WO2018126914A1 - Method and device for coding of quasi-cyclic low-density parity-check code, and storage medium - Google Patents

Abstract

Provided are a method and device for coding of a quasi-cyclic low-density parity-check code, and a storage medium. The method comprises: determining an expansion factor z and a base check matrix Hb; and using the determined z and Hb to perform low-density parity-check (LDPC) coding on a bit sequence I to be coded, wherein Hb comprises a block A having a size of mb rows and kb2 columns and corresponding to systematic bits and a block B having a size of mb rows and mb columns and corresponding to check bits, kb2＝nb-mb, kb2 is an integer greater than or equal to 4, each of mb and nb is an integer.

Description

Coding method and device for quasi-cyclic low-density parity check code, storage medium

Cross-reference to related applications

This application is based on a Chinese patent application with the application number of 201710014296.6, the application date is January 09, 2017, and the Chinese patent application with the application number of 201710449155.7 and the application date of June 14, 2017, and requires the Chinese patent application. Priority is hereby incorporated by reference in its entirety in its entirety in its entirety in its entirety in its entirety in its entirety in

Technical field

The present application relates to the field of communications, and in particular, to a coding method and apparatus, and a storage medium for a quasi-cyclic low-density parity check code.

Background technique

The transmitting end of the digital communication system usually includes a source, a source encoder, a channel coder and a modulator, and the receiving end usually includes a demodulator, a channel decoder, a source decoder and a sink. The channel coder is used to introduce information bits into the information bits according to certain rules so that the receiving channel decoder can correct the errors occurring when the information is transmitted on the channel to some extent.

Generally speaking, Forward Error Correction (FEC) coding is a process of generating a check bit sequence from an information bit sequence. The information bit sequence and the check bit sequence together constitute a codeword bit sequence that we often say. . The commonly used FEC codes include a Turbo code, a Low Density Check Code (LDPC), a polarization code, a convolutional code, etc.; for example, in a Long-Term Evolution (LTE) system. Turbo codes are used for data transmission; LDPC codes and convolutional codes are used in IEEE 802.11 systems.

The LDPC code is a linear block code based on the sparse check matrix. It is the sparsity of its check matrix that can realize the high-throughput and low-complexity codec, which makes the LDPC code practical. LDPC codes have many decoding algorithms. Among them, Message Passing algorithm or Belief Propagation Algorithm (BP) is the mainstream and basic algorithm of LDPC codes. Currently, there are many improved effective decoding. algorithm.

The graphical representation of the LDPC parity check matrix is a bipartite graph. There is a one-to-one correspondence between the bipartite graph and the check matrix, and an M*N parity check matrix H defines a constraint that each codeword having N bits satisfies M parity sets. A bipartite graph includes N variable nodes and M parity nodes. When the mth check involves the nth bit, that is, the element Hm of the mth row and the nth column in H, n=1, there will be a wire connecting the check node m and the variable node n. In the bipartite graph, there is no connection between any nodes of the same class, and the total number of edges in the bipartite graph is equal to the number of non-zero elements in the check matrix.

A special type of LDPC code has become a mainstream application due to its structured features. Let the parity check matrix H of this LDPC code be a (M×z)×(N×z) matrix, which is composed of M×N block matrices, each of which is a basic permutation of z×z. For different powers of the matrix, when the basic permutation matrix is a unit matrix, they are cyclic shifting matrices of the unit array (the default is right shift), so the structured LDPC code is also called quasi-cyclic LDPC code. Has the form as follows:

in case

in case

Is an integer greater than or equal to 0, then define

Where P is a standard permutation matrix of z × z, the specific form is as follows:

Through such powers

It is possible to uniquely identify each of the block matrices. If a block matrix is an all-zero matrix, the matrix is generally represented by -1, and if the cyclic shift s of the unit array is obtained,

Equal to s, so all

A basic check matrix Hb can be constructed. And z is the dimension indicating the standard permutation matrix, where z is called the spreading factor. At this time, the structured LDPC code can be uniquely determined by the basic check matrix Hb and the spreading factor z. The basic check matrix includes a plurality of parameters: mb, nb, and kb2, where mb is the number of basic check matrix rows (which can be said to be the number of check columns of the basic check matrix), nb basic check matrix columns, and kb =nb-mb is the number of system columns of the underlying check matrix.

For example, the base check matrix Hb (2 rows and 4 columns) is as follows, and the expansion factor z is equal to 4:

Then the parity check matrix is:

When decoding, the LDPC code can use hierarchical decoding, that is, a partial parallel decoding method. The parity check matrix as described above has 8 rows, indicating that there are 8 parity check codes. When decoding, each parity check matrix needs to be decoded separately, if all 8 parity check codes are updated, For an iteration. In each iteration, if partial parallelism (ie, hierarchical decoding) is adopted, such as parallelism is p, that is, there are p parity codes simultaneously updated, then the current and next p parity codes in the iteration The operation is to use the same update module, the complexity of the decoder is much lower, and the data update of the next layer in the layered decoding can use the currently updated data, so the number of iterations required is lower. The code throughput is higher. As H shown above, if the degree of parallelism is 2, every 4 rows of the parity check matrix (one row of the basic check matrix) have two parallel parity codes simultaneously updated.

If a basic matrix is used for each different spreading factor LDPC code, then for each different code length, the LDPC code codec needs to store a basic matrix, and when the code length is large, it is stored. There are many basic matrices, which can cause presentation and storage problems. Therefore, when it is necessary to implement the variable code length, a low-density parity check code of a plurality of code lengths within a certain range of the same code rate uses a basic matrix of a form, which is defined as a unified basic matrix.

When different code lengths, if yes

By performing correction and expansion, the parity check matrix H can be obtained, so that the generated codec can be applied to a case where the code length is variable.

The correction is to correct the non-negative value elements in the basic matrix Hb by using the spreading factors of different code lengths, and the corrected element value should be smaller than the expansion factor value under the code length. There are many correction algorithms. For example, mod, scale+floor, or scale+round can be used. Let P _ij be the non-negative of the i-th row and j-th column of the basic matrix H _b . 1 element, P _ij ' is corrected

The non-negative 1 element of the i-th row and j-th column has:

For the mod method:

For the rounding/floor method:

For rounding (round+round) methods:

Where z is the expansion factor corresponding to the current code length, that is, the number of rows or columns of the block square matrix; z _max is the expansion factor corresponding to the maximum supported code length, or the maximum expansion factor. Mod is the modulo operation, [·] is the next rounding operation, and Round is the rounding operation.

However, the use of structured LDPC codes also has some problems in supporting flexible code lengths. For example, for a structured LDPC with a system column of kb columns and a spreading factor of z, the length K of the information bit sequence input by the encoder should be Satisfying K=kb*z; when K<kb*z, it is necessary to fill the information bit sequence with known bits so that its length reaches kb*z, and then encode the filled information bit sequence. This method is called Shorten the code code. It can be seen that the number of padding bits for information bit sequences of different lengths is also different. When the number of bits is too large, the performance of shortening code coding will deteriorate. That is, the structured LDPC coding in the related art has a problem that the coding performance deteriorates when the length of the bit sequence to be coded continuously changes.

In view of the above technical problems, an effective solution has not been proposed in the related art.

Summary of the invention

An embodiment of the present application provides a coding method and apparatus for a quasi-cyclic low-density parity check code, and a storage medium, to at least solve the problem that the coding performance of the bit sequence to be encoded is continuously changed when the length of the bit sequence to be coded is changed by using the structured LDPC code in the related art. problem.

According to an embodiment of the present application, there is provided a coding method of a quasi-cyclic low-density parity check code, comprising: determining a spreading factor z, and a basic check matrix Hb; using the determined z and the Hb to be encoded The bit sequence I performs low density parity check code LDPC encoding; wherein the Hb includes a block A corresponding to a mb row kb2 column of system bits and a block B corresponding to a mb row mb column of parity bits, kb2=nb- Mb, kb2 is an integer greater than or equal to 4, and both mb and nb are integers.

Optionally, performing the LDPC encoding on the I by using the determined z and the Hb comprises: determining a kb column from a kb2 column of the block A included by the Hb, where z=n*2 ⁱ , The kb is determined from a first set kbset, the n is determined from a second set nset, the z, n, kb2, kb are all positive integers and kb is less than or equal to kb2, i is non-negative An integer; performing the LDPC encoding on the I using the determined z and the Hb determining the kb column.

