  CA-Polar codes have been selected for all control channel communications in
5G NR, but accurate, computationally feasible decoders are still subject to
development. Here we report the performance of a recently proposed class of
optimally precise Maximum Likelihood (ML) decoders, GRAND, that can be used
with any block-code. As published theoretical results indicate that GRAND is
computationally efficient for short-length, high-rate codes and 5G CA-Polar
codes are in that class, here we consider GRAND's utility for decoding them.
Simulation results indicate that decoding of 5G CA-Polar codes by GRAND, and a
simple soft detection variant, is a practical possibility.
