# 5G V2X Performance Comparison for Different Channel Coding Schemes and Propagation Models
## 4 Simulation Results
### Simulation Results for 128-Bit Frame Length
The highway traffic model creates 3- to 4-times smaller BER than the urban traffic model for SNR up to 4 dB, but as the SNR increases, the difference is significantly smaller between the two scenarios. The main cause of this phenomenon is that, as the SNR remains low, the multipath is scattered by the rich scatterers, uniformly distributed around the receiver dominating the LOS component. Nevertheless, as the SNR rises, the LOS signal component dominates among all other scattering components, making them negligible [69]. This means that as the SNR increases, the traffic model has less impact on BER performance. Scenarios 3, 4 and 5 refer to the urban traffic model and different channel states (LOS, NLOS and NLOSv). Comparing these three scenarios, we can observe the effect of the channel state on system efficiency. From Table 8, we infer that the presence of a dominant LOS component has a great impact on BER performance, especially for algorithms that can converge fast at low SNR. BER for BCJR and logBCJR is, in the third scenario, 40-times smaller than the other two urban scenarios when the SNR equals 4 dB. Contrariwise, BER is 2- to 3-times smaller for the rest of the algorithms and for the same SNR, mainly because these algorithms are characterised by a slow rate of convergence at low SNR regions. When \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**BER** & **Scenario** & **BCJR** & **logBCJR** & **maxlogBCJR** & **SOVA** & **LDPC** & **Polar** \\ \hline \multirow{8}{*}{\(10^{-3}\)} & 1 & 3.4 & 3.4 & 3.6 & 4.9 & 5.2 & 4.7 \\ \cline{2-7}  & 2 & 4.4 & 4.4 & 4.7 & 6.8 & 6.8 & 6.3 \\ \cline{2-7}  & 3 & 3.8 & 3.8 & 4.1 & 5.9 & 6 & 5.6 \\ \cline{2-7}  & 4 & 4.3 & 4.3 & 4.5 & 6.8 & 6.7 & 6.2 \\ \cline{2-7}  & 5 & 4.3 & 4.3 & 4.5 & 6.6 & 6.7 & 6.2 \\ \hline \multirow{8}{*}{\(10^{-6}\)} & 1 & 6.8 & 6.8 & 7.2 & - & \textgreater{}7 & \textgreater{}8 \\ \cline{2-7}  & 2 & - & - & - & - & - & \textgreater{}8 \\ \cline{2-7}  & 3 & 8.4 & 8.2 & 7.8 & - & 10 & \textgreater{}7 \\ \cline{2-7}  & 4 & 9.6 & 9.6 & 9.6 & - & - & \textgreater{}9 \\ \cline{2-7}  & 5 & 10 & - & 10 & - & - & \textgreater{}8 \\ \hline \hline \end{tabular}
\end{table} 
Table 7: SNR in dBs for BER values of \(10^{-3}\), \(10^{-6}\) and 128-bit frame length. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**SNR (dB)** & **Scenario** & **BCJR** & **logBCJR** & **maxlogBCJR** & **SOVA** & **LDPC** & **Polar** \\ \hline \multirow{8}{*}{4} & 1 & \(2.1\times 10^{-4}\) & \(2.3\times 10^{-4}\) & \(3.4\times 10^{-4}\) & \(3.5\times 10^{-3}\) & \(1.1\times 10^{-2}\) & \(3.5\times 10^{-3}\) \\ \cline{2-7}  & 2 & \(2\times 10^{-3}\) & \(1.8\times 10^{-3}\) & \(2.6\times 10^{-3}\) & \(1.2\times 10^{-2}\) & \(5\times 10^{-2}\) & \(2.6\times 10^{-2}\) \\ \cline{2-7}  & 3 & \(8\times 10^{-4}\) & \(8\times 10^{-4}\) & \(10^{-3}\) & \(8\times 10^{-3}\) & \(3\times 10^{-2}\) & \(1.5\times 10^{-2}\) \\ \cline{2-7}  & 4 & \(2\times 10^{-3}\) & \(2\times 10^{-3}\) & \(2.5\times 10^{-3}\) & \(10^{-2}\) & \(6\times 10^{-2}\) & \(3\times 10^{-2}\) \\ \cline{2-7}  & 5 & \(2\times 10^{-3}\) & \(2\times 10^{-3}\) & \(2.5\times 10^{-3}\) & \(1.2\times 10^{-2}\) & \(5\times 10^{-2}\) & \(3\times 10^{-2}\) \\ \hline \multirow{8}{*}{9} & 1 & \(2.3\times 10^{-7}\) & \(2.3\times 10^{-7}\) & \(3.5\times 10^{-7}\) & \(4.5\times 10^{-5}\) & 0 & 0 \\ \cline{2-7}  & 2 & \(1.4\times 10^{-6}\) & \(2.1\times 10^{-6}\) & \(3.2\times 10^{-6}\) & \(2.2\times 10^{-4}\) & \(2.3\times 10^{-5}\) & 0 \\ \cline{2-7}  & 3 & \(4\times 10^{-7}\) & \(3\times 10^{-7}\) & \(4\times 10^{-7}\) & \(1.5\times 10^{-4}\) & \(5\times 10^{-6}\) & 0 \\ \cline{2-7}  & 4 & \(2\times 10^{-6}\) & \(3\times 10^{-6}\) & \(3\times 10^{-6}\) & \(2.5\times 10^{-4}\) & \(6\times 10^{-6}\) &the SNR increases, this gap gradually narrows, although LOS channel state still has superior performance among the three scenarios. If we focus our study on the last two scenarios, we can easily conclude that for low SNR, we obtain identical performance.