Optionally, the kbset and the nset include one of: the kbset={8, 9, 10, 11, 12}, and the nset={2, 3}; the kbset={8, 9,10,11,12}, and said nset={2,3,4}; said kbset={8,9,10,11,12}, and said nset={2,3,4, 5}; kbset={8,9,10,11,12}, and the nset={2,3,4,5,6}; the kbset={8,9,10,11,12 }, and said nset={4,5,6,7}; said kbset={9,10,11,12}, and said nset={2,3,4,5}; said kbset= {9, 10, 11, 12}, and the nset = {3, 4, 5}; the kbset = {9, 10, 11, 12}, and the nset = {4, 5, 6}; The kbset={9,10,11,12}, and the nset={5,6,7}; the kbset={9,10,11,12}, and the nset={4,5 , 6,7}; the kbset={10,11,12}, and the nset={4,5,6,7}; the kbset={12,13,14,15,16}, and The nset={2,3,4,5}; the kbset={12,13,14,15,16}, and the nset={3,4,5,6}; kbset={12 , 13, 14, 15, 16}, and the nset = {4, 5, 6, 7}; the kbset = {12, 13, 14, 15, 16}, and the nset = {3, 4 , 5, 7}; the kbset = {13, 14, 15, 16}, and the nset = {3, 4, 5}; the kbset = {13, 14 , 15, 16}, and the nset={4, 5, 6}; the kbset={13, 14, 15, 16}, and the nset={2, 3, 4, 5}; Kbset={13,14,15,16}, and the nset={3,4,5,6}; the kbset={13,14,15,16}, and the nset={4,5 , 6, 7}; the kbset={13, 14, 15, 16}, and the nset={3, 4, 5, 7}; the kbset={14, 15, 16}, and the Nset={4,5,6,7}; the kbset={8,9,10,11,12,13,14,15,16}, and the nset={2,3}, the kbset = {20, 21, 22, 23, 24}, and the nset = {4, 5, 6, 7}; the kbset = {21, 22, 23, 24}, and the nset = {4, 5,6,7,8}.

Optionally, performing the foregoing LDPC encoding on the I by using the determined z and the foregoing Hb includes: adding x=kb2*z-k1 known bits to the k1 bit before or after the bit sequence I to be encoded, to obtain kb2* Z-bit bit sequence J. Where k1 is the length of the bit sequence I to be encoded, the spreading factor z=n*2i, n is a positive integer greater than 1, i is a non-negative integer less than 10, and the n is determined from the second set nset. Let kb=ceil(k1/z), where ceil() denotes an up-rounding operation, then kb has one of the following characteristics: if the nset={2,3}, then kb is kbset={8,9,10 An element of 11,12}; if the nset={2,3,4}, then kb is an element of kbset={8,9,10,11,12}; if the nset={2, 3,4}, then kb is an element of kbset={8,9,10,11,12}; if the nset={2,3,4,5}, then kb is kbset={8,9, An element of 10, 11, 12}; if the nset = {2, 3, 4, 5, 6}, then kb is an element of kbset = {8, 9, 10, 11, 12}; Nset={4,5,6,7}, then kb is an element of kbset={8,9,10,11,12}; if the nset={2,3,4,5}, then kb is Kbset={9,10,11,12} an element; if the nset={3,4,5}, then kb is an element of kbset={9,10,11,12}; if the nset ={4,5,6}, then kb is an element of kbset={9,10,11,12}; if the nset={5,6,7}, then kb is kbset={9,10, An element of 11,12}; if the nset={4,5,6,7}, then kb is an element of kbset={9,10,11,12}; if the nset={4,5 , 6,7}, then kb is an element of kbset={10,11,12}; if the nset={2,3, 4,5}, then kb is an element of kbset={12,13,14,15,16}; if the nset={3,4,5,6}, then kb is kbset={12,13, An element of 14,15,16}; if the nset={4,5,6,7}, then kb is an element of kbset={12, 13, 14, 15, 16}; if the nset= {3,4,5,7}, then kb is an element of kbset={12,13,14,15,16}; if the nset={3,4,5}, then kb is kbset={13 An element of 14,15,16}; if the nset={4,5,6}, then kb is an element of kbset={13,14,15,16}; if the nset={2, 3,4,5}, then kb is an element of kbset={13,14,15,16}; if the nset={3,4,5,6}, then kb is kbset={13,14, An element of 15,16}; if the nset={4,5,6,7}, then kb is an element of kbset={13,14,15,16}; if the nset={3,4 , 5,7}, then kb is an element of kbset={13,14,15,16}; if the nset={3,4,5}, then kb is kbset={14,15,16} An element; if the nset={4,5,6}, then kb is an element of kbset={14,15,16}; if the nset={2,3,4,5}, then kb is Kbset={14,15,16} an element; if the nset={3,4,5,6}, then kb is kbset={14,15, An element of 16}; if the nset={4,5,6,7}, then kb is an element of kbset={14,15,16}; if the nset={3,4,5,7 }, then kb is an element of kbset={14,15,16}; if the nset={2,3}, then kb is kbset={8,9,10,11,12,13,14,15 , an element of 16}; if the nset={4, 5, 6, 7}, then kb is an element of kbset={20, 21, 22, 23, 24}; if the nset={4, 5,6,7,8}, then kb is an element of kbset={21,22,23,24}. The obtained bit sequence J is subjected to low density parity check code LDPC encoding using the determined z and the Hb pair to obtain a coded sequence of nb*z bits.

Optionally, performing the LDPC encoding on the I by using the determined z and the Hb comprises: modifying a non-negative element s in the Hb by: for a preset threshold a, when z≥a when using the function f s of said first pair of Hb ₁ is corrected; when 0 <z <a, the use of the function f s of said second pair of Hb ₂ is corrected; wherein , f1 and f2 are at least the s, the function of z and the a, when z ≥ a, the modified non-negative element s' = f1 (s, z, a); when 0 < z < When a, the corrected non-negative element s'=f2(s, z, a).

Optionally, the f _{1 is} at least a maximum expansion factor z _max , the s, the function of the z and the a, when z≥a, the modified non-negative element s'=f ₁ (s, z, z _max , a).

Optionally, a=2 ^j , where j is a positive integer.

Optionally, the s comprises a binary representation of a sequence of bit lengths [s ₀ s ₁ s ₂ ... s _n-1 ] in binary, wherein s ₀ is the highest bit and s _n-1 is the lowest bit , the f ₁ represents the first r ₁ bit of the bit stream, f ₁ (s, z, z _max , a)=[s ₀ s ₁ s ₂ ... s _r1-1 ], wherein the r ₁ is an integer, and r ₁ = njt ₁ , where t ₁ is an integer, and 2 ^t1 ≤ z _max /z<2 ^t1+1 .

Optionally, the s comprises a binary representation of a sequence of bit lengths [s ₀ s ₁ s ₂ ... s _n-1 ] in binary, wherein s ₀ is the highest bit and s _n-1 is the lowest bit , the f ₂ represents truncating the first r ₂ bits in the last j bits of the bit stream, f ₂ (s, z, a)=[s _nj-1 s _nj s _n-j+1 ... s _{n- j+r2-2} ], the r ₂ is an integer, and r ₂ =jt ₂ , where t ₂ is an integer, and 2 ^t2 ≤ a/z<2 ^t2+1 .

Optionally, the first function f _{1 is} expressed as:

Where mod(x,y) represents x to y for remainder operations, and [·] means takes integer operations, including rounding up, rounding down, or rounding rounding.

Optionally, the first function f _{1 is} expressed as:

Among them, [·] means taking integer operations, including rounding up, rounding down, or rounding rounding.

Optionally, the second function f _{2 is} expressed as:

Where mod(x, y) represents x to y for remainder operations, and [·] means takes integer operations, including rounding up, rounding down, or rounding rounding.

According to another embodiment of the present application, there is also provided an apparatus for encoding a quasi-cyclic low-density parity check code, comprising: a determining module configured to determine a spreading factor z, and a basic check matrix Hb; and an encoding module configured to utilize Determining the z and the Hb to perform low density parity check code LDPC encoding on the encoded bit sequence I; wherein the Hb includes a block A corresponding to a mb row kb2 column of system bits and an mb corresponding to a parity bit The block B of the row mb column, kb2=nb-mb, kb2 is an integer greater than or equal to 4, and both mb and nb are integers.

Optionally, the encoding module includes: a determining unit, configured to determine a kb column from a kb2 column of the block A included by the Hb, where z=n*2 ⁱ , the kb is from the first set kbset Determining that the n is determined from the second set nset, the z, n, kb2, kb are all positive integers and kb is less than or equal to kb2, i is a non-negative integer; the coding unit is configured to utilize the determined The z and the Hb determining the kb column perform the LDPC encoding on the I.

