`
`(cid:11)(cid:20)(cid:28)(cid:12)(cid:3)(cid:46)(cid:82)(cid:85)(cid:72)(cid:68)(cid:81)(cid:3)(cid:44)(cid:81)(cid:87)(cid:72)(cid:79)(cid:79)(cid:72)(cid:70)(cid:87)(cid:88)(cid:68)(cid:79)(cid:3)(cid:51)(cid:85)(cid:82)(cid:83)(cid:72)(cid:85)(cid:87)(cid:92)(cid:3)(cid:50)(cid:73)(cid:73)(cid:76)(cid:70)(cid:72)(cid:3)(cid:11)(cid:46)(cid:53)(cid:12)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:51)(cid:88)(cid:69)(cid:79)(cid:76)(cid:70)(cid:68)(cid:87)(cid:76)(cid:82)(cid:81)(cid:3)(cid:49)(cid:82)(cid:17)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:20)(cid:19)(cid:16)(cid:21)(cid:19)(cid:19)(cid:27)(cid:16)(cid:19)(cid:19)(cid:19)(cid:23)(cid:19)(cid:21)(cid:24)(cid:3)
`
`Publicized Patent 10-2008-0004025
`
`(cid:11)(cid:20)(cid:21)(cid:12)(cid:3)(cid:51)(cid:88)(cid:69)(cid:79)(cid:76)(cid:70)(cid:3)(cid:51)(cid:68)(cid:87)(cid:72)(cid:81)(cid:87)(cid:3)(cid:49)(cid:82)(cid:87)(cid:76)(cid:73)(cid:76)(cid:70)(cid:68)(cid:87)(cid:76)(cid:82)(cid:81)(cid:3)(cid:11)(cid:36)(cid:12)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:51)(cid:88)(cid:69)(cid:79)(cid:76)(cid:70)(cid:68)(cid:87)(cid:76)(cid:82)(cid:81)(cid:3)(cid:71)(cid:68)(cid:87)(cid:72)(cid:3)(cid:3)(cid:3)(cid:3)(cid:19)(cid:20)(cid:18)(cid:19)(cid:28)(cid:18)(cid:21)(cid:19)(cid:19)(cid:27)(cid:3)
`
`(51)
`
`Int. Cl.
`H04L 25/49 (2006.01)
`(21) Application No. 10-2006-
`0062467
`(22) Filed 07/04/2006
`Date
`of
`Request No
`
`Examination
`
`(71) Applicant
`LG Electronics Inc.
`20, Yoeuido-dong, Yeongdeungpo-gu, Seoul
`(72) Inventors
`Yeong-Hyeon Kwon
`No. 402, Smile Bill. 103-6 Yuljeon-dong,
`Jangan-gu, Suwon-si, Gyeonggi-do
`Seung-Hi Han
`42-35, Yeokchon 1-ding, Eunpyeong-gu, Seoul
`
`Total No. of Claims: 20
`
`Yong-In Kim, Chang-Seop Shim
`
`(Continued on next page)
`(74) Attorney
`
`(cid:1659)
`
`(54) Title of the invention CODE SEQUENCE IN COMMUNICATION SYSTEM, AND METHOD AND
`DEVICE FOR TRANSMITTING, GENERATING, AND ANALYZING THE SAME
`(57) Abstract
`
`(cid:1659)
`
`The present invention relates to a code sequence for transmitting control information, and more particularly,
`to the structure of a constant amplitude zero autocorrelation (CAZAC) sequence and a technology to
`generate and analyze the same. To this end, the present invention proposes a method and device that
`selects a maximum prime number length equal to or smaller than a required code sequence length when
`the length of a code sequence required in a communication system is not a prime number, generates a
`sequence that has the selected maximum prime number length, and inserts a padding portion that has a
`length corresponding to the difference between the length of the code sequence required in the
`communication system and the maximum prime number length, and the present invention proposes a code
`sequence that is generated by the method and device. Since the code sequences generated in this way may
`increase the number of code sequences that may be generated, without redundancy between them, and
`maintain good autocorrelation and cross-correlation properties, it is possible to obtain more accurate
`synchronization information than the related art.
