Coexistence Analysis of 5G C-Band Indoor Deployments and Fixed Satellite Service (FSS) in Malaysia

2.1 Location of measurement for received signal

This section describes indoor measurement scenarios. As shown in Figure 3, the location of the indoor scenario was in the RekaScape building and parking. There are also two paths: result line-of-sight propagation (LOS) and non-line-of-sight propagation (NLOS). On the other hand, the interference effect with various distances in parking and crossing the road with a distance (130) meters nearest the building of Cyberview and the other distance was nearest to the MEASAT station with a distance of 3 km. The FSS signals used in this study are shown in Figures 4 and 5.

Figure 3. Map 1 for RekaScape building.

Figure 4. The distance of received signal (130 m), from RekaScape to Cyberview.

Figure 5. The distance of received signal (3 km), from RekaScape to MEASAT.

2.2 Receiver antenna parameters

The description is shown in Table 1, where the linear polarized Periodic Broadband Antenna Logarithmic (aluminum tubing) for receiving and transmitting applications.^13,14

Moreover, the signal intensity variation was close to the location. In addition, the indoor radio transmission system varies significantly from the conventional cellular radio channel in terms of defended lengths. Relevant features, such as the building structure and positions of the antennas, affect propagation inside buildings. The location of the 5G base station inside the ZTE organization hall is 2 m higher from the ground, polarization vertical, and a transmit power of 35 dBm, as shown in Figure 7, and the yellow area covers the position of the points receiving the signal from the 5G station with a range distance between 1 m to 40 m.

Otherwise, as shown in Figure 6, the gap between the 5G base station and receiver antenna sites is approximately 5 m, with a special symbol (■). The display block settings were as follows: RBW =1 MHz, VBW = 1 MHz, and SWT = 100 ms. The resolution bandwidth (RBW) specified as the frequency range of the final filter that extends to the input signal. Relatively small RBWs provide more natural frequency resolution and the ability to separate signals with closer frequencies.¹⁵ Another aspect influencing a spectrum analyzer is that trace efficiency is the video bandwidth (VBW). This noise makes it difficult to detect tiny signals when VBW is high. As we lower the VBW, the small signal is even more evident. The sweep time (SWT) is the amount of time it takes from the start to the stop frequency from sweeping the detector. This noise makes it difficult to detect tiny signals when VBW is high. As we lower the VBW, the small signal is even more evident. The sweep time (SWT) is the amount of time it takes from the start to the stop frequency from sweeping the detector. The (SWT) value can be determined from the following equation: $\mathit{SWT}=\frac{K_T+\mathit{\text{SPAN}}}{{\mathit{RWB}}^2}$ ; the time required affects the RBW and VBW ratio. The VBW is typically set to a value greater than or equal to the RBW when we do not rely on noise, whereas the principal effect of the VBW and RBW detectors is to smooth the tracing and noise,¹⁶ Moreover, innovations in RF receiver front-end design, encompassing rectifier technologies and energy harvesting architectures for simultaneous wireless information and power transfer (SWIPT) systems, have illustrated that shared-spectrum environments necessitate meticulous attention to receiver sensitivity, multi-band operation, and power conversion efficiency to guarantee dependable coexistence among diverse wireless services.¹⁷

Figure 6. Map 2 5G points locations in RekaScape building Cyberview.

3.1 Measurement result

The first results, as shown in Figure 7, indicate that the particular range in the received power has the highest signal, with frequency of 3.49 GHz, −54.34 dBm, in the same lap as the 5G transmission station, where the gap between the two sites is approximately 1 to 5 meters.

Figure 7. Experiment result with distance 1 to 5 m.

Figure 8, the signal is in the smooth mode from 3 GHz to 4 GHz with −50 dBm power level. The first peak received at the frequency 3.4 GHz with power − 30 dBm, and at the 3.48 the system received the highest peak in the −13.41 dBm from the received power signal with distance 10 m from the antenna of 5G station.

Figure 8. Experiment result with distance 10 m.

Figure 9, demonstrates that the first three puls received starts from 3.4 GHz to 3.5 GHz. The highest peak of the received power signal from the 5G station antenna at −28.41 dBm, with a distance of 20 m.

Figure 9. Experiment result with distance 20 m.

Figure 10, at a frequency of 3.42 GHz, indicates the maximum hold that will be obtained from the 5G station antenna at −54.61 dBm at the 30 m distance.

Figure 10. Experiment result with distance 30 m.

Figure 11, at a frequency of 3.41 GHz, shows the highest control received from the 5G station antenna at −52.34 dBm over a distance of 35 m.

Figure 11. Experiment result with distance 35 m.

Figure 12 indicates that the signal is prevented by the cement wall between Tx and Rx. This point was collected from the 5G antenna at the highest distance. The first peak appeared within the initial range of 3,456 GHz at a power level of −74.02 dBm.

Figure 12. Experiment result with distance 40 m.

3.2 The distance model between Tx and Rx antenna

This section explains the comparison between the received power signals and propagation length (m). Figure 13 shows the maximum receiving power transmitted by the higher 5G antenna transmission approximately at 0.43 m with approximately 35 dBm.

Figure 13. Distance of 1 m (Tx to Rx) Antenna.

Figure 14 indicates the highest signal at 10 m with −13 dBm, while at the 20 m the power received was less than approximately −30 dBm.

Figure 14. Distance of 10 m (Tx to Rx) Antenna.

Figure 15 shows the received signals at different distances and antenna transmissions, where the transmission power approximately is −32 dBm to −54 dBm, at 20 m.

Figure 15. Distance of 20 m (Tx to Rx) Antenna.

Figure 16 shows that the receiving signal is low at approximately − −55 dBm to −74 dBm at 30 m.

Figure 16. Distance of 30 m (Tx to Rx) Antenna.

Figure 17 shows that the received power signal transmission by the service antenna signal is exceeded. Moreover, at 35 m the power received was approximately −63 dBm to −72.19 dBm.

Figure 17. Distance of 35 m (Tx to Rx) Antenna.

The optimal exclusion zone between the 5G indoor model and FSS Inter-cell interference proved to be the most significant restricting factor at high altitudes; therefore, many industries and researchers are seeking to use less congested radio components in the total spectrum. The 3.4–3.8 GHz (C-band) is one of the world’s most significant pioneer frequencies for the early launch of 5G networks. However, this band is already being used for fixed satellite services (FSS) in Malaysia and is not significantly affected by rain. The coexistence of mobile broadband networks should be investigated to better define the business conditions in specific environments. This section examines and demonstrates the numerical and measurement results for 5G indoor locations. It is notable from the last received data that there is no interference between the 5G signals and FSS spectrum. This study considers the following parameters, as explained in Table 2.

It is notable from Table 2 that the best optimization exclusion zone for the indoor scenario, the distance between the 5G indoor station and FSS station should be approximately 100 m and the forbidden band from 50 to 100 MHz should be between the usage frequency.