Interleaver and method for interleaving in communication system

FIELD: communication systems.

SUBSTANCE: proposed interleaver with partial reverse order of bits provides for sequential column-by-column configuring of size N input data stream in matrix that has 2^m lines and J - 1 columns, as well as R lines in column J, interleaving of configured data, and line-by-line reading of interleaved data.

EFFECT: optimized parameters of interleaver.

5 cl, 7 dwg, 2 tbl

The technical field to which the invention relates.

The present invention relates essentially to the alternation in the communication system, and more particularly to a method of optimizing the parameters in accordance with the size of the interleaver to interleave with partial reverse the order of bits (H-OPB) and uses his interleaver.

The level of technology

Although sablotny channel interleaver designed according to the specifications of IS-2000 release C(1×EV-DV) F/L, performs H-OPB operation to permutation of rows as well as the existing channel interleaver designed according to the specifications of IS-2000 release a/b, sablotny channel interleaver is different from the channel interleaver fact that the shaper otherwise generates a read address and requires a full accounting of the influence of selected parameters of the interleaver on the choice of characters quasitopological of turbo code (CDTC, QCTC).

Therefore, there is a need for analysis of the principles of functioning subpackage channel interleaver and channel interleaver and the establishment of a criterion for determining the optimal parameters for channel premaritally. The optimal settings will provide the best efficiency in channel peremerzaesh arranged in accordance with IS-2000 release a/b, IS-2000, issue C.

The invention

The purpose of this image is the shadow is essentially, the elimination of at least the above problems and/or disadvantages and provide at least the advantages described below. Accordingly, the present invention is to provide a method of optimizing the parameters for H-OPB alternation and the interleaver using optimized parameters.

Another objective of the present invention is to provide a method of optimizing the parameters m and J in accordance with the size of the interleaver for H-OPB alternation and interleaver that uses them.

To solve the above and other objectives of the proposed H-OPB interleaver and method for optimizing parameters in accordance with the size of the interleaver for H-OPB of the interleaver. H-OPB interleaver sequentially, column by column, configures the input data stream of size N in a matrix with 2^mrow and (J-1) columns and R rows in the J-th column. H-OPB interleaver punctuates configured data and reads line by line peremerzanie data. Here, N, m, J and R are set as follows:

Brief description of drawings

The foregoing objectives, features and advantages of the present invention will become more apparent from the subsequent detailed description of preferred embodiments of the invention with regard to the attached drawings.

Figure 1 illustrates the H-OPB interleaving for N=384, m=7 and J=3 according to a variant implementation of the present invention.

Figure 2 illustrates the distance between the address read after H-OPB alternation for N=384, m=7 and J=3 according to a variant implementation of the present invention.

Figure 3 illustrates the H-OPB interleaving when N=408, m=7, J=3 and R=24 according to a variant implementation of the present invention.

Figure 4 illustrates the minimum distance within the row after H-OPB alternation when N=408, m=7 and J=3 according to a variant implementation of the present invention.

Figure 5 is a functional diagram of the interleaver, which used a variant of implementation of the present invention.

6 is a block diagram illustrating a first example of an operation of determining the optimal parameters of the interleaver according to a variant implementation of the present invention.

Fig.7 is the POC scheme, explaining another example of the operation of determining the optimal parameters of the interleaver according to a variant implementation of the present invention.

A detailed description of the preferred embodiments

Below, with reference to the attached drawings, described in detail several preferred embodiments of the present invention. In the drawings used sequentially numbered. In the following description, for clarity, omitted a detailed description of known functions or configurations.

Below will be described H-OPB alternation, which are different embodiments of the present invention, and the principles for determining the parameters for the optimal H-OPB interleave according to the options of implementing the present invention.

