CN102201884B - Blind identification method for pseudo-random interleaving - Google Patents

Abstract

The invention discloses a blind identification method for pseudo-random interleaving. In the method, after the interleaving length and the interleaving start of a pseudo-random are determined through linear transformation, mathematic analysis is conducted on a matrix and coding parameters of a block code used before interleaving are determined. By analyzing a relation equation between code elements before and after interleaving, an interleaving rule is found out so as to determine an interleaving relation. The invention better solves the problems of determining the interleaving length of the pseudo-random, determining the interleaving starting point of the pseudo-random, determining the coding parameters of the block code before interleaving, determining the interleaving relation and the like, realizes the interleaving of the pseudo-random and the blind identification of the coding parameters of the block code before interleaving only through communication contents, and has the characteristics of simple algorithm, clear process, high identification speed and the like. The invention is suitable for the fields such as intelligent communication, communication reconnaissance, information counterwork and the like.

Description

A kind of blind-identification method of pseudo random interleaving

Technical field

The present invention relates to the blind-identification method of a kind of pseudo random interleaving in digital communication system, described pseudo random interleaving is refered in particular to information data in the pseudo random interleaving of carrying out carrying out after Binary Linear Block Codes coding.The present invention is applicable to the fields such as intelligent communication, signal reconnaissance, information countermeasure.

Background technology

Pseudo random interleaving is applied very extensive in modern communications, and along with the development of digital communication technology, increasing field all can produce the demand to the blind recognition technology of pseudo random interleaving, and the blind recognition technology of pseudo random interleaving is also the Disciplinary Frontiers of current Communication Studies.

How from information code current, correctly to identify pseudo random interleaving and interweave before the chnnel coding relevant parameter that uses, thereby be correctly decoded, be a basic problem in information reconnaissance and information acquisition field, rare report also at present.Realize intercepting and capturing and the attack of information, particularly in Adaptive Modulation and Coding application more and more widely in situation, the problem that first will solve to the blind identification of chnnel coding (comprise and interweaving), an important basic research job, only have and accurately identify the chnnel coding system of scouting object, the scouting based on Information Level and antagonism just have the possibility of realization.

The blind discriminance analysis of pseudo random interleaving comprises weaving length, the starting point that interweaves and the relation that interweaves of determining pseudo random interleaving.In addition the correlated channels coding parameter using before pseudo random interleaving, is also the important content that needs identification.

Summary of the invention

Technical problem to be solved by this invention is to propose a kind of clear process, widely applicable pseudo random interleaving blind-identification method.The inventive method through linear transformation after definite pseudo random interleaving length and pseudo random interleaving starting point, matrix is carried out to mathematical analysis, determine the chnnel coding parameter using before interweaving, relation equation between code element before and after interweaving by analysis, find out the rule that interweaves, determine the relation that interweaves.

In order to solve the problems of the technologies described above, the blind-identification method of pseudo random interleaving provided by the invention, comprises the steps:

1. according to the sequence of data decimation appropriate length receiving as recognition sequence, the fixing matrix line number p that will arrange, p is at least greater than the weaving length of 2 times;

2. get and determine columns maximum and minimum value, change data sequence is lined up to matrix form by columns, calculate this rank of matrix, and write down the train value that order is not equal to columns, determine weaving length L;

3. matrix columns is taken as successively: L, 2L, 3L, 4L ..., line number is greater than columns; Code sequence is shifted, each matrix is asked respectively to order, rank of matrix under difference dimensions while writing down L kind displacement situation (without displacement displacements different from L-1 kind), the Analysis deterrmination starting point that interweaves;

4. analyzing columns is weaving length L, rank of matrix R when the starting point of interlacing frames is the first as matrix, obtain about (n before interweaving, k) equation of block code (wherein t is complete packet code word number contained in every interlacing frames), Analysis deterrmination block code coding parameter n, k and generator polynomial thereof;

$\left\{\begin{array}{c}(n-k)t=L-R\\ \mathrm{nt}=L\end{array}\right.$

5. analyzing columns is weaving length L, the matrix when starting point of interlacing frames is the first as matrix, the constraint equation before and after comparison interweaves, the Analysis deterrmination displacement relation that interweaves.