`
`Representative drawing – Fig. 2
`
`(cid:1659)
`
`(cid:1659)
`
`(cid:1672)(cid:1659)(cid:1676)(cid:1659)(cid:1672)(cid:1659)
`
`1
`
`APPLE 1016
`
`
`
`(72) Inventors
`Hyun Hwa Park
`1133 Sinanmetrocan, 1115 Bisan-dong,
`Dongangu, Anyang-city, Gyeonggi-do
`Dong Chul Kim
`401 Daemyungsweetvill, 763 Naeson-dong,
`Uiwang-city, Gyeonggi-do
`
`Hyun Woo Lee
`204 Neovill, 1103-3 Hogye-dong, Dongan-gu,
`Anyang-city, Gyeonggi-do
`Min Seok Noh
`211, studio Miraegio 2F, Kuro-3dong, Kuro-gu,
`Seoul
`
`(cid:1672)(cid:1659)(cid:1677)(cid:1659)(cid:1672)(cid:1659)
`
`2
`
`
`
`Publicized Patent 10-2008-0004025
`
`What is claimed is:
`
`Claim 1
`
`A code sequence having a length required in a communication system to transmit control
`information, comprising:
`
`a first sequence portion having a prime number length; and
`
`a second sequence portion inserted with a padding portion having a length corresponding with the
`difference between the required length and the prime number length.
`
`Claim 2
`
`A code sequence having a length required in a communication system to transmit control
`information, comprising:
`
`a first sequence portion having a prime number length; and
`
`a second and a third sequence, each inserted with a padding portion, and
`
`the sum of the lengths of the second and third sequence portions is equal to the difference
`between the required length and the prime number length.
`
`Claim 3
`
`The code sequence of claim 1 or claim 2,
`
`wherein the code sequence comprises sequences generated on the basis of a non-primary
`number length and an overlapping sequence interposed between the sequences.
`
`Claim 4
`
`The code sequence of claim 1 or claim 2,
`
`wherein the prime number length is a maximum prime number length same or smaller than the
`required length.
`
`Claim 5
`
`A method for transmitting signals comprising the steps of: selecting a code sequence having a
`length required in a communication system; and
`
`transmitting the selected code sequence to a receiver,
`
`wherein the code sequence comprises:
`
`a first sequence portion having a prime number length; and
`
`- 1 -
`
`3
`
`
`
`Publicized Patent 10-2008-0004025
`
`a second sequence portion inserted with a padding portion having a length corresponding with the
`difference between the required length and the prime number length.
`
`Claim 6
`
`A method for transmitting signals comprising the steps of: selecting a code sequence having a
`length required in a communication system; and
`
`transmitting the selected code sequence to a receiver,
`
`wherein the code sequence comprises:
`
`a first sequence portion having a prime number length; and
`
`a second and a third sequences each inserted with a padding portion,
`
`the sum of the lengths of the second and third sequence portions is equal to the difference
`between the required length and the prime number length.
`
`Claim 7
`
`An apparatus for transmitting signals comprising: a code sequence selector for selecting a code
`sequence having a length required in a communication system for transmitting control information;
`and
`
`a transmitter which transmits the code sequence selected by the sequence selector to a receiver,
`
`wherein the code sequence comprises:
`
`a first sequence portion having a prime number length; and
`
`a second sequence portion inserted with a padding portion having a length corresponding with the
`difference between the required length and the prime number length.
`
`Claim 8
`
`A method for generating a code sequence for transmitting control information at a transmitting
`terminal of a communication system, the method comprising the steps of:
`
`selecting a maximum prime number length same of smaller than the length of sequence required in
`the communication system;
`
`generating a first sequence portion having the maximum prime number length on the basis of the
`selected maximum prime number length; and
`
`generating a second sequence portion inserted with a padding portion having a length
`corresponding with the difference between the required length of the sequence and the maximum
`prime number length.
