KR100930894B1 - Code Sequences in Communication Systems and Methods and Devices for Transmitting, Generating, and Analyzing Them - Google Patents

Abstract

The present invention relates to a code sequence for transmitting control information, specifically, a structure of a CAZAC sequence and a technique for generating and analyzing the same. To this end, the present invention selects the maximum fraction length less than the length of the required code sequence when the length of the code sequence required in the communication system is not prime, generates a sequence having the maximum fraction length selected as described above, and then communicates. A method, an apparatus for inserting a padding unit having a length corresponding to a difference between the length of a code sequence required by a system and the maximum fractional length described above, and a code sequence generated thereby are proposed. The generated code sequences can increase the number of code sequences that can be generated without overlapping them, and maintain good autocorrelation and cross-correlation characteristics, thereby obtaining more accurate synchronization information than in the related art.

CAZAC sequence, padding

Description

Code Sequence in Communication System, Method and Apparatus for Transmitting, Generating and Analyzing It {Code Sequence In The Communication System, Method And Apparatus For Transmiting, Generating, And Analysing The Same}

1 illustrates an example of a conventional CAZAC sequence and its generation method.

2 is a view for explaining a CAZAC sequence and a method and apparatus for generating the same according to an embodiment of the present invention.

3 is a diagram illustrating an example of processing a padding unit in a CAZAC sequence and a method of generating the same according to another embodiment of the present invention.

4 is a block diagram illustrating an apparatus for transmitting a CAZAC sequence according to an embodiment of the present invention.

5 is a block diagram illustrating an apparatus for generating a CAZAC sequence according to an embodiment of the present invention.

6 is a diagram for explaining an example of boosting the power of a CAZAC sequence generated according to one embodiment of the present invention;

7A and 7B are diagrams illustrating probability density function (PDF) characteristics of a CAZAC sequence generated by a conventional CAZAC sequence generation method and a CAZAC sequence generated according to an embodiment of the present invention, respectively.

8 is a diagram illustrating a cumulative probability density function (CDF) characteristic of a CAZAC sequence generated by a conventional CAZAC sequence generation method and a CAZAC sequence generated according to an embodiment of the present invention.

The present invention relates to a communication system, and more particularly to a code sequence in a communication system and a method and apparatus for transmitting, generating and analyzing the code sequence.

In the communication system, there are a number of sequences used to transmit control information including IDs and synchronization information for distinguishing types of sequences. However, in the case of 3GPP LTE, a constant amplitude zero auto-correlation (CAZAC) sequence is present. It is the basis. The places where the CAZAC sequence can be used are channels for extracting various IDs or information using the sequence. These channels include synchronization channels (eg, primary-SCH, secondary-SCH, BCH) for downlink synchronization, synchronization channels (eg, RACH) for uplink synchronization, pilot channels (eg, , Data pilot, channel quality pilot). In addition, the above-described CAZAC sequence may be used for scrambling.

Two types of CAZAC sequences are GCL CAZAC and Zadoff-Chu CAZAC. They are conjugated to each other and GCL CAZAC can be obtained by taking the conjugate complex number of Zadoff-Chu. Zadoff-Chu CAZAC is given by

Here k denotes a sequence index, N denotes a length of a CAZAC sequence to be generated, and M denotes a sequence ID.

When the Zadoff-Chu CAZAC sequence given by Equation 1 and Equation 2 and the GCL CAZAC sequence in a conjugate complex relationship thereof are represented by c (k; N, M), all three features are as follows.

Equation 3 shows that a CAZAC sequence always has a size of 1, and Equation 4 shows that an auto-correlation function of a CAZAC sequence is represented as a delta function. Here autocorrelation is based on circular correlation. In addition, Equation 5 shows that the cross-correlation is always a constant. Hereinafter, for convenience of description, a sequence characteristic such as Equation 3 is referred to as a "CA characteristic", and characteristics such as Equation 4 and Equation 5 will be referred to as a "ZAC characteristic".

In a conventional system for applying a CAZAC sequence, the length to be applied is L, a method for generating a CAZAC sequence includes (1) setting N in Equation 1 or Equation 2 to N = L regardless of the L value. By using the CAZAC sequence, and (2) a method for generating by setting N to a number greater than L is considered.

Briefly referring to the characteristics of the CAZAC sequence generated by a specific L, if the L is not a prime number, the generated CAZAC sequence can contain M = 1,2, ..., L-1, but among these, Duplicate code occurs. In other words, the actual number of different codes is less than L-1. On the other hand, if L is a prime number, L-1 different codes are generated. Therefore, if the length of the code to be applied to the system is not a prime number and the number of codes to be used is large, the smallest prime number larger than L is selected rather than the same method as the method (1) to generate a CAZAC sequence therefrom. Consider how to cut and write.

