Method and apparatus for processing information, communications device, and communications system
This application discloses a method and an apparatus for processing information, a communications device, and a communications system. The communications device is configured to obtain a starting position of an output bit sequence in a coded block in a circular buffer, and determine the output bit sequence in the coded block based on a length of the output bit sequence and the starting position. A value of the starting position is one of {p 0 , p 1 , p 2 . . . , p k max −1 }, where 0≤p k <N CB , P k is an integer, k is an integer, 0≤k<k max , N CB is a size of the coded block, and k max is an integer greater than or equal to 4.
1. A method for performing rate matching in a communications system, comprising:
obtaining, by a communication device, a size of a coded block N CB ;
obtaining, by the communication device, a starting position k 0 (i) of an output bit sequence in the coded block, wherein i is an integer greater than or equal to 0, a quantity of i indicates an i th transmission, a value of k 0 (i) is one of {p 0 , p 1 , p 2 , p 3 }, wherein p 0=0 , p 1 , p 2 , and p 3 are integers based on the size of the coded block N CB , wherein 0<p 1 <p 2 21 p 3 ≤N CB , and p 2 −p 1 <p 3 −p 2 ;
outputting, by the communication device, the output bit sequence, wherein the output bit sequence comprises a plurality of bits starting from the starting position k 0 (i) in the coded block, wherein the coded block is stored in a circular buffer;
generating, by the communication device, one or more modulation symbols based on the output bit sequence; and
transmitting, by the communication device, the one or more modulation symbols.
2. The method according to claim 1 , further comprising determining, by the communication device, a length of the output bit sequence that comprises the plurality of bits.
3. The method according to claim 1 , wherein, during initial transmission, the output bit sequence includes information bits and parity bits that correspond to weight-2 columns.
4. The method according to claim 1 , wherein the starting position k 0 (i) is determined based on a redundancy version number.
5. The method according to claim 4 , wherein the redundancy version number is obtained through signaling.
6. The method according to claim 4 , wherein the redundancy version number is obtained based on a sequence of redundancy version numbers and the quantity of i.
7. The method according to claim 6 , wherein the sequence of the redundancy version numbers is read from a memory, or the sequence of the redundancy version numbers is determined based on an initial transmission code rate.
8. An 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, the programming instructions instruct the at least one processor to:
obtain a starting position k 0 (i) of an output bit sequence in a coded block, wherein i is an integer greater than or equal to 0, a quantity of i indicates an i th transmission, a value of k 0 (i) is one of {p 0 , p 1 , p 2 , p 3 }, wherein 0≤p 0 <p 1 <p 2 <p 3 ≤N CB , N CB is a size of the coded block, and p 2 −p 1 <p 3 −p 2 ;
output the output bit sequence, wherein the output bit sequence comprises a plurality of bits starting from the starting position k 0 (i) in the coded block, wherein the coded block is stored in a circular buffer;
generate one or more modulation symbols based on the output bit sequence; and
transmit the one or more modulation symbols.
9. The apparatus according to claim 8 , wherein the programming instructions further instruct the at least one processor to determine a length of the output bit sequence that comprises the plurality of bits.
10. The apparatus according to claim 8 , wherein, during initial transmission, the output bit sequence includes information bits and parity bits that correspond to weight-2 columns.
11. The apparatus according to claim 8 , wherein the starting position k 0 (i) is determined based on a redundancy version number.
12. The apparatus according to claim 11 , wherein the redundancy version number is obtained through signaling.
13. The apparatus according to claim 11 , wherein the redundancy version number is obtained based on a sequence of redundancy version numbers and the quantity of i.
14. The apparatus according to claim 13 , wherein the sequence of the redundancy version numbers is read from a memory, or the sequence of the redundancy version numbers is determined based on an initial transmission code rate.