Loading...

Physical Layer Security in Cooperative Multiple Access Networks

Bastami, Hamed | 2024

0 Viewed
  1. Type of Document: Ph.D. Dissertation
  2. Language: Farsi
  3. Document No: 58353 (05)
  4. University: Sharif University of Technology
  5. Department: Electrical Engineering
  6. Advisor(s): Behroozi, Hamid
  7. Abstract:
  8. 6G, the next generation of communication technology, is already under discussion alongside the commercialization of 5G networks. In order to achieve faster data transmission rates and greater reliability, 6G technologies are being explored and developed. There are several important requirements for both 5G and 6G networks, including extensive connectivity, high throughput, low latency, massive connections, security, fairness and energy efficiency. Because of their increased spectral efficiency, multiple access techniques have gained attention as a solution to meet these requirements. However, it is so important to consider the security implications of these technologies. The simultaneous transmission of signals from multiple users over a shared bandwidth presents a security risk, as an external eavesdropper (Eve) could intercept the signals and compromise the privacy of multiple users. Addressing these security issues is crucial, and one effective approach is the use of Physical Layer Security (PLS) techniques, which can enhance or potentially replace by traditional encryption methods. As a starting point, we investigate the max-min secrecy fairness of UAV-aided cellular networks, in which cooperative rate-splitting (CRS) aided downlink transmissions are employed by each multi-antenna UAV base station to safeguard the downlink of a two-user multi-input single-output (MISO) system against an external eavesdropper (Eve). Realistically, only imperfect channel state information is assumed to be available at the transmitter. In the next step, we study the Secrecy Energy Efficiency (SEE) of a multi-carrier UAV-aided cellular networks, in which CRS is employed by each multi-antenna UAV-BS for protecting their downlink transmissions against an Eve. We further consider a difficult scenario in terms of security in which only imperfect channel state information of Eve is available at the Tx. Accordingly, we conceive a robust secure resource allocation algorithm, which maximizes the SEE by jointly optimizing both the user association matrix and the network parameter allocation problem. Finally, we have also studied the uplink scenario. Briefly, we investigate the effective secrecy throughput of the UAV-aided uplink, in which RSMA is employed by each legitimate user for secure transmission under the scenario of massive access. To maximize the effective network secrecy throughput in the uplink, the transmission rate vs. power allocation relationship is formulated as a max-min optimization problem, relying on realistic imperfect CSI of both the legitimate users and of the potential Eves. We then propose a novel transformation of the associated probabilistic constraints for decoupling the variables. Our simulation results confirm that these schemes significantly improve the security criterions compared to the existing orthogonal and non-orthogonal benchmarks and enhance security
  9. Keywords:
  10. Physical Layer Security ; Multiple Access ; Rate Splitting Multiple Access ; Unmanned Aerial Vehicles (UAV) ; Effective Secrecy Throughput ; Secrecy Capacity ; Connection Outage Probability ; Secrecy Energy efficiency

 Digital Object List

 Bookmark

...see more