Low complexity rate matching for polar codes

Abstract

Aspects of the disclosure provide polar code rate matching methods. A first method can include determining whether to puncture or shorten a mother polar code according to a mother code rate and/or a rate matched code rate, and selecting K positions in the sequence of N input bits for input of K information bits to a polar encoder according to an offline prepared index list ordered according to the reliabilities of respective synthesized channels. Frozen input bits caused by puncturing or shortening are skipped during the selection. A second method includes generating a mother polar code, rearranging code bits of the mother polar code to form a rearranged sequence that can be stored in a circular buffer, and performing, in a unified way, one of puncturing, shortening, or repetition on the rearranged sequence to obtain a rate matched code.