## 5 Performance Evaluation for C Band Signals
### Performance Analysis  
The Gabor bandwidth and code tracking errors of the abovementioned signals are shown in Figure 7, where \(B\) is 20 MHz. It is obvious that the Gabor bandwidth of Q_M_2 RC(10) is very close to that of the others below 9.5 MHz pre-filtering bandwidth, while the Gabor bandwidth of Q_M_2 RC(10) appears to outperform the others and finally tends to converge to a value when \(B\) is higher than 9.5 MHz. In addition, it is also observed from Figure 7b that the proposed Q_M_2 RC(10) signal can offer superior tracking accuracy performance compared to other candidates at around 20 MHz for C band navigation service.  
Figure 8 shows the comparison of multi-path mitigation for the three candidate signals in the C band with the same parameters as the former simulation. As seen from the Figure 8, the Q_M_2 RC(10)  
Figure 7: (**a**) Gabor bandwidth of modulation candidates for C band; (**b**) Code tracking errors of modulation candidates for C band.  
signal has almost equivalent performance to MSK(10) in the aspects of multi-path error envelopes and running average errors, and both of them are superior to BPSK(10).  
Table 4 lists the anti-jamming merit factors of C band signals with 20 MHz pre-filtering bandwidth and 50 bps message rate. In the \(Q_{\mathit{CTALWN}}\) and \(Q_{\mathit{CTALRS}}\) aspects the QM2 RC(10) signal only behaves approximately 0.8 dB worse than MSK(10), while it reveals the best \(Q_{\mathit{Dent\in\textit{UMS}}}\) and \(Q_{\mathit{Dent\in\textit{UNF}}}\) performance. As a whole, the QM2 RC(10) almost shows similar or comparable anti-jamming performance as other candidates.  
It is assumed that the BPSK(10), MSK(10) and QM2 RC(10) signals centered at the same carrier frequency close to 5020 MHz are broadcast as C band signals. A receiver pre-filtering bandwidth of 20 MHz is used. Table 5 calculates the SSC of the above signals. In terms of self-SSC, the QM2 RC(10) is 0.15 dB and 0.71 dB lower than MSK(10) and BPSK(10), respectively, and far better than the minimum shift keying-binary coded signal (MSK-BCS) [7,28], whose self-SSC is \(-67.2531\) dB in the C band [7]. By the above analysis, the QM2 RC(10) has a better compatibility performance than the others.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Merit Factors** & **QM2 RC(10)** & **BPSK(10)** & **MSK(10)** \\ \hline \(Q_{\mathit{CTALRS}}\) & 73.4678 & 73.7855 & 74.2665 \\ \(Q_{\mathit{CTALWN}}\) & 70.2342 & 70.0984 & 70.9042 \\ \(Q_{\mathit{Dent\in\textit{UMS}}}\) & 55.5892 & 54.8792 & 55.4381 \\ \(Q_{\mathit{Dent\in\textit{UNF}}}\) & 54.8397 & 52.1400 & 54.0212 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Anti-jamming merit factors of candidate signals in the C band [dB].  
Figure 8: **(a)** Multi-path error envelopes of modulation candidates for C band; **(b)** Average multi-path errors of modulation candidates for C band.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**SSC** & **QM2 RC(10)** & **BPSK(10)** & **MSK(10)** \\ \hline QM2 RC(10) & \(-72.5789\) & \(-72.6223\) & \(-72.6020\) \\ BPSK(10) & \(-72.6223\) & \(-71.8689\) & \(-72.2611\) \\ MSK(10) & \(-72.6020\) & \(-72.2611\) & \(-72.4278\) \\ \hline \hline \end{tabular}
\end{table}
Table 5: SSC of candidate signals in the C band [dB].