# A New Improved Multi-Sequence Frequency-Hopping Communication Anti-Jamming System
## 5 Simulation Results and Analysis
### Simulation Result Analysis  
Due to the decrease in the signal-to-noise ratio, the frequency point detection network can learn less information from the spectrum waterfall. Moreover, due to the presence of multiple instances of jamming in complex jamming environments, this paper utilizes intelligent reactive jamming. As the JSR increases, unused jamming can also affect system performance. Therefore, we first verified the bit error rate (BER) performance of IMSFH in different signal-to-noise ratio (SNR) environments. In the simulation, we set the power of non-utilized jamming and set three different reactive jamming values, with JSR = {0, 5, 10}, to achieve an SNR of {\(-\)10, \(-\)8, \(-\)6, \(-\)4, \(-\)2.0}. The simulation results are shown in Figure 7. From Figure 7, it can be seen that under the same JSR, the system error rate performance increases with the increase in SNR. This is because as the SNR increases, the noise decreases, making it easier for IMSFH to obtain reactive jamming from the spectrum waterfall, improving the efficiency of utilizing reactive jamming. We can also see from Figure 7 that under the same JSR, for every 2 dB increase in SNR, the bit error rate performance can be improved by 1.6 dB. In addition, we can also see from Figure 7 that in the case of a low SNR, as the power of reactive jamming increases, the communication performance of IMSFH improves. Therefore, this paper also designed corresponding simulations to analyze and illustrate the performance. We analyzed the performance of SNR = {0, \(-\)5, \(-\)10} under different JSR = {11, 9, 7, 5, 3, 1, \(-\)3, \(-\)5} conditions, and the simulation results are shown in Figure 8.  
From Figure 8, we can observe that under the same Signal-to-Noise Ratio (SNR) conditions, the system's bit error rate (BER) performance increases with the increase in Jamming-to-Signal Ratio (JSR). This is because as the JSR increases, the characteristics of the reactive jamming signal become more prominent in the spectrum waterfall diagram. Consequently, the system is able to learn more reactive jamming information under the same SNR conditions. This increased information enhances the efficiency of leveraging reactive jamming, thereby improving the system's communication performance. As mentioned earlier, in the receiver section, we replace the filtering and non-coherent detection components from reference [25] with a frequency-detection network that has frequency-detection and intelligent learning capabilities. To further demonstrate the improvement of IMSFH in this area, we conducted corresponding experiments for performance validation. In addition, we also compared the performance of IMSFH with other  
Figure 7: BER performance of IMSFH under different SNR. MSFH schemes in experiments and analyzed the performance differences under the same jamming environment. Figure 9 shows the accuracy of user frequency signals received by IMSFH, WGMPFH [26], and MPFH [25] system receivers in a communication environment using only intelligent reactive jamming. In this scenario, the SNRs for the WGMPFH and MPFH systems are set to 13.35 dB, while the SNR for the IMSFH system is 0 dB. From Figure 9, we can see that due to the decrease in SJR, the accuracy of the user signals received by each system receiver will also decrease, but the IMSH will slightly increase (greater than 99%). This is because as SJR decreases, the jamming power will increase, and the reactive jamming characteristics in the spectrum waterfall become more prominent. This enhances the ability of the frequency-detection network to effectively learn reactive jamming rules. On the basis of the unchanged experimental conditions in Figure 9, we verified the impact of frequency mismatch on BER performance and added a demonstration of the BER performance of traditional FH/BPSK (SNR = 13.35 dB). The accuracy of IMSFH in Figure 9 has always been greater than 99%, and it can be seen from Figure 10 that its BER performance is also very excellent.