## 2 Proposed Radio over Fiber Network  
The detailed structure of the proposed full-duplex RoF model, aiming to suppress the factors of NLIs and PAPRIs, is presented in Figure 1. WDM multiplexing and demultiplexing techniques are applied, linking \(N\) channels within the central station (CS) and base station (BS) for upstream and downstream signals. At input side, the CS block covers continuous wave (CW) laser with 193.1 THz launching frequency and 5 MHz linewidth, launch power under \(-20\) to 0 dBm range, pseudo-random bit sequence (PRBS) generator to induce 100 Gbps for initiating Gaussian pulse generator, and radio frequency (RF) based amplitude modulator, converting baseband signals into RF clock utilizing amplitude shift keying (ASK) [22]. Similarly, essential parameters like hybrid coupler (HC) operating at 90\({}^{\circ}\) is also installed inside CS. Which function is to attain the integrated RF and subcarrier multiplexed signals. Moreover, the process of getting information in the optical domain is performed in the CS section with the help of a dual drive and dual-port liNb much Zehnder modulator (MZM). It takes two forms of signals from 90\({}^{\circ}\) HC and optical waves from CW laser. The CS outflow is connected to WDM multiplexer reflective wavelength block-1 for transmitting and receiving the upstream and downstream signals. WDM multiplexer transmitter optical signals over single-mode fiber (SMF), purposing to cover long-range. In order to minimize the impact of NLIs and PAPRIs and balance the phase of propagating signals, SMF is followed by DCF and erbium-doped fiber amplifier (EDFA). Correspondingly, the BS block comprises WDM de-multiplexer, PIN photodetector, bandpass filter (BPL), RF de-modulator, BER analyzer and reflected wavelength block-2. The block of reflected wavelength reuses the downstream wavelength without the extra component of the CW laser. The performance of the received upstream signal through SMF is evaluated by a BER analyzer. The list of used parameters for investigating outcomes of the proposed full-duplex RoF model is depicted in Table 1.  
Figure 1: WDM based full duplex RoF system including CS and BS. Mathematical Calculations for Optical and Electronic Domains Based Parameters in Radio over Fiber Network  
The fiber cable provides medium to deliver the wireless signals in their own RF waves as declared in Figure 2. It can be seen that the RoF system directly convert the optical signals into RF at high frequency. The optical signal of RF waves at the transmitter can be estimated [23; 24; 25] as  
\[\mathrm{E}(t)=\mathbb{A}+cos[\mathbf{v_{0}}+3\mathbf{w_{LO}}(t+\mathrm{d_{\tau} })+\theta] \tag{1}\]  
where \(\mathbb{A}\) is the amplitude of the signal, \(\mathbf{w_{0}}\) denotes angular frequency of the optical signal, \(\mathbf{w_{LO}}\) describes the angular frequency of local oscillator (LO), \(\mathrm{d_{\tau}}\) is the time delay and \(\theta\) is the phase of the optical signal. The induced multilevel pulses are estimated as [26; 27; 28] as  
\[N_{out}(t)= \begin{cases}a,0\leq t<t_{1}\\ bN_{in}(t)+a,t_{1}\leq t<t_{1}+t_{c}\\ a,t_{1}+t_{c}\leq t<T\end{cases}  \tag{2}\]  
where the incoming signals are denoted by \(N_{in}\), linear gain is presented by \(b\), \(a\) is applied for bias parameters, bit period is defined by \(T\), \(t_{c}\) is the duty cycle and pulse position \begin{table}
\begin{tabular}{l c} \hline \hline
**Description** & **Magnitude** \\ \hline Effective area & 80 \(\mu\)m\({}^{2}\) \\ Launch power & \(-\)19 to 1 dBm \\ Transmission range & 1 to 10 km \\ Received power & \(-\)40 dBm to \(-\)20 dBm \\ Spacing among channels & 25 to 50 GHz \\ Reference wavelength & 1553 nm \\ Channel Quantity & 4–16 \\ Nonlinear dispersion & \(-\)2.5 ps\({}^{3}\)/km \\ RF range & 4 to 6 GHz \\ Line width & 5 MHz \\ Extension ratio & 10 dB \\ \hline \hline \end{tabular}
\end{table} 
Table 1: List of elements applied for measuring the proposed model outcomes. Figure 2: RF and optical waves convergence scheme. is denoted by \(t_{1}\).