Maximizing lifetime in multi-source multi-relay non-regenerative OFDM networks

This paper presents a resource allocation strategy for maximizing the lifetime of amplify-and-forward (AF) dualhop cooperative OFDM networks. The high computational complexity for optimization necessitates our study of suboptimal approaches. Our centralized scheme is implemented in two steps. Specifically, during each transmission interval, source-relay selection and subcarrier pairing can be decided according to channel state information of the relay links and residual energy information at each terminal. Next, energy-aware power loading can be solved by employing standard Lagrange techniques. Numerical examples verify the effectiveness of our proposal.