Optimal Power Allocation for Hybrid Energy Harvesting and Power Grid Coexisting System With Power Upper Bounded Constraints

As one of the green energy resources, the technique of energy harvesting harnesses energy from its surrounding environment. In this setting, a power grid is also utilized to serve as a supplementary source to regulate the not-so-stable harvested energy supply of the system. The power allocated to the user(s) from the sum of the harvested energy and the power grid is subject to peak power constraints. The background of these constraints comes from field requirements, such as avoiding the saturation of power allocated to the user(s), avoiding system level out-of-band power leakage, and reducing interference with other transmitter(s) due to the nonlinearity generated via the transmitting mechanisms to the user(s). The proposed problem considers simultaneously 1) the hybrid paradigm of both energy harvesting and grid power supplies, and 2) the peak power constraints in such systems. For our proposed problem, the most efficient known-to-date and popular convex optimization method of primal-dual interior method (PD-IPM) only computes an $\epsilon$ solution, not an optimal solution, even with more computations. The novelty of the proposed algorithms is that they compute the exact solutions with the low degree polynomial computational complexity. To the best of the authors’ knowledge, under the same assumptions, no prior publication, including PD-IPM, can arrive at such results. Numerical examples also illustrate efficiency of the proposed algorithms.