## 4 Integrated Signal Performance Metrics from Simulation Experiments  
We verify the effectiveness of the design and processing method of the proposed integrated signal waveform through simulation experiments in MATLAB 2018a. Some of the simulation parameters are shown in Table 1. Figure 10 shows the constellation diagram of the received signals before and after channel compensation for the 16-QAM integrated system, which can be seen to be clearer after channel compensation. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Symbol** & **Name** & **Value** \\ \hline \(B\) & signal bandwidth (MHZ) & 5 \\ \(F_{S}\) & sample rate (MHZ) & 50 \\ \(f_{c}\) & carrier frequency (GHZ) & 3 \\ \(T\) & signal bandwidth (\(\mu\)s) & 5 \\ \(N\) & number of subcarriers & 2048 \\ \(N_{cp}\) & length of cyclic prefix & 512 \\ \(N_{VC}\) & length of virtual carrier & 256 \\ \(N_{frame}\) & number of symbols per frame & 5 \\ \(M\) & modulation order & 16 \\ _PRF_ & pulse repetition frequency & 2000 \\ _SNR_ & signal-to-noise ratio & 0–12 dB \\ \(\gamma_{\text{rate}}\) & code rate at LDPC & 1/2 \\ \(\alpha\) & correction factor & 0.8 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Simulation parameters. In radar detection, a lower peak-to-side lobe ratio (PSLR) reduces the likelihood of the main lobe of a weak target being overwhelmed by the side lobe of a nearby strong target. Similarly, a lower integral side lobe ratio (ISLR) in the image makes the dark echo regions in the image less susceptible to being affected by nearby strong scattering. In the simulation experiments, the imaging results for five randomly generated target signals after passing through a Gaussian channel are shown in Figure 11. By applying pulse compression to the received echoes, we can obtain the velocity and distance of the five sets of targets. The performance comparison is obtained through simulation experiments. Figure 12 shows the pulse-compressed echoes with a PSLR of \(-13.81\) dB, which is better than the \(-13.24\) dB reported in [19]. The ISLR is \(-8.98\) dB, which is an improvement compared to the traditional method's \(-6.04\) dB. Figure 13 shows the communication BER analysis of the transmitted image information. It can be observed that after using LDPC encoding, the bit error rate is lower than that of the OFDM chirp-integrated signal. With an SNR of 10 dB, after timing synchronization and Doppler compensation, the communication BER of the OFDM chirp-integrated signal mentioned in this paper is \(4.8\times 10^{-4}\) under the Gaussian channel, and the BER for the integrated signal with LDPC encoding is \(7\times 10^{-5}\), both of which are lower than the \(7.1\times 10^{-4}\) reported in [19]. Compared to Reference [19], under the signal-to-noise ratio (SNR) range of 0-12 dB, the average BER of OFDM chirp-integrated  
Figure 11: Speed and distance of radar detection. (**a**) Two-dimensional images of target information; (**b**) Three-dimensional images of target information. Figure 10: Constellation diagram of the received signal before and after channel compensation. (**a**) Before channel compensation; (**b**) after channel compensation. signals decreased by 55.97%. For the OFDM chirp-integrated signals with LDPC encoding, the average BER decreased by 90.96%. Moreover, within the proposed approach in this paper, the scheme incorporating LDPC coding exhibited a 78.91% reduction in average BER compared to the scheme without LDPC integration. In practical scenarios, due to system imperfections such as phase noise, carrier leakage, and other defects, the position of the signal on the constellation diagram may deviate from the ideal locations. To comprehensively assess the quality of the modulated signal, we computed the vector differences between the reference signal and the actual transmitted signal. Figure 14 illustrates the discrepancies between the actual signal and the ideal signal according to the proposed approach. As shown in Figure 15, a comparison of the transmitted image quality at different SNRs is shown.