Achievable rate analysis and maximisation for the SWIPT‐based half‐duplex quantise‐and‐forward cooperation in IoT networks

Abstract

To achieve reliable and green communication in the internet of things (IoT) networks, the authors extend the traditional half-duplex quantise-and-forward (QF) cooperation into the simultaneous wireless information and power transfer (SWIPT) regime. This study investigates the achievable rate of the SWIPT-based half-duplex QF cooperation with the channel state information available only at the receivers. The source and destination are provided by the external power supply and the relay simultaneously implements the information transmission and the energy harvesting by SWIPT technology with the power-splitting protocol. The achievable rate of the proposed system over the additive white Gaussian noise channels is analysed and further maximised by optimising the power-splitting factor. Furthermore, the expected rate of the proposed system over the slow-fading channels is analysed. Theoretical analysis and simulation results show that the achievable rate or expected rate of the SWIPT-based QF cooperation is obviously superior to that of the SWIPT-based amplify-and-forward or SWIPT-based decode-and-forward cooperation. Meanwhile, the SWIPT-based QF cooperation can achieve similar performance to the traditional QF cooperation when the external power supply at the relay is not provided.