KR100957430B1 - Apparatus and method for interleaving in a wireless communication system - Google Patents

Abstract

The present invention provides a channel interleaving method in which a systematic channel and parity bits can experience even channel conditions when a plurality of code blocks are transmitted during one TTI in an OFDMA system supporting circular buffer-based HARQ. To provide.

According to the present invention, a sequence of information to be transmitted is divided into one or a plurality of coding blocks, and turbo coding is performed on the coding blocks, respectively, to form a circular buffer and a sub packet. Thereafter, interleaving is performed on the subpackets of the respective coding blocks. If a plurality of coding blocks are transmitted in one OFDM symbol, interleaving is performed on additionally coded symbols transmitted in one OFDM symbol.

Through the channel interleaving method proposed by the present invention, it is possible to prevent only a specific coding block from experiencing a bad channel environment, thereby improving overall data reception performance.

HARQ, subpacket, circular buffer, channel interleaving

Description

Interleaving apparatus and method in wireless communication system {APPARATUS AND METHOD FOR INTERLEAVING IN A WIRELESS COMMUNICATION SYSTEM}

1A is a timing diagram of transmission of data and signals for explaining an HARQ scheme;

1B is a block diagram conceptually illustrating a configuration between a transmitter and a receiver in an OFDMA mobile communication system in which HARQ operation is performed;

2 is a view for explaining a method of configuring a subpacket using a circular buffer in a mobile communication system;

3 is a conceptual diagram illustrating a case where a sub packet is mapped to a resource block;

4 is a control flowchart of channel interleaving according to a first embodiment of the present invention;

5 is a flowchart illustrating channel interleaving according to a second embodiment of the present invention;

6 is a diagram illustrating a configuration process of transmission data according to a first embodiment of the present invention;

7 is a diagram illustrating a configuration process of transmission data according to a second embodiment of the present invention;

8 is a control flowchart of a receiver according to the first embodiment of the present invention;

9 is a control flowchart of a receiver according to a second embodiment of the present invention;

10 is a block diagram illustrating the main internal block of the transmitter according to the first embodiment of the present invention;

11 is a block diagram illustrating the main internal block of the transmitter according to the second embodiment of the present invention;

12 is a block diagram illustrating a main internal block of the receiver according to the first embodiment of the present invention;

13 is a block diagram illustrating a main internal block of the receiver according to the second embodiment of the present invention;

14 is a flowchart illustrating channel interleaving according to a third embodiment of the present invention;

15 is a control flowchart of a receiver according to a third embodiment of the present invention;

16 is a block diagram illustrating a main internal configuration of a transmitter according to a third embodiment of the present invention;

17 is a block diagram illustrating the main internal block of the receiver according to the third embodiment of the present invention.

The present invention relates to an interleaving apparatus and method in a communication system, and more particularly to an interleaving apparatus and method in a wireless communication system.

In general, a communication system may be divided into a wired communication system and a wireless communication system. Such wireless communication systems are evolving in various directions in order to provide communication to users. In the wireless communication system, only the initial voice communication is provided, and various types of communication including data communication as well as voice communication are currently performed. In addition, voice communication basically means a real-time service, data communication means a non-real-time service. In the case of a real-time service, even if a loss of transmitted data occurs, retransmission is usually meaningless. However, non-real-time services require retransmission for more accurate data transmission. As such, a hybrid automatic repeat request (HARQ) method is used as a method of performing data retransmission in the non-real time service.

On the other hand, orthogonal frequency division multiplexing (hereinafter, referred to as "OFDM") has been actively studied in a mobile communication system as a method useful for high-speed data transmission in a wired or wireless channel. The OFDM method is a method of transmitting data using a multi-carrier. Accordingly, in the OFDM scheme, a series of symbol strings input in series are converted in parallel, and each of the parallel converted symbols has a plurality of sub-carriers, that is, a plurality of sub-carriers. It is a kind of multi-carrier modulation (hereinafter, referred to as "MCM") that modulates and transmits through channels. Orthogonal frequency division is generally used for a system that distinguishes multiple users through the plurality of subcarriers while taking the OFDM scheme as a basic transmission scheme, that is, a system supporting multiple users by assigning different subcarriers to different users. This is called an Orthogonal Frequency Division Multiplex Access (hereinafter referred to as "OFDMA") scheme.

