Polar code rate matching method and apparatus for satellite communication and terrestrial communication
The present disclosure relates to polar code rate matching methods, apparatuses, and mediums. One example method includes obtaining K to-be-coded bits and a mother code length N, where N=2 n performing polar code encoding on the K to-be-coded bits based on the mother code length N to obtain an encoded bit sequence, performing rate matching on the polar-encoded bit sequence based on a rate matching sequence to obtain a rate matched sequence with a length of M, and outputting the rate matched sequence.
1 . A polar code encoding rate matching method, comprising:
obtaining K to-be-encoded bits, a target code length M, and a mother code length N, wherein N=2 n , and M, K, n, and N are positive integers;
performing polar code encoding on the K to-be-encoded bits based on the mother code length N to obtain an encoded bit sequence;
performing rate matching on the encoded bit sequence based on a rate matching sequence to obtain a rate matched sequence, wherein the rate matching sequence is a subsequence of a first sequence, the first sequence is a sequence 1, a sequence 2, or a sequence 3 in Appendix I, the sequence 1 comprises N 2 polarized sub-channel sequence numbers starting from 0, the sequence 2 comprises N 2 /2 polarized sub-channel sequence numbers starting from 0, the sequence 3 comprises N 2 different values, and N 2 is greater than or equal to N; and
outputting the rate matched sequence.
2 . The method according to claim 1 , wherein performing the polar code encoding on the K to-be-encoded bits based on the mother code length N comprises:
mapping the K to-be-encoded bits to K polarized sub-channels in M-P non-punctured polarized sub-channels, wherein reliability of the K polarized sub-channels on which the K to-be-encoded bits are located is higher than reliability of remaining M-P-K polarized sub-channels, wherein P represents a quantity of pre-frozen polarized sub-channels, and wherein P is greater than or equal to 0.
3 . The method according to claim 1 , wherein before performing the rate matching on the encoded bit sequence based on the rate matching sequence to obtain the rate matched sequence, interleaving is performed on the encoded bit sequence.
4 . The method according to claim 1 , wherein a rate matching manner is a puncturing operation, wherein:
if the first sequence is the sequence 1, the puncturing operation comprises taking, based on the target code length M, bits carried by sub-channels corresponding to last M polarized sub-channel sequence numbers in the rate matching sequence, or deleting, based on the target code length M, bits carried by sub-channels corresponding to first N-M polarized sub-channel sequence numbers in the rate matching sequence;
if the first sequence is the sequence 2, the puncturing operation comprises deleting, based on the target code length M, bits carried by sub-channels corresponding to first N-M polarized sub-channel sequence numbers in the rate matching sequence; or
if the first sequence is the sequence 3, the puncturing operation comprises deleting, based on the target code length M, bits carried by polarized sub-channels at which N-M smallest values in the rate matching sequence are located, or taking, based on the target code length M, bits carried by polarized sub-channels corresponding to M largest values in the rate matching sequence.
5 . The method according to claim 1 , wherein:
when N=8192, the rate matching sequence is a sequence 1a, a sequence 2a, or a sequence 3a;
when N=4096, the rate matching sequence is a sequence 1b, a sequence 2b, or a sequence 3b;
when N=2048, the rate matching sequence is a sequence 1c, a sequence 2c, or a sequence 3c;
when N=1024, the rate matching sequence is a sequence 1d, a sequence 2d, or a sequence 3d; or
when N=512, the rate matching sequence is a sequence 1e, a sequence 2e, or a sequence 3e, wherein:
the sequence 1a, the sequence 1b, the sequence 1c, the sequence 1d, and the sequence 1e are subsequences of the sequence 1;
the sequence 2a, the sequence 2b, the sequence 2c, the sequence 2d, and the sequence 2e are subsequences of the sequence 2; and
the sequence 3a, the sequence 3b, the sequence 3c, the sequence 3d, and the sequence 3e are subsequences of the sequence 3.
6 . The method according to claim 1 , wherein the K to-be-encoded bits comprise cyclic redundancy check bits.
7 . The method according to claim 1 , wherein the K to-be-encoded bits comprise parity check bits.
8 . A polar code rate dematching method, comprising:
obtaining a to-be-decoded information sequence of M bits, wherein the to-be-decoded information sequence comprises K to-be-decoded bits;
determining a mother code length N, wherein N=2 n , and M, K, n, and N are positive integers;
performing rate dematching and decoding on the to-be-decoded information sequence based on the mother code length N and a rate matching sequence to obtain a decoding result, wherein the rate matching sequence is a subsequence of a first sequence, the first sequence is a sequence 1, a sequence 2, or a sequence 3 in Appendix I, the sequence 1 comprises N 2 polarized sub-channel sequence numbers starting from 0, the sequence 2 comprises N 2 /2 polarized sub-channel sequence numbers starting from 0, the sequence 3 comprises N 2 different values, and N 2 is greater than or equal to N; and
outputting the decoding result.
