## 6 Simulation Experiments and Performance Analysis
### Jamming Performance Analysis  
To meet the requirements for dense false target jamming, the simulation experiments employed a fixed number of false targets, set to \(I_{M}=600\). Each false target is placed around the true target. For ease of simulation analysis, the parameter \(n\) in Equation (12) is set to the smallest positive integer, i.e., let \(n=2\). To assess the jamming effect of the integrated signal on the radar, the detection performance of the jammed radar is simulated using the parameters specified in Table 2.  
Figure 10(a) shows the time-frequency analysis results of the UFMC chirp-based relay jamming signal, encompassing 16 radar pulses and employing a Hamming window, which can be seen by taking one of the range lines and analyzing it in the time-frequency domain.  
Figure 10(b) shows the analysis results of a single UFMC chirp jamming pulse in the time-frequency domain, and Figure 10(c) is a locally enlarged version of Figure 10(b). The horizontal axis in the figure represents the time sample points, while the vertical axis represents the frequency sample points. From Figure 10(c), it can be obse  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Parameter** & **Value** \\ \hline PRT & 1.5 ms \\ Bandwidth & 10 MHz \\ Number of pulses & 16 \\ Pulse width & 50 us \\ Carrier frequency & 4 GHz \\ Number of symbols & 100 \\ Number of false targets & 600 \\ Modulation mode & 4 QAM \\ SNR & 10 dB \\ \hline \hline \end{tabular}
\end{table}
Table 2: Simulation radar parameter settings.  
Figure 10(a) shows the time-frequency analysis results of the UFMC chirp-based relay jamming signal, encompassing 16 radar pulses and employing a Hamming window, which can be seen by taking one of the range lines and analyzing it in the time-frequency domain.  
Figure 11: Integrated waveform time–frequency analysis based on UFMC chirp: (**a**) overall time-frequency chart results; (**b**) the result with dense false target spacing; (**c**) the result of local magnification.  
jamming signal in this article can target frequency, and the frequency of the jamming signal changes linearly over time and continues throughout the entire jamming cycle.  
To further evaluate the radar jamming capability of the integrated system, a predefined real target and jamming signal are configured according to the specifications in Table 2. The processing results with and without jamming in the echo signal are illustrated in Figure 11(a),d. Enlarged views of specific regions are provided in Figure 11(b),e. In addition, Figure 11(c),f depicts the impact on CFAR detection thresholds with and without multiple false target jamming.  
From Figure 11(a),b, it can be observed that in the absence of jamming, the target echo, after MTD processing, enables the accurate detection of the target's position. Figure 11(c) shows the result after CFAR processing, indicating the successful detection of the real target by the radar system.  
When the jamming signal designed in this study is introduced to the echo signal, as depicted in Figure 11(d),e, the real target becomes submerged among a large number of false targets after MTD processing. Figure 11(f) represents the CFAR processing result, where the radar system fails to detect the real target. The jamming signal infiltrates the reference unit of the radar's CFAR detection, causing the CFAR detection algorithm to estimate higher noise power. This results in a CFAR detection threshold exceeding 20 dB above the power of the target signal. As the increased CFAR detection threshold surpasses the power of the jamming signal, the radar system is unable to recognize the jamming signal, effectively achieving the objective of masking the real target.