# Hybrid FSK-FDM Scheme for Data Rate Enhancement in Dual-Function Radar and Communication
## 6 Conclusions and Future Work  
A novel approach to a dual-function radar communication system was introduced in the paper. The proposed technique increased the data rate for the communication receiver. Moreover, it delivered information to the communication receivers with an improved BER regardless of their location in the main or side lobes of the radar beam. Next, orthogonal frequency and waveform-based combinations were used to transmit binary information to each communication user, facilitating double the PRF-based data rate with improved secrecy. Finally, diverse scenarios were considered and extensive simulations were conducted to validate the effectiveness of the proposed technique. Currently, only one waveform is considered using likelihood-based estimation for DFRC. Keeping all constraints, such as inter-symbol interference and SNR vs. BER, more than one waveform shall be considered using FDM techniques. In addition, a different scenario needs to be developed when the radar lies in the side lobe, and communications are in the main lobe. In addition, an algorithm needs to be developed to decide when ASK-based techniques should be used and which scenario will work well with PSK-based techniques.  
\begin{table}
\begin{tabular}{c c c c c} \hline  & **Waveform** & **Beam Pattern** & **Beam Pattern** & **FSK–FDM** \\
**BER** & **Diversity** & **ASK** & **PSK** & **(Proposed)** \\ \hline \(10^{-1}\) & 34 & 32 & 6 & 4 \\ \(10^{-2}\) & 24 & 22 & 4 & 3 \\ \(10^{-3}\) & 17 & 15 & 3 & 1.5 \\ \(10^{-4}\) & 10 & 8 & 1.5 & 1 \\ \hline \end{tabular}
\end{table}
Table 4: The effectiveness of the proposed technique over existing techniques in terms bit error rate vs. security against intercept at the communication receiver (beam width in degrees) for \(\theta_{c}=50^{o}\).  
\begin{table}
\begin{tabular}{c c c c c} \hline  & **Waveform** & **Beam Pattern** & **Beam Pattern** & **FSK–FDM** \\
**SNR** & **Diversity** & **ASK** & **PSK** & **(Proposed)** \\ \hline \(0\) & 912 & 913 & 862 & 804 \\ \(2\) & 872 & 903 & 809 & 711 \\ \(4\) & 830 & 886 & 738 & 568 \\ \(6\) & 760 & 864 & 635 & 3391 \\ \(8\) & 665 & 835 & 485 & 007 \\ \(10\) & 516 & 791 & 264 & 003 \\ \hline \end{tabular}
\end{table}
Table 3: The effectiveness of the proposed technique over existing techniques in terms of BER vs. SNR.  
**Author Contributions:** Conceptualization: M.F.M., A.B. and W.K.; methodology: M.F.M., A.S., A.B. and W.K.; software: M.F.M., A.S. and A.W.; formal analysis: S.A.A., P.P. and A.D. ; investigation: M.F.M., A.B. and M.M.K.; resources: M.F.M., S.A.A., P.P. and A.D.; project administration: S.A.A., P.P. and A.D.; writing--original draft preparation: M.F.M., A.S. and M.M.K. ; writing--review and editing, M.F.M., A.S., A.W. and A.D.; supervision: S.A.A., P.P. and A.D.; All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research is funded by the Research Supporting Project Number (RSPD2023R585), King Saud University, Riyadh, Saudi Arabia.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Not applicable.  
**Conflicts of Interest:** The authors declare no conflict of interest.