Optimized constellations for two-way wireless relaying with physical network coding
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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Relay Selection in Two-Hop Wireless Communications
TL;DR: Thesis (Ph.D, Electrical & Computer Engineering) as mentioned in this paper, 2010-08-23 15:29:50.026 -15:29.50.000.
Proceedings ArticleDOI
Physical-layer network coding with multiple antennas: An enabling technology for smart cities
TL;DR: Simulation results confirm that full diversity order can be achieved in a PNC system by using antenna selection schemes based on the Euclidean distance metric, and propose simple and effective solutions based upon the use of multiple antenna systems.
Journal ArticleDOI
Denoising Mapping Utilizing Constellation Symmetry in Denoise-and-Forward Two-Way Relay Channels
TL;DR: The denoising mapping with the closest-neighbor clustering (CNC) method in denoise-and-forward two-way relay channels is studied and an enormous complexity reduction can be achieved.
Journal ArticleDOI
Comprehensive Performance Analysis of Two-Way Multi-Relay System with Amplify-and-Forward Relaying
Journal ArticleDOI
Network-coding-based hybrid-ARQ for bi-directional regenerative relaying
TL;DR: It is demonstrated that the proposed protocol outperforms the traditional hybrid retransmission request protocol for two-way relaying system by a throughput gain of about 9% when the relay lies close to the midpoint of the two users.
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