# Cooperative SWIPT MIMO-NOMA for Reliable THz 6G Communications
## 3 Related Works  
Cooperative networking has been previously investigated utilizing a variety of cases and situations; the major benefits were clearly demonstrated while the drawbacks of adopting this strategy were addressed. Other technologies of this study, i.e., EH, NOMA, and THz, were discussed separately or in combination to attain a specific influence on the field. The drawbacks of employing those technologies were thoroughly explored, including the flaws, restrictions, and lack of performance. In [23, 24], despite the consideration of the IRS as an edge of technology to improve source to destination transmission in particular cases of interrupted communication path, it must outperform the usage of relaying regarding complexity, energy, and cost, as shown in Figure 2. Briefly, when comparing IRS to the older DF relay, the general impression of this work stated that a supreme data rate is necessary to outperform the DF relay regarding transmit power minimization and EE maximization. Furthermore, IRS requires additional hardware.  
[PERSON] et al. [14] discussed the difficulties in designing and deploying IRS to support 6G communication networks, i.e., aligning transmission beams for time-based steering, interference management, and EE degradation. The obstacles that IRS implementation faces include further required procedures, such as the impact of physical coverage area, equipment, system components, and additional maintenance/cost for wireless communications when deploying IRS. Atmospheric effects cause aggregate or proportional failures. IRS uniformity system implementation and interactivity with radio traffic are required for efficient signaling. However, the additional steps will complicate and exhaust network resources. Thus, despite using the promising IRS technology, the proposed system still faces difficulties and noticeable drawbacks.  
In [25], clustered, pre-coded, and power-allocated systems were all investigated. They developed an AI-based algorithm to present a clustering technique for THz MIMO-NOMA designs. This methodology comes at the cost of the required running time of the huge dataset, as well as the updated dataset acquisition needed. On the other hand, in [26],  
Figure 1: SWIPT with cooperative NOMA.  
Figure 2: Relay-based transmission strategy.  
a widely used spatially multiplexed was presented, while sub-THz was investigated to produce very high data rates and spectral efficiency. For data rate maximization, an investigation [27] was conducted for the power allocating issue in NOMA-based cooperative MIMO in HD and FD THz communications, which is still insufficient compared to the assumed targets of the proposed system in this paper.  
[PERSON] and [PERSON] studied in their recent work [28] the contribution of EH and other key enabling technologies to enhance system performance, considering a relatively similar concept with a simplified system of single-input single-output (SISO) scheme equipment. However, our previous papers [29, 30] investigated the impact of the multihoming principle on improving system reliability, operational efficiency, and the overall performance. The value of multihoming management was addressed to keep communication going for the multihomed user, in addition to presenting an interface selectivity technique.