## 5 Numerical Results
Beginning from K \(<\) 50, the SNR of the 1D-SWZCC code decreases rapidly; meanwhile, the SNR of the 2D-SWZCC code keeps outperforming the SNRs of the other codes until K \(\geq\) 200, where its values become less than the SNR of the 3D-DCS/MD code. Overall, the SNRs of the 3D codes PD, PD/MD, and DCS/MD are almost close, and the differences between them can be described by a constant along with the studied number of users. Finally, both 3D ZCC codes, SWZCC and MD, produce greater SNRs compared to other codes, but the dominant code is always our proposed code. This can be seen from the \begin{table}
\begin{tabular}{c c c} \hline \hline
**Parameter** & **Symbol** & **Value** \\ \hline PD sensitivity & \(\Re\) & 0.75 \\ Optical bandwidth & \(\Delta f\) & 5 THz \\ \hline Effective source power & \(P_{r}\) & \(-10\) dBm \\ \hline Load resistor at receiver & \(R_{L}\) & 1030 \(\Omega\) \\ \hline Receiver noise temperature & \(T_{n}\) & 300 K \\ \hline Electron charge & \(e\) & \(1.6\times 10^{-19}\) c \\ \hline Boltzmann constant & \(K_{b}\) & \(1.38\times 10^{-23}\) J\(\cdot\)K\({}^{-1}\) \\ \hline Data rate & \(R_{b}\) & 1 Gbps \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Parameters Used for Numerical Analysis. SNR values at K = 150, which were 30.79, 1.63.2, 1191, 99.97, 141.1, 136.9, and 773 for the 1D, 2D, and 3D SWZCC codes and the PD, PD/MD, DCS/MD, and PTZCC codes, respectively. Figure 6 shows the BER alteration as a function of the data rate for 200 active users. As discussed, the system attained the required BER for optical communication networks: BERs of 4.8, 3, 0.72, 0.56, and 0.51 Gbps were obtained for the 3D codes SWZCC, PTZCC, DCS/MD, PD/MD, and PD, respectively. Consequently, employing our proposed code in an OCDMA system can supply a great data rate, nearly 5 Gbps, while other codes cannot reach 1 Gbps, with the exception of the 3D-MD code. This optimization can be explained by the ZCC property of our code, which positively and effectively optimizes the OCDMA system performance. Additionally, the 1D and 2D SWZCC codes enable each user in the OCDMA system to exploit up to 0.12 and 0.67 Gbps, respectively. Note that the  
Figure 4: BER versus the number of simultaneous users for L\({}_{1}=7\), L\({}_{2}=13\), and L\({}_{3}=3\). Figure 5: SNR versus number of simultaneous users for L\({}_{1}=7\), L\({}_{2}=13\), and L\({}_{3}=3\). differences between 1D and 3D and 2D and 3D in terms of the allowable data rate amount to approximately 40 and 7.1 times, respectively. Figure 7 displays the BER alteration as a function of the received power for 150 active users and a data rate of 1 Gbps. For \(P_{r}<-30\) dBm, all codes have roughly the same performance; in other words, all OCDMA systems tested in this investigation are the same in terms of the BER, referring to the restriction case for curves. On the other side, the curves of the 3D-PD and 3D-PD/MD codes and even the 3D-DCS/MD code vary speedily from \(P_{r}>-25\) dBm, and they do not have the ability to achieve the BER floor due to the intense influence of PIN. Nonetheless, the latter can achieve the BER floor, but with difficulty, at \(P_{r}=-5.8\) dBm. Regarding the other codes, they start in variation until the BER floor is achieved at \(-6.6\), \(-10.3\), \(-14.9\), and\(-13.8\) dBm for the 1D, 2D, 3D SWZCC, and 3D-MD codes, respectively. In accordance with the above outcomes, employing our proposed code enables each user in the OCDMA system to require only minor power at the receiver level and saves around \(-9.1\) and \(-1.1\) dBm compared with the 3D-DCS/MD and 3D-MD codes [24; 25], respectively. In addition, the transitions from 1D to 3D and from 2D to 3D save around \(-8.3\) and \(-4.6\) dBm, respectively. The fifth parameter to be discussed in this investigation is the BER alteration, which is shown as a function of the optical bandwidth for 100 active users in Figure 8. It is plain that the 1D-SWZCC curve is not drawn, since its ZCC feature and its SNR expression do not include the '\(\Delta\)f' symbol.