# Efficient Resource Management for Sum Capacity Maximization in 5G NOMA Systems
## 5 Results and Analysis  
This section presents our simulation results based on the provided schemes discussed in Sections 3 and 4. We evaluate the following NOMA schemes:  
* **Prop-Sch1:** It is the proposed power optimization technique as presented in Section 4. * **Sch2:** This is the solution for power allocation scheme presented in Reference [12]. According to this scheme, the minimum capacity of one user satisfies first and then allocate all the remaining power to another user. * **Prop1:** This denotes the user minimum capacity requirement based sub-channel assignment using proposed power allocation scheme. * **Prop2:** This is the user channel condition based sub-channel allocation using proposed power technique. * **Enh1 [12]:** This corresponds to the user minimum capacity requirement based sub-channel allocation using power optimization technique given in paper [12]. * **Enh2 [12]:** It is the user channel condition based sub-channel allocation using power optimization technique provided in Reference [12]. * **SProp:** This is the random sub-channel assignment using proposed power allocation scheme. * **SEnh [12]:** This denotes the random sub-channel assignment using power allocation scheme given in Reference [12]. In Figure 2, we plot the capacity of the Prob-Sch1 and Sch2 against the total power of BS. We show the individual capacity of \(CU_{i}\) and \(CU_{j}\) on \(SC_{m}\) as well as the sum capacity of both users over \(SC_{m}\) for both Prob-Sch1 and Sch2, respectively. As is expected, the sum capacity of Prop-Sch1 significantly outperforms the Sch2. More specifically, for fixed transmit power of BS, ie, 10, the sum capacity of the Prop-Sch1 is 6.7 bps/Hz while for the same value of transmit power, the sum capacity of the Sch2 is 5.8 bps/Hz. This is because the Prop-Sch1 is better than Sch2. Moreover, the gap between \(CU_{i}\) and \(CU_{j}\) using Prop-Sch1 is far less than the one in Sch2. It is because in the Prop-Sch1, we first satisfy the minimum capacity requirement of both users and then optimize the remaining power among \(CU_{i}\) and \(CU_{j}\). However, in Sch2, the minimum capacity requirement of one user is satisfied first and then allocate all the remaining power to the other user. Figure 3 depicts the sum capacity of different NOMA schemes versus total power of BS. We compare Prop1 with Enh1 [12], Prop2 with Enh2 [12] and Sprop with SEnh [12], respectively. We can see that our proposed techniques significantly outperforms the benchmark schemes. In addition, we can also observe that the schemes using Algorithm 2 for sub-channel assignment achieve high capacity from those using Algorithm 1. For instance, the capacity of Prop1 using Algorithm 2 is 4.1 bps/Hz when transmit power is 20, while it is 4 bps/Hz for Prop2 which using Algorithm 1. It shows that user minimum capacity requirement based sub-channel assignment as discussed in Algorithm 2 is more efficient than the user channel condition based sub-channel assignment presented in Algorithm 1. In Figure 4, we provide the capacity of Prop-Sch1 and Sch2 against the user minimum capacity requirement. Here we can observe that for increasing values of minimum capacity requirement, the Prop-Sch1 achieves high capacity compared to Sch2. Moreover, we can see that \(CU_{i}\) using Sch2 closely follows the minimum capacity requirement and also see the decrease in the capacity of \(CU_{j}\) for high values of minimum capacity. It is because the transmit power of \(CU_{j}\) may reduce when \(CU_{i}\) unable to achieve the minimum capacity with its available transmit power. However, the capacity of \(CU_{i}\) and \(CU_{j}\) using Prop-Sch1 remains unchanged for increasing values of user minimum capacity which shows the effectiveness of Prop-Sch1 over Sch2. In Figure 5, we plot the capacity for Prop-Sch1 and Sch2 by setting the minimum capacity of \(CU_{i}\) on \(SC_{m}\) as \(C_{in}^{\min}=1\) bps/Hz and increasing the capacity of other users. The results show that Prop-Sch1 achieves high sum capacity compared to the Sch2.