Complete the blind identification of pseudo random interleaving.

Preferably, in the blind-identification method of the above-mentioned pseudo random interleaving of the present invention, weaving length L determines: p × q matrix (p > 2L that pseudo random interleaving is formed, q < p), if q is the integral multiple of L or L, in unit rear left, the dimension of angular unit battle array equates, and now rank of matrix is not equal to columns q.

Preferably, in the blind-identification method of the above-mentioned pseudo random interleaving of the present invention, determining of the starting point that interweaves: p × q matrix (p > 2L that pseudo random interleaving is formed, q is L multiple), in the time that the starting point that interweaves (must be block code starting point) overlaps with the every beginning-of-line of matrix, its order minimum (corresponding solution space dimension maximum).

Preferably, in the blind-identification method of the above-mentioned pseudo random interleaving of the present invention, before interweaving, block code coding parameter is definite: p × L matrix (p > L) that pseudo random interleaving is formed, if its order is R, have following equation to set up, wherein t is complete packet code word number contained in every interlacing frames.

$\left\{\begin{array}{c}(n-k)t=L-R\\ \mathrm{nt}=L\end{array}\right.$

Preferably, in the blind-identification method of the above-mentioned pseudo random interleaving of the present invention, the relation that interweaves determine: if block code does not interweave, can obtain its check matrix, obtain coding bound equation; Interweave if had, the certain and former constraint equation of coding bound equation obtaining after interweaving has relation, the relation that interweaves exactly of the transformational relation between these two kinds of equations, and the satisfied dependency relation of code element after interweaving develops by the equation before interweaving.

Preferably, in the blind-identification method of the above-mentioned pseudo random interleaving of the present invention, pseudo random interleaving is refered in particular to information data in the pseudo random interleaving of carrying out carrying out after Binary Linear Block Codes coding, and this pseudo random interleaving has following characteristics:

1. continuity in frame.In sequence U after interweaving, appoint and get L position, as this L position belongs to an interlacing frames just, after corresponding inverse permutation, can form continuous L position block code sequence so; If this L position does not belong to same interlacing frames, conversion come what may, also cannot generate the long continuous separate group code sequence in L position.

2. the timing of interframe.Because pseudo random interleaving is carried out taking frame as unit, in a frame, the bit-order of C sequence is upset, time sequencing between frame and frame is not affected, if j > is i, in code sequence C, after the L bit one of j frame fixes on i frame L bit.

3. property at same frame on the same group.The n position of the same grouping of block code sequence must be in same interlacing frames, and conversely, the n position of same grouping can not be distributed in two frames.

With respect to prior art, the present invention after definite pseudo random interleaving length and pseudo random interleaving starting point, carries out mathematical analysis to matrix through linear transformation, determines the block code coding parameter using before interweaving.Before and after interweaving by analysis, relation equation between code element, finds out the rule that interweaves, thereby determines the relation that interweaves.The present invention has solved preferably pseudo random interleaving length and has determined, pseudo random interleaving starting point is determined, before interweaving block code coding parameter determine and interweave relation determine etc. problem, only can realize pseudo random interleaving by Content of Communication and interweave before the blind identification of block code coding parameter, there is algorithm simple and direct, the features such as process is clear, and recognition speed is fast.

Brief description of the drawings

Fig. 1 is the basic flow sheet of the blind identification of pseudo random interleaving of the present invention.

Fig. 2 is that pseudo random interleaving length of the present invention is determined flow chart.

Fig. 3 is that pseudo random interleaving starting point of the present invention is determined flow chart.

Fig. 4 is matrixing figure before interweaving in the embodiment of the present invention.

Fig. 5 is matrixing figure after interweaving in the embodiment of the present invention.

