# Natural Brain-Inspired Intelligence for Non-Gaussian and Nonlinear Environments with Finite Memory
## 5 CDS Implementation Case Study: OFDM Long-Haul Fiber Optic Communications
### Simulation Results and Discussions
#### 5.2.2 Results for the System with the CDS Focus Level One
Therefore, the executive updates policy and FEC threshold or \(\textit{Threshold}^{m=1}=4.7\times 10^{-3}\). Then, the executive sends the new policy (\(\textit{Threshold}^{m=1}=4.7\times 10^{-3}\)) and the internal command (increasing focus level) to the perceptor. Using, the model extracted in focus level one, the perceptor provides the BER under updated FEC threshold (see Figure 12, \(c_{5}\): 236 Gb/s and Figure 14b). Also, the internal rewards decreased correspondingly (see Figure 14a). 6. Sixth PAC (focus level one): The executive predicts the virtual internal rewards and the BER for virtual action of \(c_{6}\) using extended model in focus level 1 (see Figure 12, Figure 13, and Algorithm 1). The executive applies 252 Gb/s as the \(c_{6}\), because the virtual BER for 256 Gb/s at \(t\) = 5 is more than the updated FEC-threshold (see Figure 13b, \(c_{6}\): prediction) and the 252 Gb/s has the minimum virtual internal rewards (See Figure 13a, \(c_{6}\): prediction) with virtual BER under updated FEC threshold (See Figure 13b, \(c_{6}\): prediction). After applying \(c_{6}\) by the CDS, the perceptor uses 236 Gb/s extracted model (see Figure 12, \(c_{6}\): 252 Gb/s prediction) to predict the BER for 252 Gb/s. Figure 12 shows that the perceptor provides the BER for 252 Gb/s under the updated FEC-threshold using the extracted model for 236 Gb/s. Similar to previous PAC, the BER can be improved further using the exact extracted model (see Figure 12, \(c_{6}\): 252 Gb/s). Figure 12: BER in perceptor after environmental actions (\(\textit{PF}=2\), \(d=4\) Gb/s, focus level one). Dash lines: BER prediction in perceptor and continuous lines: BER using exact model. Figure 13: BER using CDS in executive prediction for virtual actions (_PF_ = 2, d = 4 Gb/s, focus level one); (**a**) learning curve for virtual internal reward and (**b**) virtual BER versus executive internal cycle). Figure 14: Results for the CDS versus perception-action cycle (PAC) numbers; (**a**) CDS learning curve and (**b**) BER versus PAC numbers. Seventh, eighth and ninth PAC (focus level one): Similar to sixth PAC, the CDS can provide 260 Gb/s, 272 Gb/s, and 280 Gb/s for the \(c_{7}\), \(c_{8}\), and \(c_{9}\), respectively. 8. 10 th PAC (focus level one): The executive finds that the predicted BER for 284 Gb/s is more than the updated FEC threshold (see Figure 13b). As a result, the executive turns on steady state for 280 Gb/s. The CDS does not increase the focus level, because the number of cells in the focus level two is more than the desired complexity threshold (see Table 3 for \(F_{m=2}^{total,k=10}\)). From Figures 12 and 14b, we see that the CDS provides the minimum BER of \(4.7\times 10^{-3}\) before HD-FEC, when the data rate is 280 Gb/s (see Figures 12 and 14b). Based on [25], the required OH can be reduced to 6.25%. As a result, an extra \(\sim\)24 Gb/s in 280 Gb/s data rate can be used for data transmission instead of assigning it for overhead.