Abstract: The disclosure provides a method and a polar code decoder for determining a to-be-flipped bit position when performing a successive cancellation list flip operation. The method includes: obtaining a polar code decoding tree generated by performing a successive cancellation list (SCL) operation on a polar code segment, and the polar code segment includes multiple bit positions, and each bit position in the polar code decoding tree includes multiple surviving paths and multiple pruned paths; in a post-processing stage for the SCL operation, estimating a correct path probability of each of the surviving paths and the pruned paths of the i-th bit position and accordingly estimating a reliability for the i-th bit position; selecting a specific bit position among the bit positions based on the reliability of each bit position; and performing an SCL flip operation on the polar code decoding tree based on the specific bit position.

Abstract: A polar code decoding apparatus and an operation method thereof are provided. The polar code decoding apparatus includes a path expanding circuit and a node processing circuit. The path expanding circuit expands each of multiple previous paths corresponding to multiple previous decoding results into multiple candidate paths according to a current node. The path expanding circuit dynamically determines a path expanding number of the candidate paths of each of the previous paths according to an unreliable information bit number of the current node. The node processing circuit performs a path competition operation to select some paths from the candidate paths to serve as multiple current paths corresponding to multiple current decoding results.

Abstract: The disclosure provides a method and a polar code decoder for determining a to-be-flipped bit position when performing a successive cancellation list flip operation. The method includes: obtaining a polar code decoding tree generated by performing a successive cancellation list (SCL) operation on a polar code segment, and the polar code segment includes multiple bit positions, and each bit position in the polar code decoding tree includes multiple surviving paths and multiple pruned paths; in a post-processing stage for the SCL operation, estimating a correct path probability of each of the surviving paths and the pruned paths of the i-th bit position and accordingly estimating a reliability for the i-th bit position; selecting a specific bit position among the bit positions based on the reliability of each bit position; and performing an SCL flip operation on the polar code decoding tree based on the specific bit position.