# Target Detection of Passive Bistatic Radar under the Condition of Impure Reference Signal
## 3 Proposed Target Detection Method under the Condition of Impure Reference Signal
### Target Detection Method Based on Impure Reference Signal
The overlap of the main lobe of the surveillance channel and the reference channel is a fundamental condition for applying the proposed method. Lastly, although the proposed method can theoretically handle any targets with different Doppler frequencies in the reference signal, in practice, there is a trade-off between performance and efficiency. Figure 8: Detection results of the traditional method and the proposed method for target 3: (**a**) results of the traditional method; (**b**) results of the proposed method. Figure 7: Detection results of the traditional method and the proposed method for target 2: (**a**) results of the traditional method; (**b**) results of the proposed method. ## 5 Conclusions

In this paper, a comprehensive investigation was conducted to analyze the implications of target-echo-induced disturbances within the reference signal on conventional target detection methods. Subsequently, a pioneering approach for addressing this scenario was introduced. Specifically, leveraging the distinctive attributes of impure reference signals, a novel signal model was devised, followed by a detailed examination of its impact on

Figure 10: Comparison of processing efficiency between the traditional method and the proposed method. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Module** & **Running Time (s)** & **Proportion (\%)** \\ \hline Feedback & 2.12 & 48.62 \\ Purification & 0.17 & 3.90 \\ Detection & 2.07 & 47.48 \\ Total & 4.36 & 100 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Running time and time proportion of each module in the proposed method. Figure 9: Comparison of the detection results of the two target detection methods in impure case: (**a**) results of the traditional method; (**b**) results of the proposed method. the principal components of target detection. Drawing upon the valuable information embedded within the reference signal, a novel target detection method was proposed that incorporates a two-step process involving signal localization and subsequent signal reconstruction. In comparison to traditional methods, the proposed approach effectively mitigates the adverse effects of impure reference signals on target detection, thereby enhancing the integrated gain of the RDCC for specific real targets while minimizing the occurrence of false targets. Extensive simulation results have corroborated the superiority of the proposed method. However, although the proposed method has achieved some satisfying results, there are still some remaining issues that deserve to be studied in the future. For example, the current implementation of the proposed method exhibits relatively low computational efficiency, which may impede its practical application. Enhancing the execution efficiency of the proposed method through the integration of parallel processors is an ongoing effort. In addition, how to deal with the problem of impure reference signals when the main lobe of the reference channel and the surveillance channel do not overlap is another valuable research topic. Conceptualization, Y.W., Z.C. and D.P. ; Methodology, Y.W. ; Software, Y.W. ; Formal analysis, Y.W. ; Writing - original draft, Y.W. ; Project administration, Z.C. ; Funding acquisition, Z.C. All authors have read and agreed to the published version of the manuscript. This research was funded by the National Natural Science Foundation of China under Grant 61701148. Due to the nature of this research, participants of this study did not agree for their data to be shared publicly, so supporting data is not available. The authors declare no conflict of interest. ## References

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