A New Reduced-Latency SC Decoder for Polar Codes

Thanks to the property of provably capacity-achieving, the recently-discovered polar codes have been taken many attentions. However, the required long code length makes the decoding latency of the successive cancellation (SC) decoder high. This paper presents a new pre-computation look-ahead technique to reduce the decoding latency of SC. Its basic idea is to simultaneously estimate 2^ko transmitted bits at the cost of extra memory elements and process elements. Usually, the cost would snowball sharply as the increase of k₀. Fortunately, the characteristics of polar codes ensure that high performance can be achieved before the cost is too heavy. The theoretical analysis shows that the proposed scheme can achieve the advantages of 37.5% decoding latency and 2.6 times throughput over the state-of-the-art designs with a bit heavy cost.