LLR-Based SC Decoding of Polar Codes for Two-User Binary-Input MAC

This letter considers a hardware-friendly log-likelihood ratio (LLR)-based successive cancellation (SC) decoding of polar codes for two-user binary-input multiple access channels. Based on the known recursive equations in the likelihood domain, we obtain LLR-based recursive equations for the SC decoding. An approximate LLR-based decoding is also introduced, which shows small performance loss at high error rate, but has significantly low complexity compared with the previous likelihood-based decoding.