m + 13s) mod L _{SP , l} , or

f (m, s) = (m + 17s) mod L _{SP , l}

Here, f ₁ represents a positive integer that is prime with L _{SP , l,} and f ₂ represents a positive integer that is prime with each other _{, such as} 0 or L _{SP , l,} and m, s, and mod are as defined above.

g ( PermSeq (), s, m, l, t) The With the formula  Can be defined as:

g ( PermSeq (), s, m, l, t) = PermSeq ({f (m, s) + s + l} mod { L _{DRU , FPi} }),

g ( PermSeq (), s, m, l, t) = PermSeq ({f (m, s) + s + h ( cell _ ID , L _{DRU , FPi} ) × l} mod { L _{DRU , FPi} }),

g ( PermSeq (), s, m, l, t) = { PermSeq ({f (m, s) + s + l} mod { L _{DRU , FPi} }) + DL _ Permbase } mod { L _{DRU , FPi} },

g ( PermSeq (), s, m, l, t) = { PermSeq ({f (m, s) + s + h ( cell _ ID , L _{DRU , FPi} ) × l} mod { L _{DRU , FPi} }) + DL _ PermBase } mod { L _{DRU , FPi} },

g ( PermSeq (), s, m, l, t) = PermSeq ({f (m, s) + s + l + q (N_ sym , cell _ ID , L _{DRU , FPi} ) × t} mod { L _{DRU , FPi} }),

g ( PermSeq (), s, m, l, t) = PermSeq ((f (m, s) + s + h ( cell _ ID , L _{DRU , FPi} ) × l + q (N_ sym , cell _ ID , L _{DRU , FPi} ) × t} mod { L _{DRU , FPi} }),

g ( PermSeq (), s, m, l, t) = {PermSeq ({f (m, s) + s + l + q (N_ sym , cell _ ID , L _{DRU , FPi} ) × t} mod {L _{DRU, FPi} }) + DL_PermBase} mod { L _{DRU , FPi} }, or

g ( PermSeq (), s, m, l, t) = {PermSeq ((f (m, s) + s + h ( cell _ ID , L _{DRU , FPi} ) × l + q (N_ sym , cell _ ID , L _{DRU , FPi} ) × t} mod { L _{DRU , FPi} }) + DL _ PermBase } mod { L _{DRU , FPi} }

Here, h ( cell _ ID , L _{DRU , FPi} ) represents a cell identifier and a function of L _{DRU , FPi} . For example, h (cell_ID, L _{DRU, FPi} ) = prime (eg, 107), D _SP , O _SP or DL _ PermBase . D _SP And O _SP will be described later.

Here, q (N_ sym , cell _ ID , L _{DRU , FPi} ) indicates the number of OFDMA symbols (N_sym), the cell identifier, and the function of L _{DRU , FPi ,} of the PRU. For example, q (N_ sym , cell _ ID , L _{DRU , FPi} ) = N_ sym , decimal, D _SP , O _SP or DL _ PermBase .

PermSeq () The With the formula  Can be defined as:

Here, D _SP determines the distance between logically adjacent subcarrier pairs in the sequence, and O _SP determines the starting position (ie, offset) of the subcarrier pair in the sequence. D _SP And O _SP Can be defined as a function of Cell_ID, L _{DRU , and FPi} . For example, D _SP And O _SP may be defined as in the following equation.

D _SP = f (SEED) and O _{SP =} g (SEED)

Here, SEED can be obtained using a function that takes a cell identifier as an argument (SEED = p (Cell_ID)). For example, SEED = {Cell_ID × decimal} mod {2 ^{Number of SEED bits} }.

Here, f (SEED) and g (SEED) each represent a function that takes a SEED value as a factor. For example, f (SEED) = floor (SEED / 2 ⁵ ) +1 and g (SEED) = {SEED} mod {2 ⁵ }. floor () represents a rounding function.

Here, D _SP and O _SP may be exchanged with each other. _SP and _SP in D O L _{DRU, FPi} -1 may be replaced with L _{DRU, FPi.} In D _SP and O _SP , +1 at the end of the equation can be omitted.

19 illustrates a block diagram of a transmitter and a receiver according to an embodiment of the present invention. In downlink, the transmitter 1910 is part of a base station and the receiver 1950 is part of a terminal. In uplink, transmitter 1910 is part of a terminal and receiver 1950 is part of a base station.

