Design of I-Polar Codes

Recently, a new family of polar codes, termed interleaved polar (i-polar) codes, was proposed. It has been shown that both i-polar codes and polar codes of the same block length generate the same synthesized channels. Therefore, conventional bit channel selection algorithms designed for polar codes can be employed for i-polar codes. However, since most of the bit channel selection algorithms are optimized under successive cancellation (SC) decoding, i-polar codes as well as polar codes are still weak at short to moderate block lengths even under ML decoding. In this letter, we propose a new bit channel selection algorithm for i-polar codes which generates a sequence termed the i-polar sequence (IPS). The IPS can be used to specify the unfrozen bit sets for any code rates. Simulation results show that stand-alone i-polar codes with IPS under SCL decoding outperform the state-of-the-art 5G LDPC codes and 5G polar codes. Also, the performance levels of stand-alone polar codes with IPS are comparable to those of the 5G LDPC codes.