Long polar codes can achieve the capacity of arbitrary binary-input discrete
memoryless channels under a low complexity successive cancelation (SC) decoding
algorithm. But for polar codes with short and moderate code length, the
decoding performance of the SC decoding algorithm is inferior. The cyclic
redundancy check (CRC) aided successive cancelation list (SCL) decoding
algorithm has better error performance than the SC decoding algorithm for short
or moderate polar codes. However, the CRC aided SCL (CA-SCL) decoding algorithm
still suffer from long decoding latency. In this paper, a reduced latency list
decoding (RLLD) algorithm for polar codes is proposed. For the proposed RLLD
algorithm, all rate-0 nodes and part of rate-1 nodes are decoded instantly
without traversing the corresponding subtree. A list maximum-likelihood
decoding (LMLD) algorithm is proposed to decode the maximum likelihood (ML)
nodes and the remaining rate-1 nodes. Moreover, a simplified LMLD (SLMLD)
algorithm is also proposed to reduce the computational complexity of the LMLD
algorithm. Suppose a partial parallel list decoder architecture with list size
L=4 is used, for an (8192, 4096) polar code, the proposed RLLD algorithm can
reduce the number of decoding clock cycles and decoding latency by 6.97 and
6.77 times, respectively.Comment: 7 pages, accepted by 2014 IEEE International Workshop on Signal
Processing Systems (SiPS