The transmit (TX) data and pilot processor 1920 at the transmitter 1910 encodes, interleaves, and symbol maps the data (eg, traffic data and signaling) to generate data symbols. In addition, the processor 1920 generates pilot symbols to multiplex the data symbols and the pilot symbols. The modulator 1930 generates a transmission symbol according to a wireless access scheme. Radio access schemes include FDMA, TDMA, CDMA, SC-FDMA, MC-FDMA, OFDMA, or a combination thereof. In addition, the modulator 1930 enables data to be distributed and transmitted in the frequency domain and the time domain using various permutation methods illustrated in the embodiments of the present invention. A radio frequency (RF) module 1932 processes (eg, analog converts, amplifies, filters, and frequency upconverts) the transmit symbol to generate an RF signal transmitted through the antenna 1934. At the receiver 1950, the antenna 1952 receives the signal transmitted from the transmitter 1910 and provides it to the RF module 1954. The RF module 1954 processes (eg, filters, amplifies, frequency downconverts, and digitizes) the received signal to provide input samples. Demodulator 1960 demodulates the input samples to provide a data value and a pilot value. Channel estimator 1980 derives a channel estimate based on the received pilot values. In addition, demodulator 1960 performs data detection (or equalization) on the received data values using the channel estimate and provides data symbol estimates for transmitter 1910. In addition, the demodulator 1960 may rearrange data distributed in the frequency domain and the time domain in an original order by performing an inverse operation with respect to the various permutation methods illustrated in the embodiment of the present invention. Rx data processor 1970 symbol demaps, deinterleaves and decodes the data symbol estimates and provides decoded data. In general, processing by demodulator 1960 and RX data processor 1970 at receiver 1950 is complementary to processing by modulator 1930 and TX data and pilot processor 1920 at transmitter 1910, respectively.

Controllers / processors 1940 and 1990 supervise and control the operation of the various processing modules residing in transmitter 1910 and receiver 1950, respectively. Memory 1942 and 1992 store program codes and data for transmitter 1910 and receiver 1950, respectively.

The module illustrated in FIG. 19 is for illustrative purposes, and the transmitter and / or receiver may further include necessary modules, some modules / functions may be omitted, or may be separated into different modules, and two or more modules may be one module. It can be integrated into.

The embodiments described above are the components and features of the present invention are combined in a predetermined form. Each component or feature is to be considered optional unless stated otherwise. Each component or feature may be implemented in a form that is not combined with other components or features. It is also possible to combine some of the components and / or features to form an embodiment of the invention. The order of the operations described in the embodiments of the present invention may be changed. Some configurations or features of certain embodiments may be included in other embodiments, or may be replaced with corresponding configurations or features of other embodiments. It is obvious that the claims may be combined to form an embodiment by combining claims that do not have an explicit citation relationship in the claims or as new claims by post-application correction.

In this document, the embodiments of the present invention have been mainly described with reference to the data transmission / reception relationship between the terminal and the base station. The specific operation described herein as being performed by the base station may be performed by its upper node, in some cases. That is, it is obvious that various operations performed for communication with the terminal in a network including a plurality of network nodes including a base station may be performed by the base station or other network nodes other than the base station. A 'base station' may be replaced by terms such as a fixed station, a Node B, an eNode B (eNB), an access point, and the like. In addition, the term "terminal" may be replaced with terms such as a user equipment (UE), a mobile station (MS), a mobile subscriber station (MSS), and the like.

Embodiments according to the present invention may be implemented by various means, for example, hardware, firmware, software, or a combination thereof. In the case of a hardware implementation, an embodiment of the present invention may include one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), FPGAs ( field programmable gate arrays), processors, controllers, microcontrollers, microprocessors, and the like.

In the case of implementation by firmware or software, an embodiment of the present invention may be implemented in the form of a module, procedure, function, etc. that performs the functions or operations described above. The software code may be stored in a memory unit and driven by a processor. The memory unit may be located inside or outside the processor, and may exchange data with the processor by various known means.

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit of the invention. Accordingly, the above detailed description should not be construed as limiting in all aspects and should be considered as illustrative. The scope of the invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the invention are included in the scope of the invention.

The present invention can be applied to a wireless communication system. Specifically, the present invention can be applied to a signal transmission method and an apparatus therefor in a wireless communication system.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included as part of the detailed description in order to provide a thorough understanding of the present invention, provide an embodiment of the present invention and together with the description, illustrate the technical idea of the present invention.

1 illustrates a wireless communication system.

2 illustrates a channel change in frequency in a wireless communication system.

3 illustrates a block diagram of a transmitter and a receiver for OFDMA and SC-FDMA.

4 illustrates a radio frame structure of an IEEE 802.16m system.

5 shows the structure of a superframe according to the duplex mode in the IEEE 802.16m system.