`
`- 2 -
`
`4
`
`
`
`Publicized Patent 10-2008-0004025
`
`Claim 9
`
`The method of claim 8,
`
`further comprising a step of inserting a sequence comprised of predetermined constants only in
`the padding portion.
`
`Claim 10
`
`The method of claim 8,
`
`further comprising a step of inserting a cyclic postfix of the generated sequences in the padding
`portion.
`
`Claim 11
`
`The method of claim 8, further comprising the steps of:
`
`generating a sequence having the required length, on the basis of the sequence length required in
`the communication system; and
`
`extracting a sequence having a length corresponding with the difference from the sequence
`generated to have the required length and inserting it in the padding portion.
`
`Claim 12
`
`The method of claim 8,
`
`further comprising a step of extracting a sequence having a length corresponding with the
`difference, from the sequences of a different type from the selected sequences generated having
`a maximum prime number length and inserting in it the padding portion.
`
`Claim 13
`
`The method of claim 8,
`
`splitting and inserting the padding portion in the opposite sides of the first sequence portion for
`utilizing it as a protective section for sub-band.
`
`Claim 14
`
`The method of claim 13,
`
`inserting any one of a predetermined constant and the cyclic postfix of the sequence generated as
`described above in the protective section.
`
`Claim 15
`
`The method of any one of claim 8 to claim 14,
`
`- 3 -
`
`5
`
`
`
`Publicized Patent 10-2008-0004025
`
`further comprising a step of: power-boosting the generated sequence by a value obtained by
`dividing the required sequence length with the maximum prime number length.
`
`Claim 16
`
`A method for analyzing a code sequence at a receiving terminal of a communication system,
`wherein the code sequence comprises a first sequence portion having a prime number length and
`a second sequence portion inserted with a padding portion having a length corresponding with the
`difference between the required length and the prime number length, the method comprising the
`steps of:
`
`receiving information providing the lengths of the code sequence and the second sequence portion;
`and
`
`obtaining control information by extracting and analyzing the portion corresponding with the length
`of the second sequence portion of the received code sequences.
`
`Claim 17
`
`The method of claim 16,
`
`obtaining synchronization information by extracting and analyzing the portion corresponding with
`the length of the second sequence portion of the received code sequences, and applying self-
`correlation or cross-correlation, in the step of obtaining the control information.
`
`Claim 18
`
`The method of claim 17,
`
`further comprising a step of obtaining the ID information of the received code sequence by
`generating a differential sequence of the received code sequence corresponding with the length of
`the second sequence portion using the obtained synchronization information.
`
`Claim 19
`
`A method for analyzing a code sequence at a receiving terminal of a communication system,
`wherein the code sequence comprises a first sequence portion having a prime number length; and
`
`a second sequence portion and a third sequence portion each inserted with a padding portion, the
`sum of the lengths of the second and third sequence portions is equal to the difference between
`the required length and the prime number length, the method comprising the steps of:
`
`receiving information of the code sequence and the second sequence portion, and the total sum of
`the length of the second sequence portion;
`
`- 4 -
`
`6
`
`
`
`Publicized Patent 10-2008-0004025
`
`obtaining the synchronization information by extracting the portion corresponding with the total sum
`of the length from the received code sequences and applying self-correlation or cross-correlation;
`and
`
`obtaining the ID information of the received code sequence by generating a differential sequence of
`the received code sequence corresponding with the total length of the code sequence using the
`obtained synchronization information.
`
`Claim 20
`
`An apparatus for generating a code sequence for transmitting control information at a transmitting
`terminal of a communication system, comprising:
`
`a controller selecting a maximum prime number length same or smaller than the length of
`sequence required in the communication system; and
`
`a sequence generator for generating a first sequence portion having the maximum prime number
`length selected from the controller, and generating a second sequence portion inserted with a
`padding portion having a length corresponding with the difference between the lengths of the
`required sequence and the maximum prime number length and combining the first and second
`sequences.
