# 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  
Figure 13 shows the time evolution of the channel power during 30 s for the streaming and VoIP test for LTE-A and 5G standards. In the case of 4G+, in the streaming scenario represented by the blue color, it can be seen how the video is gradually loaded at different timestamps, while in VoIP the signal is somewhat constant. The same can be observed  
Figure 11: CCDF mean and peak values as measured by the SDR platform and the SA for an 802.11 ax channel with 40 MHz bandwidth. Figure 12: CCDF values from the SDR platform and SA: signal power above average for an 802.11 ax channel with 40 MHz bandwidth. in 5G, wherein the VoIP experiment the signal is kept constant, while in streaming it is observed how it is loaded at 4, 8, 24 and 27 s.  
The differences observed in the CP measurements for the VoIP and streaming scenarios can be attributed to the application characteristics and capabilities of the two mobile networks. In the case of the VoIP experiment, the signal remains relatively constant also due to the real-time communication feature. The network maintains a constant channel strength to ensure stable and continuous voice transmission. On the other hand, in the case of streaming, the channel power is not evenly distributed, the increase in channel power is best observed in the case of 5G when the video load is high. Differences are observed for streaming in LTE-A versus 5G due to the adaptation of data transmission to the available bandwidth. By using the SDR-based measurement system, we can highlight the different behavior of the LTE-A and 5G signals with respect to CP. These peculiarities are due to the different channel bandwidths (20 MHz vs. 100 MHz) and modulation schemes enabled by the two communication standards. Modulation schemes have varying power requirements due to their inherent characteristics and the trade-offs they make between data rate, spectral efficiency, and power efficiency [40]. Besides the bandwidth extension, to achieve higher data rates, 5G employs more complex modulation and coding techniques, which require additional power to accurately transmit and receive the signal. In order to study and test the measurement system to its maximum, several experiments were performed on the IEEE 802.11 ax network. The scenario consisted of configuring the router successively to 40/80/160 MHz and downloading a file for each bandwidth. Figure 14 shows the power measurements over time for the three bandwidths. For the scenario described, the channel performance was similar when using 40 MHz and 80 MHz bandwidths with slightly higher CP values being measured for 80 MHz. The increase in CP with channel bandwidth is more visible when a 160 MHz bandwidth was used and the measured channel power was visibly higher. This can be explained by the fact that signals with larger bandwidths tend to exhibit higher channel power requirements because, in a wider bandwidth, there are more available frequencies or subcarriers that need to be powered to transmit the signal. It is important to note that while larger bandwidths generally require higher power, advancements in technology and signal processing techniques continue to improve the power efficiency of wideband communication systems. These advancements aim to achieve higher data rates and improved performance while minimizing power consumption [41]. The next scenario aims to test all services for 4G+ and 5G networks. The measurements analyzed comparatively refer to the channel power, i.e., the average (mean) and peak power extracted from the CCDF curve. Figure 15 illustrates the measurement results and we can observe significant differences in download and upload services between the two standards. The higher values of CP, average power and peak power observed for the LTE-A standard  
Figure 13: Time evolution for CP in LTE-A (**a**) and 5G (**b**). VoIP and streaming use cases.