## 5 Properties Analysis of the Functions \(\varphi_{m}^{s}\)
### Single-Resource-Block Maritime User Allocation
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Symbol** & **Quantity** & **Value (Unit)** \\ \hline \(d\) & Radius of offshore area & 5000 (m) \\ \(f\) & Carrier frequency & 2.6 (GHz) \\ \(\sigma\) & Noise power spectral density & \(-\)174 (dB/Hz) \\ \(B\) & System channel bandwidth & 5 (MHz) \\ \(H_{T}\) & Height of BS transmitting antenna & 15 (m) \\ \(H_{R}\) & Height of maritime receiving antenna & 5 (m) \\ \(\Delta h\) & Terrain irregularity parameter & 0 (smooth water) \\ TSite Criteria & BS deployment parameter & 2 (very careful) \\ RSite Criteria & Receiver deployment parameter & 0 (random) \\ radio\_climate & Climate parameter & 3 (tropical ocean climate) \\ _pol_ & Antenna polarization method & 1 (vertical polarization) \\ eps\_permittivity & Relative permittivity of sea water & 81 (F/m) \\ sgm\_conductivity & Sea water conductivity & 5 (S/m) \\ eno\_refractivity & Surface refractivity & 370 (\(N\)-units)\({}^{3}\) \\ \(S\) & Number of resource blocks & 10 \\ \(T\) & Number of maritime users & [10, 80] \\ \(\xi\) & Error tolerance (Grad) & \(10^{-4}\) \\ \(P_{\max}\) & Total power budget & [5, 50] (W) \\ \(J\) & Number of power values (MCKP-DP) & \(10^{3}\) \\ \(p\) & Minimum transmit power & 0.01 (W) \\ \(p\) & (MCKP-DP) & 0.01 (W) \\ \(\varepsilon\) & Approximate error value (DP-FPTA) & 0.1, 0.01 \\ \(A\) & Maximum number of users & \\  & multiplexed on a resource block & 1 (OMA), 10 (NOMA) \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Simulation parameters. of 5 km over the sea. Therefore, if the height of the 5G BS transmitting antenna is more than 10 m, a good transmission loss result can be maintained in our subsequent work. Figure 3 shows the path loss value achieved with the increase in distance based on different terrain irregular parameters. We set the effective height of the coastal BS transmitting antenna as 15 m. Within the communication distance of 5 km specified in this paper, the propagation loss values corresponding to irregular parameters \(\Delta h=0\) and \(\Delta h=5\) are almost equal. Referring to previous test results, we can regard the sea surface as calm and smooth under an offshore background without typhoon invasion. Therefore, in the subsequent simulation process, we suppose that the terrain irregularity parameter is zero. This value is still applicable even if there are slight waves on the sea surface. The transmission loss reflected by the experimental results (Figures 2 and 3) is the absolute value. In the subsequent simulation, those propagation loss values are negative in the maritime communication system. Figure 4 compares the WAR performance optimization between RBUA and the improved scheme RBPUA based on NOMA and OMA, respectively. The NOMA system supports an upper limit of 10 marine users multiplexed on a resource block. At the same time, the power budget provided by the coastal BS increases from 5 W to 50 W. When the power budget reaches 10 W, the WAR performance of the NOMA system with a single

Figure 3: Longley–Rice transmission loss of different irregular terrain parameters vs. communication distances. Figure 2: Longley–Rice transmission loss of different BS antenna heights vs. communication distances. resource block is increased by 4.08% compared with OMA. As the power budget increases to 50 W, the WAR of NOMA becomes better than that of OMA by 4.59%. In addition, we prove that the low-complexity RBPUA scheme is the same in terms of performance optimization as the RBUA scheme. For the NOMA or OMA system with 10 power budgets, Figure 5 compares the computational complexity for the RBUA algorithm and the improved optimization algorithm RBPUA. According to the numerical result, for 10 maritime users, the NOMA-based RBPUA scheme is less complex than the NOMA-based RBUA algorithm by 80%. Consequently, applying our improved algorithm RBPUA in the multi-resource-block schemes can effectively reduce the computational difficulty while maintaining the performance optimization results.