A half-duplex relay coding scheme optimized for energy efficiency

We explore the issue of the network energy efficiency in relay channels. We first propose a half-duplex decode-forward coding scheme. We then optimize the power allocation to minimize the total power consumption while maintaining a desired source rate. We show that this scheme significantly outperforms direct and two-hop transmissions. Moreover, it reduces the relay energy consumption by up to 7dB, which is beneficial for shared relay stations, and smooths out transmit power peaks, which simplifies interference management.