HARQ, as described above, is one of important technologies used to increase the reliability and data throughput of data transmission in a packet-based mobile communication system. HARQ refers to a technique that combines an Automatic Repeat Request (hereinafter referred to as "ARQ") technology and Forward Error Correction (hereinafter referred to as "FEC"). ARQ is a technique widely used in wired / wireless data communication systems. The transceiver assigns a series of numbers to a data packet transmitted according to a predetermined method, and the receiver transmits a missing number of packets received using the number. A technique for achieving reliable data transmission by asking the transmitter to retransmit the number. In addition, the FEC adds redundant bits to data to be transmitted, such as convolutional coding or turbo coding, according to a predetermined rule, thereby transmitting errors generated in an environment such as noise or fading generated during data transmission and reception. This technique overcomes and demodulates initially transmitted data. In the mobile communication system using HARQ combining the ARQ and the FEC, the receiver determines whether an error exists in the decoded data through a predetermined FEC reverse process on the received data through a cyclic redundancy check (CRC) check. As a result of determining whether the error exists, the transmitter feeds back an acknowledgment (ACK) to the transmitter when there is no error, thereby causing the transmitter to transmit the next data packet. On the contrary, when the transmitter determines whether the error exists, if the received data has an error, the transmitter feeds back a non-acknowledgement (NACK) to the transmitter to retransmit the previously transmitted packet. In the retransmission process, the receiver obtains an energy gain by combining the retransmitted packet with the previously transmitted packet, thereby obtaining a much improved performance compared to the conventional ARQ without the combining process.

1A is a timing diagram of transmission of data and signals for explaining an HARQ scheme.

In FIG. 1A the horizontal axis represents the time axis. The data channel represents a channel through which data packets are transmitted. In step 101 of FIG. 1A, the transmitter initially transmits a data packet through a data channel. In step 102, the receiver receives the initially transmitted data packet and demodulates the data packet. In this demodulation process, it is determined whether a reception error is received for the data packet transmitted through the data channel. If the receiver determines that demodulation on the initially transmitted data packet was not successful, the receiver feeds back a NACK to the data transmitter. In this case, whether the error is determined may be performed through a CRC test.

When the NACK is received as described above, the transmitter performs the first retransmission of the data packet in step 103. In step 103 of performing the first retransmission, even if the transmitter retransmits the same data as the data packet transmitted during the initial transmission, different redundancies, that is, different coded symbols, are generated for the same data. Can be sent. Hereinafter, the same data packet transmitted in steps 101, 103, and 105 will be described as 'sub packet'. In step 104 of FIG. 1A, the receiver receives the first retransmitted data packet through the data channel, and then combines the first retransmitted data packet and the initially transmitted data packet according to a predetermined rule. The demodulation of the data channel is attempted. In step 104, the receiver feeds back a NACK to the data transmitter when it is determined that the received packet data has not been successfully demodulated through the CRC check on the packet data transmitted through the data channel during the demodulation process. Then, after receiving the NACK in step 105, the transmitter performs a second retransmission after a predetermined time interval from the first retransmission time point. Therefore, the packet data of the initial transmission performed in step 101, the first retransmission performed in step 103, and the second retransmission performed in step 105 are transmitted by encoding the same data.

After receiving the second retransmission data, the receiver of FIG. 1A performs combining of the initial retransmission, the first retransmission, and the second retransmission data packet according to a predetermined rule, and demodulates the packet data transmitted on the data channel. do. The receiver may determine whether the transmitted packet data was successfully transmitted and demodulated through the CRC check on the packet data transmitted through the data channel during the demodulation process. If the received packet data is successfully demodulated as a result of this determination, the receiver feeds back an ACK to the transmitter in step 106. Then, since the transmitter receives the ACK in step 107, the transmitter transmits an initial transmission subpacket for the next data packet together with the control channel.

1B is a block diagram conceptually illustrating a configuration between a transmitter and a receiver in an OFDMA mobile communication system in which HARQ operation is performed.

In the transmitter 110, an encoder 111 encodes a predetermined data packet and outputs encoded symbols. In the transmitter 110, the subpacket generator 112 selects some symbols or all symbols of the encoder output in the kth transmission, and outputs the encoded symbols. Create Subpacket k). Here k has a value of 0 ~ m, m is the maximum number of retransmissions. In FIG. 1B, the transceiver chain 120 transmits the selected subpacket k to the receiver 130 through a predetermined transmission / reception procedure such as OFDM.

The decoder 131 of the receiver 130 decodes the received subpacket k and feeds back an ACK or NACK to the subpacket component 112 of the transmitter 110 according to the decoding result. According to the feedback result, the subpacket configuring unit 112 configures a retransmission data packet of the transmitted data packet, that is, a next subpacket, or configures and transmits an initial transmission subpacket of a new data packet.

Then, the encoder 111 and the sub packet construction unit 112 for the HARQ operation will be described in more detail. 2 is a diagram for describing a method of configuring a subpacket using a circular buffer in a mobile communication system.

