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
Sum-Rate Optimal Network Beamforming and Subcarrier Power Allocation for Multi-Carrier Asynchronous Two-Way Relay Networks
TL;DR: It is proved rigorously that maximizing the sum-rate under a total power budget, through jointly optimal network beamforming at the relays and subcarrier power loading at the two transceivers, leads to a relay selection scheme, where only those relays which contribute to one tap of the end-to-end channel impulse response, have to be active and the remainder of the relay has to be switched off.
Journal ArticleDOI
Design and Analysis of Multi-Level Physical-Layer Network Coding for Gaussian Two-Way Relay Channels
TL;DR: This paper first derive the achievable rate for the transmission of arbitrary constellations and then proves that MPLNC with multistage decoding (MPLNC/MSD) can achieve the achieved rate if binary code rates are properly chosen for both sources.
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Linear Precoder-Decoder Design of MIMO Device-to-Device Communication Underlaying Cellular Communication
TL;DR: This paper proposes linear precoder-decoder schemes for a multiple-input multiple-output (MIMO) underlay device-to-device (D2D) communication system by considering two D2D modes: two-way relaying based D1D and direct D2 D.
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Cellular Multiuser Two-Way MIMO AF Relaying via Signal Space Alignment: Minimum Weighted SINR Maximization
E. Chiu,Vincent K. N. Lau +1 more
TL;DR: This paper applies an interference management model exploiting signal space alignment and proposes a transceiver design algorithm, which allows for alleviating the loss in spectral efficiency due to half-duplex operation and providing flexible performance optimization accounting for each user's quality of service priorities.
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Design and Analysis of Heterogeneous Physical Layer Network Coding
Haoyuan Zhang,Lei Zheng,Lin Cai +2 more
TL;DR: Physical layer network coding with heterogeneous modulations (HePNC) is proposed for the asymmetric two-way relay channel (TWRC) scenario and can substantially enhance the throughput and energy efficiency compared with the existing PNC.
References
More filters
Book
Elements of information theory
Thomas M. Cover,Joy A. Thomas +1 more
TL;DR: The author examines the role of entropy, inequality, and randomness in the design of codes and the construction of codes in the rapidly changing environment.
Journal ArticleDOI
Network information flow
TL;DR: This work reveals that it is in general not optimal to regard the information to be multicast as a "fluid" which can simply be routed or replicated, and by employing coding at the nodes, which the work refers to as network coding, bandwidth can in general be saved.
Book
Sphere packings, lattices, and groups
TL;DR: The second edition of this book continues to pursue the question: what is the most efficient way to pack a large number of equal spheres in n-dimensional Euclidean space?
Journal ArticleDOI
XORs in the air: practical wireless network coding
TL;DR: The results show that using COPE at the forwarding layer, without modifying routing and higher layers, increases network throughput, and the gains vary from a few percent to several folds depending on the traffic pattern, congestion level, and transport protocol.
Journal ArticleDOI
Spectral efficient protocols for half-duplex fading relay channels
B. Rankov,Armin Wittneben +1 more
TL;DR: Two new half-duplex relaying protocols are proposed that avoid the pre-log factor one-half in corresponding capacity expressions and it is shown that both protocols recover a significant portion of the half- duplex loss.