Abstract
Existing research on a simultaneous wireless information and power transfer (SWIPT) system is based on the assumption of Gaussian inputs. However, the optimal design on Gaussian inputs may lead to dramatic performance loss for practical systems with finite-Alphabet inputs. This paper focuses on the precoder design for a SWIPT system with finite-Alphabet inputs and instantaneous channel state information over a multiple-input multiple-output channel. We formulate the optimal precoder design as an optimization problem, in which the objective is to maximize the mutual information over the channel from the transmitter to the information receiver under the constraints of transmit power and harvested energy threshold. The formulated problem is NP-hard, so a global optimal solution cannot be found within the polynomial time. The main contributions of this paper are as follows: 1) By using its structure, the NP-hard problem is relaxed to a semidefinite programming problem. Then, a general solving framework for both co-located and separated receiver cases, based on the semidefinite relaxation (SDR) technique, is developed to achieve a near optimal precoder. 2) For the case of co-located receivers, we show that the optimal precoder design is a concave problem with respect to power allocation; then, a specific algorithm for co-located receivers is proposed. Compared with the general SDR-based method, the specific algorithm for co-located receivers exhibits almost the same performance but much lower complexity. 3) The performance of several practical co-located receiver designs is analyzed in SWIPT systems with finite-Alphabet inputs. Finally, we provide simulation results to show the efficacy of the proposed algorithms.
Recommended Citation
X. Zhu et al., "Precoder Design for Simultaneous Wireless Information and Power Transfer Systems with Finite-Alphabet Inputs," IEEE Transactions on Vehicular Technology, vol. 66, no. 10, pp. 9085 - 9097, article no. 7942091, Institute of Electrical and Electronics Engineers, Oct 2017.
The definitive version is available at https://doi.org/10.1109/TVT.2017.2712774
Department(s)
Electrical and Computer Engineering
Keywords and Phrases
Finite-Alphabet inputs; precoder design; simultaneous wireless information and power transfer (SWIPT)
International Standard Serial Number (ISSN)
0018-9545
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2024 Institute of Electrical and Electronics Engineers, All rights reserved.
Publication Date
01 Oct 2017
Comments
Fundamental Research Funds for the Central Universities, Grant 61101034