WO2008105588A1

WO2008105588A1 - Transmitting device and method and receiving device and method in communication system

Info

Publication number: WO2008105588A1
Application number: PCT/KR2008/000812
Authority: WO
Inventors: Nam-Il Kim; Young-Hoon Kim; Hye-Kyung Jwa; Young-Min Choi; Tae-Joong Kim
Original assignee: Electronics And Telecommunications Research Institute; Samsung Electronics.Co., Ltd.
Priority date: 2007-02-26
Filing date: 2008-02-12
Publication date: 2008-09-04
Also published as: KR100888505B1; KR20080079163A

Abstract

A transmitting device of a communication system in which a physical channel includes a combination of symbols of a plurality of time domains and subcarriers of a plurality of frequency domains divides data into a plurality of data blocks, interleaves the data blocks, maps the interleaved data blocks on at least one physical channel, and transmits the mapped data blocks to a receiving device of the communication system, thereby reducing a time delay caused by data interleaving.

Description

TRANSMITTING DEVICE AND METHOD AND RECEIVING DEVICE AND METHOD IN COMMUNICATION SYSTEM

Technical Field

[1] The present invention relates to a transmitting method and device and a receiving method and device in the communication system. More particularly, the present invention relates to a method and device for mapping transport channel data on a physical channel and transmitting resultant data, and a receiving method and device thereof.

[2] This work was supported by the IT R&D program of MIC/IITA [2005-S-404-13,

Research & Development of Radio Transmission Technology for 3G evolution]. Background Art

[3] A transmitting device in the communication system channel encodes upper layer data, rate matches the data, and divides the rate mapped data stream into one or more physical channels so as to map the upper layer data mapped on a transport channel on the physical channel and transmit the resultant data. The transmitting device data interleaves the data stream that is divided into each physical channel in the corresponding physical channel, maps the interleaved data stream on each physical channel, and transmits the mapped data stream to a receiving device through a radio channel. A receiving device in the communication system collects data by demapping the data that are received through the radio channel for each physical channel, data interleaves the collected data for each physical channel, performs a derate mapping process on the interleaved data, channel decodes them, and transmits resultant data to an upper layer.

[4] Particularly, in the Multiplexing and Channel Coding of the mobile communication system such as the 3GPP WCDMA, when the data transmitted from the upper layer are interleaved and mapped on a plurality of physical channels, the data are mapped on a symbol in the time domain of the first physical channel, mapped on a symbol in the time domain of the second physical channel, and then mapped on symbols in the time domain of other physical channels in a like manner since a single physical channel has a plurality of time -based symbols.

[5] However, the physical channel is configured by combination of a plurality of symbols in the time domain and a plurality of subcarriers in the frequency domain in the cases of the orthogonal frequency division multiple (OFDM) transmission system and the single carrier-frequency division multiple access (SC-FDMA) transmission system. That is, a physical channel has a plurality of time domain symbols, and a time domain symbol has a plurality of subcarriers. In the above-noted communication system, a physical channel is divided into groups of subcarriers in the frequency domain, and the time domain symbols for the groups of subcarriers in the frequency domain are configured as a physical channel.

[6] In this instance, when the data interleaving and the physical channel mapping are performed in a like manner of the WCDMA communication system, a number of clock signals that is twice the number of data bits transmitted from the upper layer is required, and when the data size is enlarged, the time delay caused by the data interleaving is problematically increased. Also, the time delay caused by the data interleaving may be decreased in the case of a plurality of physical channels, but a long time delay is generated so as to map the data on each physical channel and transmit the mapped data. Further, it requires a long time delay for the receiving device to collect data in the physical channel and deinterleave the collected data.

[7] The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. Disclosure of Invention Technical Problem

[8] The present invention has been made in an effort to provide a transmitting method and device for reducing a time delay caused by data interleaving and physical channel mapping in the communication system. The present invention has been made in another effort to provide a receiving method and device for reducing a time delay caused by data collection and collected data deinterleaving. Technical Solution

[9] In one aspect of the present invention, a method for transmitting data of an upper layer in a communication system includes dividing the data into a plurality of data blocks, interleaving the divided data blocks, and mapping the interleaved plurality of data blocks on at least one physical channel and transmitting the mapped data blocks.