1 is a view for explaining an example of a conventional CAZAC sequence and a method for generating the same as described above.

The method as shown in FIG. 1 can extend the code type, but since the code sequence generated by the above method cuts out a part of the sequence, the delay in the autocorrelation and cross-correlation characteristics is reduced as shown in Equation 4 above. If only 0, the value of 1 is deteriorated, otherwise the property of having a value of 0, and the property that the cross-correlation value always has a constant as shown in Equation 5 deteriorates. In addition, when removing a sequence having poor correlation characteristics, it cannot be guaranteed that the number of sequences is larger than L-1.

As described above, in the prior art, in order to obtain a desired length and to obtain as many kinds of CAZAC sequences as possible, a CAZAC sequence was selected from a minimum prime number X larger than L when the required length L is not prime. However, in this case, the correlation property is deteriorated, and thus there is a disadvantage in that ZAC characteristics such as Equations 4 and 5, which are characteristics of the CAZAC sequence, are not provided.

SUMMARY OF THE INVENTION In order to solve the above problems, an object of the present invention is to provide a code sequence having a length of a sequence required in a system and capable of delivering maximum information without duplication, and a method and apparatus for generating the same.

Another object of the present invention is to provide a sequence capable of delivering the maximum information as described above and having a good autocorrelation and cross-correlation property, a method of generating the same, and an apparatus for generating the same.

Still another object of the present invention is to provide a method and apparatus for transmitting and analyzing a sequence generated as described above.

A code sequence according to an embodiment of the present invention for achieving the above object is a code sequence having a length required in the communication system for transmitting control information, the first sequence portion having a fractional length; And a second sequence portion into which a padding portion having a length corresponding to a difference between the length required in the communication system and the fractional length is inserted.

A code sequence according to another embodiment of the present invention for achieving the above object is a code sequence having a length required in a communication system for transmitting control information, the first sequence portion having a fractional length; A padding portion comprising a second sequence portion and a third sequence portion respectively inserted, wherein the sum of the lengths of the second sequence portion and the third sequence portion is equal to the difference between the length required in the communication system and the above-described fractional length. .

Here, the code sequence described above is a sequence in which a duplicate sequence exists between sequences generated based on a non-fractional length when the code sequence is generated. The CAZAC sequence may be an example, but the above-described characteristics are maintained. It is not limited to this.

In addition, the above-mentioned fractional length is preferably the maximum fraction length less than or equal to the length required in the communication system, but may be any other fractional length depending on the needs of the communication system.

On the other hand, a signal transmission method according to another embodiment of the present invention for achieving the above object comprises the steps of selecting a code sequence having a length required in the communication system for transmitting control information; And transmitting the selected code sequence to a receiving side, the code sequence comprising: a first sequence portion having a fractional length; And a second sequence portion in which a padding portion having a length corresponding to the difference between the required length and the above-described minority length is inserted as described above.

A signal transmission method according to another embodiment of the present invention for achieving the above object comprises the steps of selecting a code sequence having a length required in a communication system for transmitting control information; And transmitting the selected code sequence to a receiving side, the code sequence comprising: a first sequence portion having a fractional length; And a second sequence portion and a third sequence portion each having a padding portion inserted therein, wherein the sum of the lengths of the second sequence portion and the third sequence portion is equal to the difference between the length required in the communication system and the above-described fractional length. It features.

In addition, the signal transmission apparatus according to another embodiment of the present invention includes a sequence selection unit for selecting a code sequence having a length required in the communication system for transmitting the control information; And a transmitter for transmitting a code sequence selected by the sequence selector to a receiver, the code sequence comprising: a first sequence unit having a fractional length; And a second sequence portion in which a padding portion having a length corresponding to a difference between the required length and the fractional length is inserted.

In addition, the signal transmission apparatus according to another embodiment of the present invention includes a sequence selection unit for selecting a code sequence having a length required in the communication system for transmitting the control information; And a transmitter for transmitting a code sequence selected by the sequence selector to a receiver, the code sequence comprising: a first sequence unit having a fractional length; And a second sequence portion and a third sequence portion each having a padding portion inserted therein, wherein the sum of the lengths of the second sequence portion and the third sequence portion is equal to the difference between the length required in the communication system and the above-described fractional length. It features.

