# A Software Defined Radio Based Anti-UAV Mobile System with Jamming and Spoofing Capabilities
## 1 Introduction  
Although drone legislation [1] exists, many unmanned aerial vehicle (UAV) operators choose not to comply with it, generating various types of incidents, either voluntarily or involuturally. Several solutions have been presented to try to solve this problem, such as birds of prey, capture nets, or even jammers as is the case below. For example, the Dutch police have trained some eagles and hawks, so that they can chase and hunt UAVs whenever necessary [2]. In Russia, a non-destructive solution was presented, the Rex-1, which comprises an emitter of an interference signal against the global navigation satellite system GNSS signal [3]. Several studies on detection and jamming of these devices have also been carried out in order to combat this problem. The paper [4] emphasizes the guidelines for drone successful jamming while presenting some solutions implementation for drones malicious function prevention and drones role in jamming efficiency improvement. In [5], the authors present commercial-of-the-shelf (COTS) applications components for various military purposes. Solutions aimed at military application based on software defined radio (SDR) systems are considered, as well as a multifunctional system development base for detection and identification of malicious drones. Implementation of RF surveillance based on COTS components is described, which resorts to ADALMPLUTO and USRP platforms. An SDR is a radio communication system that contains various reconfigurable software-based components for processing and converting digital signals. Unlike traditional radio communication systems, these radio devices are highly flexible, versatile and configurable. In this paper, the SDR used was the BladeRF x40 from the manufacturer Nuand. In past studies, the present authors have also studied techniques to solve the problem. In [6], we evaluated the use of low cost SDR platforms for the implementation of a jammer able to generate aneffective interfering signal aimed at the GPS navigation system. Using a programmable BladeRF x40 platform from Nuand and the GNU radio software development toolkit, several interference techniques were studied and evaluated, considering the spectral efficiency, energy efficiency and complexity. The different types of UAVs, the regulatory laws for UAV activities, their use cases, recreational and military UAV incidents have already been discussed in [7]. Various techniques for monitoring and preventing UAV attacks were studied and described along with case studies in [8]. In [9], the authors conducted extensive market research of 581 counter-unmanned aerial system (C-UAS) systems from 282 manufacturers in 39 countries around the world based on the literature and practice, making it a four-way statistical analysis. Based on this, they classified and summarized the most advanced weapon systems according to different technologies. In [10], the authors presented the results from the field test of UAV GPS jamming by using software defined radio (SDR) and GNU radio software. The field test was carried out to study the performance of the jamming signal produced and the effect of elevation angle on the jamming range. The test subject used in this field test was a DJI Phantom 4 Pro, a commercial consumer grade drone. A different approach to jamming consists in gaining control of the UAV by spoofing the control commands, which normally rely on radio waves. However, different UAVs may operate with different communication protocols, depending on the UAV brands or models. Furthermore, since some UAVs may communicate under a dedicated communication protocol, this command-and-control spoofing solution may not work. It becomes simpler to perform satellite navigation signal spoofing, since global positioning system (GPS) signals are widely used by most UAVs, especially for autonomous operations [11]. Studies have already been carried out with the subject of spoofing the GNSS signals against systems that depend on these, namely UAVs and smart grid devices.