[10] In another aspect of the present invention, a device for transmitting data of an upper layer in a communication system includes a data interleaver for dividing the data into a plurality of data blocks and interleaving the divided data blocks, and a channel mapper for mapping the plurality of interleaved data blocks on a physical channel and transmitting the mapped data blocks.

[11] The physical channel includes combination of symbols of a plurality of time domains and subcarriers of a plurality of frequency domains.

[12] In another aspect of the present invention, a method for receiving data in a commu- nication system includes demapping received data in at least one physical channel, dividing the received data into a plurality of data blocks, and deinterleaving the plurality of data blocks.

[13] In another aspect of the present invention, a device for receiving data in a communication system includes a channel demapper for demapping received data at a physical channel, and a data deinterleaver for dividing the demapped data into a plurality of data blocks and deinterleaving the plurality of data blocks.

[14] The at least one physical channel includes a combination of symbols of a plurality of time domains and subcarriers of a plurality of frequency domains.

Advantageous Effects

[15] According to an exemplary embodiment of the present invention, the time delay caused by data interleaving and physical channel mapping is reduced in the transmitting device, and the time delay caused by data collection and data deinterleaving according to physical channel demapping is reduced in the receiving device. Brief Description of the Drawings

[16] FIG. 1 is a communication system according to an exemplary embodiment of the present invention.

[17] FIG. 2 is a transmitter according to an exemplary embodiment of the present invention.

[18] FIG. 3 is a flowchart for a transmitter to transmit a data bit stream according to an exemplary embodiment of the present invention.

[19] FIG. 4 is a physical channel mapping method according to a first exemplary embodiment of the present invention.

[20] FIG. 5 is a physical channel mapping method according to a second exemplary embodiment of the present invention.

[21] FIG. 6 is a receiver according to an exemplary embodiment of the present invention.

[22] FIG. 7 is a flowchart for a receiver to receive data according to an exemplary embodiment of the present invention. Mode for the Invention

[23] In the following detailed description, only certain exemplary embodiments of the present invention have been shown and described, simply by way of illustration. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification.

[24] Throughout this specification and the claims which follow, unless explicitly described to the contrary, the word comprising and variations such as comprises will be understood to imply the inclusion of stated elements but not the exclusion of any other elements. Also, the terms of a unit, a device, and a module in the present specification represent a unit for processing a predetermined function or operation, which can be realized by hardware, software, or combination of hardware and software.

[25] A transmitting method and device and a receiving method and device in a communication system according to an exemplary embodiment of the present invention will be described in detail with reference to accompanying drawings.

[26] FIG. 1 is a communication system according to an exemplary embodiment of the present invention.

[27] As shown in FIG. 1, the communication system includes a transmitter 100 and a receiver 200. The transmitter 100 transmits data bit streams that are transmitted from an upper layer to a physical layer through a plurality of transport channels, maps data of a plurality of transport channels on at least one physical channel in the physical layer, and transmits mapped data to the receiver 200 through the radio channel. In the exemplary embodiment of the present invention, the physical channel includes a combination of a plurality of symbols in the time domain and a plurality of subcarriers in the frequency domain. The communication system includes the OFDM transmission system and the SC-FDMA transmission system.

[28] The receiver 200 receives data through the radio channel, collects data for each physical channel in the physical layer, and transmits the data to the upper layer.

[29] The transmitter 100 and a method for the transmitter 100 to transmit the data bit stream will now be described with reference to FIG. 2 and FIG. 3.

[30] FIG. 2 is a transmitter 100 according to an exemplary embodiment of the present invention, and FIG. 3 is a flowchart for a transmitter 100 to transmit a data bit stream according to an exemplary embodiment of the present invention.

