Channel optimization and LLR approximation based SC of polar codes

We consider polar coded BPSK receiver performance improvement based on the concepts of channel log-likelihood ratio (LLR) approximation and the maximum achievable transmission rate on fading channel. Based on symmetry condition of random variables, uniform scaling factors are applied to correct soft messages at the absence of channel state information (CSI) at the receiver side. The searching method followed to find the required optimal factor stayed away from using exhaustive search methods. Simulation results demonstrate how information and bit error rates performances of the approximated model could approach true performances.