Optionally, the kbset and the nset include one of: the kbset={8, 9, 10, 11, 12}, and the nset={2, 3}; the kbset={8, 9,10,11,12}, and said nset={2,3,4}; said kbset={8,9,10,11,12}, and said nset={2,3,4, 5}; kbset={8,9,10,11,12}, and the nset={2,3,4,5,6}; the kbset={8,9,10,11,12 }, and said nset={4,5,6,7}; said kbset={9,10,11,12}, and said nset={2,3,4,5}; said kbset= {9, 10, 11, 12}, and the nset = {3, 4, 5}; the kbset = {9, 10, 11, 12}, and the nset = {4, 5, 6}; The kbset={9,10,11,12}, and the nset={5,6,7}; the kbset={9,10,11,12}, and the nset={4,5 , 6,7}; the kbset={10,11,12}, and the nset={4,5,6,7}; the kbset={12,13,14,15,16}, and The nset={2,3,4,5}; the kbset={12,13,14,15,16}, and the nset={3,4,5,6}; the kbset={ 12, 13, 14, 15, 16}, and said nset = {4, 5, 6, 7}; said kbset = {12, 13, 14, 15, 16}, and said nset = {3, 4,5,7}; said kbset={13,14,15,16}, and said nset={3,4,5}; said kbset={13 , 14, 15, 16}, and the nset = {4, 5, 6}; the kbset = {13, 14, 15, 16}, and the nset = {2, 3, 4, 5}; The kbset={13, 14, 15, 16}, and the nset={3, 4, 5, 6}; the kbset={13, 14, 15, 16}, and the nset={4 , 5,6,7}; the kbset={13,14,15,16}, and the nset={3,4,5,7}; the kbset={14,15,16}, and The nset={4,5,6,7}; the kbset={8,9,10,11,12,13,14,15,16}, and the nset={2,3}, Kbset={20, 21, 22, 23, 24}, and the nset={4, 5, 6, 7}; the kbset={21, 22, 23, 24}, and the nset={ 4,5,6,7,8}.

Optionally, the encoding module includes: a modifying unit, configured to modify the non-negative element s in the Hb by: for a preset threshold a, when z≥a, adopting the first function f1 Correcting the s in the Hb; when 0 < z < a, correcting the s in the Hb by using a second function f2; wherein, both f1 and f2 are at least the s, The function of z and the a, when z≥a, the modified non-negative element s'=f1(s,z,a); when 0<z<a, the corrected non-negative element s'= F2(s,z,a).

According to still another embodiment of the present application, a storage medium is also provided. The storage medium is arranged to store program code for performing the above steps.

Through the present application, since the low-density parity check code LDPC encoding is performed according to the determined spreading factor z and the basic check matrix Hb, the bit sequence I to be encoded, the length of the bit sequence to be encoded using the structured LDPC encoding can be solved continuously. The problem of poor coding performance at the time of change achieves the effect of improving the performance of LDPC coding.

DRAWINGS

The drawings described herein are intended to provide a further understanding of the present application, and are intended to be a part of this application. In the drawing:

1 is a block diagram showing the hardware structure of a mobile terminal for encoding a quasi-cyclic low-density parity check code according to an embodiment of the present application;

2 is a flowchart of a method for encoding a quasi-cyclic low density parity check code according to an embodiment of the present application;

3 is a schematic diagram of a basic parity check matrix Hb used for encoding in the specific embodiment;

4 is a structural block diagram of an apparatus for encoding a quasi-cyclic low-density parity check code according to an embodiment of the present application;

5 is a structural block diagram (1) of an encoding module 44 of an encoding apparatus for a quasi-cyclic low-density parity check code according to an embodiment of the present application;

FIG. 6 is a structural block diagram (2) of an encoding module 44 of an encoding apparatus for a quasi-cyclic low-density parity check code according to an embodiment of the present application.

detailed description

The present application will be described in detail below with reference to the drawings in conjunction with the embodiments. It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict.

It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or order.

Embodiment 1:

The method embodiment provided in Embodiment 1 of the present application can be executed in a mobile terminal, a computer terminal or the like. Taking a mobile terminal as an example, FIG. 1 is a hardware structural block diagram of a mobile terminal of a quasi-cyclic low-density parity check code encoding method according to an embodiment of the present application. As shown in FIG. 1, mobile terminal 10 may include one or more (only one shown in FIG. 1) processor 102 (processor 102 may include, but is not limited to, a processing device such as a microprocessor MCU or a programmable logic device FPGA. A memory 104 for storing data, and a transmission device 106 for communication functions. It will be understood by those skilled in the art that the structure shown in FIG. 1 is merely illustrative and does not limit the structure of the above electronic device. For example, the mobile terminal 10 may also include more or fewer components than those shown in FIG. 1, or have a different configuration than that shown in FIG.

The memory 104 can be used to store software programs and modules of application software, such as program instructions/modules corresponding to the encoding method of the quasi-cyclic low-density parity check code in the embodiment of the present application, and the processor 102 runs the software stored in the memory 104. Programs and modules to perform various functional applications and data processing, that is, to implement the above methods. Memory 104 may include high speed random access memory, and may also include non-volatile memory such as one or more magnetic storage devices, flash memory, or other non-volatile solid state memory. In some examples, memory 104 may further include memory remotely located relative to processor 102, which may be connected to mobile terminal 10 over a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

Transmission device 106 is for receiving or transmitting data via a network. The network embodiment described above may include a wireless network provided by a communication provider of the mobile terminal 10. In one example, the transmission device 106 includes a Network Interface Controller (NIC) that can be connected to other network devices through a base station to communicate with the Internet. In one example, the transmission device 106 can be a Radio Frequency (RF) module for communicating with the Internet wirelessly.

In this embodiment, a code sending method is provided. FIG. 2 is a flowchart of a method for encoding a quasi-cyclic low density parity check code according to an embodiment of the present application. As shown in FIG. 2, the process includes the following steps. :

Step S202, determining an expansion factor z, and a basic check matrix Hb;

Step S204, performing low-density parity check code LDPC encoding on the to-be-coded bit sequence I using the determined z and the Hb; wherein the Hb includes a block A corresponding to a mb row kb2 column of system bits and a parity bit corresponding to the parity bit. Block B of the mb row mb column, that is, Hb=[A,B], kb2=nb-mb, kb2 is an integer greater than or equal to 4, nb is an integer, i=1, 2,..., mb, j=1 , 2,...nb.

Through the above steps, since the low-density parity check code LDPC encoding is performed according to the determined spreading factor z and the basic check matrix Hb; the bit sequence I to be encoded, the length of the bit sequence to be encoded using the structured LDPC encoding can be solved continuously. The problem of poor coding performance at the time of change achieves the effect of improving the performance of LDPC coding.

In an embodiment, the execution body of the foregoing steps may be a terminal (which may be an encoder or the like), but is not limited thereto.

In an optional embodiment, performing the foregoing LDPC encoding on the I by using the determined z and the Hb includes: determining a kb column from a kb2 column of the block A included by the Hb, where z=n*2 ⁱ , The above kb is determined from the first set kbset, and the above n is determined from the second set nset, wherein the z, n, kb2, and kb are positive integers and kb is less than or equal to kb2, and i is a non-negative integer; The above-described z and the above-described Hb determining the kb column are subjected to the above LDPC encoding.

In an optional embodiment, the above kbset and the above nset include one of the following: kbset={8, 9, 10, 11, 12}, and the above nset={2, 3}; the above kbset={8, 9,10,11,12}, and the above nset={2,3,4}; the above kbset={8,9,10,11,12}, and the above nset={2,3,4,5}; The above kbset={8,9,10,11,12}, and the above nset={2,3,4,5,6}; the above kbset={8,9,10,11,12}, and the above nset= {4,5,6,7}; the above kbset={9,10,11,12}, and the above nset={2,3,4,5}; the above kbset={9,10,11,12}, And the above nset={3,4,5}; the above kbset={9,10,11,12}, and the above nset={4,5,6}; the above kbset={9,10,11,12}, And the above nset={5,6,7}; the above kbset={9,10,11,12}, and the above nset={4,5,6,7}; the above kbset={10,11,12}, And the above nset={4,5,6,7}; the above kbset={12,13,14,15,16}, and the above nset={2,3,4,5}; the above kbset={12,13 , 14, 15, 16}, and the above nset={3,4,5,6}; kbset={12,13,14,15,16}, and the above nset={4,5,6,7} The above kbset={12,13,14,15,16}, and the above nset={3,4,5,7}; the above kbset={13,14,15,16}, and the above nset={3, 4,5} The above kbset={13,14,15,16}, and the above nset={4,5,6}; the above kbset={13,14,15,16}, and the above nset={2,3,4,5 }; above kbset={13,14,15,16}, and the above nset={3,4,5,6}; the above kbset={13,14,15,16}, and the above nset={4,5 ,6,7}; the above kbset={13,14,15,16}, and the above nset={3,4,5,7}; the above kbset={14,15,16}, and the above nset={4 , 5,6,7}; the above kbset={8,9,10,11,12,13,14,15,16}, and the above nset={2,3}, the kbset={20,21, 22, 23, 24}, and said nset = {4, 5, 6, 7}; said kbset = {21, 22, 23, 24}, and said nset = {4, 5, 6, 7, 8}. In this embodiment, the value of the above kbset and nset is a preferred value, and may be other values, and the value is not limited.