6 shows an example of a physical structure of a subframe in the IEEE 802.16m system.

7 illustrates a block diagram for a transmission chain in an IEEE 8002.16m system.

8 illustrates a process of mapping a resource unit.

9 illustrates a subchannelization process.

10A and 10C illustrate an example of performing permutation using block interleaving.

11 is a flowchart illustrating a method of performing permutation in consideration of time and transmitting data using distributed resources according to an embodiment of the present invention.

12 illustrates an example of performing permutation in consideration of time according to an embodiment of the present invention.

FIG. 13 is a flowchart for performing internal permutation in consideration of time and transmitting data using distributed resources according to an embodiment of the present invention.

14 illustrates a process of dividing a downlink DRU into permutation units.

15A and 15C illustrate an example of performing internal permutation when NDRU = 5 according to an embodiment of the present invention.

16-18 illustrate results of time-varying permutation on distributed resources according to an embodiment of the present invention.

19 illustrates a block diagram of a transmitter and a receiver according to an embodiment of the present invention.

Claims (28)

In a method for transmitting a signal by a base station in a wireless communication system, Grouping a plurality of subcarriers in a first Orthogonal Frequency Division Multiple Access (OFDMA) symbol by a predetermined number in one or more Distributed Resource Units (DRUs); Permutating a plurality of subcarrier groups to have a first pattern in the first OFDMA symbol; Transmitting a signal on a distributed subcarrier group in the first OFDMA symbol; Grouping a plurality of subcarriers in a second OFDMA symbol by a predetermined number in the one or more DRUs; Permutating a plurality of subcarrier groups to have a second pattern in the second OFDMA symbol; And Transmitting a signal on a distributed subcarrier group in the second OFDMA symbol. The method of claim 1, The first pattern and the second pattern is characterized in that different from each other. The method of claim 1, The plurality of subcarrier groups in each OFDMA symbol is configured from the remaining subcarriers excluding the pilot subcarriers. The method of claim 1, The first and second patterns are configured differently using the OFDMA symbol index. The method of claim 1, The first and second patterns are obtained using a permutation sequence of length L _{DRU, FPi, and} the permutation sequence of length L _{DRU, FPi} is cyclically shifted or masked using an OFDMA symbol index, and the L _{DRU, FPi} indicates the number of DRUs in an i -th frequency partition. The method of claim 1, Wherein the first and second patterns are obtained using at least one of time variant intra-row permutation and time variant intra-column permutation. The method of claim 1, The first and second pattern is a signal transmission method, characterized in that obtained using the following equation: Equation g (PermSeq (), s, m, l) = {PermSeq ({X ()} mod {L _{DRU, FPi} }) + DL_PermBase} mod {L _{DRU, FPi} } Where PermSeq () represents a permutation sequence of length L _{DRU, FPi} , X () is a function with s, m and l as arguments, and L _{DRU, FPi} is the i -th frequency partition Where m represents the subcarrier pair index, s represents the Logical DRU (LDRU) index, l represents the OFDMA symbol index, DL_PermBase represents an integer of 0 or more, and mod represents a modulo operation. . In a method of processing a signal by a terminal in a wireless communication system, Receiving a signal from at least one distributed resource unit (DRU) from a base station; Grouping a plurality of subcarriers in a first Orthogonal Frequency Division Multiple Access (OFDMA) symbol in the one or more DRUs by a predetermined number; Obtaining data from a plurality of subcarrier groups permutated to have a first pattern in the first OFDMA symbol; Grouping a plurality of subcarriers in a second OFDMA symbol by a predetermined number in the one or more DRUs; And And obtaining data from the plurality of subcarrier groups permutated to have a second pattern in the second OFDMA symbol. The method of claim 8, And the first pattern and the second pattern are different from each other. The method of claim 8, And a plurality of subcarrier groups in each OFDMA symbol are configured from the remaining subcarriers except for the pilot subcarriers. The method of claim 8, The first and second patterns are configured differently using the OFDMA symbol index. The method of claim 8, The first and second patterns are obtained using a permutation sequence of length L _{DRU, FPi, and} the permutation sequence of length L _{DRU, FPi} is cyclically shifted or masked using an OFDMA symbol index, and the L _{DRU, FPi} represents the number of DRUs in an i -th frequency partition. The method of claim 8, Wherein said first and second patterns are obtained using at least one of time variant intra-row permutation and time variant intra-column permutation. The method of claim 8, The first and the second pattern is a signal processing method, characterized