Influences of Channel Estimation Error and Energy Scavenging Non-linearity on MIMO NOMA

Non-orthogonal multiple access (NOMA) significantly improves spectral efficiency by superposing multiple user signals for simultaneous transmission. Also, radio frequency energy sources surrounding transmitters should be exploited by realistic non-linear energy scavengers for meliorating energy efficiency for NOMA networks. Additionally, deployment of innumerable antennas at power sources and NOMA users enables efficient energy transfer-and-scavenging and improves the reliability of information transmission and reception using antenna array processing. In practical scenarios, obtaining perfect channel state information is challenging because of erroneous channel estimation. Therefore, the paper discusses the performance evaluation of NOMA networks considering various practical factors including non-linear energy scavenging (nlES), deployment of numerous antennas at power sources and NOMA users, and channel estimation error (CEE). Illustrative results expose that nlES and CEE considerably degrade system performance, which is governed flexibly by several parameters. Notably, NOMA networks can prevent a complete outage and achieve the best performance with a proper parameter selection. Moreover, their performance is considerably ameliorated with accreting the quantity of antennas. Further, the NOMA is drastically better than the OMA reference.