Polar code rate matching method and apparatus
The embodiments of the application provides a polar code rate matching method and apparatus. The method includes: obtaining, by a communications device, to-be-encoded information; determining, by the communications device, a to-be-used rate matching manner based on the code rate, a code rate threshold, a target code length, and a target code length threshold, where the rate matching manner is a puncturing manner or a shortening manner; and rate matching, by the communications device based on the determined rate matching manner, a polar code of the to-be-encoded information.
1. A rate matching method, comprising:
obtaining to-be-encoded information bits, wherein a quantity of to-be-encoded information bits is K and the K is positive integer;
polar encoding the to-be-encoded information bits to obtain encoded bits;
rate matching the encoded bits to obtain rate matched bits according to a rate matching manner determined based on a code rate R, a code rate threshold, a target code length, and a target code length threshold, wherein the rate matching manner is a puncturing manner or a shortening manner, wherein the R=K/M, wherein the M is the target code length, and the M is positive integer; and
outputting the rate matched bits.
2. The method according to claim 1 , further comprising:
if the M is less than a first code rate threshold and the R is less than or equal to the first code rate threshold, determining the rate matching manner to be the puncturing manner.
3. The method according to claim 1 , further comprising:
if the M is less than a first code rate threshold and the R is larger than a second code rate threshold, determining the rate matching manner to be the shortening manner.
4. The method according to claim 3 , wherein the first code rate threshold and the second code rate threshold are the same.
5. The method according to claim 2 , wherein rate matching the encoded bits comprises:
if the rate matching manner is the puncturing manner, puncturing the encoded bits from beginning of the encoded bits based on a quantity of to-be-punctured bits and at least one position of the to-be-punctured bits.
6. The method according to claim 3 , wherein rate matching the encoded bits comprises:
if the rate matching manner is the shortening manner, shortening the encoded bits from an end of the encoded bits based on a quantity of to-be-shortened bits and at least one position of the to-be-shortened bits.
7. A rate matching apparatus, comprising:
at least one processor; and
a non-transitory computer-readable storage medium coupled to the at least one processor and storing programming instructions for execution by the at least one processor, wherein the programming instructions instruct the at least one processor to:
obtain to-be-encoded information bits, wherein a quantity of to-be-encoded information bits is K and the K is positive integer;
polar encode the to-be-encoded information bits to obtain encoded bits;
rate match the encoded bits to obtain rate matched bits according to a rate matching manner determined based on a code rate R, a code rate threshold, a target code length, and a target code length threshold, wherein the rate matching manner is a puncturing manner or a shortening manner, wherein the R=K/M, wherein the M is a target code length, and the M is positive integer; and
output the rate matched bits.
8. The apparatus according to claim 7 , wherein the programming instructions instruct the at least one processor to determine the rate matching manner to be the puncturing manner if the M is less than a first code rate threshold and the R is less than or equal to the first code rate threshold.
9. The apparatus according to claim 7 , wherein the programming instructions instruct the at least one processor to determine the rate matching manner to be the shortening manner if the M is less than a first code rate threshold and R is larger than a second code rate threshold.
10. The apparatus according to claim 9 , wherein the first code rate threshold and the second code rate threshold are the same.
11. The apparatus according to claim 8 , wherein the programming instructions instruct the at least one processor to puncture the encoded bits from beginning of the encoded bits based on a quantity of to-be-punctured bits and at least one position of the to-be-punctured bits if the rate matching manner is puncturing manner.
12. The apparatus according to claim 9 , wherein the programming instructions instruct the at least one processor to shorten the encoded bits from an end of the encoded bits based on a quantity of to-be-shortened bits and at least one position of the to-be-shortened bits if the rate matching manner is shortening manner.
13. A non-transitory, computer-readable storage medium storing one or more instructions executable by an apparatus to perform operations comprising:
obtaining to-be-encoded information bits, wherein a quantity of to-be-encoded information bits is K and the K is positive integer;
polar encoding the to-be-encoded information bits to obtain encoded bits;
rate matching the encoded bits to obtain rate matched bits according to a rate matching manner determined based on a code rate R, a code rate threshold, a target code length, and a target code length threshold wherein the rate matching manner is a puncturing manner or a shortening manner, wherein the R=K/M, wherein the M is the target code length, and the M is positive integer; and
outputting the rate matched bits.
