  Polar codes are capacity achieving error correcting codes that can be decoded
through the successive-cancellation algorithm. To improve its error-correction
performance, a list-based version called successive-cancellation list (SCL) has
been proposed in the past, that however substantially increases the number of
time-steps in the decoding process. The simplified SCL (SSCL) decoding
algorithm exploits constituent codes within the polar code structure to greatly
reduce the required number of time-steps without introducing any
error-correction performance loss. In this paper, we propose a faster decoding
approach to decode one of these constituent codes, the Rate-1 node. We use this
Rate-1 node decoder to develop Fast-SSCL. We demonstrate that only a
list-size-bound number of bits needs to be estimated in Rate-1 nodes and
Fast-SSCL exactly matches the error-correction performance of SCL and SSCL.
This technique can potentially greatly reduce the total number of time-steps
needed for polar codes decoding: analysis on a set of case studies show that
Fast-SSCL has a number of time-steps requirement that is up to 66.6% lower than
SSCL and 88.1% lower than SCL.
