The Energy Efficiency Analysis of HARQ in Hybrid Relaying Systems

In this paper, we analyze the Hybrid Automatic Repeat re-Quest (HARQ) protocols used in conjunction with hybrid relaying schemes from the energy efficiency perspective. In cooperative communications, hybrid relaying strategy allows the relay to dynamically switch between different forwarding schemes according to its decoding status and provide either transmit or receive diversity to the users depending on the current channel condition. The energy efficiency analysis takes the circuitry energy consumption of all involved nodes into consideration and the energy efficiency is optimized in terms of energy per bit by manipulating the activation time and the transmission energy.