Software Defined Radio Based Multi-band Audio Broadcasting System for Drone Based Communications

Abstract

Traditional light weight wireless communication modules like ZigBee, Bluetooth, LoRa have fixed frequency band and fixed protocol stack and hence lack flexibility of changing frequency, modulation techniques, waveforms etc. and may also prone to interference, jamming. Due to obstacles in between the transmitter and receiver, the communication coverage range is not large. But in emergency situations like war field or any disaster, there is need for robust communication in which the soldiers or public have to receive crucial information from base station. Software defined Radios like Universal Radio Software Peripheral (USRP), WARP boards needs to interface with computer for signal processing. Hence it is not suitable for drone based communication. So we proposed a solution to overcome bulkier system and limited communication range problem. In this work, a light-weight communication platform was developed which acts as a repeater for broadcasting voice commands that were transmitted from base station. The repeater is mounted on the drone and it is hovered at a certain altitude to make line of sight communication possible with both transmitter and receiver. This system was designed by interfacing Radio Frequency (RF) board present in USRP 2900 with Raspberry Pi 4, a credit card sized computer. The RF board overcomes the difficulty of standard wireless communication modules mentioned above, could easily mounted on drone, capable of communicating in different modulation schemes at multiple frequency bands and also one could implement cognitive radio features like spectrum sensing and taking automatic decisions based on data which is obtained from various sensors that are connected to Raspberry Pi.