Robust joint multiple resources allocation algorithm for cooperative underwater acoustic communication networks

In this article, a joint relay selection, power control and time allocation problem is studied to maximize the energy efficiency for the cooperative underwater acoustic communication networks. The joint optimization problem is full of challenges due to the strong coupling of multiple resources and the uncertain characteristics of the underwater acoustic communication scenario. To address this issue, the worst-case method is employed to transform an original uncertain problem into a deterministic problem. Furthermore, we propose the block coordinate descent-based method to decouple the strongly coupling multi-resource allocation problem into three relatively independent sub-problems. The coupling of multiple resources is completely decoupled, thereby greatly reducing the solving difficulty. In addition, given that the sub-problems with the fractional objective function are still non-convex and hard to solve, the Dinkelbach-based method is proposed to transform the fractional objective function into a subtractive form. At last, the relay selection sub-problem is transformed into a integer programming problem, and the time allocation sub-problem is transformed into a linear programming problem, whose optimal solutions can be obtained by some well-established solution methods. The power allocation problem is transformed into a convex optimization problem, which can be solved by the Lagrangian dual method. Finally, in the proposed iteration structure, the three sub-problems are alternatingly solved until convergence. Simulation results are presented to demonstrate the efficiency and robustness of the proposed algorithm.