  Concatenating the state-of-the-art codes at moderate rates with repetition
codes has emerged as a practical solution deployed in various standards for
ultra-low-power devices such as in Internet-of-Things (IoT) networks. In this
paper, we propose a novel concatenation mechanism for such applications which
need to operate at very low signal-to-noise ratio (SNR) regime. In the proposed
scheme, the outer code is a hybrid polar code constructed in two stages, one
with a binary kernel and another also with a binary kernel but applied over a
binary extension field. The inner code is a non-binary multiplicative
repetition code. This particular structure inherits low-complexity decoding
structures of polar codes while enabling concatenation with an inner non-binary
multiplicative repetition scheme. The decoding for the proposed scheme is done
using cyclic redundancy check (CRC) aided successive cancellation list (SCL)
decoder over AWGN channel. Simulation results demonstrate that the proposed
hybrid non-binary repeated polar code provides performance gain compared to a
polar-repetition scheme with comparable decoding complexity.
