## 4 Performance Evaluation  
In this section, we propose to compare the performances of the proposed LDS-F-OFDM and LDS-UFMC schemes with the LDS-OFDM over a vehicular channel with different speed limits and over a multipath fading channel. The main simulation parameters are used to match the 3 GPP Release 16 standard. Based on 3 GPP Release 16, we have fixed the total bandwidth to \(B=10\) MHz and a carrier frequency of \(f_{c}=5.9\) GHz to match the NR-V2X operating bands in FR1 [23]. Table 2 summarises the simulation parameters. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Window** & \multicolumn{2}{c}{**Window Function**} \\ \hline [PERSON] & \(w[n]=0.5\times(1+cos(\frac{2\pi n}{L-1}))\) \\ \hline [PERSON] & \(w[n]=\frac{25}{46}+\frac{21}{45}\times cos(\frac{2\pi n}{L-1})\) \\ \hline [PERSON] & \(w[n]=\frac{7938}{18608}+\frac{9240}{18608}\times cos(\frac{2\pi n}{L-1})+\frac{1 430}{18608}\times cos(\frac{4\pi n}{L-1})\) \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Window function of the filters. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Parameters** & **Symbol** & **Value** \\ \hline \multicolumn{3}{c}{Release 16 Parameters} \\ \hline Bandwidth & \(B\) & 10 MHz \\ \hline Carrier frequency & \(f_{c}\) & 5.9 GHz \\ \hline Number of symbols & \(N_{sym}\) & 14 \\ \hline Subcarriers spacing & \(\Delta_{f}\) & 15 kHz \\ \hline Number of Resource Blocks & \(N_{RB}\) & 52 \\ \hline FFT Size & \(N_{FFT}\) & 1024 \\ \hline Cyclic Prefix Length & \(L_{CP}\) & 72 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Simulation parameters. No error correction is employed, so the evaluation is carried out for uncoded bits. The LDS spreading matrix is generated randomly for all the simulated schemes. However, we do believe that a well designed matrix with small number of cycle-of-four and a high girth can achieve better performance. In order to respect the 3 GPP recommendations, no overloading scenario is deployed due to the use of pilots and the waveforms offset. We have overcome this circumstance by respecting the rule of interfering several users in the same resource and allocating a few subcarriers to the same user i.e., respecting the LDS structure to justify these new schemes performances. The maximum number of iterations of the LDS detector is ten. The first channel we have chosen to evaluate the performance of these schemes is the Tapped Delay Line model, specifically the TDL-A channel. The TDL-A channel model has a Doppler spectrum which is characterised by a Jake's spectrum shape. The Power Delay Profile (PDP) of the model is presented in [24] and the delay spread used to scale the normalised taps delays is \(D_{s}=93\,\mathrm{\SIUnitSymbolMicro s}\). This delay spread is chosen to correspond to a short delay profile in an Urban Macro environment for a 5.9 GHz carrier frequency. Figure 4 depicts the simulation results of LDS-F-OFDM and LDS-UFMC over TDL-A channel. We first fix the bandwidth at \(B=10\) MHz, then we investigate the schemes under two systems, the first with 1024 subcarriers and \(\Delta_{f}=15\) kHz subcarrier spacing and the second with 512 subcarriers and \(\Delta_{f}=30\) kHz. According to the simulation results, the LDS-F-OFDM shows better performance over both LDS-UFMC and LDS-OFDM. The fact that the f-OFDM subband regroups all the available