  This paper presents non-binary polar codes for the two-user multiple-access
channel (MAC). The bit error rate (BER) performances of the non-binary polar
codes with different kernel factors have been investigated in detail to select
a proper parameter from GF(q) for the generator matrix. Furthermore, the
successive cancellation decoding for the non-binary polar codes in the two-user
MAC is introduced in detail. Simulation results show that the choice of the
kernel factors has a significant impact on the block error rate (BLER)
performance; moreover, the non-binary polar codes provide a better BLER
performance than their binary counterpart in the two-user MAC.
