Decoding apparatus and decoding method for decoding operation in channel coding

An apparatus for polar decoding, the apparatus being configurable to sequentially determine a series of source bits from a codeword encoded based on a polar code by comprising:

• a reliability calculator configured to calculate at least 2L reliability values from L bit sequences, where L is an integer greater than 0;
• a first processing circuit configured to sort the at least 2L reliability values and respectively generate first L new bit sequences with L upper reliability values;
• a second processing circuit configured to determine a source bit in each of the L bit sequences based on the at least 2L reliability values and generate second L new bit sequences;
• and
• a selection circuit configured to select one of the first processing circuit and the second processing circuit based on indices of source bits included in the series of source bits.

A polar decoding method by which a series of source bits is obtained from a codeword encoded based on a polar code, the method comprising:

• performing a first decoding operation in which source bits included in a first bit group are sequentially determined from the codeword based on a successive cancellation list (SCL) decoding scheme;
• and
• performing a second decoding operation in which source bits included in a second bit group are sequentially determined from the codeword based on a successive cancellation (SC) decoding scheme,
• wherein the first bit group comprises an initially determined source bit, and
• the second bit group comprises a finally determined source bit.