PMID- 34450907
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20210830
IS  - 1424-8220 (Electronic)
IS  - 1424-8220 (Linking)
VI  - 21
IP  - 16
DP  - 2021 Aug 13
TI  - Time Switching Based Wireless Powered Relay Transmission with Uplink NOMA.
LID - 10.3390/s21165467 [doi]
LID - 5467
AB  - Non-orthogonal multiple access (NOMA) utilizes power domain multiplexing to 
      improve spectrum efficiency compared with orthogonal multiple access (OMA). In 
      the Internet of Things (IoT) uplink NOMA networks, if the channel between the 
      far-end node and the base station is in deep fading, allocating larger 
      transmitting power for this node cannot achieve higher spectrum efficiency and 
      overall system throughput. Relay cooperative communication reduces the 
      transmitting power at the far-end node but leads to extra energy expenditure at 
      the relay node. Fortunately, simultaneous wireless information and power transfer 
      (SWIPT) is advocated in energy-constrained IoT networks to save energy 
      consumption. However, early works all focus on energy harvesting (EH) from one 
      source node or one dedicated power supply station. In this paper, we propose a 
      time switching based wireless powered relay transmission model with uplink NOMA 
      where our EH technique can harvest energy from two simultaneously transmitting 
      nodes. More importantly, by optimizing relay position more energy is harvested 
      from the near-end node at the relay and relay signal attenuation to the 
      destination is reduced as well. Furthermore, the closed-form expressions of 
      outage probability and overall system throughput are derived, and numerical 
      results prove that NOMA in our EH scheme achieves better performance compared to 
      the traditional EH scheme and OMA by optimizing the position of the relay node, 
      time switching factor and so on.
FAU - Lin, Zhihua
AU  - Lin Z
AD  - Faculty of Information Technology, Macau University of Science and Technology, 
      Avenida Wai Long, Taipa 999078, Macau, China.
AD  - College of Electronic and Information Science, Fujian Jiangxia University, Fuzhou 
      350108, China.
FAU - Cao, Shihua
AU  - Cao S
AD  - QianJiang College, Hangzhou Normal University, Hangzhou 310012, China.
FAU - Li, Jianqing
AU  - Li J
AUID- ORCID: 0000-0002-6768-1483
AD  - Faculty of Information Technology, Macau University of Science and Technology, 
      Avenida Wai Long, Taipa 999078, Macau, China.
LA  - eng
PT  - Journal Article
DEP - 20210813
PL  - Switzerland
TA  - Sensors (Basel)
JT  - Sensors (Basel, Switzerland)
JID - 101204366
SB  - IM
PMC - PMC8399243
OTO - NOTNLM
OT  - energy harvesting
OT  - relay cooperative communication
OT  - spectrum efficiency
OT  - time switching
OT  - uplink NOMA
COIS- The authors declare no conflict of interest.
EDAT- 2021/08/29 06:00
MHDA- 2021/08/29 06:01
PMCR- 2021/08/13
CRDT- 2021/08/28 01:01
PHST- 2021/07/06 00:00 [received]
PHST- 2021/07/31 00:00 [revised]
PHST- 2021/08/09 00:00 [accepted]
PHST- 2021/08/28 01:01 [entrez]
PHST- 2021/08/29 06:00 [pubmed]
PHST- 2021/08/29 06:01 [medline]
PHST- 2021/08/13 00:00 [pmc-release]
AID - s21165467 [pii]
AID - sensors-21-05467 [pii]
AID - 10.3390/s21165467 [doi]
PST - epublish
SO  - Sensors (Basel). 2021 Aug 13;21(16):5467. doi: 10.3390/s21165467.