Optimized constellations for two-way wireless relaying with physical network coding
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TLDR
The proposed modulation scheme can significantly improve end-to-end throughput for two-way relaying systems and is applicable to a relaying system using higher-level modulations of 16QAM in the MA stage.Abstract:
We investigate modulation schemes optimized for two-way wireless relaying systems, for which network coding is employed at the physical layer. We consider network coding based on denoise-and-forward (DNF) protocol, which consists of two stages: multiple access (MA) stage, where two terminals transmit simultaneously towards a relay, and broadcast (BC) stage, where the relay transmits towards the both terminals. We introduce a design principle of modulation and network coding, considering the superposed constellations during the MA stage. For the case of QPSK modulations at the MA stage, we show that QPSK constellations with an exclusive-or (XOR) network coding do not always offer the best transmission for the BC stage, and that there are several channel conditions in which unconventional 5-ary constellations lead to a better throughput performance. Through the use of sphere packing, we optimize the constellation for such an irregular network coding. We further discuss the design issue of the modulation in the case when the relay exploits diversity receptions such as multiple-antenna diversity and path diversity in frequency-selective fading. In addition, we apply our design strategy to a relaying system using higher-level modulations of 16QAM in the MA stage. Performance evaluations confirm that the proposed scheme can significantly improve end-to-end throughput for two-way relaying systems.read more
Citations
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Journal ArticleDOI
Physical layer network coding for wireless multi-way relaying with finite signal sets
TL;DR: This survey article considers the wireless multi-way relaying scenario, in which there is no direct link connecting the nodes and multiple nodes exchange information with the help of a relay node, and discusses about the extension of the schemes developed for the two-way and three way relaying scenarios.
Journal ArticleDOI
Optimal energy-efficient scheme for two-way relay channel using physical layer network coding
TL;DR: In this article, a joint power allocation and relay selection scheme was proposed to minimize the transmit power with required rates in a two-way relay channel using amplify-and-forward protocol of physical layer network coding.
Relay-Assisted Spectrum and Infrastructure Sharing between Multiple Operators
Jianhui Li,Jianshu Zhang,Florian Roemer,Martin Haardt,Christian Scheunert,Miroslav Hekrdla,Jan Sykora +6 more
TL;DR: In this article, the authors proposed a relay-assisted physical resource sharing scheme to improve the spectral efficiency, enhance the coverage, and decrease the expenditures for opera- tors by sharing the spectrum and the relay.
Proceedings ArticleDOI
Optimal power allocation and network beamforming for OFDM-based relay networks
TL;DR: The simulation result shows that the proposed algorithm significantly outperform an equal power allocation scheme, where all subcarriers at all nodes receive the same levels of power and the total power is equal to that consumed in the proposed solution.
Proceedings ArticleDOI
Performance of AdaBoost classifier in recognition of superposed modulations for MIMO TWRC with physical-layer network coding
TL;DR: An algorithm for recognition of sources modulations for MIMO TWRC with PLNC is proposed and simulation results show the ability of the proposed algorithm to provide a good recognition performance at acceptable signal-to-noise values.
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