Performance of low-power underwater modem for shallow water communications

The low-power underwater acoustic modem is usually an important component of the Underwater Wireless Sensor Network (UWSN). Network nodes have predetermined energy resources that will not be replenished during the life of the node. In shallow waters, multipath propagation is constantly occurring and for the modem to work effectively, solutions to overcome them must be used, which will also meet the important criterion of energy efficiency. The article presents the concept of a low-power underwater modem using Multiple Frequency-Shift Keying (MFSK) modulation and the fast frequency-hopping spread spectrum technique. In order to determine the performance of the modem, simulation tests were carried out using the Watermark simulator using the measured impulse responses of channels in shallow waters.