A CRC-aided Perturbed Decoding of Polar Codes

Abstract

We propose a CRC-aided perturbed decoding method for polar codes. Our technique is an iterative process that makes available multiple codeword candidates from a received signal. A CRC decoder is used to assess each decoded sequence. When a decoded sequence fails the CRC a random perturbation noise is added to the received signal, and then the perturbed signal is decoded again by a conventional decoder. This process continues until a valid codeword is found or the threshold for maximum iterations is attained. The simulation results indicate that the proposed scheme has a 0.4dB performance gain over existing schemes at the expense of a minimal increase in complexity. The proposed algorithm has the added advantage of being applicable to most concatenating decoding techniques.