`
`pecification
`
`(cid:3) S
`
`Detailed Description of the Invention
`
`Object of the Invention
`
`Technical Field and Technical Background
`
`The present invention relates to a communication system, and more particularly, to a code
`sequence in a communication system, and a method and device for transmitting, generating,
`and analyzing the code sequence.
`
`There are many sequences that are used to transmit an ID for identifying a type of sequence
`in the communication system and control information that includes synchronization
`information, but the current 3GPP LTE is based on a constant amplitude zero autocorrelation
`(CAZAC) sequence.
`
`- 5 -
`
`7
`
`
`
`Publicized Patent 10-2008-0004025
`
`These CAZAC sequences are used by channels that extract various IDs or information by
`using these sequences. These channels include synchronization channels for downlink
`synchronization (e.g., a primary-SCH, a secondary-SCH, BCH), synchronization channels
`for uplink synchronization (e.g., a random access channel (RACH)), a pilot channel (e.g., a
`data pilot, a channel quality pilot) or the like. Also, the CAZAC sequence may also be used
`for scrambling.
`
`Two types of CAZAC sequences, GCL CAZAC and Zadoff-Chu CAZAC, are being mostly
`used. These are complex conjugate numbers and the GCL CAZAC may be obtained by
`taking the complex conjugate number of the Zadoff-Chu CAZAC. The Zadoff-Chu CAZAC
`is provided as follows:
`
`Equation 1
`
`Equation 2
`
`where k denotes a sequence index, N denotes the length of a CAZAC sequence to be
`generated, and M denotes a sequence ID.
`
`When representing, by c (k;N,M), the Zadoff-Chu CAZAC sequence and the GCL CAZAC
`sequence being the complex conjugate number thereof that are provided by Equations 1 and
`2, the following three characteristics appear:
`
`Equation 3
`
`- 6 -
`
`8
`
`
`
`Publicized Patent 10-2008-0004025
`
`Equation 4
`
`Equation 5
`
`Equation 3 means that the amplitude of the CAZAC sequence is always 1, and Equation 4
`shows that the autocorrelation function of the CAZAC sequence is expressed by Delta
`function. In this example, autocorrelation is based on circular correlation. Also, Equation 5
`shows that cross-correlation is always a constant. In the following, the sequence property as
`in Equation 3 is referred to as a “CA property” and the properties as in Equations 4 and 5
`are referred to as a “ZAC property,” for the convenience of description.
`
`When a length to be applied in a system that applies a CAZAC sequence is L, two CAZAC
`sequence generation methods are considered: (1) a method of setting N in Equation 1 or 2 to
`N = L irrespective of a value of L to use a CAZAC sequence and (2) a method of setting and
`generating N to a prime number larger than L.
`
`To briefly mention the characteristic of the CAZAC sequence generated with a specific value
`L, the CAZAC sequence generated when L is not a prime number may enable M = 1,2,...,L-
`1 but there are redundant codes. That is, the number of different codes is actually smaller
`than L–1. On the contrary, when L is a prime number, L-1 different codes are generated.
`Thus, in the event that the length of a code to be applied to a system is not a prime number
`and there are a number of codes to be used, a method of selecting a minimum prime number
`
`- 7 -
`
`9
`
`
`
`Publicized Patent 10-2008-0004025
`
`larger than L to generate a CAZAC sequence therefrom and truncate a portion thereof is
`considered rather than the method (1).
`
`FIG. 1 is a diagram for explaining examples of a typical CAZAC sequence and a method of
`generating the sequence as described above.
`
`The method as shown in FIG. 1 may extend a type of code but since the code sequence
`generated by the method above truncates a portion of the sequence, an autocorrelation
`property that an autocorrelation value is 1 only when a delay is 0 as in Equation 4 and is 0
`in other cases, and a cross-correlation property that a cross-correlation value is always a
`constant as in Equation 5 are worsened. Also, when actually removing a sequence having a
`bad correlation property, it is difficult to ensure that the number of sequences is larger than
`L-1.
