CN105119608A - High-speed QC-LDPC (quasi-cyclic low-density parity-check) encoder based on three-stage assembly line in CMMB (China mobile multimedia broadcasting) - Google Patents

Abstract

The invention provides a high-speed QC-LDPC (quasi-cyclic low-density parity-check) encoder based on a three-stage assembly line in CMMB (China mobile multimedia broadcasting). The encoder comprises an I-type backward iteration circuit, a high-density matrix and vector multiplier and an II-type backward iteration circuit. The high-density matrix and vector multiplier is used for implementing the multiply operation of a high-density matrix and a vector, and the I-type and the II-type backward iteration circuits are used for implementing the backward iteration operation. An entire encoding process is divided into three stages of assembly lines. The 3/4 code-rate high-speed QC-LDPC encoder in a CMMB system has the advantages of simple structure, low cost, large throughput and the like.

Description

Based on the high speed QC-LDPC encoder of three class pipeline in CMMB

Technical field

The present invention relates to field of channel coding, particularly in a kind of CMMB (ChinaMobileMultimediaBroadcasting) system based on the high speed QC-LDPC encoder of three class pipeline.

Background technology

Low-density checksum (Low-DensityParity-Check, LDPC) code is one of efficient channel coding technology, and quasi-cyclic LDPC (Quasi-CyclicLDPC, QC-LDPC) code is a kind of special LDPC code.The generator matrix G of QC-LDPC code and check matrix H are all the arrays be made up of circular matrix, have the feature of stages cycle, therefore are called as QC-LDPC code.The first trip of circular matrix is the result of footline ring shift right 1, and all the other each provisional capitals are results of its lastrow ring shift right 1, and therefore, circular matrix is characterized by its first trip completely.Usually, the first trip of circular matrix is called as its generator polynomial.

CMMB standard adopts the LDPC code of system form, and exchanged by ranks, generator matrix and check matrix all can be transformed the circulation form that is as the criterion, and the left-half of its generator matrix G is a unit matrix, and right half part is by e × c b × b rank circular matrix G _i,jthe array that (0≤i<e, e≤j<t, t=e+c) is formed, as follows:

Wherein, I is b × b rank unit matrixs, and 0 is the full null matrix in b × b rank.The continuous b of G capable and b row are called as the capable and block row of block respectively.From formula (1), G has e block capable and t block row.CMMB standard have employed a kind of QC-LDPC code of code check η=3/4, for this code, and t=36, e=27, c=9, b=256.

In CMMB standard, the existing solution of 3/4 code check QC-LDPC encoder is the serial encoder adding accumulator (Type-IShift-Register-Adder-Accumulator, SRAA-I) circuit based on 9 I type shift registers.The serial encoder be made up of 9 SRAA-I circuit, completes coding within 6912 clock cycle.The program needs 4608 registers, 2304 two inputs input XOR gate with door and 2304 two, also needs 62208 bit ROM to store the generator polynomial of circular matrix.The program has two shortcomings: one is need a large amount of memory, causes circuit cost high; Two is serial input information bits, and coding rate is slow.

Summary of the invention

In CMMB system there is the shortcoming that cost is high, coding rate is slow in the existing implementation of 3/4 code check QC-LDPC encoder, for these technical problems, the invention provides a kind of high speed QC-LDPC encoder based on three class pipeline.

As shown in Figure 2, the high speed QC-LDPC encoder based on three class pipeline in communication system forms primarily of 3 parts: after I type to iterative circuit, high-density matrix and vector multiplier and II type after to iterative circuit.Cataloged procedure divides 3 steps to complete: the 1st step, to iterative circuit compute vector q and x after use I type; 2nd step, uses high-density matrix to verify vectorial p with the multiplier calculating section of vector _x; 3rd step, verifies vectorial p to iterative circuit calculating section after using II type _y, thus obtain verifying vectorial p=(p _x, p _y).

