Conditions for Robustness of Polar Codes in the Presence of Channel Mismatch

A challenging problem related to the design of polar codes is "robustness against channel parameter variations" as stated in Ar{\i}kan's original work. In this paper, we describe how the problem of robust polar code design can be viewed as a mismatch decoding problem. We propose conditions which ensure a polar encoder/decoder designed for a mismatched B-DMC can be used to communicate reliably. In particular, the analysis shows that the original polar code construction method is robust over the class of binary symmetric channels.