Input-distribution-aware successive cancellation list decoding of polar codes

TL;DR

This paper introduces input-distribution-aware SCL decoding for polar codes, enabling dynamic adjustment of decoder parallelism at run-time to reduce complexity and power consumption without sacrificing error correction performance.

Contribution

It proposes a novel input-distribution-aware approach that dynamically determines decoder parallelism, allowing fixed latency and power savings during SCL decoding of polar codes.

Findings

Up to 50% reduction in run-time complexity.

Guarantees fixed, short latency for decoding.

Compatible with existing power reduction techniques.

Abstract

Polar codes are linear block codes that can achieve channel capacity at infinite code length. Successive cancellation list (SCL) decoding relies on a set of parallel decoders; it yields good error-correction performance at finite code length, at the cost of increased implementation complexity and power consumption. Current efforts in literature focus on design-time decoder complexity reduction, while lacking practical run-time power reduction methods. In this work, input-distribution-aware SCL (IDA-SCL) decoding is proposed, that allows to determine the parallelism to adopt by performing simple observations on the input of the decoder. This technique guarantees fixed, short latency and allows hardware SCL decoders to dynamically shut down part of the internal parallelism before each decoding process. It can be combined with existing complexity- and power- reduction techniques. Simulation results show that IDA-SCL can reduce the run-time complexity of SCL of up to 50\%.