## 4 Numerical Results  
In this section, simulation results are provided to assess the performance of the proposed MISO-NOMA-CR aided by SWIPT with EH users, in comparison with an SDMA approach and with a scheme without AN. We used MATLAB software on a Core i7-6700K CPU with 16 GB of main memory to perform the simulations over several channel realizations. The simulation parameters listed in Table 2 were selected based on the work in [15; 41; 42]. More specifically, the transmission power of the SU-Tx is set to 30 dBm since it is a common value used in the literature for CR systems [30; 41]. In addition, the channel vectors parameters such as the channel gain and the Rician factor were set to \(10^{-3}\) and 5 dB, respectively, based on the work in [15]. The number of SUs and the value for the path-loss exponent are stablished according to the reference [42]. In the considered paper, we consider a quasi-static channel condition, which is usually assumed for indoor channels where the degree of time variation in the signal strength is small compared with the symbol duration. The channel model used in the simulations considers different distances from the SU-TX to the users, as well as different angle directions. The channel vectors were modeled based on an independent Rician fading, which is composed of a line-of-sight component and scattering components, and it is given as follows [15]:  
\[\mathbf{g}_{l}=\sqrt{L_{o}\left(d_{\text{SU}}^{-\alpha}\right)}\left(\sqrt{ \frac{K_{R}}{1+K_{R}}}\mathbf{g}_{l}^{LOS}+\sqrt{\frac{1}{1+K_{R}}}\mathbf{g }_{l}^{NLOS}\right), \tag{23}\] \begin{table}
\begin{tabular}{c c c} \hline \hline
**Parameter** & **Notation** & **Value** \\ \hline Number of SUs & \(L\) & 2 \\ Number of EH users & \(M\) & 2 \\ Number of PUs & \(K\) & 2 \\ Number of SU-Tx antennas & \(N\) & 8 \\ Maximum SU-Tx transmission power & \(\text{pmax}\) & 30 dBm \\ Channel gain & \(L_{o}\) & \(10^{-3}\) \\ Path-loss exponent & \(\alpha\) & 2 \\ Rician factor & \(K_{R}\) & 5 \\ Distance from the SU-Tx to the SU 1 & \(d_{\text{SU},1}\) & 10 \\ Distance from the SU-Tx to the SU 2 & \(d_{\text{SU},2}\) & 15 \\ Distance from the SU-Tx to the EH user 1 & \(d_{\text{EH},1}\) & 5 \\ Distance from the SU-Tx to the EH user 2 & \(d_{\text{EH},2}\) & 5 \\ Distance from the SU-Tx to the PU 1 & \(d_{\text{PU},1}\) & 20 \\ Distance from the SU-Tx to the PU 2 & \(d_{\text{PU},2}\) & 20 \\ Distance from the SU-Tx to the eavesdropper & \(d_{\text{PU}}\) & 13 \\ Direction from the SU-Tx to the SU 1 & \(\phi_{\text{SU},1}\) & \(30^{\circ}\) \\ Direction from the SU-Tx to the SU 2 & \(\phi_{\text{SU},2}\) & \(40^{\circ}\) \\ Direction from the SU-Tx to the EH user 1 & \(\phi_{\text{EH},1}\) & \(-15^{\circ}\) \\ Direction from the SU-Tx to the EH user 2 & \(\phi_{\text{EH},2}\) & \(-25^{\circ}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Simulation parameters. where \(\mathbf{g}_{l}^{NLOS}\) is the Rayleigh fading component, which follows a circularly symmetric complex Gaussian random variable with zero mean and unit variance, and \(\mathbf{g}_{l}^{LOS}\) is the line-of-sight component. The line-of-sight component is based on a uniform linear array from [16] with a wavelength equal to the double of the spacing between successive antenna elements, and it is given as follows:  
\[\mathbf{g}_{l}^{LOS}=\left[1\ e^{-j\pi\sin\left(\phi_{\text{SU},l}\right)}\ e^{-j2\pi\sin\left(\phi_{\text{SU},l}\right)}\...\ e^{-j(N-1)\pi\sin\left(\phi_{\text{SU},l}\right)}\right]^{T}, \tag{24}\]  
where \(\phi_{\text{SU},l}\) denotes the direction from the SU-Tx to the \(l\)-th SU, set at \(\phi_{\text{SU},1}\) and \(\phi_{\text{SU},2}\).