# Spoofing Traction Strategy Based on the Generation of Traction Code
## 4 Discussion  
### Discussion on Simulation Results  
This section discusses the results obtained in Section 3.1.  
First, the advantages and theoretical feasibility of the proposed strategy compared to the conventional traction strategy are discussed.  
The simulation results for the three strategies are presented in Figures 11-13. All \(\tau_{\mathrm{sl}}\) in Figures 11a, 12a and 13a finally approach 0, indicating successful code-loop traction of the three strategies. According to Figure 12f, the local Doppler fd\({}_{\mathrm{l}}\) is finally equal to the spoofing Doppler f\({}_{\mathrm{drag}}\), and the carrier-loop traction of Strategy 2 is successful.  
As can be observed in Figure 11a,c and Figure 12a,c, the code phase, code rate, and carrier frequency of the local loop cannot be followed up in real time, and there is a long loop adjustment process. Successful traction requires P\({}_{\mathrm{s}}\) to be at least equal to P\({}_{\mathrm{a}}\) within a certain period of time, which directly leads to considerable distortion when the correlation peaks are superimposed. The power will inevitably increase significantly, and distortion of the correlation peak and fluctuation of observations will be inevitable, as illustrated in Figures 11b and 12b. Therefore, conventional traction strategies are at risk of being detected  
Figure 23: Ratio Test metric behavior under traction Strategy 2.  
Figure 24: Ratio Test metric behavior under the proposed Strategy.  
by power and TOA detection. Based on this limitation, a novel traction strategy for covert spoofing against TOA and power detection is proposed.  
Therefore, because the conventional traction method risks being detected by power and TOA detection, we expect that the proposed strategy can circumvent these problems.  
Figure 13 shows that the simulation results of the proposed method differ from those of the previous two methods. The conventional traction idea is a correlation peak superposition, and the spoofing signal slightly increases the spoofing signal power to take advantage. However, the proposed traction strategy essentially suppresses part of the genuine signals while realizing the generation of an ideal composite correlation peak.  
The outputs of the correlators fluctuated slightly only when spoofing was added or when the traction speed returned to 0. This is because the adjustment process of the tracking loop causes \(\tau_{\text{al}}\) to lag behind the changes in \(\
u_{\text{drag}}\) for a short period at the beginning and end of the traction. Most of the time, we have  
\[\
u_{\text{drag}}\approx\tau_{\text{al}} \tag{35}\]  
Then we have  
\[\text{I}_{\text{P}}(\text{n})\approx\frac{\sqrt{\text{P}_{\text{a}}}}{2} \tau_{\text{coh}}\text{R}(0), \tag{36}\]  
\[\delta_{\text{cp}}=\frac{\text{I}_{\text{E}}-\text{I}_{\text{L}}}{\text{I}_{ \text{E}}+\text{I}_{\text{L}}}\approx\frac{\text{R}^{-}(0)-\text{R}^{+}(0)}{ \text{R}^{-}(0)+\text{R}^{+}(0)}=0 \tag{37}\]  
Therefore, the proposed strategy is theoretically feasible. Compared to conventional strategies, it has a more ideal spoofing effect.  
The second part is the comparison of two conventional strategies.  
Compared with Strategy 1, it can be determined that Strategy 2 leads to the deterioration of the stability of the carrier loop, and the change in the phase discriminator output is more complicated owing to the influence of the carrier.  
The third part is the discussion on traction speed and traction duration.  
From Table 3, it can be observed that the value range of the traction speed is extended under the proposed strategy. Because the selection of \(\
u_{\text{drag}}\) directly affects the adjustment time of the loop traction, these two indicators must be weighed. In actual navigation wars, it is usually necessary to quickly seize the control of the tracking loop, and the traction time should not be too long, i.e., the traction speed should not be too slow. Compared to conventional traction strategies, the proposed strategy can more covertly and promptly control of the tracking loop.