In FIG. 2, one code block 201 indicates one data packet to be transmitted at a given point in time. The encoder 202 receives the one code block 201 and generates and outputs predetermined coded symbols 203. The total number of coded symbols 203 output from the coder 202 is defined by a code rate of the coder 202, which is generally referred to as a mother code rate. The reason why the total number of coded symbols output as described above is called a mother code rate is because some or all coded symbols of the output of the encoder 202 are selected for each subpacket, which will be described later. As shown in FIG. 2, the encoded symbols 203 output from the encoder 202 include systematic symbols S, first parity symbols 1: P1, and second parity. Parity Symbols 2: P2, each of which is referred to as a sub block. Each subblock output from the encoder 202 is interleaved in the subblock interleaver 204. Interleaving in the block interleaver interleaves the systematic symbols S, the first parity symbols P1, and the second parity symbols P2 in each subblock. In the sub-block interleaver 204, the entirety of the interleaved symbols for each sub block is mixed with the first parity symbols P1 and the second parity symbols P2 as shown in FIG. It is considered stored in 205 or stored in circular buffer 205. The reason for the term 'circular buffer' is that the configuration of symbols for each subpacket is performed by selecting consecutive symbols on the circular buffer during HARQ operation, and when a specific subpacket exceeds the last symbol point of the circular buffer, This is because we go back to the first symbol and select the next symbols for the subpacket. That is, the transmitter configures each subpacket by selecting some consecutive symbols on the circular buffer, and the receiver maps the received encoded symbols to the proper positions on the circular buffer of the same structure, and then performs a decoding process.

Referring to the example of a sub packet configuration shown in FIG. 2, reference numeral 206 denotes a symbol configuration for an initial transmission subpacket, reference numeral 207 denotes a symbol configuration for a first retransmission packet, that is, a second subpacket. Numeral 208 denotes a symbol configuration for the second retransmission packet, that is, the third subpacket.

3 is a conceptual diagram illustrating a case where a sub packet is mapped to a resource block.

Referring to FIG. 3, reference numeral 301 shows the output of the circular buffer 205 for the first coding block, and 302 shows the output of the circular buffer 205 for the first coding block. As shown in FIG. 3, the coding blocks output from the circular buffer 205 are composed of systematic bits and parity bits. The part indicated by reference numeral 303 indicates the subpacket configuration for the first coding block. A portion indicated by reference numeral 304 shows a subpacket configuration for the second coding block. Each subpacket configured as described above is independently interleaved. This independent interleaving is shown at 305 and 306. Reference numeral 307 denotes encoded symbols independently of each other, such as reference numeral 305 and 306. A portion corresponding to 309 among the interleaved symbols is symbols to be transmitted in the first OFDM symbol.

Typically, one data packet is transmitted over a plurality of OFDM symbols in an OFDMA system, and a time length corresponding to the plurality of OFDM symbols may be referred to as a transmission time interval (TTI). In this case, the first OFDM symbol means that the first OFDM symbol in the TTI in which the data packets illustrated in FIG. 3 are transmitted. The number of symbols to be transmitted in the first OFDM symbol is typically determined according to the number of subcarriers available for data transmission and the modulation scheme. Reference numeral 310 denotes a channel response on the frequency axis. In reference numeral 310, the vertical axis represents the strength of the channel. Accordingly, as shown by reference numeral 310, the frequency portion through which the first coding block is transmitted is generally good, whereas the frequency portion through which the second coding block is transmitted is relatively poor. Therefore, the probability that the first coding block is successfully received is high while the probability that the second coding block is successfully received is low.

In general, in a HARQ system, when a plurality of coding blocks are transmitted in one TTI, ACK / NACK feedback is not performed separately for each coding block, but one ACK / NACK feedback is performed. For example, if two coding blocks are transmitted and only one of them is successfully demodulated, the data receiver feeds back a NACK, and the data transmitter retransmits both previously transmitted blocks. I'm using the way. Therefore, in the HARQ scheme, it is preferable that all of a plurality of coding blocks are transmitted through an even channel. However, since the environment of the channel that is actually transmitted is continuously variable, it may be severely changed in time as shown by reference numeral 310 described with reference to FIG. 3. Such a severe change in time causes unnecessary retransmission during the transmission / reception period. In addition, there is a problem that waste of channel resources through unnecessary retransmission.

Accordingly, an aspect of the present invention is to provide an interleaving apparatus and method capable of preventing unnecessary retransmission in a mobile communication system.

The present invention also provides an interleaving apparatus and method capable of preventing waste of resources in a mobile communication system.

The present invention also provides an effective interleaving apparatus and method when a plurality of coding blocks are transmitted through one transport block in a mobile communication system.

To this end, the interleaving method of the present invention uses an automatic complex retransmission method and uses a channel interleaving method in a wireless communication system that can transmit two or more coding blocks through one OFDM symbol. After subdividing into coding blocks and encoding each coded block, interleaving the subpackets and performing channel interleaving on the OFDM symbols when a plurality of subpackets are transmitted in one OFDM symbol. It includes the process of doing.

The deinterleaving method of the present invention for achieving the above objects is a channel deinterleaving method in a wireless communication system that uses an automatic complex retransmission scheme and can transmit two or more coding blocks through one OFDM symbol, from subcarriers Collecting encoding symbols, checking whether a plurality of coding blocks are included in one OFDM symbol, and deinterleaving all received OFDM symbols when a plurality of coding blocks are included in one OFDM symbol Demodulating and decoding the block.

The interleaving apparatus of the present invention for achieving the above objects, the information sequence to be transmitted to the channel interleaving apparatus in a wireless communication system that uses an automatic complex retransmission scheme, and can transmit two or more coding blocks through one OFDM symbol Is divided into one or a plurality of coding blocks, which is composed of sub-packets, and then code block interleaving to output code blocks, an interleaver for interleaving two or more code blocks, and a plurality of codes in one OFDM symbol. And a controller for checking whether the blocks should be transmitted and controlling the interleaver to interleave the entirety of the code blocks.