`
`In order to obtain a desired length and a maximum number of types of CAZAC sequences
`corresponding to the length, when the required length L is not a prime number, a minimum
`prime number X larger than L is selected and a CAZAC sequence is generated from the
`selected number but in this case, a correlation property is worsened and thus there is a
`drawback in that ZAC properties as in Equations 4 and 5 which are the characteristics of the
`CAZAC sequence are not ensured.
`
`Problems to be Solved
`
`In order to solve the limitations above, an object of the present invention is to provide a code
`sequence that has a sequence length required in a system and may deliver maximum
`information without redundancy, and a method and device for generating the code sequence.
`
`Another object of the present invention is to provide a sequence that may deliver maximum
`information as described above and also has good autocorrelation and cross-correlation
`properties, and a method and device for generating the sequence.
`
`- 8 -
`
`10
`
`
`
`Another object of the present invention is to provide a method and device for transmitting
`and analyzing the sequence generated as described above.
`
`Publicized Patent 10-2008-0004025
`
`Configuration and action of the Invention
`
`A code sequence according to an embodiment of the present invention for achieving the
`objects includes, as a code sequence that has a length required in a communication system
`in order to transmit control information, a first sequence portion that has a prime number
`length; and a second sequence portion into which a padding portion that has a length
`corresponding to the difference between the length required in the communication system
`and the prime number length is inserted.
`
`A code sequence according to another embodiment of the present invention for achieving
`the objects includes, as a code sequence that has a length required in a communication system
`in order to transmit control information, a first sequence portion that has a prime number
`length; and a second sequence portion and a third sequence portion into each of which a
`padding portion is inserted, wherein a sum of a length of the second sequence portion and a
`length of the third sequence portion is the same as the difference between the length required
`in the communication system and the prime number length.
`
`In this example, the code sequence is a sequence in which there are redundant sequences
`among sequences that are generated based on a length, not a prime number when generating
`the code sequence, and may be, e.g., a CAZAC sequence but is not limited thereto as long
`as the property described above is maintained.
`
`Also, the prime number length may be a maximum prime number length equal to or smaller
`than the length required in the communication system, but may also be a prime number
`length different therefrom according to the need of the communication system.
`
`A signal transmission method according to another embodiment of the present invention for
`achieving the objects includes selecting a code sequence that has a length required in a
`communication system in order to transmit control information; and transmitting the selected
`
`- 9 -
`
`11
`
`
`
`Publicized Patent 10-2008-0004025
`
`code sequence to a reception side, wherein the code sequence includes a first sequence
`portion that has a prime number length; and a second sequence portion into which a padding
`portion that has a length corresponding to the difference between the required length as
`described above and the prime number length is inserted.
`
`A signal transmission method according to another embodiment of the present invention for
`achieving the objects includes selecting a code sequence that has a length required in a
`communication system in order to transmit control information; and transmitting the selected
`code sequence to a reception side, wherein the code sequence includes a first sequence
`portion that has a prime number length; and a second sequence portion and a third sequence
`portion into each of which a padding portion is inserted, and a sum of a length of the second
`sequence portion and a length of the third sequence portion is the same as the difference
`between the length required in the communication system and the prime number length.
`
`A signal transmission device according to another embodiment of the present invention
`includes a sequence selection unit selecting a code sequence that has a length required in a
`communication system in order to transmit control information; and a transmission unit
`transmitting the code sequence selected by the sequence selection unit to a reception side,
`wherein the code sequence includes a first sequence portion that has a prime number length;
`and a second sequence portion into which a padding portion that has a length corresponding
`to the difference between the required length and the prime number length is inserted.
`
`A signal transmission device according to another embodiment of the present invention
`includes a sequence selection unit selecting a code sequence that has a length required in a
`communication system in order to transmit control information; and a transmission unit
`transmitting the code sequence selected by the sequence selection unit to a reception side,
`wherein the code sequence includes a first sequence portion that has a prime number length;
`and a second sequence portion and a third sequence portion into each of which a padding
`portion is inserted, and a sum of a length of the second sequence portion and a length of the
`third sequence portion is the same as the difference between the length required in the
`communication system and the prime number length.
