  This work analyzes the latency of the simplified successive cancellation
(SSC) decoding scheme for polar codes proposed by Alamdar-Yazdi and
Kschischang. It is shown that, unlike conventional successive cancellation
decoding, where latency is linear in the block length, the latency of SSC
decoding is sublinear. More specifically, the latency of SSC decoding is
$O(N^{1-1/\mu})$, where $N$ is the block length and $\mu$ is the scaling
exponent of the channel, which captures the speed of convergence of the rate to
capacity. Numerical results demonstrate the tightness of the bound and show
that most of the latency reduction arises from the parallel decoding of
subcodes of rate $0$ or $1$.
