[1] [1] Andrews J G, Buzzi S, Choi W, et al. What will 5G be? ［J］. IEEE Journal on Selected Areas in Communications, 2014,32(6):1065-1082.

[2] [2] Liu X D, Chen Z Z, Wang Y H, et al. BER Analysis of NOMA-enabled Visible Light Communication Systems with Different Modulations ［J］.IEEE Transactions on Vehicular Technology,2019,68(11):10807-10821.

[3] [3] Uysal M,Miramirkhani F,Narmanlioglu O,et al.IEEE 802.15.7R1 Reference Channel Models for Visible Light Communications ［J］. IEEE Communications Magazine, 2017, 55(1):212-217.

[5] [5] Pathak P H, Feng X T, Hu P F, et al. Visible Light Communication, Networking and Sensing: A Survey, Potential and Challenges［J］. IEEE Communications Surveys & Tutorials, 2015, 17(4):2047-2077.

[7] [7] Yin L, Popoola W O, Wu X P, et al. Performance Evaluation of Non-Orthogonal Multiple Access in Visible Light Communication［J］. IEEE Transactions on Communications, 2016, 64(12):5162-5175.

[8] [8] Kizilirmak R C, Narmanlioglu O, Uysal M. Relay-assisted OFDM-based Visible Light Communications ［J］. IEEE Transactions on Communications, 2015, 63(10):3765-3778.

[9] [9] Feng L F, Rose Q Y, Wang J P, et al. Deployment Issues and Performance Study in a Relay-assisted Indoor Visible Light Communication system［J］. IEEE Systems Journal, 2019, 13(1):562-570.

[11] [11] Yang Y, Zeng Z M, Cheng J L, et al. A Relay-Assisted OFDM System for VLC Uplink Transmission ［J］. IEEE Transactions on Communication, 2019, 67(9):6268-6281.

[12] [12] Xiao Y, DIamantoulakis P D, Fang Z Q, et al. Hybrid Lightwave/RF Cooperative NOMA Networks［J］. IEEE Transactions on Wireless Communications, 2020, 19(2):1154-1166.

[13] [13] Sun Z G, Yu H Y, Zhu Y J, et al. A Superimposed Relaying Strategy and Power Allocation for Outdoor Visible Light Communications ［J］. IEEE Access, 2017, 5:9555-9561.

[14] [14] Nauryzbayev G, Abdallah M, Al-Dhahir N. Outage Analysis of Cognitive Electric Vehicular Networks over Mixed RF/VLC Channels ［J］. IEEE Transactions on Cognitive Communications and Networking, 2020, 6(3):1096-1107.

[15] [15] Yang Y, Zeng Z M, Cheng J L, et al. An Amplify-and-Forward based OFDM System for VLC Uplink Transmission［C］//IEEE Global Communications Conference 2017. Singapore: IEEE, 2017, 17506706:1-6.

[17] [17] Han Y, Zhou X T, Yang L Q, et al. A Bipartite Matching based User Pairing Scheme for Hybrid VLC-RF NOMA Systems［C］//International Conference on Computing, Networking and Communications (ICNC) 2018. Maui, HI, USA: IEEE, 2018:480-485.

[18] [18] Alkhori J, Nauryzbayev G, Abdallah M, et al. Secrecy Performance of Decode-and-Forward based Hybrid RF/VLC Relaying Systems ［J］. IEEE Access, 2019, 7:10844-10856.

[19] [19] Papanikolaou V K, Diamantoulakis P D, Karagiannidis G K, et al. User Grouping for Hybrid VLC/RF Networks with NOMA: A Coalitional Game Approach ［J］. IEEE Access, 2019, 7:103299-103309.

[20] [20] Rakia T, Yang H C, Gebali F, et al. Optimal Design of Dual-Hop VLC/RF Communication System with Energy Harvesting［J］. IEEE Communications Letters, 2016,20(10):1979-1982.

[21] [21] Pan G F, Ye J, Ding Z G, et al. Secure Hybrid VLC-RF Systems with Light Energy Harvesting ［J］. IEEE Transactions on Communications, 2017,65(10):4348-4359.

[22] [22] Narmanlioglu O, Kizilirmak R C, Uysal M. Relay-Assisted OFDM-based Visible Light Communications over Multipath Channels［C］//17th International Conference on Transparent Optical Networks (ICTON) 2015. Budapest, Hungary: IEEE, 2015:1-4.

[24] [24] Gheth W, Rabie K M, Adebisi B, et al. Energy-per-Bit Performance Analysis of Relay-based Visible Light Communication Systems［J］. Physical Communication, 2019, 35(AUG):100699.1-100699.8.

[25] [25] Dissanayake S D, Armstrong J. Comparison of ACO-OFDM, DCO-OFDM and ADO-OFDM in IM/DD Systems ［J］. Journal of Lightwave Technology, 2013, 31(7):1063-1072.

[27] [27] Na Z Y, Wang Y Y, Xiong M D, et al. Modeling and Throughput Analysis of an ADO-OFDM based Relay-Assisted VLC System for 5G Networks ［J］. IEEE Access, 2018, 6:17586-17594.

[29] [29] Zhou X T, Li S S, Zhang H X, et al. Cooperative NOMA based VLC/RF System with Simultaneous Wireless Information and Power Transfer［C］//IEEE/CIC International Conference on Communications in China (ICCC) 2018. Beijing, China: IEEE, 2018:100-105.

[30] [30] Chen C, Zhong W D, Yang H L, et al. On the Performance of MIMO NOMA based Visible Light Communication Systems ［J］. IEEE Photonics Technology Letters, 2018, 30(4):307-310.

[31] [31] Nauryzbayev G, Abdallah M, Elgala H. Outage of SEE-OFDM VLC-NOMA Networks ［J］. IEEE Photonics Technology Letters, 2019, 31(2):121-124.

[32] [32] Arafa A, Panayirci E, Poor H V, et al. Relay-Aided Secure Broadcasting for Visible Light Communications ［J］. IEEE Transactions on Communications, 2019, 67(6):4227-4239.

[33] [33] Narmanlioglu O, Kizilirmak R C, Miramirkhani F, et al. Cooperative Visible Light Communications with Full-Duplex Relaying［J］. IEEE Photonics Journal, 2017, 9(3):1-11.

[34] [34] Namdar M, Basgumus A, Tsiftsis T A, et al. Outage and BER Performances of Indoor Relay-Assisted Hybrid RF/VLC Systems［J］. Iet Communications, 2018, 12(17):2104-2109.

[35] [35] Pan G F, Ye J, Zhang C, et al. Secure Cooperative Hybrid VLC-RF Systems［J］. IEEE Transactions on Wireless Communications, 2020, 19(11):7097 - 7107.

[36] [36] Alkhori J, Nauryzbayev G, Abdallah M, et al. Secrecy Capacity of Hybrid RF/VLC DF Relaying Networks with Jamming［C］//International Conference on Computing Networking and Communications (ICNC) 2019. Honolulu, HI, USA: IEEE, 2019:67-72.

[37] [37] Zenaidi M R, Rezki Z, Abdallah M, et al. Achievable Rate-Region of VLC/RF Communications with an Energy Harvesting Relay［C］//IEEE Global Communications Conference 2017. Singapore: IEEE, 2017,17506105:1-7.