Cellular Communication Propagation at Drone around Building Environment with Single Knife Edge at 10 GHz

The drone communication systems used a cellular network for controlling a drone from a long distance. That communication propagations between drone and base station were analyzed. The drone moved at the track around building environment. That environment used variations in building height. The communication propagation around building environment caused diffraction mechanism. Single knife edge method is used for that diffraction mechanism. The frequency of communication used 10 GHz. That frequency was influenced by atmospheric attenuation. This research was using some variations such as height of drone track location, transmitter power, and AMC (Adaptive Modulation Coding). MCS (Modulation Coding Scheme) was used AMC such as QPSK, 16 QAM, and 64 QAM. Some result was obtained at this research consist of LOS and NLOS distance, SNR, MCS probability, and percentage of drone coverage. NLOS propagation was caused by building height. The SNR value become increase when higher at drone position, such as drone was moving at 20 meters with height of flying drone 80 m and transmitter power 30 dBm obtained SNR 38.21 dBm. That SNR is affected AMC, so a higher SNR value increases AMC. The drone’s coverage 100%, with a height of flying drone 80 meters and transmitter power of 30 dBm. That condition showed more increasing coverage percentage than 64.8% for height of flying drone 20 meters and transmitter power 30 dBm. That result showed that more drone height increased of coverage percentage, probability modulation, and SNR value.

This research modeled the communication propagation of drones with the cellular network around the building environment. The communication frequency used 10 GHz. Analysis with that frequency caused the development of spectrum frequency for cellular communication. The atmospheric attenuation affected communication. That frequency was influenced by atmospheric attenuation, such as water vapor and oxygen. The analysis of communication propagation for this research used the uplink condition. Uplink condition because of part of communication transmission. The effect of the building environment is modeled with a diffraction mechanism By using a single knife-edge method. SNR communication is obtained from LOS and NLOS propagation. NLOS condition was caused by building height. That SNR determined AMC that used MCS variation. That MCS used modulations such as QPSK, 16 QAM, and 64 QAM. Every modulation used code rate variation. This research is used parameter variation such as drone height, transmitter power, and AMC. The drone used various heights, such as 40 meters, 60 meters, and 80 meters. The transmitter power that has been used 20 dBm and 30 dBm. This research showed LOS and NLOS effect, SNR communication, MCS probability for AMC, and coverage percentage at the drone. This research aimed to analyze drone communication propagation around building environments with the cellular network for a remote drone from a long distance. This research was important for the development of drone communication. This research is modeled with a simulation.

A. Environment Model
The drone is moved around the building environment on the straight track. The flying drone uses various heights such as 40 meters, 60 meters, and 80 meters. Figure 1 shown communication propagation of drone at 40 meters with RBS. The communication propagation of drone at 60 meters with RBS is shown in Fig. 2. While Fig. 3 showed communication propagation of drone at 80 meters with RBS. That building environment is modeled with a high variation of building that shows NLOS propagation caused by their diffraction. Single knife edge method used for calculation of diffraction mechanism [24]. Figure 4 showed single knife-edge method [25].

B. Single Knife Edge Method
A diffraction mechanism caused the building height. This research used a single knife-edge method for diffraction mechanism. Equation 1 showed single knife edge method. Parameter of λ, h, v, d1, and d2 was longwave (meters), high of diffraction (meters), Fresnel Kirchoff, transmitter distance through the node (meters), and receiver distance through the node (meters) [24].
Approximation to the diffraction used Fresnel Kirchoff diffraction at Fresnel Zone. Fresnel Zone is used between a transmitter and receiver. Diffraction with LOS condition, then h is negative and v also negative. Transmitter power variations used 20 dBm and 30 dBm. Parameter of s, N, and SNR was signal value, noise power, and signal to noise ratio [22].
The attenuations of communication were caused by atmospheric attenuation. Atmospheric attenuations were influenced by oxygen, and water vapor could be observed int equation (4) [26]. and parameters were described with gaseous attenuation and path length (km).

V. CONCLUSION
This section described the research conclusion about communication propagation between drones and RBS. This research aimed to analyse drone communication propagation around a building environment with the cellular network for remote drone from a long distance. The communication frequency used 10 GHz. That frequency was influenced by attenuation atmospheric. The drone used various heights, such as 40 meters, 60 meters, and 80 meters. The transmitter power used 20 dBm and 30 dBm. The single knife-edge method is used for the diffraction mechanism. The communication propagation showed SNR value for the height of flying drone variation. Some data that resulted in more drone height obtained more coverage percentage, probability modulation, and SNR value. The necessity with drone communication used video, pictures, sensor data, etc. The height of the flying drone position is adjusted with location and necessity.