Gaussian Approximation Optimized SC- Flip Decoding Algorithm of Polar Codes

The polar codes proposed by Arikan is the first channel code proved to achieve the symmetric capacity of any binary input discrete memoryless channel (BDMC). Besides, the polar codes have been chosen for the eMBB control channels in the 5th generation mobile communication system. However, the successive cancellation flip (SCF) decoding algorithm of polar codes has a high average complexity at low SNR. To overcome the problem, the segmented SCF (SSCF) algorithm significantly has reduced the complexity of the SCF algorithm by using segmented cyclic redundancy check (CRC) bits. To further reduce the complexity, we have proposed a Gaussian approximation optimized SCF (G-SCF) decoding algorithm, which sets a threshold based on the Gaussian approximation algorithm to avoid unnecessary flip operations. Simulation results have shown that when the SNR is 1.5dB, the average complexity of the SSCF decoding algorithm is reduced by 14.4% compared with SSCF at (1024,512).