14. The non-transitory, computer-readable storage medium according to claim 13 , wherein the operations further comprise determining, the rate matching manner is the puncturing manner if the M is less than a first code rate threshold and R is less than or equal to the first code rate threshold.
15. The non-transitory, computer-readable storage medium according to claim 13 , wherein the operations further comprise determining the rate matching manner to be the shortening manner if the M is less than a first code rate threshold and the R is larger than a second code rate threshold.
16. The non-transitory, computer-readable storage medium according to claim 13 , wherein the code rate threshold comprises a first code rate threshold and a second code rate threshold, and the first code rate threshold and the second code rate threshold are the same.
17. The non-transitory, computer-readable storage medium according to claim 14 , wherein rate matching the encoded bits comprises puncturing the encoded bits from beginning of the encoded bits based on a quantity of to-be-punctured bits and at least one position of the to-be-punctured bits if the rate matching manner is the puncturing manner.
18. The non-transitory, computer-readable storage medium according to claim 15 , wherein rate matching the encoded bits comprises shortening the encoded bits from an end of the encoded bits based on a quantity of to-be-shortened bits and at least one position of the to-be-shortened bits if the rate matching manner is the shortening manner.
19. A program product, wherein the program product comprises execution instructions, the execution instructions are stored in a computer-readable storage medium, and the execution instructions cause a rate matching apparatus to perform operations comprising:
obtaining to-be-encoded information bits, wherein a quantity of to-be-encoded information bits is K and the K is positive integer;
polar encoding the to-be-encoded information bits to obtain encoded bits; and
rate matching the encoded bits according to a rate matching manner based on a code rate R, a code rate threshold, a target code length, and a target code length threshold wherein the rate matching manner is a puncturing manner or a shortening manner, wherein the R=K/M, wherein the M is the target code length, and the M is positive integer.
20. The method according to claim 1 , wherein rate matching the encoded bits comprises puncturing the encoded bits based on a quantity of to-be-punctured bits and preset puncturing locations.
21. The method according to claim 20 , wherein the quantity of to-be-punctured bits is P, and wherein the puncturing the encoded bits from beginning of the encoded bits based on the quantity of to-be-punctured bits and the preset puncturing locations comprises:
if the P≤N/4, wherein the N is a mother code length of the to-be-encoded information bits, the preset puncturing locations are first P bits, or
if the P>N/4, the preset puncturing locations are bits 1 to N/4 and a bit j, wherein j is determined according to the following formulas:
j=N/ 4, . . . , N/ 4+ (( P−N/ 4)/2) −1;
j=N/ 2, . . . , N/ 2+ (( P−N/ 4)/2) −1;
wherein the symbol indicates rounding up to the nearest integer, and the symbol indicates rounding down to the nearest integer.
22. The method according to claim 1 , wherein rate matching the encoded bits comprises shortening the encoded bits based on a quantity of to-be-shortened bits and preset shortening locations.
23. The apparatus according to claim 7 , wherein rate matching the encoded bits comprises puncturing the encoded bits based on a quantity of to-be-punctured bits and preset puncturing locations.
24. The apparatus according to claim 23 , wherein the quantity of to-be-punctured bits is P, and wherein the puncturing the encoded bits from beginning of the encoded bits based on the quantity of to-be-punctured bits and the preset puncturing locations comprises:
if the P≤N/4, wherein the N is a mother code length of the to-be-encoded information bits, the preset puncturing locations are first P bits, or
if the P>N/4, the preset puncturing locations are bits 1 to N/4 and a bit j, wherein j is determined according to the following formulas:
j=N/ 4, . . . , N/ 4+ (( P−N/ 4)/2) −1;
j=N/ 2, . . . , N/ 2+ (( P−N/ 4)/2) −1;
wherein the symbol indicates rounding up to the nearest integer, and the symbol indicates rounding down to the nearest integer.
25. The apparatus according to claim 7 , wherein rate matching the encoded bits comprises shortening the encoded bits based on a quantity of to-be-shortened bits and preset shortening locations.