# Real-Time Statistical Measurement of Wideband Signals Based on Software Defined Radio Technology
## 4 Results and Discussion
### LTE-A, 5G and IEEE 802.11 ax Signals Measurements
compared to the 5G network indicate that LTE-A faces more challenges in achieving efficient data throughput performance as compared to the 5G system. This observation is valid for data hunger applications like video calls, file upload and file download. Along with CP measurement, the use of the CCDF measurement gives direct access to the main statistical indicators of mean and peak power values. The temporal variability of the mean and peak power together with the obtained CCDF curve can be used to derive specific usage profiles depending on the enabled type of application, information that is extremely useful for communication reconnaissance missions. The difference between the peak and the mean signal value is the PAPR of the signal. One can observe that even though both LTE-A and 5G signals use OFDM for accessing the radio environment, our results indicate higher PAPR values for the 5G network in all usage scenarios. This was theoretically expected and can be explained by the differences in their underlying modulation schemes and transmission techniques. 5G networks often utilize more complex modulation schemes, such as higher-order Quadrature Amplitude Modulation (QAM), compared to LTE-A, which can result in a higher PAPR. In addition, 5G introduces new waveform technologies, such as filtered OFDM (f-OFDM) which aims to further improve spectral efficiency and mitigate interference. This waveform often exhibits higher PAPR than the traditional cyclic prefix-based OFDM used in LTE-A networks. Figure 14: Time evolution of CP in 802.11 ax—file download. Figure 15: Channel power boxplots (**a**), Mean and Peak power boxplots (**b**) for the tested 4G+ and 5G application service. The values provided with the CCDF curve are very important for designing transmitters that are not built for the highest power that could ever occur, but for a power that has a certain probability of occurring (e.g., 0.01%). These values are also shown in Figure 16, which shows the tail CCDF curves for all scenarios considered. It can be seen that in the case of 5G measurements, the average power for 0.01% is exceeded by 12 dB compared to 4G+ where the average power for the same probability is exceeded by 10 dB. The shape of the CCDF curve is related to the power distribution of the signal. Signals with wider bandwidths and higher data rates tend to have more complex power distributions. Some signal types, such as Gaussian signals, have a well-defined CCDF that follows a known mathematical function. The more the CCDF curve is shifted to the right, the more stochastic the distribution, an effect that is more visible in the case of the 5G measured signals as compared to the LTE-A signals. The following figures (Figures 17 and 18) show the results of the statistical CCDF and channel power measurements for download and upload scenarios at different bandwidths specific to the 802.11 ax standard. The graphical results show the higher channel power level for download at higher bandwidths (most noticeable is the 160 MHz bandwidth), while the upload area shows a relatively constant average/peak power for all three bandwidths analyzed. In Figure 17, we can observe a slight increase in the bandwidth for the peak values of the 802.11 ax measured signal. The wider bandwidth increases the number of subcarriers used in the OFDM modulation scheme, contributing to higher PAPR as the peaks of individual subcarriers may align and result in larger power excursions. Figure 18 shows the CCDF values referring to the peak signal amplitudes for the three bandwidths, both download and upload 802.11 ax channels. For the download measurements, the router performance was monitored and for the upload, the mobile phone was monitored. It can be seen that in both situations the results present good theoretical agreement for OFDM systems, with values of less than 5 dB for 10% and no more than 12 dB for 0.01%. Figure 16: Signal power above average power for 4G+ (**a**) and 5G (**b**) application service tests—boxplot representation.