A Novel Puncturing Scheme of Low Rate Polar Codes Based on Fixed Information Set

Puncturing is often used as a method of rate matching for polar codes with low code rates. Conventional puncturing algorithms focus more on selecting information set after determining a suitable puncturing pattern. However, in some practical systems, the information set should be unchanged. Thus, in this letter, we investigate the impact of the punctured positions on the fixed information set. Moreover, we propose an information set approximation puncturing (ISAP) algorithm, which sets a certain amount of guard bits before the known information bits and then calculates the required puncturing pattern according to the actual transmission block length. Our simulations demonstrate that the proposed ISAP algorithm is more stable and accurate than the conventional puncturing algorithms for low-code-rate polar codes. Especially, compared to the 3rd Generation Partnership Project (3GPP) rate matching scheme, the proposed ISAP algorithm gets about 0.18dB performance gain at a block error rate (BLER) of 10
^-3
with R = 1/3.