The deinterleaver apparatus of the present invention for achieving the above objects is a channel deinterleaving apparatus in a wireless communication system that uses an automatic complex retransmission scheme and can transmit two or more coding blocks through one OFDM symbol, from subcarriers A subcarrier demapper for collecting and outputting encoded symbols, a first deinterleaver for deinterleaving the entire output of the demapper, a second deinterleaver for deinterleaving the output of the demapper per subpacket, and one received signal When the OFDM symbol includes a plurality of code blocks, the output of the demapper is controlled to be output to the first deinterleaver. When the OFDM symbol includes one code block, the output of the demapper is output to the second deinterleaver. It includes a control unit for controlling to output.

Hereinafter, with reference to the accompanying drawings will be described in detail the operating principle of the preferred embodiment of the present invention. In the following description of the present invention, detailed descriptions of well-known functions or configurations will be omitted if it is determined that the detailed description of the present invention may unnecessarily obscure the subject matter of the present invention. 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.

4 is a flowchart illustrating channel interleaving according to a first embodiment of the present invention.

In step 401, the data transmitter divides the information string to be transmitted into one or a plurality of coding blocks according to a predetermined rule. For example, assume that the number of information bits that the base station intends to transmit to a specific terminal is 10,000 bits, and assume that the encoder is a turbo encoder. In this case, the transmitter's turbo encoder typically does not encode 10,000 bits at a time. This is because the complexity of decoding at the receiver becomes too large when turbo encoding too much information at once. Therefore, when the number of information bits is as large as 10,000 bits, it is common to divide the 5000 bits into two parts and to turbo-encode each of the 5000 bits divided into the two parts. As described above, a detailed rule of dividing one information string into a plurality of coding blocks may vary according to a system. Therefore, the present invention is not limited to a specific rule for dividing an information string into a plurality of coding blocks, and it will not be described in detail because it is difficult to search for each system.

In step 402, the data transmitter turbo-codes one or a plurality of coding blocks that are divided into a predetermined number as described above and stores the encoded symbols in a circular buffer. Each circular buffer configuration method is the same as the method described with reference to FIG. The data transmitter then constructs a subpacket from each circular buffer by a predetermined method in step 403. The sub packet configuration is configured by selecting a plurality of consecutive encoded symbols from the circular buffer as described with reference to FIG. In step 404, the data transmitter performs interleaving on each coding block. Interleaving for each coding block is performed on the subpackets generated for each code block as described in FIG. 3 of the prior art. Accordingly, interleaving the subpackets generated for each code block is referred to as code block interleaving hereinafter. In step 405, the data transmitter determines whether additional interleaving is necessary. The determination may be determined according to whether a plurality of coding blocks are transmitted in one OFDM symbol. If the result of the determination of step 405 is to transmit the symbols of a plurality of coding blocks in one OFDM symbol, the process proceeds to step 406 to perform interleaving again on all of the encoded symbols to be carried in the OFDM symbol. In the above process, since all of the encoded symbols carried in one OFDM symbol are interleaved, the following description is referred to as OFDM symbol interleaving. After performing step 406, the transmitter proceeds to step 407 to sequentially map the interleaved symbols to available subcarriers of the corresponding OFDM symbol.

On the other hand, if it is determined in step 405 that symbols of a plurality of coding blocks are not transmitted in one OFDM symbol, that is, if the coding symbols transmitted in the OFDM symbol correspond to only one coding block, the process proceeds to step 407. do. Thereafter, in step 408, the data transmitter generates and transmits the encoded symbols mapped to the OFDM signal through a predetermined procedure. Meanwhile, in the above description, the coding symbols are mapped to the resource blocks, but the modulation symbols may be mapped to the resource blocks after the modulation symbols such as QPSK, 16-QAM, and 64-QAM. Alternatively, after coding symbols are mapped to resource blocks, a modulation process may be performed. In the present specification, the above-described modulation processes will be omitted, but it should be noted that the methods proposed in the present invention may be equally applied even if the modulation processes are included.

5 is a control flowchart of channel interleaving according to a second embodiment of the present invention.

The data transmitter divides the information string to be transmitted in step 501 into one or a plurality of coding blocks according to a predetermined rule. This process can be divided into blocks in the same manner as in FIG. The data transmitter stores one or more coding blocks configured through the above-described process in the circular buffer through the turbo coding process, respectively. The circular buffer configuration method is the same as the method described with reference to FIG. 2. In step 503, the data transmitter constructs a sub packet from each circular buffer by a predetermined method. As described above with reference to FIG. 2, the sub packet is configured by selecting a plurality of encoded symbols consecutive from the circular buffer. In step 504, the data transmitter determines whether a plurality of coding blocks are transmitted to one OFDM symbol. According to the determination result of step 504, if symbols of a plurality of coding blocks are transmitted in one OFDM symbol, the process proceeds to step 505 to perform OFDM symbol interleaving.