Figure 5 is a functional diagram H-OPB of the interleaver, which used a variant of implementation of the present invention. According to figure 5, the generator 511 address takes the size N of the interleaver, the first parameter m (i.e. Dwight), the second parameter J (i.e Verniel) and the synchronization signal the synchronization Signal, and generates a read address for reading the symbol bits of the memory 512 of the interleaver. The parameters m and J are defined in the controller (not shown) is fed to the generator 511 addresses or determined in accordance with the size N PE is Emeritus generator 511 addresses. The memory 512 of the interleaver in the record mode, sequentially stores the symbol bits of the input data in the address record corresponding to the values of the counter 513, and in the reading mode displays the symbol bits of the address reading, taken from the generator 511 addresses. Counter 513 receives the synchronization signal. The synchronization signal, generates a counter value and supplies it as the address of record ADR Recording in the memory 512 of the interleaver.

As described above, H-OPB interleaver sequentially writes the input data in the memory 512 of the interleaver in the recording mode and reads data from the memory 512 of the interleaver in accordance with the address of the reading generated by the generator 511 addresses. More H-OPB interleaver described in the patent application Korea No. 1998-54131 registered 10 December 1998.

When the function generator 511 generates addresses the read address A_ifor the permutation symbol by the formula

where i=0, 1,..., N-1 and N=2^m×J.

In equation (1) N denotes the size of the input data of the interleaver, and m and J are parameters of the interleaver, called Dwight and Verniel respectively.

Figure 1 illustrates the H-OPB interleaving for N=384, m=7 and J=3. According to figure 1 matrix alternation is 2^mlines starting with index 0 and J columns, akinoshima index 0. After step 101, the row index and column index of the symbol in the resulting matrix are expressed asand (i mod J), respectively. Therefore, afterthe i-th symbol of the sequence of input data is read address number correspondingrow and (i mod J)-th column. In each row there is a J symbol, and the distance between the characters in the string is 2^m.

At step 102 above the index linethe operation OPB. If the distance between the symbols in adjacent rows, one column is the distance of the rows of d_row, the operation OPB over the indices of rows leads to a permutation of rows to two minimum distances of the rows of d_rowwas 2^m-2and 2^m-1as illustrated in figure 2. Therefore, afterthe i-th symbol of the sequence of input data is read address number corresponding to the OPB_mrow and (i mod J)-th column of the third matrix on the left. As a result, the sequence of addresses read is formed by permutations of the rows of the matrix 2^m×J in H-OPB-interleaver. Matrix rearranged rows is read first by row from top to bottom with posledeistviem each row from left to right.

For clarity of description, the distance between adjacent addresses in one line is defined as the distance within a row of d_intra". If J≠1, d_intra=2^m. If J=1 then the distance within the row is missing (not defined).

The distance between adjacent addresses in different lines, namely the distance between the last address in the string and the first address in the next line, defined as the distance between the rows of d_inter". The distance d_interis one of several values, calculated as a function of the parameters m and j When m and J are defined, the resulting minimum distance between the lines

d_interdefined as.

As the two minimum distances of the rows of d_rowform 2^m-2and 2^m-1then

If J=1,

Otherwise

Whyis calculated by equation (2) when J≠1, it is clear from figure 2. If J=1, which implies that the interleave matrix has only one column, thenisi.e. the 2^m-2 _.

As described above, the parameters of the interleaver m and J are the numbers of rows and columns in the matrix sequence of addresses read and how couples the format function, determining the distance between the address read. Therefore, characteristics of H-OPB channel interleaver depend on the parameters of the interleaver m and J.

Before describing the method for determining the parameters subpackage channel interleaver that provides the best efficiency alternation, according to a variant implementation of the present invention will be described tasks channel premaritally in accordance with the specification IS-2000 editions of a/b and C. Then describes the determination of the parameters of the interleaver separately in two cases: N=2^m×J and N=2^m×J+R.

According to the specification of IS-2000 release a/b, the task of the channel interleaver is to increase the efficiency of the decoding, which decreases the adverse effects of damping on consecutive code symbols, by dispersion of the error, which occurs as a result of rearrangement of the symbols. To improve the efficiency of the decoding interleaving should be performed so that the distance between adjacent addresses (the distance between locations) was maximum.