Embodiment

Below in conjunction with the drawings and specific embodiments, further set forth the present invention.These embodiment are interpreted as being only not used in and limiting the scope of the invention for the present invention is described.After having read the content of the present invention's record, those skilled in the art can make various changes or modifications the present invention, and these equivalences change and modification falls into the scope of the claims in the present invention equally.

If the channel coding method using before pseudo random interleaving is (n, k) linear block codes, information sequence M is formation sequence C after block encoding, C produces channel sequence U after pseudo random interleaving, the weaving length of an interlacing frames is L, under normal circumstances, and for ensureing the maximum performance of block encoding and the combination that interweaves, between pseudo random interleaving and block encoding, meet following condition: L >=n, and the L integral multiple that is n.

The feature of pseudo random interleaving:

(1) continuity in frame.In sequence U, appoint and get L position, as this L position belongs to an interlacing frames just, after corresponding inverse permutation, can form continuous L position block code sequence so; If this L position does not belong to same interlacing frames, conversion come what may, also cannot generate the long continuous separate group code sequence in L position.

(2) timing of interframe.Because pseudo random interleaving is carried out taking frame as unit, in a frame, the bit-order of C sequence is upset, time sequencing between frame and frame is not affected, if j > is i, in code sequence C, after the L bit one of j frame fixes on i frame L bit.

(3) property at same frame on the same group.The n position of the same grouping of block code sequence must be in same interlacing frames, and conversely, same grouping n position can not be distributed in two frames.

The pseudo random interleaving of following examples indication of the present invention, refers to meet the pseudo random interleaving of These characteristics.

As shown in Figure 1, the blind-identification method of the pseudo random interleaving that the preferred embodiment of the present invention provides, comprises the steps:

1. according to the sequence of data decimation appropriate length receiving as recognition sequence, the fixing matrix line number p that will arrange, p is at least greater than the weaving length of 2 times.

In order to ensure the lower continuous 2. middle definite validity of weaving length, this step data length should be greater than p ², matrix line number p at least should be 2 times of unknown weaving length.

2. get and determine columns maximum and minimum value, change data sequence is lined up to matrix form by columns, calculate this rank of matrix, and write down the train value that order is not equal to columns, determine weaving length L.

The matrix form of data sequence being lined up to the capable q row of p, wherein 3≤q < p, carries out Applying Elementary Row Operations to each matrix, calculates and write down its order.The theorem 1 of determining weaving length is p × q matrix (p > 2L that pseudo random interleaving is formed, q < p), if q is the integral multiple of L or L, in unit rear left, the dimension of angular unit battle array equates, and now rank of matrix is not equal to columns q.

Proof to theorem 1 is as follows: the data after pseudo random interleaving, compared with the data before interweaving, have just changed the relative position of code element, so by linear transformation, can recover the dependency relation between code element before not interweaving completely.To (the n before not interweaving, k) linear block codes: C=m*G, output vector C is the linear transformation of input vector m, arbitrarily the represented linear restriction relation of complete linear block codes is identical, (n, k) the n-k bit check of linear block codes only plays restriction relation to the k position information of this code character, and its coding bound degree is code length n.When block code is lined up p × q matrix (p > 2L, q < is p) time, obviously working as q=n and every row is a complete code character of block code just, in the time that every beginning-of-line of matrix is block code starting point just, after unit, (p > 2L) order of this p × n matrix is grouping information bit length k.When q=a*n (a > 1), to p × q matrix (p > 2L, q=a*n), often walk to less the complete code character that has (a-1) individual position complete matching and linear correlation, now rank of matrix must be less than q.In like manner, in the time that q and n do not have multiple to be related to, every row or do not have a complete code character (q < n), although there is complete code character, but its position be no alignment (q > n), for matrix, be exactly each row linear independence, its order must be columns q.Weaving length L is n multiple again, even if this has just ensured that by linear transformation, the block code matrix correlation relation before not interweaving can not become through interweaving.So (p > 2L, p), if its order is not equal to columns q, columns q is now the integral multiple of weaving length or weaving length to q < to p × q matrix that pseudo random interleaving is formed.

