# A Novel Approach to Enhance the Energy Efficiency of a NOMA Network
## 1 Introduction  
Future 5G cellular mobile communication systems require further ultra-reliability, availability, low latency, and high throughput to fulfil the high projected requirements. Besides its expected enormous connectivity, the Internet of Things (IoT) is intended to support diverse employments for a wide range of devices and applications. Future 5G cellular mobile communication systems are poised to demand even greater levels of ultra-reliability, availability, low latency, and high throughput in order to meet the increasingly ambitious requirements. In addition to its anticipated extensive connectivity, the Internet of Things (IoT) is envisaged to facilitate a broad spectrum of applications catering to diverse needs across a wide array of domains For instance, crucial IoT applications such as digitalis health, smart cities, geological monitoring and control will impose considerable difficulties on spectrum use regarding energy consumption and low latency.  
For instance, critical IoT applications such as digital health, smart cities, and geological monitoring and control will present significant challenges in terms of spectrum utilization. In this regard, non-orthogonal multiple access (NOMA) is intended to accomplish the massive expansion of wireless data traffic, resolve the shortage of frequency resources for the next generation of wireless networks [1], and significantly enhance the spectral efficiency of 5G networks [2]. NOMA can be incorporated into various wireless communications techniques like Multiple-Input Multiple-Output (MIMO), beamforming, cooperative communications, and network coding [3, 4]. In [5], it was shown that NOMA enhances the IoT structure by utilizing several temporarily unused computational and storage resources by requesting cooperative caching and computing. Unlike Orthogonal Frequency DivisionMultiple Access (OFDMA), where each channel can largely be allocated to a single user, NOMA enables multiple user allocations per channel by implementing power-multiplexing and resolves multiple-access interference by applying successive interference cancellation (SIC) at the receivers [6]. However, SIC adds significant complexity to the NOMA structure [6]. In other words, NOMA enhances the spectral efficiency at the expense of a higher complexity compared to OFDMA [7].  
On the other hand, MIMO systems employ spatial multiplexing to increase data capacity by establishing multiple paths and effectively using them as additional \"channels\" to transfer data. By considering the advantages of MIMO, the implementation of NOMA within MIMO systems was considered in [8; 9]. As a related technology, it was shown in [10; 11] that the implementation of Full Duplex (FD) mode alongside NOMA brings a significant improvement to the performance compared to Half-Duplex (HD) NOMA. The authors of [12] illustrated that the FD-NOMA scheme can achieve tremendous throughput in a multi-cell system concerning user assistance and resource optimization. Based on the above, NOMA and FD systems can coexist cooperatively, and their integration has evolved progressively to enhance spectrum efficiency.