in that obtained using the following equation: Equation g (PermSeq (), s, m, l) = {PermSeq ({X ()} mod {L _{DRU, FPi} }) + DL_PermBase} mod {L _{DRU, FPi} } Where PermSeq () represents a permutation sequence of length L _{DRU, FPi} , X () is a function with s, m and l as arguments, and L _{DRU, FPi} is the i -th frequency partition Where m represents the subcarrier pair index, s represents the Logical DRU (LDRU) index, l represents the OFDMA symbol index, DL_PermBase represents an integer of 0 or more, and mod represents a modulo operation. . An RF module configured to receive a signal from a base station; And A processor configured to process the received signal, Here, the processor is Group a plurality of subcarriers in a first Orthogonal Frequency Division Multiple Access (OFDM) symbol by a predetermined number in one or more Distributed Resource Units (DRUs), Obtaining data from a plurality of subcarrier groups permutated to have a first pattern in the first OFDMA symbol, Group a plurality of subcarriers in a second OFDMA symbol by a predetermined number in the one or more DRUs, And a terminal configured to obtain data from the plurality of subcarrier groups permutated to have a second pattern in the second OFDMA symbol. The method of claim 15, The first pattern and the second pattern, characterized in that different from each other. The method of claim 15, And a plurality of subcarrier groups in each OFDMA symbol are configured from the remaining subcarriers except for the pilot subcarriers. The method of claim 15, The first pattern and the second pattern, characterized in that different from each other. The method of claim 15, The first and second patterns are obtained using a permutation sequence of length L _{DRU, FPi, and} the permutation sequence of length L _{DRU, FPi} is cyclically shifted or masked using an OFDMA symbol index, and the L _{DRU, FPi} is a terminal characterized in that it represents the number of DRU of the i -th frequency partition (frequency partition). The method of claim 15, The first and second patterns are obtained using at least one of time variant intra-row permutation and time variant intra-column permutation. The method of claim 15, The first and the second pattern is characterized in that obtained by using the following equation: Equation g (PermSeq (), s, m, l) = {PermSeq ({X ()} mod {L _{DRU, FPi} }) + DL_PermBase} mod {L _{DRU, FPi} } Where PermSeq () represents a permutation sequence of length L _{DRU, FPi} , X () is a function with s, m and l as arguments, and L _{DRU, FPi} is the i -th frequency partition Where m represents the subcarrier pair index, s represents the Logical DRU (LDRU) index, l represents the OFDMA symbol index, DL_PermBase represents an integer of 0 or more, and mod represents a modulo operation. . An RF module configured to transmit a signal to a terminal; And A processor configured to process the signal, Here, the processor is Group a plurality of subcarriers in a first Orthogonal Frequency Division Multiple Access (OFDMA) symbol by a predetermined number in one or more Distributed Resource Units (DRUs), Permutating a plurality of subcarrier groups to have a first pattern in the first OFDMA symbol, Transmits a signal through a distributed subcarrier group in the first OFDMA symbol, Group a plurality of subcarriers in a second OFDMA symbol by a predetermined number in the one or more DRUs, Permutating a plurality of subcarrier groups to have a second pattern in the second OFDMA symbol, And a base station configured to transmit a signal on a distributed subcarrier group in the second OFDMA symbol. The method of claim 22, And the first pattern and the second pattern are different from each other. The method of claim 22, And a plurality of subcarrier groups in each OFDMA symbol are configured from the remaining subcarriers excluding the pilot subcarriers. The method of claim 22, The first and second patterns are configured differently using the OFDMA symbol index. The method of claim 22, The first and second patterns are obtained using a permutation sequence of length L _{DRU, FPi, and} the permutation sequence of length L _{DRU, FPi} is cyclically shifted or masked using an OFDMA symbol index, and the L _{DRU, FPi} is a base station, characterized in that it represents the number of DRU of the i -th frequency partition (frequency partition). The method of claim 22, Wherein the first and second patterns are obtained using at least one of time variant intra-row permutation and time variant intra-column permutation. The method of claim 22, The base station, characterized in that the first and second patterns are obtained using the following equation: Equation g (PermSeq (), s, m, l) = {PermSeq ({X () + s + l} mod {L _{DRU, FPi} }) + DL_PermBase} mod {L _{DRU, FPi} } Where PermSeq () represents a permutation sequence of length L _{DRU, FPi} , X () is a function with s, m and l as arguments, and L _{DRU, FPi} is the i -th frequency partition Where m represents the subcarrier pair index, s represents the Logical DRU (LDRU) index, l represents the OFDMA symbol index, DL_PermBase represents an integer of 0 or more, and mod represents a modulo operation. .

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