Meanwhile, the task subpackage channel alternation, as described in the specification IS-2000 release, is the ability to selector characters CDTC "output" of the interleaver to select the appropriate character code corresponding to the coded speed is I, and, therefore, to provide the best efficiency at this rate coding, as well as to dispel errors by permutation characters. To achieve this goal interleaving should be performed so that the distance between the addresses were maximum and uniform.

Accordingly, in order to meet the requirements on the channel interleaver specification IS-2000 release a/b, and sablotny channel interleaver specification IS-2000 release, the interleaver should be designed so that the permutation sequence of addresses read alternation was carried out uniformly. This can be done by estimating the parameters of the interleaver m and J that maximizes the minimum distance between addresses and minimizes the difference between the distances between addresses.

As described above, distances between locations are categorized by distance within a row of d_intraand the distance between the rows of d_inter. The distance within the row is a function of m, and the distance between rows is a function of m and J. because there are several distances between rows, then calculates the minimum distance between rows. The minimum distance between locations when J is equal to 1 always equals 2^m-2and when J is not equal to 1 is the smaller value of the mini is the real distance between rows and the minimum distance within the string. The difference between the distances between addresses when J is equal to 1 is equal to 2^m-2asdistance within a row of d_intrais 0, and when J is not equal to 1 is equal to the difference between the distance within a row of d_intraand the minimum distance between rows.

This can be expressed as follows:

If J=1, |0-2^m-2|=2^m-2,

Otherwise

Since N=2^m×J, 2^min equation (3) is replaced by N/J, from which it follows:

If

Otherwise

When J=3 in equation (4) the difference between the distances between locations is minimized. Therefore,=0,166667N.

Table 1 below illustrates the changes in the distances between the addresses read with increasing m when N=384. When J=3, the maximum difference between the distances between addresses is minimized, 64, and the minimum distance between locations d^minmaximized, 128.

Table 1
N	m	J	dintra			d min
384	4	24	16	360	344	16
5	12	32	336	304	32
6	6	64	288	224	64
7	3	128	192	64	128

The above-described method of determining optimal parameters of the interleaver with N=2^m×J. Below describes how to determine the optimal parameters of the interleaver with N=2^m×J+R. Here R is the remainder of dividing N by 2^m. Therefore, R is a positive integer lower than 2^m.

Figure 3 illustrates the H-OPB interleaving when N=408, m=7, J=3 and R≠0. According to figure 3, similarly to the case where R=0, the matrix is rotated with row after step 302 is read as an address read by rows from top to bottom, each line is read from left to right, as shown in step 303. Since R≠0, then the number of columns is equal to J+1, and rooms made only in R rows (J+1)-th column, the remaining (2^m-R) rows of numbers are missing.

In fact, when R≠0, the sequence of addresses read is formed by permuting the rows of the matrix 2^m×J, ka is the Mae string which contains J or J+1 elements in H-OPB-interleaver. Matrix rearranged rows read row by row from top to bottom, each line is read from left to right.

Additionally, when R≠0 the parameters of the interleaver m and J is defined so that the minimum distance between locations read was maximized, and the difference between the distances between addresses reading was minimized.

The distance between the rows of d_interis a function of m, 2^mregardless of whether R=0 or R≠0. However, while at R=0 the minimum distance between rowsis a function of m and J, with R≠0 it is a function of m, J and R

The minimum distance between rows is determined in accordance with J through equation (5) and equation (6).

