# A Fast Acquisition Algorithm for Hybrid Signals of 5G and BeiDou B1
## 3 Results and Discussion
### 5G Out-of-Band and B1 Signal Performance Analysis  
Analyzing the B1 signal performance under 5G, out-of-band interference requires statistical quantification of the data at the end of the traversal simulation and actual measurements, including peak capture, the standard deviation of the carrier tracking output error, and the standard deviation of the code tracking output error. These parameters are the direct response to the navigation signal performance. The peak capture values of the B1I and B1C signals in different scenarios are shown in Figure 13.  
Figure 13 shows that with only 5G out-of-band radiation as interference, the peak correlation for acquisition is higher than usual with only white noise, and acquisition can proceed normally, so 5G radiation does not cause much impact on acquisition. On the other hand, for the acquisition peak, the smaller the 5G power, the better the acquisition  
Figure 12: SC-PMF-FFT algorithm acquisition time test results under different configurations. Figure 13: (**a**) B1 acquisition peaks for different out-of-band SIR cases. (**b**) B1C acquisition peaks for different out-of-band SIR cases. \begin{table}
\begin{tabular}{c c c c c c} \hline \multirow{2}{*}{**C/No (dB-Hz)**} & \multirow{2}{*}{**Number of Acquisitions**} & \multirow{2}{*}{**Success Rate**} & \multicolumn{3}{c}{**Phase Search Time (ms)**} \\ \cline{3-5}  & & & **300 Hz** & **600 Hz** & **900 Hz** \\ \hline
38.9 & 500 & 100.0\% & 2 & 5 & 7 \\
35.9 & 500 & 100.0\% & 2 & 5 & 7 \\
32.9 & 498 & 99.6\% & 4 & 10 & 15 \\
29.9 & 483 & 96.6\% & 5 & 11 & 16 \\
26.9 & 432 & 86.4\% & 10 & 20 & 40 \\
23.9 & 359 & 71.8\% & 15 & 29 & 60 \\
20.9 & 261 & 52.2\% & 47 & 93 & 121 \\
17.9 & 146 & 29.2\% & 289 & 465 & 567 \\ \hline \end{tabular}
\end{table} 
Table 13: SC-PMF-FFT algorithm acquisition sensitivity test. performance, and the larger the frequency interval, the better the acquisition performance. This is because the peak of the relevant operation at the acquisition time is related to the signal's energy. Traversing the time- and frequency-domain diagrams of BeiDou B1I+5G during the simulation, we can find that as the frequency interval increases and the 5G power decreases, the energy ratio of the BeiDou B1I signal to the total signal also increases. In Figure 13, the acquisition can still be carried out smoothly at the maximum 5G power, and the impact of the acquisition is not significant. The statistical plot of the capture follows the expected pattern, the larger the frequency interval, the better the capture performance, and the smaller the 5G power, the better the performance capture performance. This is because the capture performance is energy dependent. The time-domain and frequency-domain plots of the traversed BD BIC+5G out-of-band radiation show that the energy share of the BD signal strictly follows the more significant the frequency interval, and the smaller the 5G power, then the more significant the energy share of B1C. Therefore, the capture-related peak statistics of B1C strictly obey the expected law. When the signal-to-interference ratio (SIR) of the 5G signal at the receiver is below \(-58\) dB (signal power \(-45\) dBW), it will have a substantial impact on the B1 signal of the BeiDou system. Then, according to the analysis of the 5G base station transmitting power, it is known that the 5G signal at the receiver end will exceed \(-45\) dBw when the receiver is very close to the 5G base station. At this time, focusing on losing the 5G signal when it propagates very close to the base station is necessary. According to the recommendations proposed by ITU-R M.1318 in assessing the compatibility of navigation signals with neighboring signals, the nominal path loss of the interfering signal during propagation should be evaluated according to the free-space loss model when the interfering source is close to the receiver. In most scenarios, the 5G signal power at the receiver will be lower than \(-45\) dBw.