In contrast, if it is determined in step 504 that a plurality of coding blocks are not transmitted to one OFDM symbol, the data transmitter proceeds to step 506 to perform coding block interleaving. In step 507, the data transmitter sequentially maps the interleaved symbols to available subcarriers of the corresponding OFDM symbol. In step 508, the data transmitter generates and transmits the encoded symbols mapped to the OFDM signal through a predetermined procedure.

6 is a diagram illustrating a configuration process of transmission data according to a first embodiment of the present invention.

Reference numeral 601 denotes a circular buffer for the first coding block, and reference numeral 602 denotes a circular buffer for the second coding block. A portion indicated by reference numeral 603 represents a sub packet configuration for the first coded block. A portion indicated by reference numeral 604 indicates a sub packet configuration for the second coding block. Each subpacket configured as described above is independently interleaved as shown by reference numeral 605 and reference numeral 606. Reference numeral 607 denotes the interleaved encoded symbols. Among the interleaved symbols, a portion corresponding to the reference numeral 608 is symbols to be transmitted in the first OFDM symbol. As a plurality of coding blocks are transmitted in one OFDM symbol according to the determination of step 405 of FIG. 4, additional OFDM symbol interleaving must be performed as described in step 406. This process is illustrated by reference numeral 609 and 610. Referring to reference numeral 610 and reference numeral 611, it can be seen that the symbols corresponding to the two coding blocks have a good channel and a bad channel. Therefore, the problem mentioned in the prior art can be solved.

7 is a diagram illustrating a configuration process of transmission data according to a second embodiment of the present invention.

Reference numeral 701 denotes a circular buffer for the first coding block, and reference numeral 702 denotes a circular buffer for the second coding block. A portion indicated by reference numeral 703 indicates a sub packet configuration for the first coded block. A portion indicated by reference numeral 704 indicates a sub packet configuration for the second coding block. Among the symbols shown by the reference numeral 703 and the reference numeral 704, the part corresponding to the reference numeral 705 is symbols to be transmitted in the first OFDM symbol. As a plurality of coding blocks are transmitted in one OFDM symbol according to the determination of step 504 of FIG. 5, OFDM symbol interleaving should be performed as described in step 505, which is indicated by reference numeral 706. Reference numeral 707 shows the interleaved symbols, and through interleaving, it can be seen that the symbols corresponding to the two coding blocks suffer even and good channels evenly. This can solve the problems mentioned in the prior art.

8 is a control flowchart of a receiver according to the first embodiment of the present invention.

The receiver first collects the coded symbols from the subcarriers promised in step 801. The promised subcarriers are subcarriers for which the data receiver is promised to receive data, but the appointment may be made in various ways, but the present invention is not limited to a specific promise method. Thereafter, in step 802, the receiver determines whether the coded symbols collected in one OFDM symbol correspond to a plurality of coded blocks or one coded block. If the encoded symbols collected from one OFDM symbol correspond to the plurality of coding blocks according to the determination result of step 802, the receiver proceeds to step 803 to perform OFDM deinterleaving on the encoded symbols obtained from the OFDM symbol. The OFDM deinterleaving is the reverse of OFDM interleaving. The receiver then proceeds to step 804.

On the other hand, if the coding symbols collected from one OFDM symbol correspond to only one coding block according to the determination process of step 802, the receiver proceeds to step 804 to deinterleave, that is, subblock deinterleaving, for each subpacket of each coding block. Do this. The subblock deinterleaving is a reverse process of subblock interleaving. The receiver maps the deinterleaved coded symbols to the appropriate locations on the circular buffer of each coded block. The receiver then performs a turbo decoding process through the circular buffer of each of the coding blocks.

9 is a control flowchart of a receiver according to a second embodiment of the present invention.

The receiver collects the coded symbols from the subcarriers promised in step 901. The receiver determines whether the coded symbols collected in one OFDM symbol correspond to a plurality of coding blocks or one coding block with respect to the collected coded symbols. If the coding symbols collected from one OFDM symbol correspond to a plurality of coding blocks according to the determination result of step 902, the receiver proceeds to step 903 to perform OFDM deinterleaving on the coding symbols obtained from the OFDM symbol. The process then proceeds to step 905. In contrast, when the coding symbols collected from one OFDM symbol correspond to only one coding block according to the determination process of step 902, the receiver proceeds to step 904 to perform deinterleaving, that is, subblock deinterleaving for each subpacket of each coding block. To perform. The receiver maps the deinterleaved coded symbols to appropriate positions on the circular buffer of each coded block. Thereafter, in step 906, the receiver performs a turbo decoding process through the circular buffer of each coding block.

10 is a block diagram illustrating a main internal block of the transmitter according to the first embodiment of the present invention.

