Enhancing Non-Orthogonal Multiple Access with Practical Successive Interference Cancellation: A MIMO Approach with Interference-Predicted MMSE Techniques

In the realm of forthcoming wireless mobile networks, non-orthogonal multiple access, commonly referred to as NOMA, has been identified as a viable radio access technique. It employs successive interference cancellation (SIC) as the primary receiver mechanism and utilizes the power domain for user multiplexing on the transmitter side, anticipating advancements in mobile devices. Nonetheless, a substantial segment of the latest research endeavors to evaluate the effectiveness of NOMA on the assumption that the receiver has full SIC capability. This study examines the potential to reconcile the disparity between the theoretical and actual efficacy of successive interference cancellation (SIC) in non-orthogonal multiple access (NOMA) systems by employing multi-input multi-output (MIMO) technology with zero-forcing (ZF) and minimum mean square error (MMSE) SIC methodologies. This document presents the interference-predicted minimum mean square error (IPMMSE) interference cancellation (IC) method, which modifies the MMSE weight factor to accommodate interference signals. Furthermore, they provide a study of the error consequences linked to practical SIC designs. We propose the remaining interference-predicted MMSE (RIPMMSE) interference cancellation as a resolution to the issue of residual interference, based on this premise. On the other hand, the findings of the simulation show that the suggested IC schemes that forecast interference signals outperform NOMA with standard ZF and MMSE IC techniques. This is despite the fact that practical IC schemes produce a higher bit error rate (BER) in comparison to traditional orthogonal multiple access (OMA).