Can obtain weaving length L therefore only need get greatest common divisor to the train value of retaining.

Be as shown in Figure 2 weaving length and determine flow chart.

3. matrix columns is taken as successively: L, 2L, 3L, 4L ..., line number is greater than columns.Code sequence is shifted, each matrix is asked respectively to order, rank of matrix under difference dimensions while writing down L kind displacement situation (without displacement displacements different from L-1 kind), the Analysis deterrmination starting point that interweaves.

The theorem 2 of determining the starting point that interweaves is p × q matrix (p > 2L that pseudo random interleaving is formed, q is L multiple), in the time that the starting point that interweaves (must be block code starting point) overlaps with the every beginning-of-line of matrix, its order minimum (corresponding solution space dimension maximum).

Proof to theorem 2 is as follows: to p × q matrix (p > 2L, q=a*L, a > 1), when q is L multiple, when L is block code length n multiple, in every row code character, must align one by one in position, if every beginning-of-line of matrix is interlacing frames starting point (must be block code starting point) just, there is a complete code character in every row, otherwise there is a-1 complete code character, obviously in the time there is a complete code character, after linear transformation, matrix internal linear correlation is the strongest, its order minimum.Therefore in the time writing down the L kind situation (without displacement and the not same position of L-1 kind) of matrix displacement, when each rank of matrix relatively displacement when minimum (solution space dimension is maximum relatively) be the starting point of pseudo random interleaving.

Be as shown in Figure 3 pseudo random interleaving starting point and determine flow chart.

4. analyzing columns is weaving length L, and the rank of matrix R when starting point of interlacing frames is the first as matrix, obtains the equation about (n, k) block code before interweaving, Analysis deterrmination block code coding parameter n, k and generator polynomial thereof.

$\left\{\begin{array}{c}(n-k)t=L-R\\ \mathrm{nt}=L\end{array}\right.$

Wherein t is complete packet code word number contained in every interlacing frames.

The theorem 3 of determining above-mentioned equation is p × L matrix (p > L) that pseudo random interleaving is formed, if its order is R, has following equation to set up, and wherein t is complete packet code word number contained in every interlacing frames.

$\left\{\begin{array}{c}(n-k)t=L-R\\ \mathrm{nt}=L\end{array}\right.$

Proof to theorem 3 is as follows: in the time that the starting point of interlacing frames is the first as matrix, order is R, and the code element of R is this moment correlated with, and the dimension that meets the solution space of coding bound equation is L-R, has L-R maximum linear independent solutions.The n-k bit check that is defined known (n, k) linear block codes by linear block codes only plays restriction relation to the k position information of this code character, and other code characters are irrelevant.Before interweaving, the irrelevant skill of the maximum linear of the block code of long L is (n-k) t.For interweaving, just exchange the sequencing of code element, can not change its linear dependence, after therefore interweaving, the irrelevant skill of its maximum linear is still constant, therefore have: L-R=(n-k) t.

Determine n, after k, get final product to obtain its generator polynomial g (x) by tabling look-up or calculating.

5. analyzing columns is weaving length L, the matrix when starting point of interlacing frames is the first as matrix, the constraint equation before and after comparison interweaves, the Analysis deterrmination displacement relation that interweaves.

If block code does not interweave, can obtain its check matrix, obtain coding bound equation; Interweave if had, between the block code code element after interweaving, still have certain restriction relation, by matrixing, still can obtain the relation equation between code element.Further, certain and the former constraint equation of coding bound equation obtaining after interweaving has relation, just change code element order because interweave, for equation, just change the position of parameter, can not change the number of parameter in equation, therefore always can find out the rule interweaving by the contrast of front and back equation.Transformational relation between these two kinds of equations is exactly the relation that interweaves that will look for, and the satisfied dependency relation of code element after interweaving develops by the equation group before interweaving.

Adopt the receiving sequence of block encoding and pseudo random interleaving as example taking a certain section below, set forth implementation process of the present invention.