An information stream 1001 to be transmitted is input to an encoding block generator 1002, and the encoding block generator 1002 encodes the input information string 1001 according to a predetermined rule. The output is divided into blocks 103. The dividing process into coding blocks is the same as described in operation 401 of FIG. 4. The plurality of encoding blocks 1003, which are outputs of the encoding block, are input to the data generators 1004 and 1005 including the turbo encoder, the circular buffer component, and the sub packet generator, are encoded, stored in the circular buffer, and the subpackets. Is generated and output. The data generating units 1004 and 1005 may actually include a circular buffer, or may control the output in the same format as the output of the data is stored in the circular buffer. In addition, the data generating units 1004 and 1005 may include other components other than the above-described configuration according to the requirements of each system, or may be replaced or omitted. In addition, although the data generators 1004 and 1005 are illustrated as one block, an actual implementation may divide the above into a plurality of blocks. The data generators 1004 and 1005 generate subpackets through the process and output the subpackets to the concatenated unit 1006. Then, the one or a plurality of subpackets are input to the concatenating unit 1006 and concatenated, and the concatenated subpackets are input to the encoding block interleaver 1007 to perform encoding block interleaving.

The output of the coding block interleaver 1007 is input to the OFDM symbol interleaver 1008 or directly to the subcarrier mapper 1010 under the control of the controller 1009. The operation of the controller is the same as described in steps 405, 406, and 407 in FIG. 4. The OFDM symbol interleaver receives input symbols and performs OFDM symbol interleaving and outputs the received symbols. The subcarrier mapper 1010 sequentially maps input symbols to available subcarriers of an OFDM symbol.

11 is a block diagram illustrating a main internal block of the transmitter according to the second embodiment of the present invention.

The information string 1101 to be transmitted is input to the coding block generator 1102, and the coding block generator 1102 may input the input information string 1101 according to a predetermined rule into one or a plurality of coding blocks 1103. The output is divided by). The plurality of coding blocks 1103, which are outputs of the coding block, are input to data generators 1104 and 1105 including a turbo encoder, a circular buffer component, and a sub packet generator, respectively. It is composed. In FIG. 11, the data generators 1104 and 1105 include a turbo encoder, a circular buffer component, and a sub packet generator, but in reality, each system has more components or fewer components. Alternatively, a specific component may be replaced by another component. In addition, although the data generators 1104 and 1105 are illustrated as one block in FIG. 11, the actual implementation may divide the above into a plurality of blocks.

The one or a plurality of subpackets are input to the concatenation unit 1106 and concatenated, and the concatenated subpackets are controlled by the control unit 1109 and input to the coding block interleaver 1107 or the OFDM symbol interleaver 1108. The operation of the controller 1109 is the same as described with reference to steps 504, 505, and 506 of FIG. 5. The coding block interleaver 1107 receives input symbols and performs coding block interleaving and outputs the encoded symbols. The OFDM symbol interleaver 1108 receives input symbols and performs OFDM symbol interleaving and outputs the received symbols. The output of the coding block interleaver 1107 or the OFDM symbol interleaver 1108 is input to the subcarrier mapper 1110. The subcarrier mapper 1110 in turn maps input symbols to available subcarriers of an OFDM symbol.

12 is a block diagram illustrating a main internal configuration of a receiver according to the first embodiment of the present invention.

The subcarrier demapper 1201 collects the coded symbols from the promised subcarriers as described in step 801 of FIG. 8. The output of the subcarrier demapper is input to the OFDM symbol deinterleaver 1203 or to the coding block deinterleaver 1204 under the control of the controller 1202. The OFDM symbol deinterleaver 1203 receives input symbols and performs OFDM symbol deinterleaving and outputs the received symbols. The coding block deinterleaver 1204 receives input symbols, performs coding block deinterleaving, and outputs the encoded symbols. The control operation of the controller 1202 is the same as described in steps 802, 803, and 804 of FIG. 8. The output of the coding block deinterleaver 1204 is input to the concatenating unit 1205 and concatenated. The output of the concatenating unit 1205 is restored to data by the data restoring units 1207 and 1208 for each coding block. As described above, the data recovery process includes storing the data back in the circular buffer and demodulating the turbo by de-coding them.

13 is a block diagram illustrating a main internal block of the receiver according to the second embodiment of the present invention.

The subcarrier demapper 1301 collects the coded symbols from the promised subcarriers as described in step 901 of FIG. 9. The output of the subcarrier demapper 1301 is input to the coding block deinterleaver 1303 or the OFDM symbol deinterleaver 1304 under the control of the controller 1302. The coding block deinterleaver 1303 receives the input symbols and performs coding block deinterleaving and outputs the encoded symbols. The OFDM symbol deinterleaver 1304 receives input symbols and performs OFDM symbol deinterleaving and outputs the received symbols. The control operation of the controller 1302 is the same as described in steps 902, 903, and 904 of FIG. 9. The output of the coding block deinterleaver 1303 or the OFDM symbol deinterleaver 1304 is input to the concatenation unit 1305 and concatenated. Is inputted to restore data 1309. As described above, the restoration process includes a process of storing the data in a circular buffer and inputting and demodulating the turbo inverse coding unit.

14 is a control flowchart of channel interleaving according to a third embodiment of the present invention.