9 . The method according to claim 8 , wherein a rate matching manner is a puncturing operation, wherein
if the first sequence is the sequence 1, the puncturing operation comprises taking, based on a target code length M, bits carried by sub-channels corresponding to last M polarized sub-channel sequence numbers in the rate matching sequence, or deleting, based on the target code length M, bits carried by sub-channels corresponding to first N-M polarized sub-channel sequence numbers in the rate matching sequence;
if the first sequence is the sequence 2, the puncturing operation comprises deleting, based on the target code length M, bits carried by sub-channels corresponding to first N-M polarized sub-channel sequence numbers in the rate matching sequence; or
if the first sequence is the sequence 3, the puncturing operation comprises deleting, based on the target code length M, bits carried by polarized sub-channels at which N-M smallest values in the rate matching sequence are located, or taking, based on the target code length M, bits carried by polarized sub-channels corresponding to M largest values in the rate matching sequence.
10 . The method according to claim 8 , wherein:
when N=8192, the rate matching sequence is a sequence 1a, a sequence 2a, or a sequence 3a;
when N=4096, the rate matching sequence is a sequence 1b, a sequence 2b, or a sequence 3b;
when N=2048, the rate matching sequence is a sequence 1c, a sequence 2c, or a sequence 3c;
when N=1024, the rate matching sequence is a sequence 1d, a sequence 2d, or a sequence 3d; or
when N=512, the rate matching sequence is a sequence 1e, a sequence 2e, or a sequence 3e, wherein:
the sequence 1a, the sequence 1b, the sequence 1c, the sequence 1d, and the sequence 1e are subsequences of the sequence 1;
the sequence 2a, the sequence 2b, the sequence 2c, the sequence 2d, and the sequence 2e are subsequences of the sequence 2; and
the sequence 3a, the sequence 3b, the sequence 3c, the sequence 3d, and the sequence 3e are subsequences of the sequence 3.
11 . The method according to claim 8 , wherein the K bits comprise cyclic redundancy check bits.
12 . The method according to claim 8 , wherein the K bits comprise parity check bits.
13 . A polar code rate matching apparatus, comprising:
at least one processor; and
one or more memories coupled to the at least one processor and storing programming instructions for execution by the at least one processor to:
obtain K to-be-encoded bits and a target code length M, wherein K is a positive integer;
determine a mother code length N, and perform polar code encoding on the K to-be-encoded bits based on the mother code length N to obtain an encoded bit sequence, wherein N=2 n , n is a positive integer, and K≤N; and
perform rate matching on the encoded bit sequence based on a rate matching sequence to obtain a rate matched bit sequence with a length of M, wherein the rate matching sequence is a subsequence of a first sequence, the first sequence is a sequence 1, a sequence 2, or a sequence 3 in Appendix I, the sequence 1 comprises N 2 polarized sub-channel sequence numbers starting from 0, the sequence 2 comprises N 2 /2 polarized sub-channel sequence numbers starting from 0, the sequence 3 comprises N 2 different values, and N 2 is greater than or equal to N.
14 . The apparatus according to claim 13 , wherein performing the polar code encoding on the K to-be-encoded bits based on the mother code length N comprises:
mapping the K to-be-encoded bits to K polarized sub-channels in M-P non-punctured polarized sub-channels, wherein reliability of the K polarized sub-channels on which the K to-be-encoded bits are located is higher than reliability of remaining M-P-K polarized sub-channels, wherein P represents a quantity of pre-frozen polarized sub-channels, and wherein P is greater than or equal to 0.
15 . The apparatus according to claim 13 , wherein before performing the rate matching on the encoded bit sequence based on the rate matching sequence to obtain the rate matched bit sequence with a length of M, interleaving is performed on the encoded bit sequence.
16 . The apparatus according to claim 13 , wherein a rate matching manner is a puncturing operation, wherein:
if the first sequence is the sequence 1, the puncturing operation comprises taking, based on the target code length M, bits carried by sub-channels corresponding to last M polarized sub-channel sequence numbers in the rate matching sequence, or deleting, based on the target code length M, bits carried by sub-channels corresponding to first N-M polarized sub-channel sequence numbers in the rate matching sequence;
if the first sequence is the sequence 2, the puncturing operation comprises deleting, based on the target code length M, bits carried by sub-channels corresponding to first N-M polarized sub-channel sequence numbers in the rate matching sequence; or
if the first sequence is the sequence 3, the puncturing operation comprises deleting, based on the target code length M, bits carried by polarized sub-channels at which N-M smallest values in the rate matching sequence are located, or taking, based on the target code length M, bits carried by polarized sub-channels corresponding to M largest values in the rate matching sequence.
17 . The apparatus according to claim 13 , wherein:
when N=8192, the rate matching sequence is a sequence 1a, a sequence 2a, or a sequence 3a;
when N=4096, the rate matching sequence is a sequence 1b, a sequence 2b, or a sequence 3b;
when N=2048, the rate matching sequence is a sequence 1c, a sequence 2c, or a sequence 3c;
when N=1024, the rate matching sequence is a sequence 1d, a sequence 2d, or a sequence 3d; or
when N=512, the rate matching sequence is a sequence 1e, a sequence 2e, or a sequence 3e, wherein:
the sequence 1a, the sequence 1b, the sequence 1c, the sequence 1d, and the sequence 1e are subsequences of the sequence 1;
the sequence 2a, the sequence 2b, the sequence 2c, the sequence 2d, and the sequence 2e are subsequences of the sequence 2; and
the sequence 3a, the sequence 3b, the sequence 3c, the sequence 3d, and the sequence 3e are subsequences of the sequence 3.