[31] As shown in FIG. 2, the transmitter 100 includes an additional bit adder 110, a channel coder 120, a rate matcher 130, a data interleaver 140, and a channel mapper 150.

[32] The additional bit adder 110 adds an additional bit to the data bit stream transmitted from the upper layer (S310). The additional bit includes a cyclic redundancy code (CRC). In this instance, the CRC is used to detect an error of the transport channel, is found by 24, 16, 12, and 8 bits through each generator polynomial, and is allocated according to each transport channel.

[33] The channel coder 120 channel codes the additional-bit- added data bit stream (S320).

In this instance, the channel coding methods include the convolutional encoding, lattice encoding, turbo encoding, low density parity check (LDPC) encoding, or concatenate encoding that concatenates at least two of the channel encoding methods. [34] The rate matcher 130 rate matches the channel coded data bit stream to control the size of the channel coded data bit stream (S330). That is, the rate matcher 130 controls the bit number of the coded data bit stream by repeating or puncturing the channel coded data bit stream according to a rate match pattern.

[35] The data interleaver 140 interleaves the rate matched data bit stream. That is, the data interleaver 140 rearranges the input order of the rate matched data bit stream so as to acquire a frequency diversity gain in the frequency domain and a time diversity gain in the time domain from the transport channel.

[36] The data interleaver 140 includes a data divider 142, block interleavers 144_!-144_n, and a data concatenator 146.

[37] The data divider 142 divides the data into a plurality of data blocks when the rate matched data bit stream is bigger than the blocks of the block interleavers 144_!-144_n (S340). Here, the block size of the block interleavers 144_!-144_n is determined by the number of bits included in one OFDM symbol in the case of the OFDM transmission system.

[38] The block interleavers 144_r144_n interleave the divided data blocks (S350). Here, the number of block interleavers 144_r 144_n corresponds to the number of data blocks divided by the data divider 142. The block interleavers 144i-144_n can interleave the data blocks after inserting a data delta bit thereto, or can interleave the same after repeating random data when the data size of the data block is smaller than the block size of the established block interleavers 144_!-144_n. When the interleaving process is finished, a random data delta bit and repeated random data are eliminated.

[39] Regarding the block interleavers 144_!-144_n, while a single block interleaver 144_X reads data of the data block and sequentially writes the same in the memory, another block interleaver 144₂ reads data of the data block. The time delay caused by interleaving can be reduced since the block interleavers 144_!-144_n interleave the respective data blocks as described above.

[40] The data concatenator 146 concatenates the data interleaved by the block interleavers

144!-144,, (836O).

[41] The channel mapper 150 maps the concatenated data on at least one physical channel to generate a modulation symbol, and transmits the generated modulation symbol to the receiver through the radio channel (200 of FIG. 1) (S370).

[42] A method for the transmitter 100 according to an exemplary embodiment of the present invention to map the data bit stream on the physical channel will be described with reference to FIG. 3 and FIG. 4.

[43] FIG. 4 is a physical channel mapping method according to a first exemplary embodiment of the present invention, and FIG. 5 is a physical channel mapping method according to a second exemplary embodiment of the present invention. [44] As shown in FIG. 4, the channel mapper 150 maps the first to last subcarriers f_o-f_F-i for the symbol in the first time domain t₀ starting from the symbol in the time domain to which the physical channel is allocated for the respective bits of the interleaved data bit stream to generate the modulation symbol and transmit the modulation symbol to the receiver 200 through the radio channel. The channel mapper 150 maps the first to last subcarriers f_o-f_F-i for the symbol in the next time domain ti to generate a modulation symbol and transmit the same to the receiver 200 through the radio channel. In a like manner, the channel mapper 150 maps the subcarriers for the symbol in the last time domain t₂-f_T-i allocated to the physical channel to generate a modulation symbol and transmit the same to the receiver 200 through the radio channel.

