TY - JOUR
T1 - NOMA for Energy-Efficient LiFi-Enabled Bidirectional IoT Communication
AU - Chen, Chen
AU - Fu, Shu
AU - Jian, Xin
AU - Liu, Min
AU - Deng, Xiong
AU - Ding, Zhiguo
N1 - Funding Information:
Manuscript received May 24, 2020; revised November 22, 2020; accepted January 8, 2021. Date of publication January 18, 2021; date of current version March 17, 2021. This work was supported in part by the National Natural Science Foundation of China under Grant 61901065 and Grant 61701054, and in part by the Fundamental Research Funds for the Central Universities under Grant 2020CDJQY-A001 and Grant 2020CDJGFWDZ014. The associate editor coordinating the review of this article and approving it for publication was M. Safari. (Corresponding author: Chen Chen.) Chen Chen and Shu Fu are with the School of Microelectronics and Communication Engineering, Chongqing University, Chongqing 400044, China, and also with the State Key Laboratory of Integrated Services Networks, Xidian University, Xi’an 710071, China (e-mail: [email protected]; [email protected]).
Publisher Copyright:
© 1972-2012 IEEE.
PY - 2021/3
Y1 - 2021/3
N2 - In this paper, we consider a light fidelity (LiFi)-enabled bidirectional Internet of Things (IoT) communication system, where visible light and infrared light are used in the downlink and uplink, respectively. In order to efficiently improve the energy efficiency (EE) of the bidirectional LiFi-IoT system, non-orthogonal multiple access (NOMA) with a quality-of-service (QoS)-guaranteed optimal power allocation (OPA) strategy is applied to maximize the EE of both downlink and uplink channels. We derive closed-form OPA sets based on the identification of the optimal decoding orders in both downlink and uplink channels, which can enable low-complexity power allocation. Moreover, we propose an adaptive channel and QoS-based user pairing approach by jointly considering users' channel gains and QoS requirements. We further analyze the EE and the user outage probability (UOP) performance of both downlink and uplink channels in the bidirectional LiFi-IoT system. Extensive analytical and simulation results demonstrate the superiority of NOMA with OPA in comparison to orthogonal multiple access (OMA) and NOMA with typical channel-based power allocation strategies. It is also shown that the proposed adaptive channel and QoS-based user pairing approach greatly outperforms individual channel/QoS-based approaches, especially when users have diverse QoS requirements.
AB - In this paper, we consider a light fidelity (LiFi)-enabled bidirectional Internet of Things (IoT) communication system, where visible light and infrared light are used in the downlink and uplink, respectively. In order to efficiently improve the energy efficiency (EE) of the bidirectional LiFi-IoT system, non-orthogonal multiple access (NOMA) with a quality-of-service (QoS)-guaranteed optimal power allocation (OPA) strategy is applied to maximize the EE of both downlink and uplink channels. We derive closed-form OPA sets based on the identification of the optimal decoding orders in both downlink and uplink channels, which can enable low-complexity power allocation. Moreover, we propose an adaptive channel and QoS-based user pairing approach by jointly considering users' channel gains and QoS requirements. We further analyze the EE and the user outage probability (UOP) performance of both downlink and uplink channels in the bidirectional LiFi-IoT system. Extensive analytical and simulation results demonstrate the superiority of NOMA with OPA in comparison to orthogonal multiple access (OMA) and NOMA with typical channel-based power allocation strategies. It is also shown that the proposed adaptive channel and QoS-based user pairing approach greatly outperforms individual channel/QoS-based approaches, especially when users have diverse QoS requirements.
KW - energy efficiency (EE)
KW - Internet of Things (IoT)
KW - light fidelity (LiFi)
KW - Non-orthogonal multiple access (NOMA)
KW - user outage probability (UOP)
UR - http://www.scopus.com/inward/record.url?scp=85099723898&partnerID=8YFLogxK
U2 - 10.1109/TCOMM.2021.3051912
DO - 10.1109/TCOMM.2021.3051912
M3 - Article
AN - SCOPUS:85099723898
SN - 0090-6778
VL - 69
SP - 1693
EP - 1706
JO - IEEE Transactions on Communications
JF - IEEE Transactions on Communications
IS - 3
M1 - 9326355
ER -