Joint Transmit Power Allocation and Splitting for SWIPT Aided OFDM-IDMA in Wireless Sensor Networks

Shanshan Li,Cheng-Xiang Wang,Wensheng Zhang,Xiaotian Zhou,Dongfeng Yuan

doi:10.3390/s17071566

Abstract

In this paper, we propose to combine Orthogonal Frequency Division Multiplexing-Interleave Division Multiple Access (OFDM-IDMA) with Simultaneous Wireless Information and Power Transfer (SWIPT), resulting in SWIPT aided OFDM-IDMA scheme for power-limited sensor networks. In the proposed system, the Receive Node (RN) applies Power Splitting (PS) to coordinate the Energy Harvesting (EH) and Information Decoding (ID) process, where the harvested energy is utilized to guarantee the iterative Multi-User Detection (MUD) of IDMA to work under sufficient number of iterations. Our objective is to minimize the total transmit power of Source Node (SN), while satisfying the requirements of both minimum harvested energy and Bit Error Rate (BER) performance from individual receive nodes. We formulate such a problem as a joint power allocation and splitting one, where the iteration number of MUD is also taken into consideration as the key parameter to affect both EH and ID constraints. To solve it, a sub-optimal algorithm is proposed to determine the power profile, PS ratio and iteration number of MUD in an iterative manner. Simulation results verify that the proposed algorithm can provide significant performance improvement.

Highlights

Allowing multiple users to communicate with each other in the same network, MultipleAccess (MA) has been considered as one of the most important techniques in the area of wireless communications
We have investigated the joint power allocation and power splitting problem in Simultaneous Wireless Information and Power Transfer (SWIPT) aided Orthogonal Frequency Division Multiplexing (OFDM)-Interleave Division Multiple Access (IDMA) for power limited networks
Due to the features of iterative Multi-User Detection (MUD) employed in OFDM-IDMA, both Energy Harvesting (EH) and Information Decoding (ID) requirements are affected by the number of iterations

Summary

Introduction

Allowing multiple users to communicate with each other in the same network, MultipleAccess (MA) has been considered as one of the most important techniques in the area of wireless communications. It is widely recognized that the existing MA schemes can be classified into two categories, namely, Orthogonal Multiple Access (OMA), and Non-orthogonal Multiple Access (NOMA) [1]. In the former case, different users access to the network utilizing different resource blocks (i.e., frequency, time, or orthogonal codes). The Multiple Access Interference (MAI) is absent, leading to the lower detection complexity. While for the latter, multiple users are served with the same resource block, where MAI exists but can be mitigated through Successive Interference Cancellation (SIC). Despite of the higher complexity paid for interference cancellation, NOMA is still expected to be the most potential candidate for the future communication networks

Objectives

Results

Conclusion