A Fast Polar Code List Decoder Architecture Based on Sphere Decoding
Polar codes are a recently discovered family of capacity achieving error correcting codes. Among the proposed decoding algorithms, successive cancellation list decoding guarantees the best error correction performance with codes of moderate lengths, but it yields low throughput. Speed up techniques have been proposed in the past: most of them rely on approximations that degrade the error correction capability of the algorithm. We propose a speed up technique for successive cancellation list decoding of polar codes that is exact for list size of 2, while its approximations bring negligible error correction performance degradation ;0.05 dB) for other list sizes. A decoder architecture is designed: the proposed technique increases the throughput of a factor of 3.16x, at the cost of 14.2% in area occupation.
IEEE Transactions on Circuits and Systems I: Regular Papers