`
`- 10 -
`
`12
`
`
`
`Publicized Patent 10-2008-0004025
`
`A sequence generation method according to another embodiment of the present invention
`includes selecting, at a transmission end, a maximum prime number length equal to or
`smaller than a required sequence length when the length of a sequence required in a
`communication system is not a prime number; generating a sequence that has the selected
`maximum prime number length; and inserting a padding portion that has a length
`corresponding to the difference between the required sequence length and the maximum
`prime number length.
`
`In this example, the sequence may be a sequence where there are redundant sequences
`among sequences that are generated in order to have a length that is not a prime number,
`when the length of the sequence is not the prime number.
`
`Also, the sequence generation method according to an embodiment of the present invention
`as described above may further include inserting a predetermined constant into the padding
`portion, and/or inserting a cyclic postfix of the generated sequence into the padding portion
`and further include generating a sequence that has a required sequence length; and extracting
`a sequence having a length that corresponds to the above-described difference from the
`sequence generated in order to have the required sequence length to insert the extracted
`sequence into the padding portion.
`
`Also, the sequence generation method according to an embodiment of the present invention
`as described above may further include extracting a sequence that has a length corresponding
`to the above-described difference among sequences different in type from sequences
`generated in order to have the maximum prime number length selected as described above
`to insert the extracted sequence into the padding portion, and alternatively, it is possible to
`use the padding portion as a lower band guard section. In this case, the sequence generation
`method may also insert any one of a predetermined constant or the cyclic postfix of the
`sequence generated as described above into the guard section.
`
`In addition, the sequence generation method according to an embodiment of the present
`invention as described above may further include power boosting the sequence generated as
`described above by a value that is obtained by a required sequence length divided by the
`maximum prime number length.
`
`- 11 -
`
`13
`
`
`
`Publicized Patent 10-2008-0004025
`
`A sequence analysis method according to another embodiment of the present invention for
`achieving the objects includes receiving, at a reception end of a communication system, a
`sequence that is generated at a transmission end, and information that represents a sequence
`length used for the sequence generation; and extracting a portion that corresponds to a
`sequence length obtained from the information received as described above, to analyze the
`received sequence to obtain control information.
`
`In this case, in the obtaining of the control information, it is possible to extract a portion that
`corresponds to a sequence length obtained from the information received as described above,
`to perform autocorrelation or cross-correlation on the received sequence to obtain
`synchronization information.
`
`A sequence analysis method according to another embodiment of the present invention for
`achieving the objects includes receiving, at a reception end of a communication system, a
`sequence that is generated at a transmission end, and information that represents a sequence
`length used for the sequence generation; and extracting a portion that corresponds to a
`sequence length obtained from the information received as described above, to perform
`autocorrelation or cross-correlation on the received sequence to obtain synchronization
`information; and using the obtained synchronization information to generate a differential
`sequence of the received sequence that corresponds to the total length of the sequence, to
`obtain ID information on the received sequence.
`
`A sequence generation device according to another embodiment of the present invention for
`achieving another object includes a control unit that determines at a transmission end of a
`communication system whether the length of a sequence required in the communication
`system is a prime number, and selects a maximum prime number length smaller than or equal
`to the length of the sequence required in the communication system as described above when
`the length is not the prime number; and a sequence generation unit that generates a sequence
`having the maximum prime number length selected in the control unit, and couples, a
`padding portion that has a length corresponding to the difference between the length of the
`sequence required in the communication system as described above and the maximum prime
`number length, to the generated sequence.
`
`- 12 -
`
`14
`
`
`
`Publicized Patent 10-2008-0004025
`
`In this example, the sequence may be a sequence in which there are redundant sequences
`among sequences that are generated in order to have a length that is not a prime number,
`when the length of the sequence is not the prime number.
`
`Also, the sequence generation unit may insert a predetermined constant into the padding
`portion, insert the cyclic postfix of the sequence generated as described above, or further
`generate a sequence that has a sequence length required in the communication system to
`extract a sequence having a length that corresponds to the difference from the sequence
`generated in order to have the required sequence length and insert the extracted sequence
`into the padding portion.
