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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Proceedings ArticleDOI
Resource Allocation for Analog Network Coding Based Bidirectional Relaying
TL;DR: In this paper , the authors developed efficient power allocation schemes for bidirectional relaying when analog network coding is used, which reduced the number of transmissions in the network and increased the overall system rate.
Journal ArticleDOI
A Study on the Binary-Coded Physical-Layer Network Coding with High-Order Modulation Techniques
TL;DR: This paper proposes a signal detection method for the binary-coded PNC with high-order modulation, such as QPSK and 16QAM, at the source nodes, while the conventional scheme only consider the BPSK at source nodes.
Patent
Methods for transmitting and receiving a digital signal implementing at least one multi-user relay in a cooperative network, and corresponding computer program and devices
TL;DR: In this paper, a method for transmitting a digital signal in the form of code words, each including information bits and detection or error correction bits, is proposed, where at least two sources transmit first code words to at least one receiver via a transmission channel, and at least a relay device implements the following steps.
Proceedings ArticleDOI
Semantic Communication-Empowered Physical-layer Network Coding
TL;DR: Experimental results show that the SC-PNC TWRC achieves high and stable reconstruction quality for images under different channel conditions and relative phase offsets, compared with the conventional bit-oriented counterparts.
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