Node Power Allocation Research Articles

Relay transmission under mobile edge computing in energy-limited networks with real-time constraints

For energy-limited networks with real-time constraints, long-distance transmission, complex calculations, and limited delay are problems to be faced in service applications. The cloud-based mobile edge computing framework is proposed in energy-limited networks to solve these problems. Under certain power and delay conditions, source node and destination node in adjacent cells, respectively, can select the appropriate relay node to complete the communication process. The mobile edge computing brings a novel idea for the application of auto-regressive and moving average model and further improves transmission efficiency and reduces transmission delay. Historical energy information of potential relay nodes can be predicted through auto-regressive and moving average model in edge computing server. Then, source node selects appropriate relay node by the proposed relay selection algorithm. Power objective function with signal-to-noise ratio that satisfies the limited delay is formulated to optimize the power allocation of nodes in terms of reducing energy consumption. The results show that our proposed relay selection algorithm under mobile edge computing architecture in energy-limited networks with real-time constraints could effectively improve the performance of networks on energy consumption and delay.

Sum-Throughput Maximization by Power Allocation in WBAN With Relay Cooperation

In this paper, we investigate an energy harvesting wireless body area network (WBAN) with relay cooperation, where the destination nodes and the relay simultaneously harvest energy from the radio frequency (RF) source, then the destination nodes transmit data to the source by maximum ratio combining (MRC) transmission mode. We study the optimal design for relay power splitting ratio in each relaying sub-slot and the destination nodes power allocation to maximize the sum-throughput with the proposed protocol. The optimization problem is divided into two cases, destination node power limit (DPL) case and relay power limit (RPL) case. In essence, the problem is a joint-objective optimization and is solved by the Lagrangian multiplier method. Simulation results show that our proposed optimal method can greatly improve the sum-throughput compared with conventional mean power allocation (MPA) method and mean time allocation (MTA) method. Moreover, a significant sum-throughput promotion is achieved on the RPL case over the DPL case.

On Multiuser Resource Allocation in Relay-Based Wireless-Powered Uplink Cellular Networks

We propose relay-based wireless-powered uplink cellular networks in which users first harvest energy from RF transmissions of base station/relay nodes and then use that energy for uplink transmission. Given the limited total transmission time and available energy at the relay node, we propose different resource allocation frameworks for the proposed relay-based networks considering two different relay-based harvest-then-transmit scenarios. We first propose iterative algorithm to determine time and relay node power allocation (for downlink wireless charging and uplink data transmission/relaying) for both scenarios. We then perform joint optimal time and power allocation for one scenario. Resource allocation results show that most of the available resources (transmission time and relay node energy) are allocated for wireless energy harvesting which is similar to that observed for downlink simultaneous wireless information and power transfer (SWIPT) in the existing literature. Simulation results on comparison of different relay-based scenarios reveal interesting insights and demonstrate remarkable improvement of different performance metrics of wireless-powered cellular networks in the presence of relay node.

Residual energy based multi-relay selection and power allocation scheme in two-way relay network

In this paper, we have proposed a multi-relay selection and power allocation scheme for two-way relay network which aims to maximize the sum-rate of two-way relay system. First, to prolong network lifetime, a multi-relay selection strategy is proposed in which both channel state information (CSI) and remaining energy (RE) are considered. Next, a multi-relay power allocation algorithm based on convex optimization (MRPA-CO) is presented. To reduce the computational complexity, it can be divided into two steps: terminal nodes power allocation (TNPA) and relay nodes power allocation (RNPA). Simulation results indicate that the proposed relay selection strategy can significantly prolong network lifetime compared to other relay selection strategies which consider CSI only, and the MRPA-CO algorithm has great advantage over equal power allocation (EPA) on sum-rate in two-way relay network.