When J=1

When J≠1,

Figure 4 illustrates the derivation of the equation (6) with m=7 and J=3. According to figure 4 at 0≤R<2^m-1the distance between rows between two adjacent rows having a length of string d_rowequal to 2^m-lwhile posledni column of the top row is empty, is the minimum distance between rows ((2J-3)·2^m-1). When 2^m-1≤R<3·2^m-2the distance between rows between two adjacent rows having a length of string d_row,equal to 2^m-2,thus the last column of the top row is empty, is the minimum distance between rows

If 3·2^m-2≤R<2^mthe line spacing between two adjacent rows having a length of string d_rowequal to 2^m-2,and the elements in the last column, is the minimum distance between rows (=(2J-1)·2^m-1). For example, if R=0, the minimum distance between rows is equal to 192, as indicated by the reference position 401. If R=64(2^m-1), the minimum distance between rows is equal to 288, as specified by the reference position 402. If R=96(3·2^m-2), the minimum distance between rows is equal to 320, as indicated by the reference position 403. Equation (5) can be derived similarly for J=1.

Table 2 below illustrates the changes in the parameters of the interleaver J and R in the distance within a row of d_intrathe minimum distance between rowsand a minimum distance between the address read d_mi in respect of the six dimensions of packages encoder (PC), in accordance with the specification of IS-2000, issue C.

As described above, similarly to the case where R=0, selects the optimal settings alternation that maximize the minimum distance between locations and minimize the difference between the distances between addresses.

In table 2 the minimum distance between the address read d^minin the eighth column is the smaller of the distances within a row of d_intraand the minimum distance between rows. Therefore, the parameters that maximize the minimum distance between the address read d^min can be obtained by selecting the rows that have the maximum value in the eighth column. For dimensions PC 2328 and 3864 three rows and two rows satisfy this condition. In this case, should be selected rows that satisfy another condition of minimizing the difference between the addresses read. They are bold and underlined in table 2. The validity (truth) of this condition is evident when comparing strings with maximum d^minin the function n(d^minin the last column. Here, n(d^min) specifies the number of address pairs having the minimum distance between hell is esami d ^min.

The lines highlighted in bold and underlined in table 2, satisfy the two conditions for the choice of optimum parameters of the interleaver specified above. As noted, if the second condition is satisfied, the first condition is satisfied obviously. For information, it is clear that the distance in row d_intraand the minimum distance between rowslisted in table 2, is equal to the one calculated on the H-OPB pererezannym addresses are read. Table 2 covers the case of dividing N by 2^mor J without residue and a case of dividing N by 2^mor J with remainder R (i.e., N=2^m×J+R(0≤R<2^m)). Here the parameters of the interleaver in bold and underlined are optimal for each size PC.

Table 3 lists the optimal parameters of the interleaver for each size of the interleaver N, when N=2^m×(J-1)+R(0≤R<2^m), i.e., N is divisible by 2^mor J or without a remainder, or residue R. the Description made in the context of J, can also be used when replacing J (J-1).

The description above provides a method for selecting parameters of the interleaver, which, it is supposed to provide the best efficiency when using, for example, channel interleaver arranged in accordance with the specification IS-2000 release a/b, and subpackage channel interleaver arranged in accordance with the specification of IS-2000, issue C.

As described above, when forming the address read in channel interleaver optimal parameters of the interleaver are the parameters that maximize the distance between locations and simultaneously minimizing the difference between the distances between addresses. Therefore, the parameters of the interleaver for subpackage channel interleave when linking subpackage channel interleaver in accordance with the specification IS-2000 release C are the values in the rows with bold and underlined in table 2. Although the choice of the parameters of the interleaver has been described for subpackage channel interleaver arranged in compliance and specification IS-2000, the issue With, it is obvious that the same idea can be used also in relation to other standards.

6 is a flowchart explaining the operation of determining the optimal parameters of the interleaver according to a variant implementation of the present invention. In particular, this operation is associated with calculation. Computingwith varying parameters (m, J)selects the optimal parameters (m, J)that minimizes parameters.