On the other hand, the sequence generation method according to another embodiment of the present invention, if the length of the sequence required in the communication system is not a prime number at the transmitting end of the communication system, selecting the maximum fraction length less than the length of the required sequence; Generating a sequence having a selected maximum fraction length; And inserting a padding portion having a length corresponding to the difference between the length of the desired sequence and the maximum fractional length.

Here, the sequence may be a sequence in which overlapping sequences exist between sequences generated to have a length other than a fraction when the length of the sequence is not a prime number.

In addition, the sequence generation method according to an embodiment of the present invention as described above further comprises the step of inserting a predetermined constant in the padding portion, and / or inserting a circular post portion of the sequence generated in the padding portion. Generating a sequence, the sequence having the required sequence length; And extracting and inserting a sequence having a length corresponding to the difference from the sequence generated to have the length of the required sequence in the padding unit.

In addition, the sequence generation method according to an embodiment of the present invention as described above, the length corresponding to the above-described difference among the sequence of the type different from the sequence generated to have the maximum fraction length selected as described above in the padding section The method may further include extracting and inserting a sequence of P. Alternatively, the padding unit may be used as a lower band guard period. In this case, the sequence generation method may insert any one of a predetermined constant or a cyclic post portion of the sequence generated as described above into the protection interval.

In addition, the sequence generation method according to an embodiment of the present invention as described above may further include power boosting the generated sequence as described above by dividing the required sequence length by the maximum fractional length.

In accordance with another aspect of the present invention, a sequence analysis method includes: receiving, at a receiving end of a communication system, information indicating a sequence generated at a transmitting end and a sequence length used for generating the sequence; And obtaining control information by extracting and analyzing a portion corresponding to the sequence length obtained from the received information as described above.

In this case, as described above, in the acquiring of the control information, the synchronization information may be obtained by extracting a portion corresponding to the sequence length obtained from the received information and autocorrelating or crosscorrelating it.

On the other hand, the sequence analysis method according to another embodiment of the present invention for achieving the above object comprises the steps of receiving at the receiving end of the communication system information indicating the sequence generated at the transmitting end and the sequence length used to generate the sequence; Obtaining synchronization information by extracting a portion corresponding to the sequence length obtained from the received information from the received information and autocorrelating or crosscorrelating the received sequence as described above; And generating ID information of the received sequence by generating a differential sequence of the received sequence corresponding to the total length of the sequence using the obtained synchronization information.

In order to achieve the above another object, a sequence generating device according to another embodiment of the present invention determines whether the length of a sequence required in a communication system is a prime number at a transmitting end of the communication system, and when it is not a prime number, A control unit for selecting a maximum fraction length less than or equal to the length of the sequence required by the communication system; And generating a sequence having the maximum fraction length selected by the controller, and combining the padding unit having a length corresponding to a difference between the length of the sequence required by the communication system and the maximum fraction length as described above. It includes a sequence generator.

 Here, the sequence may be a sequence in which overlapping sequences exist between sequences generated to have a length other than a fraction when the length of the sequence is not a prime number.

In addition, the sequence generator inserts a predetermined constant into the padding unit, inserts a cyclic post-section of the generated sequence as described above, or further generates a sequence having a sequence length required by the communication system. A sequence having a length corresponding to the difference may be extracted and inserted from a sequence generated to have a length of the required sequence.

The sequence generator may extract and insert a sequence having a length corresponding to the difference among sequences of a type different from a sequence generated to have a maximum fraction length selected by the padding unit, or may be predetermined by the padding unit. The padding part may be used as a lower band guard period by inserting either a constant or a cyclic post part of the generated sequence.

In addition, the sequence generating apparatus according to the embodiment of the present invention may further include a power boosting unit for power boosting the generated sequence as described above by dividing the sequence length required by the communication system by the maximum fractional length. have.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The detailed description, which will be given below with reference to the accompanying drawings, is intended to explain exemplary embodiments of the present invention and is not intended to represent the only embodiments in which the present invention may be practiced. The following detailed description includes specific details in order to provide a thorough understanding of the present invention. However, one of ordinary skill in the art appreciates that the present invention may be practiced without these specific details. In some instances, well-known structures and devices are omitted or shown in block diagram form, centering on the core functions of each structure and device, in order to avoid obscuring the concepts of the present invention. In addition, the same components will be described with the same reference numerals throughout the present specification.

2 is a view for explaining a CAZAC sequence according to an embodiment of the present invention, and a method and apparatus for generating the same.

In generating a sequence for transmitting control information at the transmitting end of the communication system, generating using more resources than required is a problem, but using less resources is not a problem. In other words, when the length of the sequence required in the communication system is L, generating a sequence having a length less than L is not a problem at all in terms of resource allocation of the communication system. Accordingly, the method and apparatus for generating a sequence according to an embodiment of the present invention as shown in FIG. 2 proposes to generate a sequence using a length smaller than L (which is referred to as "X"). Herein, the length L of a sequence required in a communication system may generally mean a length of a sequence allocated for transmission of predetermined control information in a transmission frame structure according to a standard determined in a communication system used, and the like. The communication system may have various meanings such as requesting that the communication system use a sequence having a predetermined length for transmitting control information.

Meanwhile, in the case of a CAZAC sequence, when the length N used for generating the sequence is not a prime number, that is, when the length L required by the communication system is not a prime number and the length N used for generating the CAZAC is set to L, the N There may be a duplicated sequence between the sequences generated using. For example, when the length L of the sequence required by the communication system to generate the CAZAC sequence is 12, and thus, when N is selected from 12 instead of 12 in Equations 1 and 2, the ID corresponding to the sequence ID When 2 is assigned to M, which is a value, and 10 is assigned to M, it has a duplicate sequence. In addition, a sequence generated according to an embodiment of the present invention exemplified as a CAZAC sequence may include zero auto-correlation (ZAC) when the sequence length N and the variable M corresponding to the sequence ID are not small. May not have characteristics.

In the present specification, a generated sequence is described as a CAZAC sequence, for example. However, as described above, when the length used for generating a sequence is not a prime number, a duplicate sequence may exist between sequences generated using the length. In the case of a sequence, an arbitrary sequence may be generated and is not necessarily limited to a CAZAC sequence.

In order to use a sequence having the characteristics described above, when the length L of the sequence required by the communication system is a small number, N = L is set to generate the sequence immediately, but in one embodiment of the present invention, the length L is If it is not a prime number, choose the largest prime number X of length L or less. Thereafter, the selected X is set to an N value of Equation 1 or 2 to generate a sequence. The type of the sequence 202 having the length X generated as described above may be X−1, and no duplicate sequence occurs between them. In addition, as described above, the generated length X sequence 202 has no process of truncating a portion of the generated sequence as described above, and thus ZAC characteristics are maintained. Therefore, the autocorrelation value of the length X sequence has a delay. Except for the case of 0, the value of 0 is displayed, and the cross correlation value is always a constant.

On the other hand, since the length of the sequence required in the communication system is L in this case, it is necessary to fill a sequence having a length corresponding to the difference between L and X corresponding to the length of the selected sequence as described above. FIG. 2 shows the addition of a sequence of length L-X by inserting a padding portion in this portion.

Generated by the sequence generating method as described above, the code sequence 203 may be divided into a sequence portion (C ₁₎ and a sequence unit (C ₂₎ of length LX generated on the basis of X, the following description convenience For the sake of clarity, the sequence portion C _{1 is} referred to as a first sequence portion, and the sequence portion C ₂ is referred to as a second sequence portion. In addition, in the above description, for example, it is described that X is the maximum prime number less than L, but as long as X is the prime number less than or equal to L, there is no overlap problem between code sequences generated based on it. The characteristics are retained and may have different values depending on the requirements of the communication system. However, it is more preferable to select X as the maximum prime number less than or equal to L to be able to generate the most combination of generateable code sequences.

Next, there may be various methods of processing the padding unit as shown in FIG. 2. First, there may be a method of inserting a predetermined constant, for example 0, in the padding unit. This may be applied to the case where the above-mentioned padding part is not important, that is, there is no problem even if all parts corresponding to the total length L are not used when searching for cells or performing random access. Second, in the above-described first sequence portion C ₁ generated by setting X to N, the portion corresponding to the initial LX is copied and located at the end of the first sequence portion C ₁ as shown in FIG. 2. There may be a cyclic extension method of inserting a cyclic postfix into the padding portion by inserting it into the padding portion. In this case, all lengths corresponding to L are used. Even when determining the ID of the generated sequence, there is an advantage that the ID of the sequence can be distinguished by using all the lengths L, and it does not distort the generated sequence. It can be seen in a way that does not. In addition, since all sequences of full length L are used to convey information such as a sequence ID, there is no need to perform a power boosting operation as will be described later. In addition, a method of obtaining control information such as a sequence ID through a sequence generated by using the above-described method will be described in detail later. Meanwhile, in the above-described embodiment, the case where the circular post portion of the first sequence portion C ₁ is inserted into the padding portion has been described as an example, but the padding portion may be disposed according to the relative position of the first sequence portion C ₁ and the padding portion. It will be apparent to those skilled in the art that a cyclic prefix of the first sequence part C ₁ may be inserted.

Meanwhile, as a third method of processing the padding unit, a sequence having a sequence length L required by a communication system, that is, a sequence is generated using N = L, and then set to N = L as described above. There may be a method of extracting a sequence having a length corresponding to the difference, that is, L-X and inserting the sequence into the padding part. In this case, the padding part has a form of inserting additional information, and another additional message can be delivered through the added value.

Fourth, there may be a method of extracting and inserting a sequence having a length corresponding to the difference, that is, L-X, from a sequence of a different type from a sequence generated to have the selected maximum fractional length X as described above. Can be. In this case, the sequence inserted into the padding unit may be a CAZAC sequence having an M value different from that of the first sequence unit C ₁ , and a part of the CAZAC having at least one of an M value and an L value may be inserted. . In addition, the sequence inserted into the padding unit may have a sequence other than the CAZAC sequence. In this case, as described above, the sequence inserted into the padding unit as a sequence of a different type from the first sequence unit C ₁ indicates additional information, and can be used for extending the sequence type and delivering messages through the combination of the sequences. Specific examples of information that may be inserted into the padding unit will be described in more detail below.

Finally, there may be a method of using the padding unit as the lower band protection interval, which will be described in detail with reference to FIG. 3.

FIG. 3 is a view for explaining an example of processing a padding unit in a CAZAC sequence and a method of generating the same according to an embodiment of the present invention, that is, an example of using the padding unit as a lower band guard period as described above.

In case of transmitting control information by using a specific sequence, in case of transmitting data without synchronizing with each other such as random access channel, in case a plurality of users in the communication system transmit data, the frequency of the received data is distorted Is present. Accordingly, in the sequence generation method according to the exemplary embodiment of the present invention, as shown in FIG. 3, when the padding parts are positioned on both sides of the sequence and used as the lower band guard interval, there is a case where there is a reception frequency distortion as described above. It is also possible to more easily obtain control information from the received data. In this case, a predetermined constant, for example, 0 is inserted into the padding portion used as the protection section as described above, or a circular post portion (and / or) of a sequence generated in the protection zones separated on both sides as described above. Circulating post-section; same hereafter) can be inserted. As described above, when the padding unit is disposed on both sides of the sequence to be used as a lower band guard interval, the inside of the sequence may be protected from frequency distortion, and particularly when zero is inserted into the guard interval, interference with a sequence adjacent to the sequence. Can be reduced. On the other hand, as described above, when inserting the cyclic post of the sequence generated in the protection zones separated on both sides of the sequence, not only can the inside of the sequence be protected from frequency distortion, but if there is no frequency distortion, the cyclic post The inserted part also has an advantage that can be used to transmit control information including a sequence ID.

The code sequence 301 generated by processing the padding unit in the manner described above may be divided into three parts. First, a sequence part C ₁ generated based on the length of X is divided into two sequence parts C ₂ and C ₃ separately inserted into both sides of the sequence part. Hereinafter, for convenience of description, the sequence unit C _{1 is} referred to as a first sequence unit and two sequence units C ₂ and C ₃ as a second sequence unit and a third sequence unit, respectively.

As described above, although the five embodiments have been described for a clearer understanding as a method of processing the padding unit, those skilled in the art know that the present invention may be modified without departing from the spirit and scope of the present invention. It is not limited to one five embodiments.

On the other hand, except for the first method in which the information is not inserted into the padding part of the five embodiments described above, all of the other methods are used to expand the combination of the sequence and message delivery by inserting additional information into the padding part. Can be. Examples of information that can be inserted into the padding unit include, for example, initial access information, timing update data, resource request information, user ID information, and channel of a random access channel (RACH). A quality indicator (CQI), a user group ID, and the like, and may include cell ID information of the sync channel (SCH), MIMO information, sync channel information having a position in a frame of the sync channel, and the like. Transmitting data for message transmission may be inserted, but is not limited thereto. Those skilled in the art will appreciate that a sequence for transmitting arbitrary information may be inserted as long as the skilled person can deliver using a sequence having a length of L-X. know.

4 is a block diagram illustrating an apparatus for transmitting a CAZAC sequence according to an embodiment of the present invention.

It is apparent that a signal transmission apparatus for transmitting such a sequence may be various apparatuses including a base station and a user equipment depending on whether uplink or downlink transmission of control signals or the like is performed in a communication system. Therefore, in FIG. 4, an apparatus capable of transmitting control signals is illustrated as a general transmitter 401.