In CMMB system provided by the invention, 3/4 code check high speed QC-LDPC coder structure is simple, under the condition significantly improving coding rate, can reduce memory, thus reduces costs, improve throughput.

Be further understood by detailed description and accompanying drawings below about advantage of the present invention and method.

Accompanying drawing explanation

Fig. 1 is the structural representation of near lower triangular check matrix after ranks exchange;

Fig. 2 is the QC-LDPC cataloged procedure based on three class pipeline;

Fig. 3 is the functional block diagram of ring shift left accumulator RLA circuit;

Fig. 4 is the multiplier of a kind of high-density matrix and the vector be made up of 3 RLA circuit;

Fig. 5 is to iterative circuit after I type;

Fig. 6 gives block position and the ring shift right figure place thereof at nonzero circle matrix place in matrix Q;

Fig. 7 is to iterative circuit after II type;

Fig. 8 gives block position and the ring shift right figure place thereof at nonzero circle matrix place in matrix Y;

Fig. 9 summarizes each coding step of encoder and the hardware resource needed for whole cataloged procedure and processing time.

Embodiment

Below in conjunction with accompanying drawing, preferred embodiment of the present invention is elaborated, can be easier to make advantages and features of the invention be readily appreciated by one skilled in the art, thus more explicit defining is made to protection scope of the present invention.

The row of circular matrix is heavy identical with column weight, is denoted as w.If w=0, so this circular matrix is full null matrix.If w=1, so this circular matrix is replaceable, is called permutation matrix, and it is by obtaining the some positions of unit matrix I ring shift right.The check matrix H of QC-LDPC code is by c × t b × b rank circular matrix H _j,kthe following array that (1≤j≤c, 1≤k≤t, t=e+c) is formed:

Under normal circumstances, the arbitrary circular matrix in check matrix H is full null matrix (w=0) or is permutation matrix (w=1).Make circular matrix H _j,kfirst trip g _j,k=(g _{j, k, 1}, g _{j, k, 2}..., g _{j, k, b}) be its generator polynomial, wherein g _{j, k, m}=0 or 1 (1≤m≤b).Because H is sparse, so g _j,konly have 1 ' 1 ', even there is no ' 1 '.

For the QC-LDPC code of 3/4 code check in CMMB system, that front 27 pieces of row of H are corresponding is information vector a, and that rear 9 pieces of row are corresponding is the vectorial p of verification.Be one section with 256 bits, information vector a is divided into 27 sections, i.e. a=(a ₁, a ₂..., a ₂₇); Verify vectorial p and be divided into 9 sections, be i.e. p=(p ₁, p ₂..., p ₉).

Check matrix H is gone and exchanges and row swap operation, be converted near lower triangular shape H _aLT, as shown in Figure 1.In FIG, the unit of all matrixes is all b=256 bit instead of 1 bit.A is made up of 6 × 27 256 × 256 rank circular matrixes, B is made up of 6 × 3 256 × 256 rank circular matrixes, T is made up of 6 × 6 256 × 256 rank circular matrixes, C is made up of 3 × 27 256 × 256 rank circular matrixes, D is made up of 3 × 3 256 × 256 rank circular matrixes, and E is made up of 3 × 6 256 × 256 rank circular matrixes.T is lower triangular matrix, and u=3 reflects check matrix H _aLTwith the degree of closeness of lower triangular matrix.In FIG, matrix A and C corresponding informance vector a, matrix B and the vectorial p of the corresponding part verification of D _x=(p ₁, p ₂, p ₃), matrix T and E be corresponding remaining verification vector p then _y=(p ₄, p ₅..., p ₉).p＝(p _x,p _y)。Above-mentioned matrix and vector meet following relation:

p _x ^Τ＝Φ(ET ^-1Aa ^Τ+Ca ^Τ)(3)

p _y ^Τ＝T ^-1(Aa ^Τ+Bp _x ^Τ)(4)

Wherein, Φ=(ET ^-1b+D) ^-1, subscript ^Τwith ^-1represent transposition and inverse respectively.As everyone knows, circular matrix inverse, product and remain circular matrix.Therefore, Φ is also the array be made up of circular matrix.Although matrix E, T, B and D are sparse matrixes, Φ is no longer sparse but highdensity under normal circumstances.

Make q ^t=T ^{– 1}aa ^t, x ^t=Eq ^t+ Ca ^tand p _x ^t=Φ x ^t.

Vector q and x can be calculated by following formula:

$\left[\begin{array}{ccc}A& T& 0\\ C& E& I\end{array}\right]{\left[\begin{array}{ccc}a& q& x\end{array}\right]}^T=Q{\left[\begin{array}{ccc}a& q& x\end{array}\right]}^T=0---\left(5\right)$

Wherein,

$Q=\left[\begin{array}{ccc}A& T& 0\\ C& E& I\end{array}\right]---\left(6\right)$

Once calculate p _x, formula (4) can be rewritten as:

[ABT][ap _xp _y] ^Τ＝Y[ap _xp _y] ^Τ＝0(7)

Wherein,

Y＝[ABT](8)

Because Q is the same with Y and T is all lower triangular matrix, so [qx] in formula (5) and the p in formula (7) _yall can adopt the account form of backward iteration.

Φ relates to high-density matrix and vectorial multiplication, and Q and Y relates to backward iterative computation.Based on the above discussion, a kind of QC-LDPC cataloged procedure based on three class pipeline can be provided, as shown in Figure 2.

P _x ^t=Φ x ^tbe equivalent to p _x=x Φ ^t.Make x=(x ₁, x ₂..., x _{u × b}).Definition u bit vectors s _n=(x _n, x _n+b..., x _{n+ (u-1) × b}), wherein 1≤n≤b.Make Φ _j(1≤j≤u) is by Φ ^tjth block row in u × b rank matrix of forming of all circular matrix generator polynomials.Then have

p _j＝(…((0+s ₁Φ _j) ^ls(1)+s ₂Φ _j) ^ls(1)+…+s _bΦ _j) ^ls(1)(9)

Wherein, subscript ^{ls (1)}represent ring shift left 1.

A kind of ring shift left accumulator (Rotate-Left-Accumulator, RLA) circuit can be obtained, as shown in Figure 3 by formula (9).The index of look-up table is u bit vectors s _n, look-up table L _jthe u bit vectors that prior storage is variable and fixing Φ _jinstitute's likely product, therefore need 2 ^uthe read-only memory (Read-OnlyMemory, ROM) of b bit.B bit register R ₁, R ₂..., R _ube respectively used to the array section x cushioning vector x ₁, x ₂..., x _u, b bit register R _u+jfor storing p _xverification section p _j.1 RLA circuit counting vector p _jneed b clock cycle.

For CMMB system, use 3 RLA circuit counting p _x=(p ₁, p ₂, p ₃) be a kind of reasonable plan, high-density matrix as shown in Figure 4 and vectorial multiplier.High-density matrix and vectorial multiplier are by 3 look-up table L ₁, L ₂, L ₃, 6 256 bit register R _2,1, R _2,2..., R _2,6with 3 256 two input XOR gate X _2,1, X _2,2, X _2,3composition.Look-up table L ₁, L ₂, L ₃store 3 variable bit vectors and fixing matrix Φ respectively ₁, Φ ₂, Φ ₃institute's likely product, register R _2,1, R _2,2, R _2,3be respectively used to the array section x cushioning vector x ₁, x ₂, x ₃, register R _2,4, R _2,5, R _2,6be respectively used to store p _xverification section p ₁, p ₂, p ₃.3 RLA circuit need use 768 two to input XOR gate, ROM and 1536 register of 6144 bits.3 RLA circuit counting vector p _xneed 256 clock cycle.Use high-density matrix and vectorial multiplier compute vector p _xstep as follows:

1st step, resets register R _2,4, R _2,5, R _2,6, input vector section x ₁, x ₂, x ₃, by them respectively stored in register R _2,1, R _2,2, R _2,3in;

2nd step, register R _2,1, R _2,2, R _2,3ring shift left 1 time simultaneously, XOR gate X _2,1, X _2,2, X _2,3respectively to look-up table L ₁, L ₂, L ₃output and register R _2,4, R _2,5, R _2,6content carry out XOR, XOR result is recycled to move to left after 1 time deposits back register R respectively _2,4, R _2,5, R _2,6;

3rd step, repeats the 2nd step 255 times, after completing, and register R _2,4, R _2,5, R _2,6the content stored is verification section p respectively ₁, p ₂, p ₃, it constitute part and verify vectorial p _x.

Formula (5) implies backward iterative operation, must solve vectorial q and x piecemeal.Definition [qx]=(q ₁, q ₂..., q ₉), and be initialized as complete zero.First, q ₁the 1st piece of row of matrix Q and vector [aqx] ^tlong-pending.Secondly, q ₂the 2nd piece of row of matrix Q and vector [aqx] ^tlong-pending.Repeat said process, until calculated q ₉till, to iterative circuit after I type as shown in Figure 5.After I type to iterative circuit by 36 b bit register R _1,1, R _1,2..., R _1,36with 9 multi input modulo 2 adder A _1,1, A _1,2..., A _1,9composition.

To calculate q _j(1≤j≤9) are example.The ring shift right version of the normally unit matrix of the nonzero circle matrix in check matrix H.Have M nonzero circle matrix in front 27 pieces of row that the jth block of hypothesis matrix Q is capable, their ring shift right figure place is s respectively _{j, k1}, s _{j, k2}..., s _{j, kM}(1≤k1, k2 ..., kM≤27), have N number of nonzero circle matrix in rear 9 pieces of row that the jth block of matrix Q is capable, their ring shift right figure place is s respectively _{j, m1}, s _{j, m2}..., s _{j, mN}(27<m1, m2 ..., mN<27+j).Then

$\begin{array}{c}{q}_j=I^{rs\left(s_{j,k1}\right)}{a}_{k1}+I^{rs\left(s_{j,k2}\right)}{a}_{k2}+\mathrm{...}+I^{rs\left(s_{j,kM}\right)}{a}_{kM}+I^{rs\left(s_{j,m1}\right)}{q}_{m1-e}+I^{rs\left(s_{j,m2}\right)}{q}_{m2-e}+\mathrm{...}+I^{rs\left(s_{j,mN}\right)}{q}_{mN-e}\\ =a_{k1}^{ls\left(s_{j,k1}\right)}+a_{k2}^{ls\left(s_{j,k2}\right)}+\mathrm{...}+a_{kM}^{ls\left(s_{j,kM}\right)}+q_{m1-e}^{ls\left(s_{j,m1}\right)}+q_{m2-e}^{ls\left(s_{j,m2}\right)}+\mathrm{...}+q_{mN-e}^{ls\left(s_{j,mN}\right)}\end{array}---\left(10\right)$

Wherein, subscript ^{rs (n)}with ^{ls (n)}represent ring shift right n position and ring shift left n position respectively.Because M and N is very little, so formula (10) can calculate complete to multi input mould 2 musical instruments used in a Buddhist or Taoist mass of input ring shift left by one within 1 clock cycle.Therefore, compute vector [qx] needs 9 clock cycle altogether.Since a total β=98 nonzero circle matrix in matrix Q, so need to use (β – 2c) b=20480 two input XOR gate to iterative circuit after I type.

