Hello Chahinez Agaba

I had similar experience before when I started transiting my research work from 3G to 4G and beyond. It seems that every a few years, researcher and students ask similar questions. Here is what I was pondering over before and hope my then thoughts and my methodology would help you a little bit, though it won't give you specific research topics right way.

[What Is The Next for Mobile System Design? I: A Single-Cell Model Perspective on Downlinks]

https://blog.familywang.org/2012/01/what-is-next-for-mobile-system-design.html

[How to Broadcast Multimedia Contents? II Lessons from The Channel]

https://blog.familywang.org/2010/10/how-to-broadcast-multimedia-content.html

As you may see, what I did may be described in three steps essentially:

In my then analysis and then examples, however, I only used then-popular and standardized 3GPP COST-231 single-cell SISO channel model. Depending on your needs or interest, if you want to reuse my methodology above, I would strongly suggest you replacing my analysis with your own channel model or system model or the ones you choose.

Please let me know if you have any other thoughts or thing.

Cheers.

Network security, encryption.

speech recognition for security, video surveillance

Integration of radar and communication systems, N-OFDM and other SEFDM, Massive MIMIO, 6G, AI

Compressive covariance sensing.

Applications of deep learning in signal processing.

Speech and music quality assessment, speech intelligibility.