Parallelism versus Latency in Simplified Successive-Cancellation Decoding of Polar Codes

12/24/2020 ∙ by Seyyed Ali Hashemi, et al. ∙ 0

This paper characterizes the latency of the simplified successive-cancellation (SSC) decoding scheme for polar codes under hardware resource constraints. In particular, when the number of processing elements P that can perform SSC decoding operations in parallel is limited, as is the case in practice, the latency of SSC decoding is O(N^1-1/μ+N/Plog_2log_2N/P), where N is the block length of the code and μ is the scaling exponent of the channel. Three direct consequences of this bound are presented. First, in a fully-parallel implementation where P=N/2, the latency of SSC decoding is O(N^1-1/μ), which is sublinear in the block length. This recovers a result from our earlier work. Second, in a fully-serial implementation where P=1, the latency of SSC decoding scales as O(Nlog_2log_2 N). The multiplicative constant is also calculated: we show that the latency of SSC decoding when P=1 is given by (2+o(1)) Nlog_2log_2 N. Third, in a semi-parallel implementation, the smallest P that gives the same latency as that of the fully-parallel implementation is P=N^1/μ. The tightness of our bound on SSC decoding latency and the applicability of the foregoing results is validated through extensive simulations.

READ FULL TEXT
POST COMMENT

Comments

There are no comments yet.

Authors

page 1

page 2

page 3

page 4

This week in AI

Get the week's most popular data science and artificial intelligence research sent straight to your inbox every Saturday.