1. getting fixed length is the identification data sequence of 35000bit, determines matrix line number p=300.

2. get and determine train value scope (15,295), change data sequence is lined up to matrix form by columns, the order of compute matrix successively, writes down the train value that order is not equal to columns, and its value is listed below shown in table 1:

Table 1

Columns	21	28	35	42	49
						Rank of matrix	14	18	22	32	38

By table 1, the train value of retaining is got to greatest common divisor and can obtain weaving length L=7.

3. matrix columns is taken as successively: 7,14,21,28,35, and line number: columns+10.Code sequence is shifted successively, each matrix is asked respectively to order, while writing down 7 kinds of displacement situations (without displacement displacements different from 6 kinds), rank of matrix under different dimensions, obtains corresponding rank of matrix, and its value is as shown in table 2 below:

Table 2

As can be seen from the table, in the time moving 2, corresponding rank of matrix minimum under different dimensional matrix number, so locate to be the starting point of interlacing frames.

4. be weaving length 7 from 3. midrange, rank of matrix has 4,5,6,7 totally 4 kinds of different values.In the time that the starting point of interlacing frames is the first as matrix, order is 4,4 relevant code elements this moment, and the dimension that meets the solution space of coding bound equation is 3, has 3 maximum linear independent solutions.If the channel coding method using before pseudo random interleaving is (n, k) linear block codes, L=nt, has:

$\left\{\begin{array}{c}(n-k)t=3\\ \mathrm{nt}=7\end{array}\right.$

By n, t is integer, can the only solution of this equation group: n=7, t=1, k=4.Known this block code code check r=k/n=4/7, is (7,4) linear block codes, tables look-up or can be calculated its generator polynomial g (x)=x3+x+1.

5. the code element before interweaving with C representative, code element after U representative interweaves, to (7 before interweaving, 4) linear block codes code element, arranging with 24 × 14 matrixes, can obtain matrixing Fig. 4, is 4 by order in 7 × 7 square formations in the dotted line of Fig. 4 upper left corner, the dimension of the solution space of corresponding homogeneous equation is 3, and one group of base of equation group is:

$\left\{\begin{array}{c}\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HSA00000061708300041.png,HSA00000061708300051.png"\; state="\{\{state\}\}">C</figure-callout>}1+C2+\mathrm{<figure-callout\; id="3"\; label="C"\; filenames="HSA00000061708300021.png"\; state="\{\{state\}\}">C</figure-callout>}3+C5=0\\ C2+\mathrm{<figure-callout\; id="3"\; label="C"\; filenames="HSA00000061708300021.png"\; state="\{\{state\}\}">C</figure-callout>}3+C4+C6=0\\ \mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HSA00000061708300041.png,HSA00000061708300051.png"\; state="\{\{state\}\}">C</figure-callout>}1+C2+C4+C7=0\end{array}\right.$

The all possible constraint equation that can form two element field is:

$\left\{\begin{array}{cc}\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HSA00000061708300041.png,HSA00000061708300051.png"\; state="\{\{state\}\}">C</figure-callout>}1+C2+\mathrm{<figure-callout\; id="3"\; label="C"\; filenames="HSA00000061708300021.png"\; state="\{\{state\}\}">C</figure-callout>}3+C5=0& \left(1\right)\\ C2+\mathrm{<figure-callout\; id="3"\; label="C"\; filenames="HSA00000061708300021.png"\; state="\{\{state\}\}">C</figure-callout>}3+C4+C6=0& \left(2\right)\\ \mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HSA00000061708300041.png,HSA00000061708300051.png"\; state="\{\{state\}\}">C</figure-callout>}1+C2+C4+C7=0& \left(3\right)\\ \mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HSA00000061708300041.png,HSA00000061708300051.png"\; state="\{\{state\}\}">C</figure-callout>}1+C4+C5+C6=0& \left(4\right)\\ \mathrm{<figure-callout\; id="3"\; label="C"\; filenames="HSA00000061708300021.png"\; state="\{\{state\}\}">C</figure-callout>}3+C4+C5+C7=0& \left(5\right)\\ \mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HSA00000061708300041.png,HSA00000061708300051.png"\; state="\{\{state\}\}">C</figure-callout>}1+\mathrm{<figure-callout\; id="3"\; label="C"\; filenames="HSA00000061708300021.png"\; state="\{\{state\}\}">C</figure-callout>}3+C6+C7=0& \left(6\right)\\ C2+C5+C6+C7=0& \left(7\right)\end{array}\right.$

The satisfied dependency relation of code element after interweaving develops by equation group above.

