## 1 Introduction
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Reference** & **Communication Domain** & **Focus Area** \\ \hline
[43] & VLC & Karush–Kuhn–Tucker (KKT) optimality conditions to enhance sum-rate performance over that of OFDMA \\
[44] & VLC & Convex optimization applied to improve data rate of downlink NOMA-VLC \\
[45] & VLC & Iterative algorithm to attain an additional sum-rate gain of 10 Mbps for NOMA users compared to time division multiple access (TDMA) \\
[46] & VLC & Harris Hawks optimization to enhance sum-rate performance by jointly optimizing power allocation and placement of unmanned aerial vehicle (UAV) \\
[47] & VLC & Gradient projection (GP) algorithm to gain higher sum-rate performance than OMA \\
[48] & VLC & Interior point approach and zero forcing (ZF) pre-coding-based NOMA techniques outperform traditional NOMA and ZF \\
[49] & VLC & Energy-efficient power allocation (EPA) technique to improve energy efficiency of NOMA-based IoT networks \\
[50] & VLC & Power allocation and user pairing approaches for downlink VLC-NOMA \\
[51] & VLC & Analytical method and power allocation method for better maximum sum-rate than fixed power allocation (FPA) and GRPA \\
[52] & VLC & KKT optimality conditions to attain higher system sum-rate than FPA and NGDPA \\
[53] & Hybrid OMA and NOMA VLC & Dynamic programming-based layer-recursion model for better achievability \\
[54] & RF communication & Thugunt than traditional NOMA and TDMA \\
[55] & RF communication & Distance-dependent power allocation (DDPA) technique for mMIMO-aided NOMA \\
[56] & RF communication & Energy-efficient power allocation for multiple-user MIMO-NOMA \\
[57] & RF communication & Power allocation to ensure QoS requirements in NOMA systems \\
[58] & RF communication & Power allocation to ensure individual QoS requirements in downlink NOMA systems \\
[59] & Hybrid RF/FSO & Binary continuous phase modulation (CPM) with modulation is considered into downlink symbol-asynchronous non-orthogonal multiple access (ANOMA) to improve spectral and power efficiency \\
[60] & Hybrid RF/VSO & Superior performance of FSO backhauling for high-reliability and high-throughput \\
[61] & Hybrid RF/FSO & NOMA systems compared to RF backhauling \\
[62] & Hybrid RF/VLC & Superior outage performance for an FSO-RF system with NOMA under a dual energy harvesting (EH) mode compared to single EH mode \\
[63] & Hybrid RF/VLC & Link selection and user pairing in cooperative-NOMA \\
[64] & Hybrid RF/VLC & Outage performance and reliability improvement of cooperative-NOMA \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Summary of recent studies on NOMA systems. In this paper, an optical NOMA communication system with a new SIC signal detection receiver was constructed to address the above problems. A novel successive interference cancellation detection algorithm was proposed to improve the accuracy of interference estimation by introducing interference coefficients in the optical NOMA system. Furthermore, the method of collecting light based on a fluorescent concentrator was used to improve the light collection efficiency in the uplink optical NOMA system. Moreover, a recurrent neural network-based guided frequency interference coefficient estimation algorithm was proposed to provide a more accurate reconstruction possibility for the level-by-level interference cancellation and improve the bit error rate (BER) performance of the downlink optical NOMA system for multiple users.