Parallel combinatory multicarrier frequency-hopped spread spectrum for long range and shallow underwater acoustic communications

A parallel combinatory (PC) multicarrier frequency-hopped spread spectrum (FHSS) underwater acoustic (UWA) communication system is proposed in this paper. Parallel combinatory is first applied in FHSS system to accomplish the subcarrier mapping, which makes the communication system not only to preserve the ability of resisting fading and narrow band interference randomly during the transmission over UWA channel, but also to take advantage of the parallel combinatory subcarrier mapping algorithm to increase the data rate of the system. Results of computer simulations and pool experiments show that the BER performance of the proposed system outperforms the traditional single-carrier FHSS system and multicarrier FHSS system, especially in the large delay multipath underwater acoustic (UWA) channel. Outfield experiment carried out in Xiamen Port shows that the BER performance of the system is on the order of 10^-3, when the data rate is 400bps and the distance of the communication is 10km and 15km, respectively.