With respect to former code word, code word is moved to right after 2, the code word starting point after displacement and the starting point of interlacing frames overlap.Analysis is below all that the code word after displacement is carried out.

Interlacing frames starting point is 0 relatively, and columns is that Fig. 5 is shown in matrixing in 24 o'clock, and in the dotted line of the upper left corner, in 7 × 7 square formations, order is 4, and the dimension of the solution space of corresponding homogeneous equation is 3, and one group of base of equation group is:

$\left\{\begin{array}{cc}\mathrm{<figure-callout\; id="1"\; label="U"\; filenames="HSA00000061708300041.png,HSA00000061708300051.png"\; state="\{\{state\}\}">U</figure-callout>}1+U2+U4+U5=0& \left(8\right)\\ U2+\mathrm{<figure-callout\; id="3"\; label="U"\; filenames="HSA00000061708300021.png"\; state="\{\{state\}\}">U</figure-callout>}3+U4+U6=0& \left(9\right)\\ \mathrm{<figure-callout\; id="1"\; label="U"\; filenames="HSA00000061708300041.png,HSA00000061708300051.png"\; state="\{\{state\}\}">U</figure-callout>}1+\mathrm{<figure-callout\; id="3"\; label="U"\; filenames="HSA00000061708300021.png"\; state="\{\{state\}\}">U</figure-callout>}3=U4+U7=0& \left(10\right)\end{array}\right.$

Code element after Ui representative herein interweaves, equation has embodied present code element dependency relation.Equation (8), (9), (10) be actually the coding bound equation (1) of former block code, (2), (3), (4), (5), (6), 3 differentiation in (7), the C in full scale equation is replaced by U.

Be analyzed as follows:

1) interweave after equation (8), (9), only have 1 common code element U4 in (10), 3 only there is the code element U5 of 1 time, U6, U7,2 all there is the code element U1 of 2 times, U2, U3.

2) comparison equation (1)～(7), list and meet 1) in relation may combine 28: 1,2,3; 1,2,5; 1,2,6; 1,2,7; 1,3,4; 1,3,6; 1,3,7; 1,4,5; 1,4,6; 1,4,7; 1,5,6; 1,5,7; 2,6,7; 2,5,6; 2,4,7; 2,4,6; 2,4,5; 2,3,7; 2,3,5; 2,3,4; 3,6,7; 3,5,7; 3,5,6; 3,4,6; 3,4,5; 4,5,7; 4,6,7; 5,6,7;

3) with 2) in may combine the Analysis deterrmination relation that interweaves, taking equation 1,4,7 as example, the total element U4 of equation after interweaving (8)～(10) must corresponding equation (1), total Elements C 5 in (4), (7); 3 only there is the C3 before U5, U6, U7 correspondence after the element of 1 time interweaves interweave, C4, C7; Remaining U1, U2, the corresponding C1 of U3, C2, C6;

4) if equation (8) corresponding equation (4), by 3) known U5 must corresponding C4, remaining U1, the corresponding C1 of U2, C6, by 3) known U3 must corresponding C2; If U6 is corresponding C7, in conjunction with 3) U7 must corresponding C3, the corresponding C6 of U2, the corresponding C1 of U1;

5) comprehensive analysis above, the context that interweaves is as shown in table 2 below:

Table 2

C	1	2	3	4	5	6	7
								U	1	6	2	5	4	7	3

Start code sequence to carry out deinterleaving from the starting point that interweaves with this displacement relation that interweaves, recover block encoding sequence, carry out check digit checking with gained block code relation in 4. to recovering sequence, encoding relation is correct, and the table 2 gained displacement relation that interweaves is errorless.If block code verification relation is false, need to reselect above 2), 3), 4) and corresponding optional part analyzes.

