FIELD

The present disclosure relates to the field of communication, and particularly to a polar code encoding method and device.

BACKGROUND

In a communication system, channel encoding is generally used to improve reliability of data transmission and ensure communication quality. A Polar code is a good code which can achieve Shannon capacity by theoretical proof and has a low encoding and decoding complexity. If the code length is short, the performance of conventional successive cancellation (abbreviated as SC) decoding is worse than performances of a low density parity check code (abbreviated as LDPC code) and a Turbo Code. In a case of decoding with list codes, the performance of the Polar code with medium code length is better than performances of the LDPC code or the Turbo Code.

The Polar code is a linear block code, and the generator matrix thereof is GN. The process of Polar code encoding is x1N=u1NGN, where x1Nis an output bit after encoding, u1Nis an input bit before encoding, GN=BNF⊗n. The code length N=2n, and n≥0. BNis a transposed matrix such as a bit reversal matrix. F⊗nis a Kronecker power (Kronecker power) of F, which is defined as F⊗n=F⊗F⊗n−1, where

F=[1011].

The Polar code may be represented as (N,K,A,uAc) with a coset code, and the encoding process is x1N=uAGN(A)⊕uAcGN(Ac) A is an information bit index set. GN(A) is a submatrix obtained from a row, which corresponds to the index in the set A, in GN. GN(Ac) is a submatrix obtained from a row, which corresponds to the index in the set Ac, in GN, uAcis Frozen bits the number of which is (N−K), with N being the code length and K being the length of information bits. For simplicity, the Frozen bit may be set to 0, and in this case, the above encoding process is briefly described as x1N=uAGN(A).

In the conventional technology, a Polar code with a code length being N and a code rate being R1is represented as (N,K1,A1), a second Polar code with a code length being N and a code rate being R2is represented as (N,K2,A2), and a Polar code with a code length being N and a code rate being R3is represented as (N,K3,A3). Polar codes with a same code length and different code rates are represented differently. For example, a first Polar code with the code length being 2048 and the number of information bits being 683 is represented as (2048, 683, A1), where A1is a subset including 683 elements of a set {0, 1, 2, . . . , 2047}. A second Polar code with the code length being 2048 and the number of information bits being 1024 is represented as (2048, 1024, A2), where A2is a subset including 1024 elements of the set {0, 1, 2, . . . , 2047}. A1and A2include a large number of same elements. However, in the conventional technology, the first Polar code and the second Polar code need to be represented by A1and A2respectively, which causes a high overhead for representing the Polar code conventionally.

SUMMARY

A method and an apparatus for Polar code encoding are provided according to embodiments of the disclosure, in which encoding is performed according to representation of Polar codes with a same code length and different code rates based on groups, and the overhead for representing the Polar codes is greatly reduced.

To achieve the above object, technical solutions adopted in the embodiments of the disclosure are as follows.

In a first aspect, a method for Polar code encoding is provided. The method includes:

representing each Polar code group in m Polar code groups by a common information bit set, where Polar codes in each Polar code group have a same code length and different code rates, and m is greater than or equal to 2;

obtaining an information bit set corresponding to each Polar code in the Polar code group based on the common information bit set corresponding to the Polar code group; and

performing Polar code encoding on information to be encoded based on the information bit set corresponding to each Polar code in the Polar code group.

In a first possible implementation of the first aspect, according to the first aspect, information bit sets respectively corresponding to all Polar codes with different code rates in each Polar code group include at least one same element.

In a second possible implementation of the first aspect, according to the first aspect or the first possible implementation of the first aspect, the common information bit set corresponding to the Polar code group is a union of information bit sets respectively corresponding to all Polar codes with different code rates in the Polar code group, or is an information bit set corresponding to a Polar code with any code rate in the Polar code group.

In a second aspect, a method for Polar code encoding is provided. The method includes:

representing each Polar code group in m Polar code groups by a common Frozen bit set, where Polar codes in each Polar code group have a same code length and different code rates, and m is greater than or equal to 2;

obtaining a Frozen bit set corresponding to each Polar code in the Polar code group based on the Frozen bit set corresponding to the Polar code group; and

performing Polar code encoding on information to be encoded based on the Frozen bit set corresponding to each Polar code in the Polar code group.

In a first possible implementation of the second aspect, in conjunction with the second aspect, Frozen bit sets respectively corresponding to all Polar codes with different code rates in each Polar code group include at least one same element.

In a second possible implementation of the second aspect, in conjunction with the second aspect or the first possible implementation of the second aspect, the common Frozen bit set corresponding to the Polar code group is a union of Frozen bit sets respectively corresponding to all Polar codes with different code rates in the Polar code group, or is a Frozen bit set corresponding to a Polar code with any code rate in the Polar code group.