In an optional embodiment, performing the foregoing LDPC encoding on the I by using the determined z and the Hb includes: adding x=kb2*z-k1 known bits to k1 bits before the bit sequence I to be encoded or Thereafter, a bit sequence J of kb2*z bits is obtained. Where k1 is the length of the bit sequence I to be encoded, the spreading factor z=n*2i, n is a positive integer greater than 1, i is a non-negative integer less than 10, and the n is determined from the second set nset. Let kb=ceil(k1/z), where ceil() denotes an up-rounding operation, then kb has one of the following characteristics: if the nset={2,3}, then kb is kbset={8,9,10 An element of 11,12}; if the nset={2,3,4}, then kb is an element of kbset={8,9,10,11,12}; if the nset={2, 3,4}, then kb is an element of kbset={8,9,10,11,12}; if the nset={2,3,4,5}, then kb is kbset={8,9, An element of 10, 11, 12}; if the nset = {2, 3, 4, 5, 6}, then kb is an element of kbset = {8, 9, 10, 11, 12}; Nset={4,5,6,7}, then kb is an element of kbset={8,9,10,11,12}; if the nset={2,3,4,5}, then kb is Kbset={9,10,11,12} an element; if the nset={3,4,5}, then kb is an element of kbset={9,10,11,12}; if the nset ={4,5,6}, then kb is an element of kbset={9,10,11,12}; if the nset={5,6,7}, then kb is kbset={9,10, An element of 11,12}; if the nset={4,5,6,7}, then kb is an element of kbset={9,10,11,12}; if the nset={4,5 , 6,7}, then kb is an element of kbset={10,11,12}; if the nset={2,3, 4,5}, then kb is an element of kbset={12,13,14,15,16}; if the nset={3,4,5,6}, then kb is kbset={12,13, An element of 14,15,16}; if the nset={4,5,6,7}, then kb is an element of kbset={12, 13, 14, 15, 16}; if the nset= {3,4,5,7}, then kb is an element of kbset={12,13,14,15,16}; if the nset={3,4,5}, then kb is kbset={13 An element of 14,15,16}; if the nset={4,5,6}, then kb is an element of kbset={13,14,15,16}; if the nset={2, 3,4,5}, then kb is an element of kbset={13,14,15,16}; if the nset={3,4,5,6}, then kb is kbset={13,14, An element of 15,16}; if the nset={4,5,6,7}, then kb is an element of kbset={13,14,15,16}; if the nset={3,4 , 5,7}, then kb is an element of kbset={13,14,15,16}; if the nset={3,4,5}, then kb is kbset={14,15,16} An element; if the nset={4,5,6}, then kb is an element of kbset={14,15,16}; if the nset={2,3,4,5}, then kb is Kbset={14,15,16} an element; if the nset={3,4,5,6}, then kb is kbset={14,15, An element of 16}; if the nset={4,5,6,7}, then kb is an element of kbset={14,15,16}; if the nset={3,4,5,7 }, then kb is an element of kbset={14,15,16}; if the nset={2,3}, then kb is kbset={8,9,10,11,12,13,14,15 , an element of 16}; if the nset={4, 5, 6, 7}, then kb is an element of kbset={20, 21, 22, 23, 24}; if the nset={4, 5,6,7,8}, then kb is an element of kbset={21,22,23,24}. The obtained bit sequence J is subjected to low density parity check code LDPC encoding using the determined z and the Hb pair to obtain a coded sequence of nb*z bits.

In an optional embodiment, performing the foregoing LDPC encoding on the I by using the determined z and the Hb includes: modifying the non-negative element s in the Hb by: for a preset threshold a, when When z≥a, the s in the above Hb is corrected by using the first function f1; when 0<z<a, the s in the above Hb is corrected by using the second function f2; wherein, both f1 and f2 are at least Is the above s, the above z and the function of a above, when z≥a, the corrected non-negative element s'=f1(s,z,a); when 0<z<a, the corrected non-negative element s'=f2(s,z,a).

In an optional embodiment, the above f _{1 is} at least a maximum expansion factor z _max , the above s, the function of the above z and the above a, when z≥a, the modified non-negative element s'=f ₁ (s , z, z _max , a).

In an alternative embodiment, a = 2 ^j , where j is a positive integer.

In an alternative embodiment, the above s comprises a binary representation of a sequence of bit lengths [s ₀ s ₁ s ₂ ... s _n-1 ] in binary, where s ₀ is the highest bit, s _{n- 1} is the lowest bit, and f ₁ represents the first r ₁ bit of the bit stream, f ₁ (s, z, z _max , a)=[s ₀ s ₁ s ₂ ... s _r1-1 ], wherein r ₁ is an integer, and r ₁ =njt ₁ , where t ₁ is an integer, and 2 ^t1 ≤z _max /z<2 ^t1+1 .

In an alternative embodiment, the above s comprises a binary representation of a sequence of bit lengths [s ₀ s ₁ s ₂ ... s _n-1 ] in binary, where s ₀ is the highest bit, s _{n- 1} is the lowest bit, and f ₂ above represents the first r ₂ bits in the last j bits of the above bit stream, f ₂ (s, z, a)=[s _nj-1 s _nj s _n-j+1 ......s _N-j+r2-2 ], the above r ₂ is an integer, and r ₂ =jt ₂ , where t ₂ is an integer, and 2 ^t2 ≤ a/z<2 ^t2+1 .

In an alternative embodiment, the first function f _{1 is} expressed as:

Where mod(x, y) represents x to y for remainder operations, and [·] means takes integer operations, including rounding up, rounding down, or rounding rounding.

In an alternative embodiment, the first function f _{1 is} expressed as:

Among them, [·] means taking integer operations, including rounding up, rounding down, or rounding rounding.

In an alternative embodiment, the second function f _{2 is} expressed as:

Where mod(x, y) represents x to y for remainder operations, and [·] means takes integer operations, including rounding up, rounding down, or rounding rounding.

In an optional embodiment, the template matrix HBG of the basic matrix Hb is the same as the first template matrix H1BG:

The first template matrix includes t sub-matrices, ie

Wherein, H1BGsub1, H1BGsub2, ..., H1BGsubt are respectively the first, second, ..., tth sub-matrices of the first template matrix; each of the sub-matrices HBGsubi comprises consecutive rows of the first template matrix, A row corresponding to a sub-matrix having a small index value is located above a row corresponding to a sub-matrix having a large index value, wherein the number of rows of the i-th sub-matrix is R1subi, and 0<R1subi≤R1BG,i=1,2,..., t, where R1BG is the number of rows of the first template matrix H1BG; wherein t is a positive integer, and and t=2, or 3, or 4, or 5.

There is one second template matrix, wherein the second template matrix has the same number of rows and columns as the first template matrix; and

The second template matrix H ² _BG includes t sub-matrices, ie

Wherein, H2BGsub1, H2BGsub2, ..., H2BGsubt are respectively the first, second, ..., tth sub-matrices of the second template matrix, and each of the sub-matrices H2BGsubi comprises consecutive rows of the second template matrix, A row corresponding to a sub-matrix having a small index value is located above a row corresponding to a sub-matrix having a large index value, wherein the number of rows of the i-th sub-matrix is R2subi, and 1≤R2subi≤R2BG,i=1,2,...,t Where R2BG is the number of rows of the second template matrix H2BGi; where t is a positive integer and t=2, or 3, or 4, or 5.

The second template matrix is a template matrix as follows:

Where kb2=10; the range of the row index is the 0th row to the 41st row; the range of the column index is the 0th column to the 51st column.

In an optional embodiment, the following relationship exists between the first template matrix and the second template matrix:

The first sub-matrix H1BGsub1 of the first template matrix is identical to the first sub-matrix H2BGsub1 of the second template matrix, wherein the first sub-matrix is a sub-matrix composed of the first four rows.

In an optional embodiment, the jth submatrix H1BGsubj of the first template matrix is the same as the jth submatrix H2'BGsubj of the adjusted second template matrix; wherein j is a positive integer, and j =2, or 3.., or t.

The a plurality of "0" elements in the sub-matrix H2'BGsubj of the adjusted second template matrix are a "1" elements at corresponding positions in the sub-matrix H2BGsubj before adjustment; wherein a is a positive integer.

The set_a' of the positions of the a 0 elements in the jth submatrix H2'BGsubj of the adjusted second template matrix is the position of 13 1 elements in the second template matrix before the adjustment (row_p , col_p) a subset of the set set_a; wherein the position set set_a of the 13 1 elements in the second template matrix before adjustment is: {(4, 1), (8, 1), (10 , 1), (13, 1), (15, 11), (17, 11), (17, 12), (18, 12), (19, 0), (20, 1), (25, 1 ), (27,1), (38,7)}; where row_p and col_p represent row index and column index of the pth 1 element in the second template matrix before adjustment, and both row_p and col_p are non-negative integers , where a=1, or 2, or 3, or 4,..., or 13.

