UNMANNED AERIAL VEHICLE FLIGHT SPEED OPTIMIZATION FOR SPECTRUM SENSING

Nowadays, small unmanned aerial vehicles are increasingly used for spectrum sensing. The movement of the unmanned aerial vehicle relative to the radio source leads to variability in the level of the received signal. This is due to small-scale signal fading, which occurs when the unmanned aerial vehicle moves by only half the wavelength of the radio signal carrier frequency. To reduce the influence of this factor on the characteristics of algorithms that use amplitude methods and are often used on unmanned aerial vehicles due to their simplicity, it is necessary to optimize the speed of its flight. The aim of the article is to develop a mathematical apparatus for calculating the optimal unmanned aerial vehicles flight speed for wideband spectrum sensing in conditions of small-scale fading. In the course of the research, the optimization criterion was determined to be the maximization of the scanning area, which depends on the range of detection of radio sources and the unmanned aerial vehicles flight speed. The dependence between the unmanned aerial vehicles flight speed and the duration of signal sample is established to reduce the effect of fading on errors in estimating the received signal strength. An analytical expression has been obtained that relates the scanning area of the unmanned aerial vehicles to its flight speed and the frequency of the radio signal, which is described by a monotonous increasing function of the flight speed. It has been established that in order to detect the maximum number of radio sources, a unmanned aerial vehicle should move at maximum speed. The signal sampling duration is calculated for a given speed and maximum signal frequency. The proposed solution will allow detecting the maximum number of radio sources for a given unmanned aerial vehicle flight time. The developed mathematical apparatus can be implemented in the development of modern radio monitoring systems for unmanned aerial vehicles.