2. BER Analysis of Time switching
and Power splitting protocols in
Wireless cooperative
communication
-Bevek Subba
(ECE department)
3. What is cooperative communication?
Figure 1: Direct communication
Figure 2: Cooperative communication uses relay
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4. UMTS capacity & coverage extension
Figure 3: Distributed relaying in UMTS
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5. WLAN capacity & coverage extension
Figure 4: Coverage extension of indoor WLAN towards outdoor users [Dohler,2007]
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7. Sensor network: A motivational factor
Figure 6: Distributed relaying sensor network for fire detection in forest [Akyildiz,2002]
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8. SWIPT
• Nodes should be SWIPT enabled
• RF signal carries both energy and information simultaneously
• Two resources in communication: Time and Power
SWIPT: Simultaneous Wireless
Information and Power Transfer
Time switching Power Splitting
Zhang, 2012
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9. Time switching
• Relay spends some time for EH and the remaining time for
information processing
S R Dhsr hrd
nsr nrd
Figure 7: Time switching protocol
Nasir, 2013
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10. 𝐸𝑡𝑠 = η. 𝑃𝑠. 𝑇. α. ℎ𝑠 𝑟
𝐸𝑡𝑠= Energy harvested at relay in time switching
η = Channel gain
𝑃 𝑠 = Transmitted power from source
𝑇 = Time block
α = Time allocated for energy harvesting
ℎ 𝑠𝑟 = Channel coefficient between source and relay
𝑃 𝑟=Transmitted power by relay
x =Transmitted signal
𝑥= Remodulated signal
𝑦 𝑟𝑑=Received signal at the receiver
𝑃 𝑟=
𝐸𝑡𝑠
(1−α)
𝑇
2
.
.
yrd= 𝑃 𝑟ℎ 𝑟𝑑 𝑥 + 𝑛 𝑟𝑑
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11. Power splitting
• The relay uses portion of received power for energy harvesting and
the remaining power for information processing
Figure 8: Power splitting protocol
Nasir, 2013
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12. 𝐸 𝑝𝑠 = (η. ρ. 𝑃𝑠. 𝑇. ℎ𝑠𝑟)/2
𝐸 𝑝𝑠= Energy harvested at relay in power splitting
η = Channel gain
𝑃 𝑠 = Transmitted power from source
𝑇 = Time block
ρ = Portion of power for energy harvesting
ℎ 𝑠𝑟 = Channel coefficient between source and relay
𝑃 𝑟=Transmitted power by relay
x =Transmitted signal
𝑥= Re-modulated signal
𝑦 𝑟𝑑= Received signal at the receiver
𝑃 𝑟=Eps
.
.
yrd= Pr(1 − ρ)ℎ 𝑟𝑑 𝑥 + 𝑛 𝑟𝑑
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14. Future scope
• Outage Probability
• Consideration with random wireless channel
• Throughput
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15. References
• http://perso.rd.francetelecom.fr/dohler/
• A.A. Nasir, X. Zhou, S. Durrani, R.A. Kennedy, Relaying protocols for wireless energy harvesting and
information processing, IEEE Trans. Wirel. Commun. 12 (7) (2013) 3622–3636.
• I.F.Akyildiz, W.Su. Y. Sankarasubramaniam, E. Cayiroi, “Wireless sensor network: A survey,” Computer
Networks, 34(4):393-422, March 2002
• T. D. Perera, D.N.K. Jayakody, “Analysis of time-switching and power-splitting protocols in wireless-powered
cooperative communication system, Physical Communication Elsevier (2018) 141-151
• L. Liu, R. Zhang, and K.-C. Chua, “Wireless information transfer with opportunistic energy harvesting,”
accepted for publication in IEEE Trans. Wireless Commun., 2012. Available: http://arxiv.org/abs/1204.2035
• D.N.K. Jayakody, J. Thompson, S. Chatzinotas, S. Durrani, Wireless Information and Power Transfer: A New
Paradigm for Green Communications, Springer- Verlag New York, USA, April 2018.
• D. Deng, M. Yu, J. Xia, Z. Na, J. Zhao, Q. Yang, Wireless powered cooperative communications with direct
links over correlated channels, Phys. Commun.28 (2018) 147–153.
• Y. Feng, V.C.M. Leung, F. Ji, Performance study for SWIPT cooperative communication systems in shadowed
Nakagami fading channels, IEEE Trans. Wirel. Commun. 17 (2) (2018) 1199–1211,
http://dx.doi.org/10.1109/TWC. 2017.2776933.
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