In an optional embodiment, the b "1" elements in the sub-matrix H2'BGsubj of the adjusted second template matrix are b "0"s at corresponding positions in the sub-matrix H2BGsubj before adjustment. Element; where b is a positive integer.

The set_b' of the positions of the b 1 elements in the jth submatrix H2'BGsubj of the adjusted second template matrix is the position of the 3 0 elements in the second template matrix before the adjustment (row_q, Col_q) is a subset of the set set_b; wherein the position set set_b of the three 0 elements in the second template matrix before adjustment is: {(25, 0), (21, 0), (38, 6)};

Where row_q and col_q represent the row index and the column index of the 0 element in the second template matrix before the adjustment. Where b=1, or 2, or 3.

In an optional embodiment, the g rows in the matrix consisting of the pre-kb2+w columns of the j-th sub-matrix H2'BGsubi of the adjusted second template matrix are before the j-submatrix H2BGsubi before the adjustment. The g rows in the matrix consisting of kb2+w columns are rearranged; wherein w and g are both non-negative integers, and w=0, or 1, or 2, or 3,..., or 10; g=2, or 3, or 4..., or 10.

The 31st row in the matrix consisting of the first 14 columns of the adjusted second template matrix is the 32nd row of the second template matrix before the adjustment; the matrix of the first 14 columns of the adjusted second template matrix is The 32rd line is the 31st line of the second template matrix before the adjustment.

The 33rd row in the matrix consisting of the first 14 columns of the adjusted second template matrix is the 34th row in the matrix consisting of the first 14 columns of the second template matrix before the adjustment; the adjusted second template The 34th line in the matrix consisting of the first 14 columns of the matrix is the 33rd line in the matrix consisting of the first 14 columns of the second template matrix before the adjustment.

The present application will be described in detail below in conjunction with specific embodiments.

Specific embodiment 1:

The specific embodiment provides a method for encoding a quasi-cyclic low-density parity check code of a low-density parity check code, which specifically includes the following steps:

Determining the basic parity check matrix Hb and the spreading factor z used for encoding, and performing low-density parity check code encoding on the bit sequence I to be encoded with length k1 bits by using the basic check matrix Hb and the spreading factor z; wherein the spreading factor z can Expressed as a product of a positive integer n and a power of 2, ie z=n*2 ⁱ , where the set of values of n is nbset, i is a non-negative integer; wherein the columns of the basic check matrix Hb are by the system The column part and the check column part are purchased, and the first kb2 column of the basic check matrix is a system column, wherein the number of system columns kb2=nb-mb, nb is the number of columns of the base matrix, and mb is the number of rows of the base matrix. And the system column can be shortened, that is, in the kb2 system columns of the basic check matrix, kb system columns can be used to encode the coded bit sequence, and kb ≤ kb2.

When the length k1 of the bit sequence I to be encoded is smaller than the size kcb of the coding block, at least kcb-k1 known bits need to be added to the bit sequence to be coded, and LDPC coding is performed on the sequence;

Kb takes a value in the set kbset; when the length k1 of the bit sequence I to be encoded is smaller than the size kcb of the coding block, at least kcb-k1 known bits need to be added to the coded bit sequence, and the sequence is LDPC-encoded;

The size of the coding block kcb=kb*z=kb*n*2 ⁱ ; and, when kb takes a value in the set kbset and when n takes a value in the set nset, at least the length k1 of the bit sequence to be encoded is added The ratio of kcb-k1 known bits to the coding block is smaller than a preset threshold T, that is, (kcb - k1) / kcb ≤ T; wherein, in one embodiment, the threshold T is a positive number not exceeding 0.1.

In one embodiment, the value set kbset of kb is {8, 9, 10, 11, 12}, and the set of values n of n is {2, 3, 4, 5, 6}; or, kbset is {12 , 13, 14, 15, 16}, and nset is {2, 3, 4, 5}; or, kbset is {8, 9, 10, 11, 12, 13, 14, 15, 16}, and nset is {2,3,4}.

The low density parity check code encoding for the coded bit sequence I includes:

When the length k1 of the bit sequence I to be encoded is smaller than kb2*z, 1=kb2*z-k1=kb2*n*2 ⁱ -k1 known bits are added to the bit sequence to be encoded, and treated with a preset basic matrix The coded bit sequence is encoded to obtain an output bit sequence of the LDPC encoder. Deleting p1 known bits in the output bit sequence to obtain an encoded bit sequence;

Alternatively, performing low density parity check code encoding on the coded bit sequence I further includes:

When the length k1 of the bit sequence I to be encoded is smaller than kcb=kb*z, the bit number I to be encoded is increased by p2=kb*z-k1=kb*n*2 ⁱ -k1 known bits; wherein kb=ceil(k1 /z); where ceil represents the rounding up operation.

After deleting the kb2-kb column from the preset basic check matrix, the remaining columns are used as the columns of the new basic check matrix, and the coded bit sequence is encoded by the new basic check matrix to obtain the LDPC code. The output bit sequence of the device. The p2 known bits in the output bit sequence are deleted to obtain an encoded bit sequence.

Specific embodiment 2:

The specific embodiment provides a method for encoding low-density parity check codes, and FIG. 3 is a schematic diagram of a basic check matrix Hb used for encoding in the specific embodiment, as shown in FIG. 3: the basic matrix is a mb=23 The basic matrix of row nb=35 columns, the number of system columns in the basic matrix kb2=nb-mb=12; that is, the first 12 columns of the basic matrix are system columns, and the system columns of the basic matrix can be shortened, and the shortest can be shortened to 8 columns. It still has better error correction performance. Therefore, in the first 12 columns of the matrix, the bit sequence I to be encoded can be encoded using the kb column therein; the shortened number of system columns kb is taken in the set kbset. Among them, kbset can be {8,9,10,11,12}.

Due to the nature of the structured LDPC code, the length of the bit sequence input to the encoder is some discrete value. In the present embodiment, these discrete values are referred to as the coding block size kcb. The size kcb of the coding block is related to the shortened number of system columns kb and the spreading factor, that is, kcb=kb*z; in this embodiment, since kb and z respectively have various possible values, there are also many kcbs. Possible values.

When the length k1 of the bit sequence I to be encoded is not equal to kcb, kcb-kb known bits need to be added to the bit sequence I to be encoded. If the number of known bits is too large, the performance of the coding is significantly deteriorated; The matrix can support the bit sequence to be encoded with any length k1, and the coding performance does not deteriorate significantly. The size of the spreading factor z must be reasonably selected so that the proportion of the padding bits kcb-k1 in the coding block is less than The set threshold T. Wherein, T may be a positive number not greater than 0.1, and may of course be other values, such as T being a positive number not greater than 0.2, and T being a positive number not greater than 0.15.

In one embodiment, the spreading factor z can be expressed as a product of a positive integer n and a power of 2, ie z=n*2 ⁱ , where i is a non-negative integer and the maximum value of 2 ⁱ is usually related to the maximum degree of parallelism, Usually limited by the hardware resources of the LDPC codec, assume 1 ≤ i ≤ 7. Another parameter n of the spreading factor z takes values in the set nset={2, 3, 4, 5, 6}, and the set nset and the set kbset together determine the set of encoding block sizes kcb of the underlying check matrix. Wherein, the set kcbset of kcb may be {32 36 40 44 48 54 60 64 66 72 80 88 90 96 100 108 110 120 128 132 144 160 176 180 192 200 216 220 240 256 264 288 320 352 360 384 400 432 440 480 512 528 576 640 704 720 768 800 864 880 960 1024 1056 1152 1280 1408 1440 1536 1600 1728 1760 1920 2048 2112 2304 2560 2816 2880 3072 3200 3456 3520 3840 4096 4224 4608 5120 5632 5760 6144 6400 6912 7040 7680 8448 9216}, of which 86 Elements.

For a bit sequence to be encoded of any length 32 ≤ k1 ≤ 9216, when k1 ≠ kcb, the known number of bits kcb-k1 to be filled does not exceed a preset threshold.

In this embodiment, it is assumed that the length of the bit sequence I to be encoded is k1=193 bits, which is larger than 193 bits, and kcb closest to 193 bits is kcb=200 bits. Add p2=kcb-k1=7 known bits to the coded bit sequence. At this time, kb=8, n=5, and the expansion factor z=n* ²ⁱ =5*22.

