Paper Info
Title
A Better Than Alamouti OSTBC for MIMO Backscatter Communications
Abstract
Backscatter communications have received increasingly attention in Internet of Things (IoT) due to its advantages of requiring no internal battery and almost zero maintenance. However, the drawback of backscatter communications is that, its channel fades deeper than conventional channel. To improve the performance, multiple-input multiple-output (MIMO) techniques have been investigated for backscatter communications. By considering duty cycle, a particular behavior of backscatter communications, as a new performance criterion, we propose a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2 \times 2$ </tex-math></inline-formula> orthogonal space-time block code for MIMO backscatter communications. The new code is a rotation of the classical Alamouti code, and in MIMO backscatter channels, this simple rotation will incur an improved duty cycle for both linear and nonlinear energy harvester models, as well as a same, or even better symbol error rate performance. We provide both rigorous mathematical proofs and numerical simulations to show the above results. An interesting thing is that, this new code does not outperform Alamouti code in conventional MIMO channels, which indicates that the space-time code design criteria for conventional channels is not the optimal one for backscatter channels, and existing space-time codes should be reconsidered and/or redesigned to achieve a higher performance in MIMO backscatter communications.
Year
DOI
Venue
2022
10.1109/TWC.2021.3102111
IEEE Transactions on Wireless Communications
Keywords
DocType
Volume
Backscatter communications,wireless power transfer,space-time block code,MIMO,duty cycle
Journal
21
Issue
ISSN
Citations 
2
1536-1276
0
PageRank 
References 
Authors
0.34
0
5
Name
Order
Citations
PageRank
Huixu Luan111.02
Xie Xie201.01
Luyang Han301.35
Chen He421.70
Z. Jane Wang540655.43