In a third aspect, an apparatus for Polar code encoding is provided, which includes:

a representing unit configured to represent each Polar code group in m Polar code groups by a common information bit set, where Polar codes in each Polar code group have a same code length and different code rates, and m is greater than or equal to 2;

an obtaining unit configured to obtain an information bit set corresponding to each Polar code in the Polar code group based on the common information bit set corresponding to the Polar code group; and

an encoding unit configured to perform Polar code encoding on information to be encoded based on the information bit set corresponding to each Polar code in the Polar code group.

In a first possible implementation of the third aspect, in conjunction with the third aspect,

information bit sets respectively corresponding to all Polar codes with different code rates in each Polar code group include at least one same element.

In a second possible implementation of the third aspect, in conjunction with the third aspect or the first possible implementation of the third aspect, the common information bit set corresponding to the Polar code group is a union of information bit sets respectively corresponding to all Polar codes with different code rates in the Polar code group, or is an information bit set corresponding to a Polar code with any code rate in the Polar code group.

In a fourth aspect, an apparatus for Polar code encoding is provided, which includes:

a processor configured to represent each Polar code group in m Polar code groups by a common information bit set, where Polar codes in each Polar code group have a same code length and different code rates, and m is greater than or equal to 2;

obtain a Frozen bit set corresponding to each Polar code in the Polar code group based on the common information bit set corresponding to the Polar code group; and

perform Polar code encoding on information to be encoded based on the information bit set corresponding to each Polar code in the Polar code group.

In a first possible implementation of the fourth aspect, in conjunction with the fourth aspect,

information bit sets respectively corresponding to all Polar codes with different code rates in each Polar code group include at least one same element.

In a second possible implementation of the fourth aspect, in conjunction with the fourth aspect or the first possible implementation of the fourth aspect, the common information bit set corresponding to the Polar code group is a union of information bit sets respectively corresponding to all Polar codes with different code rates in the Polar code group, or is an information bit set corresponding to a Polar code with any code rate in the Polar code group.

In a fifth aspect, an apparatus for Polar code encoding is provided, which includes:

a representing unit configured to represent each Polar code group in m Polar code groups by a common Frozen bit set, where Polar codes in each Polar code group have a same code length and different code rates, and m is greater than or equal to 2;

an obtaining unit configured to obtain an information bit set corresponding to each Polar code in the Polar code group based on the Frozen bit set corresponding to the Polar code group; and

an encoding unit configured to perform Polar code encoding on information to be encoded based on the Frozen bit set corresponding to each Polar code in the Polar code group.

In a first possible implementation of the fifth aspect, in conjunction with the fifth aspect, Frozen bit sets respectively corresponding to all Polar codes with different code rates in each Polar code group include at least one same element.

In a second possible implementation of the fifth aspect, in conjunction with the fifth aspect or the first possible implementation of the fifth aspect, the common Frozen bit set corresponding to the Polar code group is a union of Frozen bit sets respectively corresponding to all Polar codes with different code rates in the Polar code group, or is a Frozen bit set corresponding to a Polar code with any code rate in the Polar code group.

In a sixth aspect, an apparatus for Polar code encoding is provided, which includes:

a processor configured to represent each Polar code group in m Polar code groups by a common Frozen bit set, where Polar codes in each Polar code group have a same code length and different code rates, and m is greater than or equal to 2;

obtain a Frozen bit set corresponding to each Polar code in the Polar code group based on the Frozen bit set corresponding to the Polar code group; and

perform Polar code encoding on information to be encoded based on the Frozen bit set corresponding to each Polar code in the Polar code group.

In a first possible implementation of the sixth aspect, in conjunction with the sixth aspect, Frozen bit sets respectively corresponding to all Polar codes with different code rates in each Polar code group include at least one same element.

In a second possible implementation of the sixth aspect, in conjunction with the sixth aspect or the first possible implementation of the sixth aspect, the common Frozen bit set corresponding to the Polar code group is a union of Frozen bit sets respectively corresponding to all Polar codes with different code rates in the Polar code group, or is a Frozen bit set corresponding to a Polar code with any code rate in the Polar code group.

In the methods and apparatuses for Polar code encoding according to the embodiments of the disclosure, each Polar code group in the m Polar code groups is represented by a common information bit set or a common Frozen bit set, where Polar codes in each Polar code group have a same code length and different code rates, and m is greater than or equal to 2; an information bit set or a Frozen bit set corresponding to each Polar code in the Polar code group is obtained based on the common information bit set or the common Frozen bit set corresponding to the Polar code group, and Polar code encoding is performed on information to be encoded based on the information bit set or the Frozen bit set corresponding to each Polar code in the Polar code group. In this way, encoding is performed according to representation of Polar codes with a same code length and different code rates based on groups, which greatly reduces the overhead for representing the Polar codes and addresses the problem of large overhead for representing the Polar codes in the conventional technology, compared with the case that each Polar code is represented by an independent information bit set or an independent Frozen bit set.