[45] When there are a plurality of physical channels, differing from FIG. 4, as shown in

FIG. 5, the channel mapper 150 maps the first to last subcarriers f_o-f_F-i for the symbol of the first time domain t₀ starting from the symbol of the time domain allocated to the physical channel for the data to be mapped on a first physical channel Ph₀ from among the interleaved data bit streams to generate a modulation symbol and transmit the generated modulation symbol to the receiver 200 through the radio channel. The channel mapper 150 maps the first to last subcarriers f_o-f_F-i for the symbol of the next time domain ti to generate a modulation symbol and transmit the modulation symbol to the receiver 200 through the radio channel. In a like manner, the channel mapper 150 maps the symbols of the next to last time domains t₂-t_τ_i allocated to the physical channel to generate a modulation symbol and transmit the modulation symbol to the receiver 200 through the physical channel. When the symbol mapping for the first physical channel Ph₀ is finished, the channel mapper 150 maps the data that will be mapped on the second physical channel Ph₁ from among the interleaved data bit streams on the second physical channel Ph₁ to generate a modulation symbol and transmit the modulation symbol to the receiver 200 through the radio channel. Subcarriers starting from the subcarrier f_F next to the last subcarrier allocated to the first physical channel Ph₀ are allocated to the second physical channel Ph₁, and in a like manner, the channel mapper 150 maps the first to last subcarriers f_F-f_2F-i from the first time domain to the last time domain VW-i to generate a modulation symbol and transmit the modulation symbol to the receiver 200 through the radio channel. In a like manner, the channel mapper 150 maps the subcarriers up to the last subcarrier

for the last time domain t_τ-i allocated to all physical channels Ph^₁ to generate a modulation symbol and transmit the modulation symbol to the receiver 200 through the radio channel.

[46] When the channel mapper 150 maps the data bit stream on the physical channel, the time delay caused by physical channel mapping can be reduced.

[47] The receiver 200 according to an exemplary embodiment of the present invention and a method for the receiver 200 to receive data will be described with reference to

FIG. 6 and FIG. 7. [48] FIG. 6 is a receiver 200 according to an exemplary embodiment of the present invention, and FIG. 7 is a flowchart for a receiver 200 to receive data according to an exemplary embodiment of the present invention. [49] As shown in FIG. 6, the receiver 200 includes a channel demapper 210, a data dein- terleaver 220, a derate matcher 230, a channel decoder 240, and an error tester 250. [50] The channel demapper 210 collects data in the physical channel by demapping the data received through the radio channel in the physical channel. [51] The data deinterleaver 220 deinterleaves the collected data. The data deinterleaver

220 includes a data divider 222, block deinterleavers 22A₁-HA_n, and a data con- catenator 226. [52] The data divider 222 divides the collected data into a plurality of data blocks depending on the block sizes of the block deinterleavers 224_r224_n when the collected data are bigger than the blocks of the block deinterleavers 224i-224_n. In this instance, the block size of the block deinterleavers 224i-224_n can be determined by the number of bits included in a single OFDM symbol in the case of the OFDM transmission system. [53] The block deinterleavers 224i-224_n deinterleave a plurality of data blocks. The block deinterleavers 224_r224_n deinterleave the data blocks according to a predetermined order such as sequentially in a like manner of the block interleavers IAA₁-IAA_n of the transmitter 100, and the time for two of the block deinterleavers 22A_r22A_n to interleave the blocks is partially superimposed. Therefore, the time delay caused by dein- terleaving can be reduced.

[54] The data concatenator 226 concatenates the deinterleaved data blocks.

