Secure Transmission in Amplify and Forward Networks for Multiple Degraded Eavesdroppers
This work addresses secure communication in relay networks for scenarios with degraded eavesdroppers, but it appears incremental as it builds on existing AF relay models with specific optimizations.
The paper tackled the problem of optimizing secrecy rates in Amplify-and-Forward relay networks with multiple eavesdroppers by developing techniques to calculate optimal scaling factors under power constraints, resulting in an efficiently solvable quadratic program and iterative scheme for sub-optimal solutions.
We have evaluated the optimal secrecy rate for Amplify-and-Forward (AF) relay networks with multiple eavesdroppers. Assuming i.i.d. Gaussian noise at the destination and the eavesdroppers, we have devised technique to calculate optimal scaling factor for relay nodes to obtain optimal secrecy rate under both sum power constraint and individual power constraint. Initially, we have considered special channel conditions for both destination and eavesdroppers, which led us to analytical solution of the problem. Contrarily, the general scenario being a non-convex optimization problem, not only lacks an analytical solution, but also is hard to solve. Therefore, we have proposed an efficiently solvable quadratic program (QP) which provides a sub-optimal solution to the original problem. Then, we have devised an iterative scheme for calculating optimal scaling factor efficiently for both the sum power and individual power constraint scenario. Necessary figures are provided in result section to affirm the validity of our proposed solution.