Bitwise ranging through underwater acoustic communication with frequency hopped FSK utilizing the Goertzel algorithm

Acoustic communication is the most common technique to communicate with an autonomous underwater vehicle (AUV) during its mission. Furthermore, this communication channel is often used for ranging, to support the navigation of the vehicle and localize it in world coordinates, whereas the vehicles dead reckoning only gives a relative position to a starting point. Due to the severe multipath propagation under water, frequency hopped frequency shift keying (FH-FSK) is often used underwater to communicate over long ranges, whereas it can be otherwise deemed bandwidth inefficient. In this work, a version of FH-FSK is realized as a software defined radio (SDR) on a system on chip, that is connected to the peripherals necessary to transmit and receive signals via acoustic transducers. Besides the communication capabilities, we demonstrate the application of this modulation scheme to ranging for each transmitted data bit.