[55] The derate matcher 230 derate matches the concatenated data to restore the number of bits controlled by rate matching to the original state. [56] The channel decoder 240 channel decodes the derate matched data. In this instance, the channel decoding method follows the channel coding method used by the channel coder (120 of FIG. 2). [57] The error tester 250 tests errors of the channel decoded data to determine the error state of the transport channel and then transmits the test result to the upper layer. [58] A method for the receiver 200 according to an exemplary embodiment of the present invention to demap the data that are received from the physical channel will now be described. [59] As shown in FIG. 4, when the transmitter 100 maps the data on a physical channel and transmits the mapped data, the channel demapper 210 collects data of the physical channel by demapping the received data from the first to last subcarriers fo-fF-i for the symbol of the time domain (t₀ of FIG. 4) allocated to the physical channel, and collects the data of the physical channel by demapping the received data from the first to last subcarriers f_o-f_F-i for the symbol of the next time domain (ti of FIG. 4). In a like manner, the channel demapper 210 demaps the received data of subcarriers f_o-f_F-i up to the last subcarrier of the last time domain (t₂-t_τ__! of FIG. 4) allocated to the physical channel to collect the data of the physical channel.

[60] Also, as shown in FIG. 5, when the transmitter 100 maps the data on a plurality of physical channels Ph₀-PlIp._! and transmits the data, the channel demapper 210 collects the data of the physical channel (Ph₀ of FIG. 5) by demapping the received data of the first to last subcarriers (f_o-f_F-i of FIG. 5) of the symbol of the first time domain (t₀ of FIG. 5) starting from the symbol of the time domain allocated to the first physical channel (Ph₀ of FIG. 5). The channel demapper 210 collects the data of the physical channel Ph₀ from the first to last subcarriers f_o-f_F-i for the symbol of the next time domain (ti of FIG. 5). In a like manner, the channel demapper 210 collects the data of the physical channel Ph₀ by demapping the received data of the symbols up to the symbol of the last time domain t₂-t_τ_i allocated to the physical channel Ph₀. When having collected the data of the first physical channel Ph₀, the channel demapper 210 collects the data of the second physical channel Phi. Since the subcarriers starting from the subcarrier f_F next to the last subcarrier f_F_i allocated to the first physical channel Ph₀ are allocated to the second physical channel Phi, the channel demapper 210 collects the data from the first to last subcarriers f_F-f_2F.i for the first to last time domains t_o-t_τ_i in a like manner of collecting the data of the first physical channel Ph₀. In a like manner, the channel demapper 210 collects the data up to the last subcarrier f_PF_i for the last time domain t_τ_i allocated to the entire physical channel Ph_p_i.

[61] Accordingly, the time delay generated for collecting the data for the physical channel can be reduced compared to the case of configuring the symbol of the time domain for a group of subcarriers in the frequency domain as a single physical channel.

[62] The above-described embodiments can be realized through a program for realizing functions corresponding to the configuration of the embodiments or a recording medium for recording the program in addition to through the above-described device and/or method, which is easily realized by a person skilled in the art.

[63] While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

[1] A method for transmitting data of an upper layer in a communication system, the method comprising: dividing the data into a plurality of data blocks; interleaving the divided data blocks; and mapping the interleaved plurality of data blocks on at least one physical channel and transmitting the mapped data blocks.

[2] The method of claim 1, wherein the physical channel includes a combination of symbols of a plurality of time domains and subcarriers of a plurality of frequency domains.

[3] The method of claim 2, wherein the step of interleaving includes: interleaving a first one of the plurality of data blocks; and interleaving a second one of the plurality of data blocks, and wherein the time for interleaving the first data block is partially superimposed on the time for interleaving the second data block.

[4] The method of claim 3, further comprising, before the step of transmitting, concatenating the plurality of interleaved data blocks.

[5] The method of claim 3, wherein the step of transmitting includes sequentially generating modulation symbols from the first time domain symbol to the last time domain symbol from among the symbols of the plurality of time domains and transmitting the modulation symbols, and the step for generating a modulation symbol for the symbol of the n-th time domain includes: generating the modulation symbol by mapping the plurality of interleaved data blocks on the first to last subcarriers for the symbol of the n-th time domain; and transmitting the generated modulation symbol.

[6] The method of claim 3, wherein the subcarriers of the plurality of frequency domains are generated into a plurality of groups, and the at least one physical channel includes a plurality of physical channels respectively corresponding to the plurality of groups, and the step of transmitting includes: mapping part of the interleaved data blocks on one of the plurality of physical channels; and mapping the remaining part of the interleaved data blocks on others of the plurality of physical channels.