Matrix Q is by 9 × 36 b × b rank circular matrix Q _j,kthe array that (1≤j≤9,1≤k≤36) are formed.Nonzero circle matrix Q _j,ks relative to the ring shift right figure place of b × b rank unit matrix _j,k, 0≤s _j,k<b.For ease of describing, complete zero circular matrix is denoted as s relative to the ring shift right figure place of b × b rank circular matrix _j,k='-'.In Figure 5, when 1≤k≤27, Q _j,kcorresponding array section a in vertical direction _k, as 27<k<27+j, Q _j,kcorresponding array section q in vertical direction _k-27.Complete zero circular matrix Q _j,karray section corresponding does not in vertical direction participate in XOR, nonzero circle matrix Q _j,karray section a corresponding in vertical direction _kor q _k-27be recycled the s that moves to left _j,kmulti input modulo 2 adder A is sent into behind position _{1, j}in carry out XOR, A _{1, j}result of calculation be q _j, stored in register R _{1, j}in.Fig. 6 gives block position and the ring shift right figure place thereof at nonzero circle matrix place in matrix Q.Step to iterative circuit compute vector q and x after use I type is as follows:

1st step, input message segment a ₁, a ₂..., a ₂₇, by them respectively stored in register R _1,10, R _1,11..., R _1,36in;

2nd step, nonzero circle matrix Q _j,karray section a corresponding in vertical direction _kor q _k-27be recycled the s that moves to left _j,kmulti input modulo 2 adder A is sent into behind position _{1, j}in carry out XOR, XOR result q _jbe stored into register R _{1, j}in, wherein, 1≤j≤9,1≤k<36,0≤s _j,k<b, when 1≤k≤27, Q _j,kcorresponding array section a in vertical direction _k, as 27<k<27+j, Q _j,kcorresponding array section q in vertical direction _k-27;

3rd step, with 1 for step-length increases progressively the value changing j, repeats the 2nd step 8 times, finally, and register R _1,1, R _1,2..., R _1,9that store is array section q respectively ₁, q ₂..., q ₉, they constitute vectorial q and x.

Formula (7) also implies backward iterative operation, must solve part piecemeal and verify vectorial p _y.Initialization p _y=(p ₄, p ₅..., p ₉) be complete zero.First, p ₄the 1st piece of row of matrix Y and vector [ap _xp _y] ^tlong-pending.Secondly, p ₅the 2nd piece of row of matrix Y and vector [ap _xp _y] ^tlong-pending.Repeat said process, until calculated p ₉till, to iterative circuit after II type as shown in Figure 7.After II type to iterative circuit by 36 b bit register R _3,1, R _3,2..., R _3,36with 6 multi input modulo 2 adder A _3,1, A _3,2..., A _3,6composition.Calculating section verifies vectorial p _yneed 6 clock cycle altogether.Since a total ξ=69 nonzero circle matrix in matrix Y, so need to use (ξ – 2c+2u) b=14592 two input XOR gate to iterative circuit after II type.Matrix Y is by 6 × 36 b × b rank circular matrix Y _j,kthe array that (1≤j≤6,1≤k≤36) are formed.Nonzero circle matrix Y _j,ks relative to the ring shift right figure place of b × b rank unit matrix _j,k, 0≤s _j,k<b.Fig. 8 gives block position and the ring shift right figure place thereof at nonzero circle matrix place in matrix Y.Vectorial p is verified to iterative circuit calculating section after using II type _ystep as follows:

1st step, input message segment a ₁, a ₂..., a ₂₇, by them respectively stored in register R _3,7, R _3,8..., R _3,33in, input validation section p ₁, p ₂, p ₃, by them respectively stored in register R _3,34, R _3,35, R _3,36in;

2nd step, nonzero circle matrix Y _j,karray section a corresponding in vertical direction _kor p _k-27be recycled the s that moves to left _j,kmulti input modulo 2 adder A is sent into behind position _{3, j}in carry out XOR, XOR result p _j+3be stored into register R _{3, j}in, wherein, 1≤j≤6,1≤k<36,0≤s _j,k<b, when 1≤k≤27, Y _j,kcorresponding array section a in vertical direction _k, as 27<k<27+j, Y _j,kcorresponding array section p in vertical direction _k-27;

3rd step, with 1 for step-length increases progressively the value changing j, repeats the 2nd step 5 times, finally, and register R _3,1, R _3,2..., R _3,6that store is array section p respectively ₄, p ₅..., p ₉, they constitute part and verify vectorial p _y.