According to Fig.6, when the step 601 is set to the size of the interleaver N and the parameters m and J, at step 603 the parameter R is calculated by subtracting the 2^m×J of N. At step 605 determines whether J unit (1). As a consequence, determine whether the matrix interleave single column. If J is equal to 1, then the procedure goes to step 607 (branch "Yes" of step 605 decision) and if J is not equal to 1, then the procedure goes to step 621 (branch "No" of step 605 decision). At step 607 determines whether R is zero (0) (i.e., whether N is an integer multiple of 2^m). Conversely, if R is equal to 0 (branch "Yes" of step 607 decision), then at step 609 the distance within a row of d_intrais set to 0. If R is not equal to 0 (branch "No" of step 607 decision), then at step 617 d_intracaps is carried out in the 2 ^m.

After determining d_intraat step 611 is defined, is there less R than 3×2^m-2. If R is less than 3×2^m-2(branch "Yes" of step 611 decision), then at step 613 the minimum distance between rowsset in 2^m-2. If R is equal to or greater than 3×2^m-2(branch "No" of step 611 decision), then at step 619set in 2^m-1.After you define aat step 615 is calculated.

However, if at step 605 it is determined that J is not equal to 1, then at step 621 d_intraset in 2^mand at step 623 is defined, is there less R than 2^m-l. If R is less than 2^m-1(branch "Yes" of step 623 decision), then at step 625is set to (2J-3)×2^m-1and then, the procedure proceeds to step 615. If R is equal to or greater than 2^m-1(branch "No" of step 623 decision), then at step 627 is defined, is there less R than 3×2^m-2. If R is less than 3×2^m-2(branch "Yes" of step 627 decision), then at step 629set in the (4J-3)×2^m-2. If R is equal to or greater than 3×2^m-2(branch "No" of step 627 decision), then at step 631be the scarfing in the (2J-1)× 2^m-1and then, the procedure proceeds to step 615.

The optimal parameters of the interleaver m and J are obtained for a given N by calculatingwhen changing (m, J). If J is one of the values 1, 2 and 3, it can be deduced logical formula, providing the choice of J without multiple calculations.

Lowering the output of the logic equations, the following is a logical equation.

J=3,

J=2,

J=1.

J=2,

J=3, (7)

J=1.

The optimal parameter m is calculated from the optimal parameter, J, is obtained from equation (7), as follows:

According to Fig.7 below briefly describes the choice of optimal parameters of the interleaver specified by simple logical equations.

1. For a given N, the optimal parameter J is obtained by equation (7).

2. The parameter m is calculated by equation (8) using N and J.

7 is a flowchart explaining the operation of determining the optimal parameters of the interleaver according to drugaware implementation of the present invention.

According to Fig.7, when set to N, at step 701 calculates the variable α throughvariable β through. At step 703, the decision is determined, less if α the first threshold value, 0,5849625. If α less than the first threshold value (branch "Yes" of step 703 decision), then at step 705 decision making; the adoption of other decisions, is there less N than β. If N is equal to or greater than β (branch "No" of step 705 decision), then the procedure goes to step 707. On the contrary, if N is less than β (branch "Yes" of step 705 decision), then at step 713 J is determined equal to 3.

Meanwhile, at step 707 decision is determined, is there less N than (3/2)×β. If N is less than (3/2)×β (branch "Yes" of step 707 decision), then at step 711 J is determined equal to 2. Otherwise, at step 709 J is defined as equal to 1 (branch "No" of step 707 decision).

If at step 703 it is determined that α equal to or greater than the first threshold value (branch "No" of step 703 decision), then at step 717 a decision is a decision, is there less N than (3/2)×β. If N is less than (3/2)×β (branch "Yes" of step 717 decision), then at step 721 J is determined equal to 2. Otherwise, at step 719 decision defines who I am, is there less N than (7/4)×β. If N is less than (7/4)×β (branch "Yes" of step 719 decision), then at step 723 J is determined equal to 3. Otherwise, at step 725 J is defined as equal to 1 (branch "No" of step 719 decision).

As described above, the optimal parameters m and J can be computed simply by logical equations using N. the Optimal m and J is equal to m and J, the resulting multiple calculations using different values of (m, J), as illustrated by table 2. This eliminates the need to store the optimal values of m and J, corresponding to the values n

For example, when N=2328 optimal values of m and J is calculated through a procedure illustrated in Fig.7, or by means of equations (8) through (10), as follows:

andTherefore J=2

For information, equation (7) is derived as follows.

