Energy-Rate Trade-Off Analysis for SWIPT in Massive MIMO Systems

Author

Rajan Shrestha, Southern Illinois University CarbondaleFollow

Date of Award

8-1-2018

Degree Name

Master of Science

Department

Electrical and Computer Engineering

First Advisor

Baduge, Gayan

Abstract

The concept of simultaneous wireless information and power transfer (SWIPT) has recently been gaining research attention due to the fact that radio frequency (RF) signals can carry both information and energy at the same time. With the employment of advance multi-antenna techniques and transmission technologies such as massive multiple-input multiple-output (MIMO) and relaying, the SWIPT can be realized in practice, and thus the harvested energy from the RF signals can be utilized to power-up low-power devices including energy constrained wireless sensor networks and rechargeable batteries. In this thesis, firstly, a max-min fairness optimal rate-energy trade-off is investigated for SWIPT in practically-viable training-based massive MIMO downlink (DL) with full-dimensional (FD) digital processing. A max-min fairness optimal power control algorithm is developed to maximize the harvested energy and achievable rate of the user node with the weakest end-to-end channel gain. Thereby, the max-min fairness optimal energy-rate trade-off is derived to guarantee fairness across spatially-distributed SWIPT users irrespective of their near-far effect. Secondly, the performance gap between the hybrid processing and FD digital processing is quantified for SWIPT in massive MIMO systems. Thirdly, a max-min fairness optimal rate-energy trade-off is investigated for SWIPT in practically-viable training-based relay assisted massive MIMO DL with FD digital processing. Finally, our final research investigates the performance of SWIPT in a hybrid relay-assisted massive MIMO DL with FD digital processing. The harvested energy and the achievable sum rate expressions are derived, and thereby, the detrimental effects of channel estimation errors and pilot contamination are quantified. These performance metrics are derived for a generalized wireless energy harvesting protocol, which facilitates performance analysis for both time-switching (TS) and power-splitting (PS) protocols. Moreover, the joint and individual effects of TS factor and PS ratio are investigated and the achievable rate-energy trade-off is quantified.