The apparatus corresponding to the transmitting side 401 includes a sequence selecting unit 402 and a transmitting unit 403. Here, the sequence selector 402 performs a function of selecting a code sequence having a length, ie, L, required by the communication system to transmit control information. The sequence selector 402 stores information about an L value corresponding to a length generally required by a communication system, and based on this, selects an appropriate code sequence for representing control information to be transmitted among sequences having a length of L. Will be chosen.

However, the code sequence selectable by the sequence selector 402 described above is a code sequence including a first sequence portion having a fractional length and a second sequence portion having a length of LX as described above, or a first sequence having a fractional length. It is preferable that the second sequence portion and the third sequence portion having the length of the first sequence portion and the LX are divided into two sides of the above-described first sequence portion, and are code sequences of the type. In addition, the length X of the first sequence portion is preferably a maximum number of L or less in terms of selecting various sequences, but need not be limited thereto.

The code sequence having such a structure is transmitted to the receiving side through the transmitting unit 403. 4 illustrates an example in which the transmitter 403 converts a serial signal in parallel to be transmitted through multiple antennas, but the transmitter 403 may transmit a code sequence having the characteristics described above to the receiver. However, it may have any configuration. Thereafter, the code sequence signal transmitted through the transmitting unit 403 is received at the receiving end, and the receiving end has better control signal in synchronization estimation by autocorrelation and cross-correlation, and the like, as described in more detail below. Can be analyzed.

5 is a block diagram illustrating an apparatus for generating a CAZAC sequence according to an embodiment of the present invention.

The transmitting end of the communication system may comprise an apparatus for generating a code sequence for conveying control information. The apparatus for generating such a code sequence includes a controller 501 and a sequence generator 502. Here, the controller 501 performs a function of selecting a maximum fractional length X equal to or less than L corresponding to the length of the sequence required by the communication system. For this purpose it may include means 501a for determining whether the L value corresponding to the length required in the communication system is a prime number and means 501b for selecting the length X on which the sequence is generated. The means 501a as described above determines whether L is a prime number, and passes the determined value to the means 501b along with the L value. Thereafter, the means 501b selects N = L when L is a prime number and sets the maximum prime number X smaller than L when L is a prime number and sets N = X based on the judgment value of the means 501a. (For convenience of description, the decimals based on sequence generation, i.e. when L is a prime and L and L are not primes, X is collectively referred to as prime X).

As described above, the selected X value is transmitted to the first sequencer generator 502a and the second sequence generator 502b of the sequence generator 502. The first sequence generator 502a generates a first sequence unit C ₁ having a length of X based on the X value. In addition, the second sequence generator 502b generates a second sequence unit C ₂ in which a padding unit having a length corresponding to the LX value is inserted. Then, the first sequence portion C ₁ and the second sequence portion C ₂ generated in these sequence portions are passed to the combining portion 502c to generate a summed code sequence C. FIG.

FIG. 5 illustrates a case where the generated code sequence includes a first sequence unit C ₁ and a second sequence unit C ₂ , but a person skilled in the art has described the first sequence generator 502a and the first embodiment. It can be appreciated that a third sequence generator (not shown) can be added to the two sequence generator 502b to generate a three-part sequence. In addition, instead of adding the third sequence generator as described above to generate a sequence divided into three parts, the second sequence portion generated by the second sequence generator 502b is divided to both sides of the first sequence portion. It will also be appreciated that a code sequence as described above can be created by adding sequence dividing means (not shown) for insertion into the.

6 is a diagram for explaining an example of boosting power of a CAZAC sequence generated according to an embodiment of the present invention.

After generating a sequence using the length of X, inserting a padding portion corresponding to the length L-X, power boosting the sequence portion generated using the length X as described above by dividing the length L by X ( boosting). As will be described in more detail below, in general, only a sequence portion generated using X corresponding to a maximum prime number less than or equal to length L among sequences of length L generated according to one embodiment of the present invention is autocorrelation and / or crossover. Since it is preferable to use correlation to convey synchronization information and the like, it is required that the sequence portion generated using the length of X be more robust to noise than other portions. As described above, the L / X power boosting effect is applied to the sequence of length X, so that when the receiver searches for the sequence, it is more robust to noise than the existing sequence, and thus, shows better detection performance. In addition, the sequence generating apparatus according to an embodiment of the present invention for the power boosting as described above may further include a power boosting unit.

However, in the above-described embodiment of the present invention, in the case of the sequence generated by inserting the cyclic post-section of the sequence generated in the padding portion, all of the sequences of full length L are used for acquiring sequence ID information. There is no need to do it.

