Optimal Energy Management for Energy Harvesting Transmitter and Receiver with Helper

We study energy harvesting (EH) transmitter and receiver, where the receiver decodes data using the harvested energy from the nature and from an independent EH node, named helper. Helper cooperates with the receiver by transferring its harvested energy to the receiver over an orthogonal fading channel. We study an offline optimal power management policy to maximize the reliable information rate. The harvested energy in all three nodes are assumed to be known. We consider four different scenarios; First, for the case that both transmitter and the receiver have batteries, we show that the optimal policy is transferring the helper harvested energy to the receiver, immediately. Next, for the case of non-battery receiver and full power transmitter, we model a virtual EH receiver with minimum energy constraint to achieve an optimal policy. Then, we consider a non-battery EH receiver and EH transmitter with battery. Finally, we derive optimal power management wherein neither the transmitter nor the receiver have batteries. We propose three iterative algorithms to compute optimal energy management policies. Numerical results are presented to corroborate the advantage of employing the helper.Comment: It is a conference paper with 5 pages and one figure, submitted to ISITA201

Performance analysis of uplink optical wireless communications in the presence of a simultaneously transmitting and reflecting reconfigurable intelligent surface

Abstract Recently, reconfigurable intelligent surface (RIS) has gained research and development interests in modifying wireless channel characteristics in order to improve the performance of wireless communications, especially when the quality of the line‐of‐sight channel is not that good. In this work, for the first time in the literature, we have used simultaneously transmitting and reflecting RIS (STAR‐RIS) in a non‐orthogonal multiple‐access visible light communication system to improve the performance of the system. Achievable rates of the users are derived for two data recovery schemes, single‐user detection (SUD) and successive interference cancellation (SIC). Then, the sum‐rate optimisation problem is formulated for two operating modes of STAR‐RIS, namely energy‐splitting and mode‐switching cases. Moreover, a sequential parametric convex approximation method is used to solve the sum‐rate optimisation problems. The authors have also compared energy‐splitting and mode‐switching cases and showed that these two modes have the same performance. Finally, numerical results for SUD and SIC schemes and two benchmarking schemes, time‐sharing and max‐min fairness, are presented, and spectral‐ and energy‐efficiency, number of STAR‐RIS elements, the position of users, and access point are discussed

Iterative symbol synchronization for bandwidth efficient burst transmission

In this paper, a new symbol timing recovery is proposed that is suitable for burst transmission scheme. It is assumed that the channel is an Additive White Gaussian Noise (AWGN) one and the transmitted data are unknown at the receiver. The contribution of the paper is exploiting Gardner Timing Error Detection (TED) algorithm for None-Data-Aided (NDA) timing delay estimation in an iterative manner. It is shown that the estimated delay also maximizes the log-likelihood function. The algorithm is suitable for different types of linear modulations such as PSK, QAM. The proposed timing recovery algorithm is bandwidth efficient which does not use any pilot symbols and proceeds without using preambles. The algorithm is capable of recovering all symbols of a short burst transmission and is practically easy to be implemented. Simulation results confirm the algorithm convergence to the maximum of the likelihood function and a good performance in terms of Mean Square Error (MSE)

Optimal Energy Management For Energy Harvesting Transmitter And Receiver With Helper

We study energy harvesting (EH) transmitter and receiver, where the receiver decodes data using the harvested energy from the nature and from an independent EH node, named helper. Helper cooperates with the receiver by transferring its harvested energy to the receiver over an orthogonal fading channel. We study an offline optimal power management policy to maximize the reliable information rate. The harvested energy in all three nodes are assumed to be known. We consider four different scenarios; First, for the case that both transmitter and the receiver have batteries, we show that the optimal policy is transferring the helper\u27s harvested energy to the receiver, immediately. Next, for the case of non-battery receiver and full power transmitter, we model a virtual EH receiver with minimum energy constraint to achieve an optimal policy. Then, we consider a non-battery EH receiver and EH transmitter with battery. Finally, we derive optimal power management wherein neither the transmitter nor the receiver have batteries. We propose three iterative algorithms to compute optimal energy management policies. Numerical results are presented to corroborate the advantage of employing the helper