Energy Efficiency Optimization and Comparison for One-Way and Two-Way Decode-and-Forward Relay Systems

Abstract

Abstract-Energy-efficient communication techniques play great roles in applications where devices are powered by batteries. Relaying is viewed as an energy saving technique because it can reduce the transmit power by breaking one long range transmission into several short range transmissions. Two-Way Relaying Transmission (TWRT) is expected to consume less transmit power than One-Way Relaying Transmission (OWRT). In this paper, we study the Energy Efficiencies (EEs) of One-Way Decode-and-Forward (OWDF) and Two-Way Decode-and-Forward (TWDF) systems with delay constraint. The maximum EEs of both systems are derived by jointly optimizing the transmission duration and the transmit power allocation. Analytical and simulation results show the impacts of packet size, time deadline and the channel gain to EE.

Energy-Efficient Cross-Layer Double Cooperative MAC for Wireless Sensor Networks

“…First, we compare the four transmission modes in ECDC-MAC protocol in performances of the energy consumption per bit and the lifetime of a sensor node. Then, we compare the network lifetime and average wasted energy of ECDC-MAC with DEC-MAC [14] and WcoopMAC [17] in the same network environment. DEC-MAC and WcoopMAC are both aimed to prolong the lifetime of the network.…”

“…But, transmit power optimization wasn't considered in [14] and [15]. On the other hand, it was demonstrated that deploying a proper relay with transmit power optimization can efficiently reduce the energy consumption [16], [17]. In [18], the device lifetime increased 12 times by deploying a power optimized cooperative relay.…”