`
`Also, the sequence generation unit may extract a sequence that has a length corresponding
`to the difference among sequences different in type from sequences generated in order to
`have the selected maximum prime number length to insert the extracted sequence into the
`padding portion, or it is possible to insert any one of a predetermined constant or the cyclic
`postfix of the generated sequence into the guard section to use the padding portion as a lower
`band guard section.
`
`In addition, a sequence generation device according to an embodiment of the present
`invention may further include a power boosting unit that power boosts the sequence
`generated as described above by a value that is obtained by the sequence length required in
`the communication system divided by the maximum prime number length.
`
`In the following, exemplary embodiments according to the present invention are described
`in detail with reference to the accompanying drawings. The detailed description to be
`disclosed below in connection with the accompanying drawings is intended to describe an
`exemplary embodiment of the present invention and is not intended to represent a unique
`embodiment that may practice the present invention. The detailed description includes
`details in order to provide a complete understanding of the present invention. However, a
`person skilled in the art would appreciate that the present invention may be practiced without
`these details. In some cases, known structures and devices are omitted in order not to obscure
`the concept of the present invention or block diagrams are shown to represent the core
`
`- 13 -
`
`15
`
`
`
`Publicized Patent 10-2008-0004025
`
`functions of each structure and device. Also, like components have like reference numerals
`throughout the specification.
`
`FIG. 2 is a diagram for explaining a constant amplitude zero autocorrelation (CAZAC)
`sequence, and a method and device for generating the sequence according to an embodiment
`of the present invention.
`
`When a transmission end in a communication system generates a sequence that delivers
`control information, using more resources than required resources is a problem but using
`less resources is not a problem. That is, when the length of a sequence required in a
`communication system is L, generating a sequence that has a length smaller than L is no
`problem in terms of resource allocation of the communication system. Thus, the sequence
`generation method and device according to an embodiment of the present invention as shown
`in FIG. 2 proposes using a length smaller than L (hereinafter, referred to as “X”) to generate
`a sequence. In this example, the length L of the sequence required in the communication
`system may generally mean a length of a sequence allocated for the transmission of
`predetermined control information in a transmission frame structure by a standard fixed to a
`used communication system, but may have various meanings, including that a
`communication system requests to use a sequence having a predetermined length for the
`transmission of control information for a specific purpose.
`
`In the case of the CAZAC sequence, when length N used for sequence generation is not a
`prime number, namely, when the length L required in a communication system is not a prime
`number and the length N used for CAZAC generation is set to L, there may be redundant
`sequences among the sequences that are generated by using N. For example, in the event
`that the length L of the sequence required in the communication system in order to generate
`the CAZAC sequence is 12 and thus Equations 1 and 2 above select, as N, 12, not a prime
`number, cases where 2 is allocated to a value of M corresponding to the ID of the sequence
`and where 10 is allocated to a value of M have redundant sequences. Also, a sequence
`generated according to an embodiment of the present invention that is illustrated as the
`CAZAC sequence may not have a ZAC property, in the case that the length N of the sequence
`and a variable M corresponding to the ID of the sequence are not relative prime.
`
`- 14 -
`
`16
`
`
`
`Publicized Patent 10-2008-0004025
`
`The specification describes that the generated sequence is, e.g., the CAZAC sequence, but
`in the case where the length used for sequence generation is not a prime number as described
`above, any sequence may be generated when there may be redundant sequences among the
`sequences generated by using the length, and is not necessarily limited to the CAZAC
`sequence.
`
`In order to use the sequence that has the above-described property, in the case where the
`length L of the sequence required in the communication system is a prime number, a
`sequence is immediately generated by N = L, but in the case where the length L in an
`embodiment of the present invention is not a prime number, a maximum prime number X
`smaller than or equal to the length L is selected. Then, the selected X is set as a value of N
`in Equation 1 or 2 to generate a sequence. The number of types of sequences 202 that are
`generated in this way and have length X may be X-1 and there are no redundant sequences
`amo