In step 1401, the data transmitter divides the information string to be transmitted into one or a plurality of coding blocks according to a predetermined rule. This process can be divided into blocks in the same manner as in FIG. In step 1402, the data transmitter stores one or more coding blocks configured through the above process in a circular buffer through turbo encoding. The circular buffer configuration method is the same as the method described with reference to FIG. 2. In step 1403, the data transmitter constructs a sub packet from each circular buffer by a predetermined method. As described above with reference to FIG. 2, the sub packet is configured by selecting a plurality of encoded symbols consecutive from the circular buffer. In step 1404, the data transmitter determines whether the number of coding blocks transmitted during the TTI is greater than the number of OFDM symbols available for data transmission in the TTI. If the determination result of step 1404 is "Yes," it proceeds to step 1405 to perform OFDM symbol interleaving.

On the other hand, if the determination result of step 1404 is no, the process proceeds to step 1406 without performing a channel interleaving process separately. In step 1406, the data transmitter maps the symbols to available subcarriers of the corresponding OFDM symbol. In step 1407, the data transmitter generates and transmits the encoded symbols mapped to the OFDM signal through a predetermined procedure.

15 is a control flowchart of a receiver according to a third embodiment of the present invention.

The receiver collects the coded symbols from the subcarriers promised in step 1501. In operation 1502, the receiver determines whether the number of coding blocks transmitted during the TTI is greater than the number of OFDM symbols available for data transmission in the TTI. If the answer to the determination result is "Yes", the receiver proceeds to step 1503 to perform OFDM deinterleaving. Thereafter, the process proceeds to step 1504. On the other hand, if the answer to the determination result of step 1502 is "no", it skips the channel deinterleaving process and proceeds directly to step 1504. In step 1504, the receiver maps the coded symbols to the appropriate positions on the circular buffer of each coded block. Thereafter, in step 1505, the receiver performs a turbo decoding process through the circular buffer of each coding block.

16 is a block diagram illustrating a main internal block of the transmitter according to the third embodiment of the present invention. The information string 1601 to be transmitted is input to the coding block generator 1602, and the coding block generator 1602 uses the input information string 1601 according to a predetermined rule in one or a plurality of coding blocks 1603. The output is divided by). The plurality of coding blocks 1603, which are outputs of the coding block, are respectively input to data generators 1604 and 1605 including a turbo encoder, a circular buffer configuration unit, and a sub packet generator. It is composed. In FIG. 16, the data generators 1604 and 1605 include a turbo encoder, a circular buffer component, and a sub packet generator, but in reality, each system has more components or fewer components. Alternatively, a specific component may be replaced by another component. In addition, although the data generators 1604 and 1605 are illustrated as one block in FIG. 16, an actual implementation may divide the above into a plurality of blocks.

The one or a plurality of subpackets output from the data generation units 1604 and 1605 are input to the concatenation unit 1606 and concatenated, and the concatenated subpackets are controlled by the control unit 1609 to the OFDM symbol interleaver 1608. Or to a subcarrier mapper 1616. The operation of the controller 1609 is the same as described in steps 1404, 1405, and 1406 in FIG. 14. The OFDM symbol interleaver 1608 receives input symbols and performs OFDM symbol interleaving and outputs the received symbols. The output of the OFDM symbol interleaver 1608 is input to a subcarrier mapper 1616. The subcarrier mapper 1616 sequentially maps the input symbols to the available subcarriers of the OFDM symbol.

17 is a block diagram illustrating a main internal block of the receiver according to the third embodiment of the present invention.

The subcarrier demapper 1701 collects the coded symbols from the promised subcarriers as described in step 1501 of FIG. 15. The output of the subcarrier demapper 1701 is input to the OFDM symbol deinterleaver 1703 under the control of the controller 1702 or to the concatenating unit 1705. The OFDM symbol deinterleaver 1703 receives input symbols and performs OFDM symbol deinterleaving and outputs the received symbols. The control operation of the controller 1702 is the same as described in operations 1502, 1503, and 1504 of FIG. 15. The output of the OFDM symbol deinterleaver 1703 is input to the concatenation unit 1705 and concatenated. The output of the concatenation unit 1705 is input to the data restoring units 1707 and 1708 for each coding block as shown by reference numeral 1706. The data 1709 is restored. As described above, the restoration process includes a process of storing the data in a circular buffer and inputting and demodulating the turbo inverse coding unit.

As described above, the channel interleaving of the present invention prevents errors from concentrating only on a specific coding block, thereby preventing unnecessary retransmissions and increasing channel resource usage efficiency. This has the advantage of improving the overall data reception performance.