The invention provides a kind of high speed QC-LDPC coding method based on three class pipeline, be applicable to 3/4 code check QC-LDPC code in CMMB system, its coding step is described below:

1st step, to iterative circuit compute vector q and x after use I type;

2nd step, uses high-density matrix to verify vectorial p with the multiplier calculating section of vector _x;

3rd step, verifies vectorial p to iterative circuit calculating section after using II type _y, thus obtain verifying vectorial p=(p _x, p _y).

Fig. 9 summarizes each coding step of encoder and the hardware resource consumption needed for whole cataloged procedure and processing time.

Be not difficult to find out from Fig. 9, when streamline is full of, whole cataloged procedure needs max (t, u+b)=259 clock cycle altogether, much smaller than 6912 clock cycle needed for the serial encoding method based on 9 SRAA-I circuit.The former coding rate is 26.7 times of the latter.

In CMMB standard, the existing solution of 3/4 code check QC-LDPC encoder needs 4608 registers, 2304 two inputs inputs XOR gate with door and 2304 two, also needs the generator polynomial of 62208 bit ROM storage circular matrixes.And the present invention needs 19968 registers, 0 two input inputs XOR gate with door and 35840 two, only need 6144 bit ROM.

As fully visible, compared with traditional serial SRAA method, the present invention has the advantages such as coding rate is fast, memory consumption is few.

The above; be only one of the specific embodiment of the present invention; but protection scope of the present invention is not limited thereto; any those of ordinary skill in the art are in the technical scope disclosed by the present invention; the change can expected without creative work or replacement, all should be encompassed within protection scope of the present invention.Therefore, the protection range that protection scope of the present invention should limit with claims is as the criterion.

Claims (5)

1. in a CMMB based on the high speed QC-LDPC encoder of three class pipeline, the check matrix H of 3/4 code check QC-LDPC code is the array be made up of c × t b × b rank circular matrix, wherein, c=9, t=36, b=256, e=t-c=27, check matrix H is exchanged by ranks and is transformed near lower triangular shape, can be divided into 6 submatrixs $H=\left[\begin{array}{ccc}A& B& T\\ C& D& E\end{array}\right],$ A is made up of 6 × 27 b × b rank circular matrixes, B is made up of 6 × 3 b × b rank circular matrixes, lower triangular matrix T is made up of 6 × 6 b × b rank circular matrixes, C is made up of 3 × 27 b × b rank circular matrixes, D is made up of 3 × 3 b × b rank circular matrixes, E is made up of 3 × 6 b × b rank circular matrixes, Φ=(ET ^-1b+D) ^-1be made up of 3 × 3 b × b rank circular matrixes, Φ _jby Φ ^tjth block row in 3 × b rank matrix of forming of all circular matrix generator polynomials, wherein, subscript ^Τwith ^-1represent transposition and inverse respectively, 1≤j≤3, $Q=\left[\begin{array}{ccc}A& T& 0\\ C& E& I\end{array}\right]$ By 9 × 36 b × b rank circular matrix Q _j,kform, wherein, I is unit matrix, and 0 is full null matrix, 1≤j≤9,1≤k≤36, nonzero circle matrix Q _j,ks relative to the ring shift right figure place of b × b rank unit matrix _j,k, wherein, 0≤s _j,k<b, Y=[ABT] are by 6 × 36 b × b rank circular matrix Y _j,kform, wherein, 1≤j≤6,1≤k≤36, nonzero circle matrix Y _j,ks relative to the ring shift right figure place of b × b rank unit matrix _j,k, wherein, 0≤s _j,k<b, A and C corresponding informance vector a, matrix B and the vectorial p of the corresponding part verification of D _x, matrix T and E be corresponding remaining verification vector p then _y, verify vectorial p=(p _x, p _y), be one section with b bit, information vector a is divided into 27 sections, i.e. a=(a ₁, a ₂..., a ₂₇), verify vectorial p and be divided into 9 sections, be i.e. p=(p ₁, p ₂..., p ₉), p _x=(p ₁, p ₂, p ₃), p _y=(p ₄, p ₅..., p ₉), vectorial q is divided into 6 sections, i.e. q=(q ₁, q ₂..., q ₆), vector x is divided into 3 sections, i.e. x=(q ₇, q ₈, q ₉), [qx]=(q ₁, q ₂..., q ₉), it is characterized in that, described encoder comprises following parts:

To iterative circuit after I type, by 36 b bit register R _1,1, R _1,2..., R _1,36with 9 multi input modulo 2 adder A _1,1, A _1,2..., A _1,9composition, for compute vector q and x;

High-density matrix and vectorial multiplier, by 3 look-up table L ₁, L ₂, L ₃, 6 256 bit register R _2,1, R _2,2..., R _2,6with 3 256 two input XOR gate X _2,1, X _2,2, X _2,3composition, verifies vectorial p for calculating section _x, look-up table L ₁, L ₂, L ₃store 3 variable bit vectors and fixing matrix Φ respectively ₁, Φ ₂, Φ ₃institute's likely product;

To iterative circuit after II type, by 36 b bit register R _3,1, R _3,2..., R _3,36with 6 multi input modulo 2 adder A _3,1, A _3,2..., A _3,6composition, verifies vectorial p for calculating section _y, thus obtain verifying vectorial p=(p _x, p _y).

2. in a kind of CMMB according to claim 1 based on the high speed QC-LDPC encoder of three class pipeline, it is characterized in that, the step to iterative circuit compute vector q and x after described I type is as follows:

1st step, input message segment a ₁, a ₂..., a ₂₇, by them respectively stored in register R _1,10, R _1,11..., R _1,36in;

2nd step, nonzero circle matrix Q _j,karray section a corresponding in vertical direction _kor q _k-27be recycled the s that moves to left _j,kmulti input modulo 2 adder A is sent into behind position _{1, j}in carry out XOR, XOR result q _jbe stored into register R _{1, j}in, wherein, 1≤j≤9,1≤k<36,0≤s _j,k<b, when 1≤k≤27, Q _j,kcorresponding array section a in vertical direction _k, as 27<k<27+j, Q _j,kcorresponding array section q in vertical direction _k-27;

3rd step, with 1 for step-length increases progressively the value changing j, repeats the 2nd step 8 times, finally, and register R _1,1, R _1,2..., R _1,9that store is array section q respectively ₁, q ₂..., q ₉, they constitute vectorial q and x.

3. in a kind of CMMB according to claim 1 based on the high speed QC-LDPC encoder of three class pipeline, it is characterized in that, described high-density matrix with vector multiplier compute vector p _xstep as follows:

1st step, resets register R _2,4, R _2,5, R _2,6, input vector section x ₁, x ₂, x ₃, by them respectively stored in register R _2,1, R _2,2, R _2,3in;

2nd step, register R _2,1, R _2,2, R _2,3ring shift left 1 time simultaneously, XOR gate X _2,1, X _2,2, X _2,3respectively to look-up table L ₁, L ₂, L ₃output and register R _2,4, R _2,5, R _2,6content carry out XOR, XOR result is recycled to move to left after 1 time deposits back register R respectively _2,4, R _2,5, R _2,6;

3rd step, repeats the 2nd step 255 times, after completing, and register R _2,4, R _2,5, R _2,6the content stored is verification section p respectively ₁, p ₂, p ₃, it constitute part and verify vectorial p _x.