After deleting kb2-kb=4 columns from the preset basic check matrix, the remaining columns are used as the columns of the new basic check matrix, and the code base sequence to be coded is obtained by using the new basic check matrix. The output bit sequence of the LDPC encoder. The p2 = 7 known bits added before encoding are deleted in the output bit sequence to obtain the encoded bit sequence.

Specific Example 3:

The difference between the solution of the specific embodiment and the solution of the specific embodiment 2 is that the basic check matrix used in the coding in this embodiment is different from that of the specific embodiment 2. In the specific embodiment, the basic matrix is a mb=33. The basic matrix of row nb=49 columns, the number of system columns in the basic matrix kb2=nb-mb=16; that is, the first 16 columns of the basic matrix are system columns, and the system columns of the basic matrix can be shortened, and the shortest can be shortened to 12 columns. It still has better error correction performance. Therefore, in the first 16 columns of the matrix, the bit sequence I to be encoded can be encoded using the kb column therein; the shortened number of system columns kb is taken in the set kbset, and in this embodiment the kbset can be {12, 13 , 14, 15, 16}.

Another difference between this embodiment and the specific embodiment 2 is that the value set nset of another parameter n of the expansion factor z can be {2, 3, 4, 5}.

Specific Example 4:

The difference between the specific embodiment and the foregoing specific embodiment 2 or embodiment 3 is that, in the specific embodiment, when the length k1 of the bit sequence I to be encoded is smaller than kb2*z, p1=kb2* is added to the bit sequence to be encoded. Z-k1=kb2*n*2i-k1 known bits, and the encoded bit sequence is encoded using a preset base matrix to obtain an output bit sequence of the LDPC encoder. The p1 known bits in the output bit sequence are deleted to obtain an encoded bit sequence.

Specific embodiment 5:

The difference between the specific embodiment and the specific embodiment 1 to the specific embodiment 4 is that, in the specific embodiment, the non-negative elements in the basic check matrix need to be corrected, and the correction method is as follows:

For the preset threshold a, when the expansion factor z≥a, the non-negative element s in the basic check matrix is corrected by the first function f1; when the expansion factor 0<z<a, the second function f2 is adopted. Correcting the non-negative elements in the basic check matrix; where f1 and f2 are at least a function of the non-negative element s, the spreading factor z and the threshold a, ie when z≥a, s'=f1(s,z,a) When 0<z<a, s'=f2(s,z,a);

Specifically, the first function f ₁ can be expressed as:

The second function f ₂ can be expressed as: Where mod(x, y) represents the remainder operation of x versus y, which means taking integer operations, including rounding up, rounding down, or rounding rounding;

Specific Example 6:

The difference between the specific embodiment and the above specific embodiment 5 is that, in the specific embodiment, the first function f ₁ is also a function of the maximum expansion factor z _max , that is, when z≥a, s'=f ₁ (s, z,z _max ,a);

Specifically, the first function f ₁ can be expressed as:

Where [·] means taking integer operations, including rounding up, rounding down, or rounding rounding;

Specific embodiment 7

The difference between this embodiment and the foregoing specific embodiment 5 or embodiment 6 is that in the specific embodiment, a can be expressed as a power of 2, that is, a=2j, where j is a positive integer;

And, the non-negative element s can be expressed in binary as a string of bit streams of length n [s0s1s2...sn-1], where s0 is the highest bit, sn-1 is the lowest bit, and function f1 represents the pre-r1 of the intercepted bit stream Bit, ie f1(s,z,zmax,a)=[s0s1s2...sr1-1], where r1 is an integer and r1=nj-t1, where t1 is an integer and 2t1≤zmax/z<2t1 +1;

The second function f ₂ represents truncating the first r ₂ bits in the last j bits, ie f ₂ (s, z, a) = [s _nj-1 s _nj s _n-j+1 ... s _{n-j + r2 2} ], r ₂ is an integer, and r ₂ = jt ₂ , where t ₂ is an integer, and 2 ^t2 ≤ a/z < 2t ²⁺¹ .

In summary, the solution described in the above embodiments is applicable to a shortened structured LDPC, and the size of the expansion factor is reasonably determined by the shortening range of the system column kb, and is reasonably determined for the expansion factor of the form z=n*2i. The values of kb and n can make the size of the coding block have a good granularity, so as to reduce the number of padding bits, and ensure that the length of the bit sequence to be encoded changes by 1 bit granularity, the padding bit can be controlled in one Within the lower proportion, so as to ensure that the length of the bit sequence to be encoded changes continuously, it also has better coding performance.

Through the description of the above embodiments, those skilled in the art can clearly understand that the method according to the above embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, by hardware, but in many cases, the former is A better implementation. Based on such understanding, the technical solution of the present application, which is essential or contributes to the prior art, may be embodied in the form of a software product stored in a storage medium (such as ROM/RAM, disk, The optical disc includes a number of instructions for causing a terminal device (which may be a mobile phone, a computer, a server, or a network device, etc.) to perform the methods described in various embodiments of the present application.

In this embodiment, an apparatus for encoding a quasi-cyclic low-density parity check code is also provided, which is used to implement the above-mentioned embodiments and preferred embodiments, and has not been described again. As used below, the term "module" may implement a combination of software and/or hardware of a predetermined function. Although the apparatus described in the following embodiments is preferably implemented in software, hardware, or a combination of software and hardware, is also possible and contemplated.

4 is a structural block diagram of an apparatus for encoding a quasi-cyclic low-density parity check code according to an embodiment of the present application. As shown in FIG. 4, the apparatus includes: a determining module 42 and an encoding module 44. Description:

The determining module 42 is configured to determine the spreading factor z and the basic check matrix Hb; the encoding module 44 is coupled to the determining module 42 and configured to perform low density parity check using the determined z and the Hb to be encoded bit sequence I Code LDPC encoding; wherein, the above Hb includes a block A corresponding to a mb row kb2 column of a system bit and a block B corresponding to a mb row mb column of a parity bit, kb2=nb-mb, and kb2 is an integer greater than or equal to 4. , nb is an integer, i = 1, 2, ..., mb, j = 1, 2, ... nb.

In an optional embodiment, FIG. 5 is a structural block diagram (1) of an encoding module 44 of an encoding apparatus for a quasi-cyclic low-density parity check code according to an embodiment of the present application. As shown in FIG. 5, the encoding module 44 is shown in FIG. The method includes: a determining unit 52 and an encoding unit 54, and the encoding module 44 is described below:

The determining unit 52 is configured to determine a kb column from the kb2 column of the block A included in the above Hb, wherein z=n*2 ⁱ , the kb is determined from the first set kbset, and the n is from the second set nset It is determined that the above z, n, kb2, kb are all positive integers and kb is less than or equal to kb2, i is a non-negative integer; the encoding unit 54, connected to the determining unit 52, is configured to determine the z and the determined using the determined The above Hb of the above kb column performs the above LDPC encoding on the above I.

In an optional embodiment, the above kbset and the above nset include one of the following: kbset={8, 9, 10, 11, 12}, and the above nset={2, 3}; the above kbset={8, 9,10,11,12}, and the above nset={2,3,4}; the above kbset={8,9,10,11,12}, and the above nset={2,3,4,5}; The above kbset={8,9,10,11,12}, and the above nset={2,3,4,5,6}; the above kbset={8,9,10,11,12}, and the above nset= {4,5,6,7}; the above kbset={9,10,11,12}, and the above nset={2,3,4,5}; the above kbset={9,10,11,12}, And the above nset={3,4,5}; the above kbset={9,10,11,12}, and the above nset={4,5,6}; the above kbset={9,10,11,12}, And the above nset={5,6,7}; the above kbset={9,10,11,12}, and the above nset={4,5,6,7}; the above kbset={10,11,12}, And the above nset={4,5,6,7}; the above kbset={12,13,14,15,16}, and the above nset={2,3,4,5}; the above kbset={12,13 , 14, 15, 16}, and the above nset={3,4,5,6}; the above kbset={12,13,14,15,16}, and the above nset={4,5,6,7} The above kbset={12,13,14,15,16}, and the above nset={3,4,5,7}; the above kbset={13,14,15,16}, and the above nset={3, 4,5 }; above kbset={13,14,15,16}, and the above nset={4,5,6}; the above kbset={13,14,15,16}, and the above nset={2,3,4 , 5}; the above kbset={13, 14, 15, 16}, and the above nset={3, 4, 5, 6}; the above kbset={13, 14, 15, 16}, and the above nset={4 , 5,6,7}; the above kbset={13,14,15,16}, and the above nset={3,4,5,7}; the above kbset={14,15,16}, and the above nset= {4,5,6,7}; the above kbset={8,9,10,11,12,13,14,15,16}, and the above nset={2,3}.

