## 7 Simulation Results
 } & \multicolumn{2}{c}{**EE (Bit/Sec/Watt)**} & \multicolumn{2}{c}{**Total Power Saving (Watt)**} & \multicolumn{2}{c}{**Sum Data Rate (Bit/Sec)**} \\ \cline{2-7}  & \multicolumn{1}{c}{**SD-**} & \multirow{2}{*}{**C-Scheme**} & \multicolumn{1}{c}{**SD-**} & \multirow{2}{*}{**C-Scheme**} & \multicolumn{1}{c}{**SD-**} & \multirow{2}{*}{**C-Scheme**} \\  & \multicolumn{1}{c}{**Scheme**} & & & & & \\ \hline
5 & 1.12 & 0.71 & 0.49 & 0.27 & \(1.3\times 10^{7}\) & \(2.0\times 10^{7}\) \\
10 & 2.06 & 0.95 & 0.91 & 0.49 & \(2.6\times 10^{7}\) & \(3.4\times 10^{7}\) \\
15 & 3.45 & 1.54 & 1.40 & 0.77 & \(3.8\times 10^{7}\) & \(4 Figure 7 shows the comparison of the outage probability with various numbers of D2D pairs. The outage probability of the SD-scheme increases in accordance with the number of D2D pairs because of the increased network interferences. Nonetheless, the suggested method and other channel-optimized algorithms reduce the probability of outages by ensuring the most efficient utilization of the resources in order to meet the minimal QoS demands for each D2D pair. By optimizing reused channels, the suggested system efficiently allows multiple D2D pairs using one particular CU's sub-channel. Despite the number of D2D pairs growing, this approach maintains low outage probability and reduced interference. Because of the unmanaged interferences of the resources that are shared among D2D pairs and between D2D pairs and CUs from the other side in benchmark methods, the outage probability significantly increases. The EE analysis for varying transmission power of CUs is illustrated in Figure 8. It is clear that there are slight decreases in EE with the incremental increase in CUs transmitting power due to high interference created by CUs and the higher transmission power of D2D pairs required to satisfy QoS demands. The EE of the suggested SD-scheme demonstrates  
Figure 6: SE versus the number of D2D pairs [17; 23; 24; 29; 30]. Figure 7: Outage probability versus the number of D2D pairs [17; 23; 24; 29; 30]. better performance in comparison to traditional schemes. The reason is that a lack of scalability and flexibility with a higher power level can be observed in traditional systems like [24; 30], which show better establishing EE but rapidly decrease as CU power rises. The suggested approach, on the other hand, demonstrates its better energy management and adaptation to varied network conditions by maintaining better EE despite changes in power levels. Figure 9 shows the sum data rate comparison of the suggested SD-scheme with traditional schemes versus the transmission power levels of CUs. The sum data rate demonstrates a slight decrease with the increase in CU transmission power. The first reason is due to the increased interference of D2D pairs that share the same spectrum of CUs. Secondly, the D2D pairs experience higher competition for limited resources in the network. The conventional approaches fail to efficiently allocate resources which results in low SINR and low sum data rate accordingly. Figure 8: EE versus transmission power of CUs [17; 23; 24; 29; 30]. Figure 9: Sum data rate versus transmission power of CUs [17; 23; 24; 29; 30]. Figure 10 demonstrates the total power saving of the proposed SD-scheme over varying transmission power levels of CUs. It is obvious that the total power saving remains stable up to 15 dBm, after that, the total power saving increases sharply due to several reasons. Firstly, the pairs can barely perform with the same power level without any requirement to enhance the transmission power strategies. Furthermore, the interference from CUs substantially affects the D2D links; consequently, the D2D pairs tend to overcome the interference threshold. As illustrated in Figure 10, the proposed SD-scheme outperforms the benchmark approaches.