In this work, we propose adaptable decision regions in the successive interference cancellation (SIC) decoder for the three-user uplink/downlink non-orthogonal multiple access (NOMA) scheme by exploiting the knowledge of the channel gains. We present scenarios in which the modified SIC decoder outperforms the traditional one and is able to replicate the performance achieved by a deep learning-based decoder. We present analytical symbol error rate (SER) expressions for the three users, compare them to simulation results, and discuss possible consequences of our analysis, such as the optimal power allocation. We also employ heatmaps to analyze the joint influence on the SER of some system parameters, such as signal-to-noise ratio and channel gains.INDEX TERMS Non-orthogonal multiple access, successive interference cancellation, symbol error rate, decision regions.

The spin Hall angle ( θSH) is a measure of efficiency of the spin-to-charge conversion process. In this paper, we report that it is possible to control the θSH by engineering an array of Ag microdisks by direct write laser lithography in multilayers formed by Pt/Ag/Pt/Py (Ni20Fe80) grown on Si/SiO2 substrates. The investigation of the spin-to-charge conversion was made using spin pumping measurements, and it was shown that as the number of disks increases, the current generated by the spin pumping also increases. This result demonstrates that it is possible to tune the spin Hall angle by changing the number of the Ag microdisks while keeping their size and shape fixed.