4. in a kind of CMMB according to claim 1 based on the high speed QC-LDPC encoder of three class pipeline, it is characterized in that, after described II type, verify vectorial p to iterative circuit calculating section _ystep as follows:

1st step, input message segment a ₁, a ₂..., a ₂₇, by them respectively stored in register R _3,7, R _3,8..., R _3,33in, input validation section p ₁, p ₂, p ₃, by them respectively stored in register R _3,34, R _3,35, R _3,36in;

2nd step, nonzero circle matrix Y _j,karray section a corresponding in vertical direction _kor p _k-27be recycled the s that moves to left _j,kmulti input modulo 2 adder A is sent into behind position _{3, j}in carry out XOR, XOR result p _j+3be stored into register R _{3, j}in, wherein, 1≤j≤6,1≤k<36,0≤s _j,k<b, when 1≤k≤27, Y _j,kcorresponding array section a in vertical direction _k, as 27<k<27+j, Y _j,kcorresponding array section p in vertical direction _k-27;

3rd step, with 1 for step-length increases progressively the value changing j, repeats the 2nd step 5 times, finally, and register R _3,1, R _3,2..., R _3,6that store is array section p respectively ₄, p ₅..., p ₉, they constitute part and verify vectorial p _y.

5. in a CMMB based on the high speed QC-LDPC coding method of three class pipeline, the check matrix H of 3/4 code check QC-LDPC code is the array be made up of c × t b × b rank circular matrix, wherein, c=9, t=36, b=256, e=t-c=27, check matrix H is exchanged by ranks and is transformed near lower triangular shape, can be divided into 6 submatrixs $H=\left[\begin{array}{ccc}A& B& T\\ C& D& E\end{array}\right],$ A is made up of 6 × 27 b × b rank circular matrixes, B is made up of 6 × 3 b × b rank circular matrixes, lower triangular matrix T is made up of 6 × 6 b × b rank circular matrixes, C is made up of 3 × 27 b × b rank circular matrixes, D is made up of 3 × 3 b × b rank circular matrixes, E is made up of 3 × 6 b × b rank circular matrixes, Φ=(ET ^-1b+D) ^-1be made up of 3 × 3 b × b rank circular matrixes, Φ _jby Φ ^tjth block row in 3 × b rank matrix of forming of all circular matrix generator polynomials, wherein, subscript ^Τwith ^-1represent transposition and inverse respectively, 1≤j≤3, $Q=\left[\begin{array}{ccc}A& T& 0\\ C& E& I\end{array}\right]$ By 9 × 36 b × b rank circular matrix Q _j,kform, wherein, I is unit matrix, and 0 is full null matrix, 1≤j≤9,1≤k≤36, nonzero circle matrix Q _j,ks relative to the ring shift right figure place of b × b rank unit matrix _j,k, wherein, 0≤s _j,k<b, Y=[ABT] are by 6 × 36 b × b rank circular matrix Y _j,kform, wherein, 1≤j≤6,1≤k≤36, nonzero circle matrix Y _j,ks relative to the ring shift right figure place of b × b rank unit matrix _j,k, wherein, 0≤s _j,k<b, A and C corresponding informance vector a, matrix B and the vectorial p of the corresponding part verification of D _x, matrix T and E be corresponding remaining verification vector p then _y, verify vectorial p=(p _x, p _y), be one section with b bit, information vector a is divided into 27 sections, i.e. a=(a ₁, a ₂..., a ₂₇), verify vectorial p and be divided into 9 sections, be i.e. p=(p ₁, p ₂..., p ₉), p _x=(p ₁, p ₂, p ₃), p _y=(p ₄, p ₅..., p ₉), vectorial q is divided into 6 sections, i.e. q=(q ₁, q ₂..., q ₆), vector x is divided into 3 sections, i.e. x=(q ₇, q ₈, q ₉), [qx]=(q ₁, q ₂..., q ₉), it is characterized in that, described coding method comprises the following steps:

1st step, to iterative circuit compute vector q and x after use I type;

2nd step, uses high-density matrix to verify vectorial p with the multiplier calculating section of vector _x;

3rd step, verifies vectorial p to iterative circuit calculating section after using II type _y, thus obtain verifying vectorial p=(p _x, p _y).