In an optional embodiment, performing the foregoing LDPC encoding on the I by using the determined z and the Hb includes: adding x=kb2*z-k1 known bits to k1 bits before the bit sequence I to be encoded or Thereafter, a bit sequence J of kb2*z bits is obtained. Where k1 is the length of the bit sequence I to be encoded, the spreading factor z=n*2i, n is a positive integer greater than 1, i is a non-negative integer less than 10, and the n is determined from the second set nset. Let kb=ceil(k1/z), where ceil() denotes an up-rounding operation, then kb has one of the following characteristics: if the nset={2,3}, then kb is kbset={8,9,10 An element of 11,12}; if the nset={2,3,4}, then kb is an element of kbset={8,9,10,11,12}; if the nset={2, 3,4}, then kb is an element of kbset={8,9,10,11,12}; if the nset={2,3,4,5}, then kb is kbset={8,9, An element of 10, 11, 12}; if the nset = {2, 3, 4, 5, 6}, then kb is an element of kbset = {8, 9, 10, 11, 12}; Nset={4,5,6,7}, then kb is an element of kbset={8,9,10,11,12}; if the nset={2,3,4,5}, then kb is Kbset={9,10,11,12} an element; if the nset={3,4,5}, then kb is an element of kbset={9,10,11,12}; if the nset ={4,5,6}, then kb is an element of kbset={9,10,11,12}; if the nset={5,6,7}, then kb is kbset={9,10, An element of 11,12}; if the nset={4,5,6,7}, then kb is an element of kbset={9,10,11,12}; if the nset={4,5 , 6,7}, then kb is an element of kbset={10,11,12}; if the nset={2,3, 4,5}, then kb is an element of kbset={12,13,14,15,16}; if the nset={3,4,5,6}, then kb is kbset={12,13, An element of 14,15,16}; if the nset={4,5,6,7}, then kb is an element of kbset={12, 13, 14, 15, 16}; if the nset= {3,4,5,7}, then kb is an element of kbset={12,13,14,15,16}; if the nset={3,4,5}, then kb is kbset={13 An element of 14,15,16}; if the nset={4,5,6}, then kb is an element of kbset={13,14,15,16}; if the nset={2, 3,4,5}, then kb is an element of kbset={13,14,15,16}; if the nset={3,4,5,6}, then kb is kbset={13,14, An element of 15,16}; if the nset={4,5,6,7}, then kb is an element of kbset={13,14,15,16}; if the nset={3,4 , 5,7}, then kb is an element of kbset={13,14,15,16}; if the nset={3,4,5}, then kb is kbset={14,15,16} An element; if the nset={4,5,6}, then kb is an element of kbset={14,15,16}; if the nset={2,3,4,5}, then kb is Kbset={14,15,16} an element; if the nset={3,4,5,6}, then kb is kbset={14,15, An element of 16}; if the nset={4,5,6,7}, then kb is an element of kbset={14,15,16}; if the nset={3,4,5,7 }, then kb is an element of kbset={14,15,16}; if the nset={2,3}, then kb is kbset={8,9,10,11,12,13,14,15 , an element of 16}; if the nset={4, 5, 6, 7}, then kb is an element of kbset={20, 21, 22, 23, 24}; if the nset={4, 5,6,7,8}, then kb is an element of kbset={21,22,23,24}; the obtained bit sequence J is subjected to low density parity check code LDPC coding using the determined z and Hb, The encoded sequence of nb*z bits.

In an optional embodiment, FIG. 6 is a structural block diagram (2) of an encoding module 44 of an encoding apparatus for a quasi-cyclic low-density parity check code according to an embodiment of the present application. As shown in FIG. 6, the encoding module 44 is shown in FIG. Including: a correction unit 62, the encoding module 44 is described below:

The correcting unit 62 is configured to correct the non-negative element s in the above Hb by correcting the s in the Hb by using the first function f ₁ for a predetermined threshold a ; when 0 <z while <a, using a second function f ₂ in the above Hb correcting s; wherein, f ₁ and f ₂ s are the above-mentioned at least, a function of z and the above-described, when z≥a When the corrected non-negative element s'=f ₁ (s, z, a); when 0 < z < a, the corrected non-negative element s' = f ₂ (s, z, a).

In an optional embodiment, the above f _{1 is} at least a maximum expansion factor z _max , the above s, the function of the above z and the above a, when z≥a, the modified non-negative element s'=f ₁ (s , z, z _max , a).

In an alternative embodiment, a = 2 ^j , where j is a positive integer.

In an alternative embodiment, the above s comprises a binary representation of a sequence of bit lengths [s ₀ s ₁ s ₂ ... s _n-1 ] in binary, where s ₀ is the highest bit, s _{n- 1} is the lowest bit, and f ₁ represents the first r ₁ bit of the bit stream, f ₁ (s, z, z _max , a)=[s ₀ s ₁ s ₂ ... s _r1-1 ], wherein r ₁ is an integer, and r ₁ =njt ₁ , where t ₁ is an integer, and 2 ^t1 ≤z _max /z<2 ^t1+1 .

In an alternative embodiment, the above s comprises a binary representation of a sequence of bit lengths [s ₀ s ₁ s ₂ ... s _n-1 ] in binary, where s ₀ is the highest bit, s _{n- 1} is the lowest bit, and f ₂ above represents the first r ₂ bits in the last j bits of the above bit stream, f ₂ (s, z, a)=[s _nj-1 s _nj s _n-j+1 ......s _N-j+r2-2 ], the above r ₂ is an integer, and r ₂ =jt ₂ , where t ₂ is an integer, and 2 ^t2 ≤ a/z<2 ^t2+1 .

In an alternative embodiment, the first function f _{1 is} expressed as:

Where mod(x, y) represents x to y for remainder operations, and [·] means takes integer operations, including rounding up, rounding down, or rounding rounding.

In an alternative embodiment, the first function f _{1 is} expressed as:

Among them, [·] means taking integer operations, including rounding up, rounding down, or rounding rounding.

In an alternative embodiment, the second function f _{2 is} expressed as:

Where mod(x, y) represents x to y for remainder operations, and [·] means takes integer operations, including rounding up, rounding down, or rounding rounding.

According to still another embodiment of the present application, a storage medium is also provided. The storage medium is arranged to store program code for performing the above steps.

In summary, the above embodiment is applicable to a shortened structured LDPC, and the size of the expansion factor is reasonably determined by the shortening range of the system column kb. For the expansion factor of the form z=n*2 ⁱ , the kb and n are reasonably determined. The value can be such that the size of the coding block has a good granularity to reduce the number of padding bits, and the padding bit can be controlled at a lower ratio when the length of the bit sequence to be encoded changes by 1 bit granularity. Therefore, it is also ensured that the length of the bit sequence to be encoded continuously changes when it is continuously changed. Increasing the LDPC code adapts to different application scenarios, different data types, etc., and can improve the decoding performance of the LDPC code while improving flexibility.

Embodiments of the present application also provide a storage medium. In the present embodiment, the above storage medium may be arranged to store program code for performing the above steps.

In this embodiment, the storage medium may include, but is not limited to, a USB flash drive, a Read-Only Memory (ROM), a Random Access Memory (RAM), a mobile hard disk, and a removable hard disk. A variety of media that can store program code, such as a disk or an optical disk.

In the present embodiment, the processor executes the above steps in accordance with the program code already stored in the storage medium.

In an embodiment, the specific examples in this embodiment may refer to the examples described in the foregoing embodiments and the optional embodiments, and details are not described herein again.

Obviously, those skilled in the art should understand that the above modules or steps of the present application can be implemented by a general computing device, which can be concentrated on a single computing device or distributed in a network composed of multiple computing devices. In the above, they may be implemented by program code executable by the computing device, such that they may be stored in the storage device for execution by the computing device, and in some cases may be performed in a different order than that illustrated herein. Or the steps described, either separately as individual integrated circuit modules, or as a plurality of modules or steps in a single integrated circuit module. Thus, the application is not limited to any particular combination of hardware and software.

The above description is only the preferred embodiment of the present application, and is not intended to limit the present application, and various changes and modifications may be made to the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this application are intended to be included within the scope of the present application.

Industrial applicability

With the present application, since the low-density parity check code LDPC encoding is performed according to the determined spreading factor z and the basic check matrix Hb; the bit sequence I to be encoded, the length of the bit sequence to be encoded using the structured LDPC encoding can be solved continuously. The problem of poor coding performance at the time of change achieves the effect of improving the performance of LDPC coding.