[7] The method of claim 6, wherein the step of interleaving includes inserting a predetermined data bit into the corresponding data block or repeating a predetermined data bit in the corresponding data block according to the length of the data block.

[8] The method of claim 6, further comprising, before the step of dividing: adding an additional bit to the data; coding the additional bit added data; and rate matching the coded data.

[9] A device for transmitting data of an upper layer in a communication system, the device comprising: a data interleaver for dividing the data into a plurality of data blocks, and interleaving the divided data blocks; and a channel mapper for mapping the plurality of interleaved data blocks on a physical channel, and transmitting the mapped data blocks, wherein the physical channel includes a combination of symbols of a plurality of time domains and subcarriers of a plurality of frequency domains.

[10] The device of claim 9, wherein the data interleaver includes: a data divider for dividing the data into the plurality of data blocks; a plurality of block interleavers for interleaving the plurality of data blocks; and a data concatenator for concatenating the plurality of interleaved data blocks, and wherein the time for a first block interleaver from among the plurality of block interleavers to interleave a data block is partially superimposed on the time for a second block interleaver from among the plurality of block interleavers to interleave a data block.

[11] The device of claim 10, wherein the channel mapper maps the plurality of interleaved data blocks on the first to last subcarriers of the corresponding time domains in the symbols of the plurality of time domains.

[12] A method for receiving data in a communication system, the method comprising: demapping received data in at least one physical channel; dividing the received data into a plurality of data blocks; and deinterleaving the plurality of data blocks.

[13] The method of claim 12, wherein the at least one physical channel includes a combination of symbols of a plurality of time domains and subcarriers of a plurality of frequency domains. [14] The method of claim 13, wherein the step of deinterleaving includes: deinterleaving a first one of the plurality of data blocks; and deinterleaving a second one of the plurality of data blocks, and wherein the time for deinterleaving the first data block is partially superimposed on the time for deinterleaving the second data block. [15] The method of claim 14, further comprising concatenating the plurality of deinterleaved data blocks. [16] The method of claim 15, further comprising derate matching the plurality of concatenated data blocks; decoding the plurality of derate matched data blocks; and testing an error of the plurality of decoded data blocks. [17] The method of claim 14, wherein the step of demapping includes sequentially demapping the received data from a symbol of the first time domain to a symbol of the last time domain from among symbols of the plurality of time domains, and the step of demapping the received data for the symbol of the n-th time domain includes demapping the received data from the first subcarrier to the last subcarrier for the symbol of the n-th time domain. [18] The method of claim 14, wherein the subcarriers of the plurality of frequency domains are generated into a plurality of groups, and the at least one physical channel includes a plurality of physical channels corresponding to the plurality of groups, and the step of demapping includes: demapping part of the received data at one of the plurality of physical channels; and demapping the remaining part of the received data at the plurality of other physical channels. [19] A device for receiving data in a communication system, the device comprising: a channel demapper for demapping received data at a physical channel; and a data deinterleaver for dividing the demapped data into a plurality of data blocks, and deinterleaving the plurality of data blocks, wherein the at least one physical channel includes a combination of symbols of a plurality of time domains and subcarriers of a plurality of frequency domains. [20] The device of claim 19, wherein the data deinterleaver includes: a data divider for dividing the demapped data into the plurality of data blocks; a plurality of block deinterleavers for deinterleaving the plurality of data blocks; and a data concatenator for concatenating the plurality of deinterleaved data blocks, and wherein the time for a first block deinterleaver from among the plurality of block deinterleavers to deinterleave a data block is partially superimposed on the time for a second block deinterleaver from among the plurality of block deinterleavers to deinterleave a data block. [21] The device of claim 20, wherein the channel demapper demaps the received data from the first to last subcarriers of the corresponding time domains from among the symbols of the plurality of time domains.