Channel Decoding for Nonbinary Physical-Layer Network Coding in Two-Way Relay Systems

In this paper, we propose a generalized channel decoding scheme for nonbinary physical-layer network coding (CD-NC) in two-way relay channels (TWRCs), where two source nodes A and B exchange their nonbinary symbols via a relay. The two sources use the same nonbinary low-density parity-check (LDPC) c...

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Vydáno v:	IEEE transactions on vehicular technology Ročník 68; číslo 1; s. 628 - 640
Hlavní autoři:	Chen, Pingping, Shi, Long, Liew, Soung Chang, Fang, Yi, Cai, Kui
Médium:	Journal Article
Jazyk:	angličtina
Vydáno:	New York IEEE 01.01.2019 The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Témata:	Algorithms Binary system channel decoding Channels Codes Coding Complexity Computer simulation Decoding Error correcting codes Modulation Network coding Noise propagation nonbinary LDPC Parity check codes Performance degradation Physical-layer network coding Pulse amplitude modulation Random noise Relay systems Relays Signal to noise ratio Symbols two-way relay channel (TWRC) Upper bound
ISSN:	0018-9545, 1939-9359
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Abstract	In this paper, we propose a generalized channel decoding scheme for nonbinary physical-layer network coding (CD-NC) in two-way relay channels (TWRCs), where two source nodes A and B exchange their nonbinary symbols via a relay. The two sources use the same nonbinary low-density parity-check (LDPC) channel code over the integer ring <inline-formula><tex-math notation="LaTeX">\mathbb {Z}_M</tex-math></inline-formula> and <inline-formula><tex-math notation="LaTeX">M</tex-math></inline-formula>-pulse-amplitude modulation, respectively. The existing channel decoding schemes for nonbinary network coding suffer severe rate loss compared with the cut-set bound of TWRC, especially in the low-to-medium signal-to-noise ratio regime. The proposed CD-NC can decrease the rate loss. Our contributions are as follows: 1) We develop a generalized nonbinary sum product algorithm (G-SPA) for CD-NC according to the principle of virtual encoding of the superimposed symbols. Simulation results show that our CD-NC can achieve significant performance gains over the conventional nonbinary network coding for both additive white Gaussian noise and fading channels; and 2) We exploit two-dimensional fast-Fourier-transform-based belief propagation (2-D-FFT-BP) and extended min-sum (EMS) decoding algorithms to reduce the decoding complexity of G-SPA. Simulation results show that the 2-D-FFT-BP has the same performance as G-SPA, while EMS can greatly reduce the decoding complexity of G-SPA at the cost of slight performance degradation.
AbstractList	In this paper, we propose a generalized channel decoding scheme for nonbinary physical-layer network coding (CD-NC) in two-way relay channels (TWRCs), where two source nodes A and B exchange their nonbinary symbols via a relay. The two sources use the same nonbinary low-density parity-check (LDPC) channel code over the integer ring [Formula Omitted] and [Formula Omitted]-pulse-amplitude modulation, respectively. The existing channel decoding schemes for nonbinary network coding suffer severe rate loss compared with the cut-set bound of TWRC, especially in the low-to-medium signal-to-noise ratio regime. The proposed CD-NC can decrease the rate loss. Our contributions are as follows: 1) We develop a generalized nonbinary sum product algorithm (G-SPA) for CD-NC according to the principle of virtual encoding of the superimposed symbols. Simulation results show that our CD-NC can achieve significant performance gains over the conventional nonbinary network coding for both additive white Gaussian noise and fading channels; and 2) We exploit two-dimensional fast-Fourier-transform-based belief propagation (2-D-FFT-BP) and extended min-sum (EMS) decoding algorithms to reduce the decoding complexity of G-SPA. Simulation results show that the 2-D-FFT-BP has the same performance as G-SPA, while EMS can greatly reduce the decoding complexity of G-SPA at the cost of slight performance degradation. In this paper, we propose a generalized channel decoding scheme for nonbinary physical-layer network coding (CD-NC) in two-way relay channels (TWRCs), where two source nodes A and B exchange their nonbinary symbols via a relay. The two sources use the same nonbinary low-density parity-check (LDPC) channel code over the integer ring <inline-formula><tex-math notation="LaTeX">\mathbb {Z}_M</tex-math></inline-formula> and <inline-formula><tex-math notation="LaTeX">M</tex-math></inline-formula>-pulse-amplitude modulation, respectively. The existing channel decoding schemes for nonbinary network coding suffer severe rate loss compared with the cut-set bound of TWRC, especially in the low-to-medium signal-to-noise ratio regime. The proposed CD-NC can decrease the rate loss. Our contributions are as follows: 1) We develop a generalized nonbinary sum product algorithm (G-SPA) for CD-NC according to the principle of virtual encoding of the superimposed symbols. Simulation results show that our CD-NC can achieve significant performance gains over the conventional nonbinary network coding for both additive white Gaussian noise and fading channels; and 2) We exploit two-dimensional fast-Fourier-transform-based belief propagation (2-D-FFT-BP) and extended min-sum (EMS) decoding algorithms to reduce the decoding complexity of G-SPA. Simulation results show that the 2-D-FFT-BP has the same performance as G-SPA, while EMS can greatly reduce the decoding complexity of G-SPA at the cost of slight performance degradation.
Author	Shi, Long Cai, Kui Fang, Yi Liew, Soung Chang Chen, Pingping
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SubjectTerms	Algorithms Binary system channel decoding Channels Codes Coding Complexity Computer simulation Decoding Error correcting codes Modulation Network coding Noise propagation nonbinary LDPC Parity check codes Performance degradation Physical-layer network coding Pulse amplitude modulation Random noise Relay systems Relays Signal to noise ratio Symbols two-way relay channel (TWRC) Upper bound
Title	Channel Decoding for Nonbinary Physical-Layer Network Coding in Two-Way Relay Systems
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