A Diplexer-Based Receiver for Simultaneous Wireless Information and Power Transfer

TL;DR

This paper introduces a novel diplexer-based receiver architecture for SWIPT systems that efficiently separates signals for simultaneous energy harvesting and information decoding, optimizing power usage in multiuser MISO setups.

Contribution

The paper proposes a new receiver design that utilizes both frequency components for energy and information, and formulates an optimization problem for power minimization in multiuser systems.

Findings

Power of harvested energy equals that of decoded information.

Diplexer acts as a power splitter with a 0.5 splitting factor.

Optimization problem solved via semi-definite relaxation.

Abstract

Simultaneous wireless information and power transfer (SWIPT) is an appealing research area because both information and energy can be delivered to wireless devices simultaneously. In this paper, we propose a diplexer-based receiver architecture that can utilizes both the doubling frequency and baseband signals after the mixer. The baseband signals are used for information decoding and the doubling frequency signals are converted to direct current for energy harvesting. We analyze the signal in the receiver and find that the power of the energy harvested is equal to that of information decoded. Therefore, the diplexer can be used as a power splitter with a power splitting factor of 0.5. Specifically, we consider a multiuser multi-input single-output (MISO) system, in which each user is equipped with the newly proposed receiver. The problem is formulated as an optimization problem that minimizes the total transmitted power subject to some constraints on each user's quality of service and energy harvesting demand. We show that the problem thus formulated is a non-convex quadratically constrained quadratic program (QCQP), which can be solved by semi-definite relaxation.