Hereinafter, a method of receiving and analyzing the sequence to obtain control information using a sequence generated according to an embodiment of the present invention as described above will be described.

As described above, the receiving end receives the sequence generated according to one embodiment of the present invention and information indicating the length X used to generate the sequence. Thereafter, control information may be obtained by extracting and analyzing a portion corresponding to the length X obtained from the received information as described above. In general, in order to obtain control information from the received signal, acquiring synchronization information of the received data should be preceded. Acquiring synchronization information using the received sequence as described above generally uses autocorrelation (Equation 6) and / or cross correlation (Equation 7) as follows.

Equation 6 shows a method of obtaining autocorrelation of a transmitted sequence having a sequence ID of M, and obtains synchronization by obtaining a d value whose autocorrelation value obtained through Equation 6 is not 0. On the other hand, Equation 7 shows a method of obtaining cross correlation with a sequence having a sequence ID of M ₂ when a sequence having a sequence ID of M ₁ is obtained, and shows a method of obtaining synchronization through this. In general, when the communication system is a synchronous network (Synchronous Network) to obtain the synchronous information using the autocorrelation, and in the case of an asynchronous network (Asynchronous Network), it is preferable to obtain the synchronous information using the cross-correlation, but the present invention Is not limited to any one method, and synchronization information can be obtained by selecting or using both methods as necessary.

After acquiring the synchronization information of the reception sequence through the above-described method, the receiving end may acquire the sequence ID by analyzing the reception sequence as follows.

은 수신 시퀀스의 차등 시퀀스(Differential Sequence)를 지칭한다. 상기 수학식 8 은 수신 시퀀스의 총 길이에 해당하는 차등 시퀀스를 이용하여 수신 시퀀스의 ID 정보를 획득하는 것을 나타내며, 이는 본 발명의 일 실시형태 중 패딩부에 생성된 시퀀스의 순환후치부를 삽 입하는 방법에 의해 생성된 시퀀스를 분석하는 경우 이용될 수 있다. 한편, 수학식 9 는 수신 시퀀스를 생성할 때 이용한 최대 소수 길이 X 의 길이를 가지는 시퀀스를 이용하여 ID 정보를 획득하는 것을 나타내며, 이는 본 발명의 일 실시형태 중 패딩부에 순환후치부를 삽입하는 방법 이외의 방법에 의해 패딩부가 처리된 시퀀스를 분석하는데 이용될 수 있다.In Equations 8 and 9

Refers to the differential sequence of the reception sequence. Equation (8) indicates that the ID information of the reception sequence is obtained by using a differential sequence corresponding to the total length of the reception sequence, which inserts a circular post portion of the sequence generated in the padding section in one embodiment of the present invention. May be used when analyzing a sequence generated by the method. On the other hand, Equation 9 indicates that the ID information is obtained by using a sequence having a length of the maximum fractional length X used when generating the reception sequence, which inserts the circular post portion into the padding portion in one embodiment of the present invention. The padding unit may be used to analyze the processed sequence by a method other than the method.

As described above, when calculating the differential sequence by Equation 8 or Equation 9, in the case of the CAZAC sequence, a first term of k representing the sequence index is generated, and when Fourier transforming the resultant value, appear. Thus, by searching for this peak value, the ID information of the sequence can be obtained.

7A and 7B are diagrams illustrating probability density function (PDF) characteristics of a CAZAC sequence generated by a conventional CAZAC sequence generation method and a CAZAC sequence generated according to an embodiment of the present invention, respectively. 7A and 7B show the probability density functions of autocorrelation values except when the delay is zero.

As shown in FIG. 7A, a smallest prime number larger than the conventional L is selected to generate a CAZAC sequence having the length of the prime number, and in the case of a sequence in which only a portion corresponding to the length L of the generated CAZAC sequence is cut and used. Since some of the sequences are removed, the ZAC characteristic deteriorates, and the probability density function value is not zero even when the delay value is zero. Therefore, when estimating synchronization information through autocorrelation using the above-described conventional CAZAC sequence, its performance may be impaired.

Meanwhile, as shown in FIG. 7B, when the length L required by the communication system according to the exemplary embodiment of the present invention is not a prime number, a CAZAC sequence generated by selecting a maximum prime number X less than or equal to N and setting it to an N value In the case of, the autocorrelation value is obtained by using the sequence portion of length X, and the value of 1 is represented only when the delay is 0. The probability density function of the autocorrelation except the delay is 0 is shown in FIG. 7B. As it will only have a value of zero. Therefore, when synchronizing information is estimated using autocorrelation values of a CAZAC sequence generated by a sequence generating method and apparatus according to an embodiment of the present invention, the synchronization information is estimated using autocorrelation values of a conventional CAZAC sequence. Compared to the case, the accuracy is increased.

