Methods and apparatuses for constructing punctured polar code
Methods and apparatuses are provided for constructing a punctured polar code in the encoding and decoding field to improve decoding performance of a punctured polar code and reduce a frame error rate of the punctured polar code. The method is as follows: comparing a phase sequence number of a current bit channel with a period index of a puncturing pattern to obtain a comparison result; obtaining a transition probability of the bit channel according to the comparison result and bit parity conditions of a sequence number of the bit channel in each phase; obtaining a reliability value of each bit channel according to the transition probability; and determining an information bit index set according to the reliability values.
1. An apparatus for constructing a punctured polar code, comprising:
a processor and a memory storage accessible to the processor, wherein the processor is configured to:
compare a phase sequence number j of a current bit channel with a period index t of a puncturing pattern to obtain a comparison result, wherein the puncturing pattern is used to produce an input parameter of the polar code, and wherein j=imod 2 t , the puncturing pattern is periodic, the period is 2 t , and i∈{0, 1, . . . , 2 t −1};
obtain a transition probability of the bit channel if the comparison result is that the phase sequence number j is less than or equal to the period index t and a bit of a binary representation of the phase sequence number of the bit channel in each phase corresponds to 0;
obtain a reliability value of each bit channel according to the transition probability, wherein the reliability value comprises a Bhattacharyya parameter and an error probability; and
select the smaller one of the error probability and the Bhattacharyya parameter of each bit channel, sort the selected smaller ones in ascending order, and select sequence numbers of bit channels corresponding to the first K smaller ones to form an information bit index set, wherein K is a positive integer less than or equal to a total quantity of the bit channels.
2. A method comprising:
comparing a phase sequence number j of a current bit channel with a period index t of a puncturing pattern to obtain a comparison result, wherein the puncturing pattern is used to produce an input parameter of the polar code, and wherein j=imod 2 t , the puncturing pattern is periodic, the period is 2 t , and i∈{0, 1, . . . , 2 t −1};
obtaining a transition probability of the bit channel if the comparison result is that the phase sequence number j is less than or equal to the period index t and a bit of a binary representation of the phase sequence number of the bit channel in each phase corresponds to 0;
obtaining a reliability value of each bit channel according to the transition probability, wherein the reliability value comprises a Bhattacharyya parameter and an error probability; and
select the smaller one of the error probability and the Bhattacharyya parameter of each bit channel, sort the selected smaller ones in ascending order, and select sequence numbers of bit channels corresponding to the first K smaller ones to form an information bit index set, wherein K is a positive integer less than or equal to a total quantity of the bit channels.