Claims (24)

In the interleaving method of a wireless communication system, Determining whether coded symbols transmitted through one modulation symbol are selected from a plurality of coding blocks; Interleaving the coded symbols in modulation symbol units when the coded symbols transmitted through the one modulation symbol are selected from a plurality of coded blocks. The method of claim 1, wherein before the process of determining whether the encoded symbols transmitted through the one modulation symbol are selected from a plurality of coding blocks, And interleaving the coded symbols in coding block units. The method of claim 1, Interleaving the coded symbols in units of coded blocks when the coded symbols transmitted through the one modulation symbol are not selected from a plurality of coded blocks. The method of claim 1, wherein the modulation symbol, An orthogonal frequency dynamic multiplex (OFDM) symbol, wherein the interleaving method of a wireless communication system. In the interleaving method of a wireless communication system, Determining whether the number of coding blocks transmitted during one transmission time interval (TTI) is greater than the number of available modulation symbols in the one TTI; If the number of coding blocks transmitted during the one TTI is larger than the number of available modulation symbols in the one TTI, the coding symbols selected from at least one coding block and transmitted through one modulation symbol may be in modulation symbol units. An interleaving method of a wireless communication system comprising interleaving. The method of claim 5, wherein the modulation symbol, An orthogonal frequency dynamic multiplex (OFDM) symbol, wherein the interleaving method of a wireless communication system. In the deinterleaving method of a wireless communication system, Determining whether coded symbols transmitted through one modulation symbol are selected from a plurality of coding blocks; And deinterleaving the coded symbols in modulation symbol units when the coded symbols transmitted through the one modulation symbol are selected from a plurality of coding blocks. The method of claim 7, wherein And deinterleaving the coded symbols deinterleaved in units of modulation symbols in units of coding blocks. The method of claim 7, wherein And deinterleaving the coded symbols in units of coding blocks when the coded symbols transmitted through the one modulation symbol are not selected from a plurality of coded blocks. The method of claim 7, wherein the modulation symbol, A method for deinterleaving a wireless communication system, characterized in that it is an Orthogonal Frequency Dynamic Multiplex (OFDM) symbol. In the deinterleaving method of a wireless communication system, Determining whether the number of coding blocks transmitted during one transmission time interval (TTI) is greater than the number of available modulation symbols in the one TTI; If the number of coding blocks is greater than the number of available modulation symbols, deinterleaving the coded symbols transmitted through the one modulation symbol in modulation symbol units. The method of claim 11, wherein the modulation symbol, A method for deinterleaving a wireless communication system, characterized in that it is an Orthogonal Frequency Dynamic Multiplex (OFDM) symbol. An interleaving apparatus of a wireless communication system, A control unit which controls to input the encoded symbols to a symbol interleaver if the encoded symbols transmitted through one modulation symbol are selected from a plurality of encoded blocks; And a symbol interleaver for interleaving the input coded symbols in modulation symbol units. The method of claim 13, And an encoded block interleaver for interleaving the encoded symbols in units of coding blocks before the encoded symbols are input to the symbol interleaver. The method of claim 13, If the coding symbols transmitted through the one modulation symbol is not selected from a plurality of coding blocks, further comprising a coding block interleaver for interleaving the input coded symbols in units of coding blocks, And the controller is configured to input the coded symbols to the coded block interleaver. The method of claim 13, wherein the modulation symbol, Interleaving apparatus of a wireless communication system, characterized in that the Orthogonal Frequency Dynamic Multiplex (OFDM) symbol. An interleaving apparatus of a wireless communication system, If the number of coding blocks transmitted during one Transmission Time Interval (TTI) is greater than the number of available modulation symbols in the one TTI, it is selected from at least one coding block and transmitted through one modulation symbol. A control unit which controls to input the encoded symbols to the symbol interleaver as follows; And a coding block interleaver for interleaving the input coded symbols in coding block units. The method of claim 17, wherein the modulation symbol, Interleaving apparatus of a wireless communication system, characterized in that the Orthogonal Frequency Dynamic Multiplex (OFDM) symbol. In the deinterleaving apparatus of a wireless communication system, A control unit which controls to input the encoded symbols to a symbol deinterleaver if the encoded symbols transmitted through one modulation symbol are selected from a plurality of encoded blocks; And a symbol deinterleaver for deinterleaving the input coded symbols in modulation symbol units. The method of claim 19, And a coded block deinterleaver for deinterleaving the coded symbols deinterleaved in units of modulation symbols in units of coding blocks. The method of claim 19, And a coding block deinterleaver for deinterleaving the coding symbols in units of coding blocks when the coding symbols transmitted through the one modulation symbol are not selected from a plurality of coding blocks. 20. The apparatus of claim 19, wherein the modulation symbol is A deinterleaving apparatus of a wireless communication system, characterized in that it is an Orthogonal Frequency Dynamic Multiplex (OFDM) symbol. In the deinterleaving apparatus of a wireless communication system, If the number of coding blocks transmitted during one Transmission Time Interval (TTI) is greater than the number of available modulation symbols in the one TTI, it may be selected from at least one coding block and through the one modulation symbol. A control unit which controls to input the transmitted encoded symbols to a symbol deinterleaver as follows; And a symbol deinterleaver for deinterleaving the input coded symbols in modulation symbol units. The method of claim 23, wherein the modulation symbol, A deinterleaving apparatus of a wireless communication system, characterized in that it is an Orthogonal Frequency Dynamic Multiplex (OFDM) symbol.

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