Novel lifetime-aware bit and power allocation in OFDM systems

OFDM-based communication systems have been widely used in several wireless network applications. In order to achieve a more efficient resource allocation, an novel bit and power allocation algorithm with lifetime consideration is proposed. In this work, the lifetime is specified by the portion of power or energy that a particular user can enjoy during the entire transmission. The proposed algorithm aims at the maximization of total transmission rate so that the lifetime constraint can be fulfilled in the long run. The proposed algorithm consists of two steps. In the first step, the optimal solution is found via the Lagrange multiplier method. However, the optimal solution is infeasible. In the second step, a suboptimal solution is achieved based on the optimal solution in the first step. Through the rigorous mathematical proof, the proposed algorithm is shown to be able to fulfill the lifetime requirement. Also, the simulation results show the validation of the theoretical derivation and the feasibility of the proposed algorithm.