  Polar codes are a class of capacity achieving error correcting codes that has
been recently selected for the next generation of wireless communication
standards (5G). Polar code decoding algorithms have evolved in various
directions, striking different balances between error-correction performance,
speed and complexity. Successive-cancellation list (SCL) and its incarnations
constitute a powerful, well-studied set of algorithms, in constant improvement.
At the same time, different implementation approaches provide a wide range of
area occupations and latency results. 5G puts a focus on improved
error-correction performance, high throughput and low power consumption: a
comprehensive study considering all these metrics is currently lacking in
literature. In this work, we evaluate SCL-based decoding algorithms in terms of
error-correction performance and compare them to low-density parity-check
(LDPC) codes. Moreover, we consider various decoder implementations, for both
polar and LDPC codes, and compare their area occupation and power and energy
consumption when targeting short code lengths and rates. Our work shows that
among SCL-based decoders, the partitioned SCL (PSCL) provides the lowest area
occupation and power consumption, whereas fast simplified SCL (Fast-SSCL)
yields the lowest energy consumption. Compared to LDPC decoder architectures,
different SCL implementations occupy up to 17.1x less area, dissipate up to
7.35x less power, and up to 26x less energy.