Claims (23)

1. A coding method for a quasi-cyclic low-density parity check code, comprising:

   Determining the expansion factor z, and the basic check matrix Hb;

   Performing low density parity check code LDPC encoding using the determined z and the Hb to be coded bit sequence I;

   Wherein, the Hb includes a block A corresponding to a mb row kb2 column of a systematic bit and a block B corresponding to a mb row mb column of a parity bit, kb2=nb-mb, kb2 is an integer greater than or equal to 4, mb, Nb is an integer.
2. The method of claim 1 wherein said LDPC encoding said I with said determined z and said Hb comprises:

   Correcting the non-negative element s in the Hb by: for a predetermined threshold a, when z≥a, correcting the s in the Hb by using the first function f1; When z<a, the s in the Hb is corrected by using a second function f2; wherein, both f1 and f2 are at least the s, the function of the z and the a, when z≥a, The corrected non-negative element s'=f1(s,z,a); when 0<z<a, the corrected non-negative element s'=f2(s,z,a).
3. The method according to claim 2, wherein said f _{1 is} at least a maximum spreading factor z _max , said s, said z and a function of said a, when z ≥ a, the corrected non-negative element s '=f ₁ (s,z,z _max ,a).
4. The method according to claim 3, wherein said s comprises binary representation of a string of bit streams of length n [s0s1s2...sn-1], wherein s0 is the highest bit and sn-1 is the lowest bit. Said f ₁ denotes the first r ₁ bit of the bit stream, f ₁ (s, z, z _max , a)=[s ₀ s ₁ s ₂ ... s _r1-1 ], wherein the r ₁ Is an integer, and r ₁ =njt ₁ , where t ₁ is an integer and 2 ^t1 ≤z _max /z<2 ^t1+-1 .
5. The method according to claim 2, wherein said s comprises binary representation of a string of bit streams of length n [s ₀ s ₁ s ₂ ... s _n-1 ], wherein s ₀ is the highest bit, s _n-1 is the lowest bit, and f ₂ represents the first r ₂ bits in the last j bits of the bit stream, f ₂ (s, z, a) = [s _nj-1 s _nj s _{n-j +1} s s _n-j+r2-2 ], the r ₂ is an integer, and r ₂ =jt ₂ , where t ₂ is an integer, and 2 ^t2 ≤ a/z<2 ^t2+1 .
6. The method of claim 2 wherein said first function f _{1 is} expressed as:

   

   Where mod(x, y) represents x to y for remainder operations, and [·] means takes integer operations, including rounding up, rounding down, or rounding rounding.
7. The method of claim 3 wherein said first function f _{1 is} expressed as:

   

   Among them, [·] means taking integer operations, including rounding up, rounding down, or rounding rounding.
8. The method of claim 2 wherein said second function f _{2 is} expressed as:

   

   Where mod(x, y) represents x to y for remainder operations, and [·] means takes integer operations, including rounding up, rounding down, or rounding rounding.
9. The method of claim 1 wherein:

   The template matrix HBG of the basic matrix Hb is the same as the first template matrix H1BG:

   The first template matrix includes t sub-matrices, ie

   

   Wherein, H1BGsub1, H1BGsub2, ..., H1BGsubt are respectively the first, second, ..., tth sub-matrices of the first template matrix; each of the sub-matrices HBGsubi comprises consecutive rows of the first template matrix, A row corresponding to a sub-matrix having a small index value is located above a row corresponding to a sub-matrix having a large index value, wherein the number of rows of the i-th sub-matrix is R1subi, and 0<R1subi≤R1BG,i=1,2,..., t, where R1BG is the number of rows of the first template matrix H1BG; wherein t is a positive integer, and and t=2, or 3, or 4, or 5.
10. The method of claim 9 wherein:

    There is one second template matrix, wherein the second template matrix has the same number of rows and columns as the first template matrix; and

    The second template matrix H ² _BG includes t sub-matrices, ie

    

    Wherein, H2BGsub1, H2BGsub2, ..., H2BGsubt are respectively the first, second, ..., t-th sub-matrices of the second template matrix, and each of the sub-matrices H2BGsubi comprises consecutive rows of the second template matrix, A row corresponding to a sub-matrix having a small index value is located above a row corresponding to a sub-matrix having a large index value, wherein the number of rows of the i-th sub-matrix is R2subi, and 1≤R2subi≤R2BG,i=1,2,...,t Where R2BG is the number of rows of the second template matrix H2BGi; where t is a positive integer and t=2, or 3, or 4, or 5.
11. The method of claim 10 wherein said second template matrix is a template matrix as follows:

    

    Where kb2=10; the range of the row index is the 0th row to the 41st row; the range of the column index is the 0th column to the 51st column.
12. The method of claim 10 wherein:

    The following relationship exists between the first template matrix and the second template matrix:

    The first sub-matrix H1BGsub1 of the first template matrix is identical to the first sub-matrix H2BGsub1 of the second template matrix, wherein the first sub-matrix is a sub-matrix composed of the first four rows.
13. The method of claim 10 wherein:

    The jth submatrix H1BGsubj of the first template matrix is identical to the adjusted jth submatrix H2'BGsubj of the second template matrix; wherein j is a positive integer, and j=2, or 3.., or t.
14. The method of claim 13 wherein:

    The a plurality of "0" elements in the sub-matrix H2'BGsubj of the adjusted second template matrix are a "1" elements at corresponding positions in the sub-matrix H2BGsubj before adjustment; wherein a is a positive integer.
15. A method according to claim 11 or 14, wherein:

    The set_a' of the positions of the a 0 elements in the jth submatrix H2'BGsubj of the adjusted second template matrix is the position of 13 1 elements in the second template matrix before the adjustment (row_p , col_p) a subset of the set set_a; wherein the position set set_a of the 13 1 elements in the second template matrix before adjustment is: {(4, 1), (8, 1), (10 , 1), (13, 1), (15, 11), (17, 11), (17, 12), (18, 12), (19, 0), (20, 1), (25, 1 ), (27,1), (38,7)}; where row_p and col_p represent row index and column index of the pth 1 element in the second template matrix before adjustment, and both row_p and col_p are non-negative integers , where a=1, or 2, or 3, or 4,..., or 13.
16. The method of claim 13 wherein:

    The b "1" elements in the sub-matrix H2'BGsubj of the adjusted second template matrix are b "0" elements at corresponding positions in the sub-matrix H2BGsubj before adjustment; wherein b is a positive integer.
17. The method of claim 16 wherein:

    The set_b' of the positions of the b 1 elements in the jth submatrix H2'BGsubj of the adjusted second template matrix is the position of the 3 0 elements in the second template matrix before the adjustment (row_q, Col_q) is a subset of the set set_b; wherein the position set set_b of the three 0 elements in the second template matrix before adjustment is: {(25, 0), (21, 0), (38, 6)};

    Where row_q and col_q represent the row index and the column index of the 0 element in the second template matrix before the adjustment. Where b=1, or 2, or 3.
18. The method of claim 13 wherein:

    The g rows in the matrix consisting of the pre-kb2+w columns of the j-th sub-matrix H2'BGsubi of the adjusted second template matrix are in a matrix consisting of the pre-kb2+w columns of the j-th sub-matrix H2BGsubi before the adjustment The g rows are rearranged; wherein w and g are both non-negative integers, and w=0, or 1, or 2, or 3,..., or 10; g=2, or 3, or 4..., or 10.
19. The method of claim 18 wherein:

    The 31st row in the matrix consisting of the first 14 columns of the adjusted second template matrix is the 32nd row of the second template matrix before the adjustment; the matrix of the first 14 columns of the adjusted second template matrix is The 32rd line is the 31st line of the second template matrix before the adjustment.
20. The method of claim 18 wherein:

    The 33rd row in the matrix consisting of the first 14 columns of the adjusted second template matrix is the 34th row in the matrix consisting of the first 14 columns of the second template matrix before the adjustment; the adjusted second template The 34th line in the matrix consisting of the first 14 columns of the matrix is the 33rd line in the matrix consisting of the first 14 columns of the second template matrix before the adjustment.
21. A coding apparatus for a quasi-cyclic low-density parity check code, comprising:

    Determining a module configured to determine an expansion factor z, and a base check matrix Hb;

    An encoding module, configured to perform low density parity check code LDPC encoding by using the determined z and the Hb to be coded bit sequence I;

    Wherein, the Hb includes a block A corresponding to a mb row kb2 column of a systematic bit and a block B corresponding to a mb row mb column of a parity bit, kb2=nb-mb, kb2 is an integer greater than or equal to 4, mb, Nb is an integer.
22. The apparatus of claim 21 wherein said encoding module comprises:

    A correction unit configured to perform the following by way of non-negative elements of the Hb s correction: For a predetermined threshold value a, when z≥a when using the function f s of said first pair of _{Hb. 1} Performing a correction; when 0 < z < a, correcting the s in the Hb by using a second function f ₂ ; wherein both f1 and f2 are at least the s, the function of the z and the a When z≥a, the corrected non-negative element s'=f1(s,z,a); when 0<z<a, the corrected non-negative element s'=f2(s,z,a) .
23. A storage medium storing computer executable instructions configured to perform the encoding method of the quasi-cyclic low density parity check code of any one of claims 1-20.

Images