Mathematic sign involved in the present invention is the art conventional sign.

Claims (3)

1. a blind-identification method for pseudo random interleaving, is characterized in that, comprises the steps:

1. according to the sequence of data decimation appropriate length receiving as recognition sequence, the fixing matrix line number p that will arrange, the weaving length that p is greater than 2 times;

2. get and determine columns maximum and minimum value, change data sequence is lined up to matrix form by columns, calculate this rank of matrix, and write down the train value that order is not equal to columns, determine weaving length L, p × q matrix that pseudo random interleaving is formed, p > 2L, q < p, if q is the integral multiple of L or L, in unit rear left, the dimension of angular unit battle array equates, and now rank of matrix is not equal to columns q;

3. matrix columns is taken as successively: L, 2L, 3L, 4L ..., line number is greater than columns; Code sequence is shifted, L under a different columns matrix is asked respectively to order, rank of matrix under different dimensions while writing down L kind displacement situation, the Analysis deterrmination starting point that interweaves, p × q matrix that pseudo random interleaving is formed, p > 2L, q is L multiple, in the time that the starting point that interweaves overlaps with the every beginning-of-line of matrix, its order minimum, corresponding solution space dimension maximum;

4. analyzing columns is weaving length L, and the rank of matrix R when starting point of interlacing frames is the first as matrix, obtains the equation about (n, k) block code before interweaving, Analysis deterrmination block code coding parameter n, k;

$\left\{\begin{array}{c}(n-k)t=L-R\\ \mathrm{nt}=L\end{array}\right.$

Definite method of block code coding parameter before wherein interweaving: p × L matrix that pseudo random interleaving is formed, wherein p > L, if its order is R, has following equation to set up, and wherein t is complete packet code word number contained in every interlacing frames,

$\left\{\begin{array}{c}(n-k)t=L-R\\ \mathrm{nt}=L\end{array}\right.$

From above-mentioned equation group Analysis deterrmination block code coding parameter n, k;

5. analyzing columns is weaving length L, the matrix when starting point of interlacing frames is the first as matrix, the constraint equation before and after comparison interweaves, the Analysis deterrmination displacement relation that interweaves;

Complete the blind identification of pseudo random interleaving.

2. method according to claim 1, is characterized in that, the relation that interweaves determine: if block code does not interweave, obtain its check matrix, obtain coding bound equation; Interweave if had, the certain and former constraint equation of coding bound equation obtaining after interweaving has relation, the relation that interweaves exactly of the transformational relation between these two kinds of equations, and the satisfied dependency relation of code element after interweaving develops by the equation before interweaving.

3. according to the method described in any one in claim 1-2, it is characterized in that, pseudo random interleaving is refered in particular to information data in the pseudo random interleaving of carrying out carrying out after Binary Linear Block Codes coding, and this pseudo random interleaving has following characteristics:

1. continuity in frame: in the sequence U after interweaving, appoint and get L position, as this L position belongs to an interlacing frames just, after corresponding inverse permutation, can form continuous L position block code sequence so; If this appoints in sequence a L position of getting not belong to same interlacing frames after interweaving, displacement come what may, also cannot generate the long continuous separate group code sequence in L position;

2. the timing of interframe: because pseudo random interleaving is carried out taking frame as unit, in a frame, the bit-order of sequence in frame before interweaving is upset, time sequencing between frame after interweaving and frame is not affected, if j > is i, in the code sequence after interweaving, before interweaving the L bit one of j frame fix on and interweave before after the L bit of i frame;

3. property at same frame on the same group: the n position of the same grouping of block code sequence must be in same interlacing frames, and conversely, the n position of same grouping can not be distributed in two frames.

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