  In this paper, we design and compare multilevel polar coding (MLPC) and
bit-interleaved polar coded modulation (BIPCM) for uplink sparse code multiple
access (SCMA) systems that operate over fast and block fading channels. Both
successive cancellation (SC) and successive cancellation list (SCL) decoding
algorithms are considered. Simulation results show that, with either decoder,
BIPCM performs better than its MLPC counterpart. Also, both BIPCM and MLPC
exhibit a performance advantage over LTE turbo-coded and WiMAX LDPC SCMA
systems when the SCL technique is used for decoding.