In each case, with the description of 6, equations (5) and equation (6),is defined as follows.

A. If J=1,

A-1. If R=0,

A-2. If 0<R<3·2^m-2,

A-3. If

Century, When J≠1,

In-1. If 0≤R<2^m-1,

B-2. If 2^m-1≤R<3·2^m-2,

In-3. If 3·2^m-2≤R<2^m,

Since N=2^m·J+R and 0≤R<2^mthen J·2^m≤N<(J+1)·2^m. After dividing this expression for J and taking from the expressions of the base-2 logarithm

Therefore,. Using, J can be expressed as a function of N for all the cases a and B.

And'. When J=1, sinceR=N-2^m=N-2. Therefore, cases a-1, a-2 and a-3 can be expressed as a function of N. it follows:

A'-1: If

A'-2: If

A'-3: If

B'. When J≠1 as

Then the cases B-1, b-2 and b-3 can be expressed as a function of N instead of R. Therefore,

B'-1: If

B'-2: If

B'-3: If

B". When J=2, since

B ' -1: If

B"-2: If

B"-3: If

B"'. When J=3,

as

B"'-1': If

B"'-2': If

B"'-3': If

B"'-1": If

B"'-2": If

B"'-3": If

If J is equal to 4 or more, this case is not considered as in any of the cases where J=1, 2, and 3cannot be less than.

Equation (7) is obtained by selecting from a'-1, A'-2, And -3, B ' -1, B ' -2, B -3, B"'-1', B"'-2' and B"'-3' case, in which the expressionone is by a minimum.

Similarly, equation (8) is obtained by selecting from a'-1, A'-2, And -3, B ' -1, B ' -2, B -3, B"'-1", B"'-2" and B"'-3" case, in which the expressionis the minimum.

According to variants of implementation of the present invention, as described above, the parameters of the interleaver m and J just optimized in accordance with the size N of the interleaver for H-OPB alternations.

Although the invention has been illustrated and described in relation to certain preferred embodiments, for specialists in the art it is obvious that not depart from the essence and scope of the invention may be made various changes in form and details, as defined by the attached claims.

1. The method for determining the parameters of the interleaver m and J in accordance with the size N of the interleaver for serial configuration column of the input data stream of size N in a matrix with 2^mrow and (J-1) columns and R rows in the J-th column, where 0≤R<2^mand interleave with partial reverse the order of bits (H-OPB) konfigurirovanii data, namely, that calculate the first variable throughand a second variable via thecompare the value of the first variable with the selected first threshold C is achenium, compare the size N of the interleaver at least one predetermined second threshold value, determined by the ratio of the second variable, define the first parameter J in accordance with the comparison result, and determines a second parameter m by

2. The method according to p. 1, characterized in that the first parameter J is determined in accordance with the following equation:

3. The method according to claim 2, characterized in that the parameters N, m, J and R are defined as follows:

4. Interleaver in the communication system containing a memory having a matrix of rows and columns, and the address generator, configured to interleave with partial reverse the order of bits (H-OPB) memory addresses, calculate the first variable throughwith the use of a given size N of the interleaver and the second variable bycomparing the value of the first variable with a given first threshold value, comparing the size N of the interleaver at least one predetermined second threshold value, opredelennym coefficient for the second variable, the definition of the first parameter J in accordance with the comparison results, wycis the value of the second parameter m by , calculating a third parameter R by N=2^m·J+R, sequential configuration along the columns of the input data stream of size N in a matrix with 2^mrow and (J-1) columns and R rows in the J-th column, where 0≤R<2^m, H-OPB alternation configured data and address generation reader for reading perenesennyj data rows.

5. Interleaver under item 4, characterized in that the parameters N, m, J and R are defined as follows: