Method and device for polar code rate matching
Embodiments of the application provide a method and device for polar code rate matching in a wireless communication network. A device of the network receives a bit sequence of K information bits. The device polar codes the bit sequence to obtain N encoded bits. The device interleaves the encoded bits to obtain N interleaved bits and then stores the N interleaved bits into cyclic cache. The device sequentially outputs M bits of the N interleaved bits from the cyclic cache according to a rate matching manner, wherein the rate matching manner is one of shortening, puncturing or repetition. When the rate matching manner is puncturing, the (N−M+1) th bit to the N th bit of the interleaved bit sequence are output from the cyclic cache.
1. A method for use in a wireless communication network, comprising:
receiving, by a communication device, K information bits, wherein K is a positive integer;
polar encoding, by the communication device, the K information bits to obtain an encoded bit sequence, wherein the encoded bit sequence has a code length of N, and N is an integer power of 2;
interleaving, by the communication device, the encoded bit sequence, to obtain an interleaved bit sequence;
sequentially storing, by the communication device, the interleaved bit sequence into a cyclic cache of the communication device; and
sequentially outputting, by the communication device, M bits of the interleaved bit sequence from the cyclic cache according to one of rate matching manners, wherein M is a positive integer;
wherein the rate matching manners are shortening, puncturing and repetition; and
wherein when the rate matching manner is puncturing, an (N−M+1) th bit to an N th bit of the interleaved bit sequence are output from the cyclic cache.
2. The method according to claim 1 , wherein when the rate matching manner is shortening, a first bit to an M th bit of the interleaved bit sequence are output from the cyclic cache.
3. The method according to claim 1 , wherein when the rate matching manner is repetition, M bits of the interleaved bit sequence are output from the cyclic cache starting from any one bit of the interleaved bit sequence to the last bit of the interleaved bit sequence, and then from the first bit of the interleaved bit sequence, until all M bits are output.
4. The method according to claim 3 , wherein when the rate matching manner is repetition, a first bit of the M bits to be output is the first bit of the interleaved bit sequence stored in the cyclic cache.
5. The method according to claim 1 , wherein when the rate matching manner is puncturing or shortening, M<N; and when the rate matching manner is repetition, M>N.
6. The method according to claim 1 , wherein polar encoding the K information bits to obtain the encoded bit sequence comprises:
generating a binary row vector u 1 N , wherein u 1 N =(u 1 ,u 2 ,K,u N ), and K bit-positions of the binary row vector u 1 N are occupied by the K information bits; and
encoding the binary row vector u 1 N according an encoding formula, to obtain the encoded bit sequence;
wherein the encoding formula is:
x 1 N =u 1 N G N ,
wherein x 1 N =(x 1 , x 2 , . . . , x N ) is the encoded bit sequence, and G N is a polar code generating matrix of N row and N columns.
7. The method according to claim 1 , wherein M is a target code length of the output sequence determined by a bit rate according to:
M =INT( K/R );
wherein R is the bit rate, and INT( ) indicates rounding.
8. A device in a wireless communication network, comprising a processor, a cyclic cache, and a memory storing program instructions for execution by the processor; wherein when executed by the processor, the program instructions cause the device to:
receive K information bits, wherein K is a positive integer;
polar encode the K information bits to obtain an encoded bit sequence, wherein the encoded bit sequence has a code length of N, and N is an integer power of 2;
interleave the encoded bit sequence, to obtain an interleaved bit sequence;
sequentially store the interleaved bit sequence into the cyclic cache; and
sequentially output M bits of the interleaved bit sequence from the cyclic cache according to one of rate matching manners, wherein M is an integer;
wherein the rate matching manners are shortening, puncturing and repetition; and
wherein when the rate matching manner is puncturing, an (N−M+1) th bit to an N th bit of the interleaved bit sequence are output from the cyclic cache.
9. The device according to claim 8 , wherein when the rate matching manner is shortening, a first bit to an M th bit of the interleaved bit sequence are output from the cyclic cache.
10. The device according to claim 8 , wherein when the rate matching manner is repetition, M bits of the interleaved bit sequence are output from the cyclic cache starting from any one bit of the interleaved bit sequence to the last bit of the interleaved bit sequence, and then from the first bit of the interleaved bit sequence, until all M bits are output.
11. The device according to claim 10 , wherein when the rate matching manner is repetition, a first bit of the M bits to be output is the first bit of the interleaved bit sequence stored in the cyclic cache.
12. The device according to claim 8 , wherein when the rate matching manner is puncturing or shortening, M<N; and when the rate matching manner is repetition, M>N.
13. The device according to claim 8 , wherein in polar encoding the K information bits to obtain the encoded bit sequence, the program instructions cause the device to:
generate a binary row vector u 1 N , wherein u 1 N =(u 1 ,u 2 ,K,u N ), and K bit-positions of the binary row vector u 1 N are occupied by the K information bits; and
encode the binary row vector u 1 N according an encoding formula, to obtain the encoded bit sequence;
wherein the encoding formula is:
x 1 N =u 1 N G N ,
wherein x 1 N =(x 1 , x 2 , . . . , x N ) is the encoded bit sequence, and G N is a polar code generating matrix of N row and N columns.
14. The device according to claim 8 , wherein M is a target code length of the output sequence determined by a bit rate according to:
M =INT( K/R );
wherein R is the bit rate, and INT( ) indicates rounding.
15. A non-transitory computer readable medium storing program codes thereon for execution by a processor in a communication device, wherein the program codes comprise instructions for:
receiving K information bits, wherein K is a positive integer;
polar encoding the K information bits to obtain an encoded bit sequence, wherein the encoded bit sequence has a code length of N, and N is an integer power of 2;
interleaving the encoded bit sequence, to obtain an interleaved bit sequence;
sequentially storing the interleaved bit sequence into a cyclic cache of the communication device; and
sequentially outputting M bits of the interleaved bit sequence from the cyclic cache according to one of rate matching manners, wherein M is a positive integer;
wherein the rate matching manners are shortening, puncturing or repetition; and
wherein when the rate matching manner is puncturing, an (N−M+1) th bit to an N th bit of the interleaved bit sequence are output from the cyclic cache.
16. The non-transitory computer readable medium according to claim 15 , wherein when the rate matching manner is shortening, a first bit to an M th bit of the interleaved bit sequence are output from the cyclic cache.
17. The non-transitory computer readable medium according to claim 15 , wherein when the rate matching manner is repetition, M bits of the interleaved bit sequence are output from the cyclic cache starting from any one bit of the interleaved bit sequence to the last bit of the interleaved bit sequence, and then from the first bit of the interleaved bit sequence, until all M bits are output.
18. The non-transitory computer readable medium according to claim 17 , wherein when the rate matching manner is repetition, a first bit of the M bits to be output is the first bit of the interleaved bit sequence stored in the cyclic cache.
19. The non-transitory computer readable medium according to claim 15 , wherein when the rate matching manner is puncturing or shortening, M<N; and when the rate matching manner is repetition, M>N.
20. The non-transitory computer readable medium according to claim 15 , wherein polar encoding the K information bits to obtain the encoded bit sequence comprises:
generating a binary row vector u 1 N , wherein u 1 N =(u 1 ,u 2 ,K,u N ), and K bit-positions of the binary row vector u 1 N are occupied by the K information bits; and
encoding the binary row vector u 1 N according an encoding formula, to obtain the encoded bit sequence;
wherein the encoding formula is:
x 1 N =u 1 N G N ,
wherein u 1 N =(x 1 , x 2 , . . . , x N ) is the encoded bit sequence, and G N is a polar code generating matrix of N row and N columns.
21. The non-transitory computer readable medium according to claim 15 , wherein M is a target code length of the output sequence determined by a bit rate according to:
M =INT( K/R );
wherein R is the bit rate, and INT( ) indicates rounding.