# Outage Performance of Wireless Powered Decode-and-Forward Relaying Networks in Rician Fading
## 4 Simulation Results
### Simulation Results and Analysis  
Figure 3 shows system outage probability versus \(\rho\) with different \(P_{\text{sum}}\) under different two-hop distance. As shown in Figure 3, when \(\rho\) is around 0.4, the system outage probability is the lowest, i.e., the system outage performance is the best. When \(\rho\geq 0.9\), the probability of system interruption is 1, which means the system is in a paralyzed state at this time. When \(P_{\text{sum}}\) is fixed, the system outage probability decreases first and then increases with the \begin{table}
\begin{tabular}{c c c} \hline \hline
**Symbol** & **Meaning** & **Value** \\ \hline \(\eta\) & Energy conversion efficiency & 0.6 \\ \(\lambda\) & The mean of channel gain & 1 \\ \(m\) & Path loss coefficient & 2 \\ \(r_{\text{min}}\) & Minimum transmission rate & \(1\) bit/s/Hz \\  & required by system & \\ \(\rho\) & Time assignment factor & 0.4 \\ \(P_{\text{sum}}\) & Total transmission power of & 30 dBm \\ \(K\) & Rice factor & 3 \\ \(E_{\text{Q}}\) & Threshold of circuit energy & \(5\times 10^{-5}\) J \\ \(N_{\text{S}}\) & Number of source nodes & 2 \\  & antenna & \\ \(N_{0}\) & Noise power & \(-25\) dBm \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Parameters used in the simulation. increment of \(\rho\). Because when \(P_{\text{sum}}\) is relatively small, the relay node has less time to collect energy, and the probability that the energy collected by the relay reaches \(E_{\text{Q}}\) is also relatively small. In this case, the system outage probability is relatively high. With the increase of \(\rho\), the relay node has more time to collect energy, so the system outage probability decreases. When the \(\rho\) is relatively large, the relay node has more time to collect energy, and the time to transmit information is insufficient, resulting in a larger system outage probability. Besides, when \(\rho\) is fixed, the system outage probability decreases with the increment of \(P_{\text{sum}}\). Because the greater the value of \(P_{\text{sum}}\), the more energy the relay can collect, the higher the probability of reaching \(E_{\text{Q}}\), and the lower the system outage probability. Moreover, the greater the \(P_{\text{sum}}\), the greater the value of \(\rho\) when the system is paralyzed. Because the larger the \(P_{\text{sum}}\), the more likely it is to accurately transmit information within a unit time. In addition, the system outage performance with equal two-hop distance is slightly better than that with unequal two-hop distance. Last but not the least, the degree of matching between the discrete points and the solid line in the figure is relatively high, i.e., the degree of matching between the theoretical analysis and the Monte Carlo Simulation experiment is high, which proves the correctness of our theoretical analysis. Figure 4 shows system throughput versus \(\rho\) with different \(P_{\text{sum}}\) under different two-hop distance. It can be found that when \(P_{\text{sum}}\) is fixed, and with the increment of \(\rho\), the system throughput first increases, then decreases, and finally becomes 0. When \(\rho\) is fixed, the system throughput increases with the increment of \(P_{\text{sum}}\). As \(P_{\text{sum}}\) increases, \(\rho\) becomes smaller when throughput peaks occur. The reason may be that the larger the \(P_{\text{sum}}\), the shorter the time for the relay to collect enough energy, and the earlier the peak throughput occurs. Besides, when \(P_{\text{sum}}\) is small, the system throughput is higher when using the equal two-hop distance. When \(P_{\text{sum}}\) is relatively large, the throughput difference between the two distance cases is exceedingly small. Furthermore, the solid line in the figure matches the discrete points very well, which proves that the theoretical analysis is accurate. Figure 3: Outage probability versus the time assignment factor. Figure 5 shows system outage probability versus \(P_{\text{sum}}\) with different \(K\) under different two-hop distance.