List Estimation-aided Successive-Cancellation List Decoding of Polar Codes

List size determines the ability of successive-cancellation list (SCL) decoding algorithm assisted by the cyclic redundancy check (CRC) for polar codes. To decode a received codeword correctly with exactly matching a list size, a just right list size is required to be estimated. In this paper, based on the reliability degree of the codeword decoded by the successive-cancellation (SC) decoding, a list estimation method has been proposed for a poor case of channel environments, where the log-likelihood ratio (LLR) from SC decoding output is utilized to estimate a list size. The list estimation aids the polar code decoding and achieves admirable results in performance.