8 is a diagram illustrating a cumulative probability density function (CDF) characteristic of a CAZAC sequence generated by a conventional CAZAC sequence generation method and a CAZAC sequence generated according to an embodiment of the present invention.

In the case of the conventional CAZAC sequence, since a part of the CAZAC sequence generated as described above is cut out and used, a portion where the cross-correlation value does not exhibit a constant constant p may occur. Accordingly, the cumulative probability density function for the cross-correlation value of the conventional CAZAC sequence also includes a peripheral value of a constant constant value (about 0.12 in FIG. 8), as shown by the solid line of FIG. 8. In contrast, in the case of the CAZAC sequence generated by the method and apparatus for generating a sequence according to an embodiment of the present invention, the cross-correlation value has a constant (about 1.2 in FIG. 8), and the cumulative probability density function thereof is shown in FIG. 8. It appears as shown by the dotted line of. Therefore, when the synchronization is estimated through the cross-correlation value of the CAZAC sequence generated using the sequence generation method and apparatus according to the embodiment of the present invention, the synchronization is estimated through the cross-correlation value of the conventional CAZAC sequence. Superior performance is achieved.

The detailed description of the preferred embodiments of the invention disclosed as described above is provided to enable any person skilled in the art to make and practice the invention. Although the above has been described with reference to the preferred embodiments of the present invention, those skilled in the art will variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. I can understand that you can. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

According to one embodiment of the present invention as described above, it is possible to bring the effect of increasing the number of sequences that can be generated without duplication.

In addition, the generated sequence maintains good autocorrelation and cross-correlation characteristics, and when the control information is transmitted using the sequence generated using the sequence generation method and apparatus according to an embodiment of the present invention, it is more accurate than the conventional method. Synchronization information can be obtained.

In addition, according to the method for processing the padding unit of the sequence generated by the sequence generation method and apparatus according to the embodiment of the present invention described above, the number of sequences that can be generated can be extended, or used as a lower band guard interval. Has an effect.

In addition, by power boosting and transmitting a sequence portion corresponding to a maximum fraction length among sequences generated by the sequence generation method and apparatus according to the embodiment of the present invention described above, it may have robustness to noise.

Claims (20)

In the method for transmitting a synchronization channel (SCH) by generating a code sequence in a wireless communication system, Generating a first code sequence C ₁ having a first length; Generating a second code sequence C ₂ having a second length; And Transmitting a sequence generated by combining the first code sequence C ₁ and the second code sequence C ₂ as a synchronization channel signal, At least one of the length of the first code sequence and the length of the second code sequence is a fractional length, and the sum of the length of the first code sequence and the length of the second code sequence is the length of the sync channel signal, The first code sequence and the second code sequence are generated using different initial values (M), The combination of the first code sequence and the second code sequence generated by using different initial values delivers cell ID information and position information within a frame of the sync channel to a receiver. delete delete delete An apparatus for generating a code sequence in a wireless communication system and transmitting a synchronization channel (SCH), A first code sequence C ₁ having a first length and a second code sequence C ₂ having a second length are generated, and the first code sequence C ₁ and the second code sequence C _{2 are generated} . A code sequence generator for generating a combined sequence by combining the sequential values; And A transmitter for transmitting the combined sequence as a synchronization channel signal, At least one of the length of the first code sequence and the length of the second code sequence is a fractional length, and the sum of the length of the first code sequence and the length of the second code sequence is the length of the sync channel signal, The first code sequence and the second code sequence are generated using different initial values (M), And a combination of the first code sequence and the second code sequence generated using different initial values delivers cell ID information and position information within a frame of the sync channel to a receiver. delete delete delete In the method for receiving a synchronization channel (SCH) using a code sequence in a wireless communication system, Receiving a combined sequence of a first code sequence C ₁ having a first length and a second code sequence C ₂ having a second length generated through different initial values M as a sync channel signal. step; And Obtaining cell ID information and in-frame position information of the synchronization channel through the combination of the first code sequence and the second code sequence generated through different initial values, Wherein at least one of the length of the first code sequence and the length of the second code sequence is a fractional length, and at least one of the length of the first code sequence and the length of the second code sequence is a fractional length. Receiving method. delete delete delete delete delete delete delete delete delete delete delete

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