Rate matching and bit freezing for systematic polar codes

Abstract

Various aspects of the present disclosure generally relate to wireless communication. For example, when an output from a systematic polar encoder has a coded bit length N that differs from a target code length E, locations for bit freezing may be selected such that a resulting set of information bit locations (including cyclic redundancy code (CRC) bit locations) satisfy a systematic encoding condition. Furthermore, when the coded bit length N exceeds the target code length E, such that shortening or puncturing is performed to achieve the target code length, locations for shortening or puncturing may be selected to ensure that the set of information bit locations satisfy the systematic encoding condition. In this way, the systematic polar code may include a set of systematic bits at the same locations as the information bits, and the systematic bits do not appear in any untransmitted (for example, punctured or shortened) locations.