Selective Dynamic Coded Cooperative Communications for Multi-Hop Underwater Acoustic Sensor Networks

Abstract

Due to the limitation of acoustic velocity in underwater environments, propagation delay is a horrible problem in multi-hop underwater acoustic sensor networks (UW-ASNs). In this paper, we proposed an improved scheme of dynamic coded cooperation called selective dynamic coded cooperation (S-DCC) for the multi-hop UW-ASNs, aiming at reducing the end-to-end delay and improving the transmission efficiency. In S-DCC scheme, the cooperative node actively transmits blocks with limited redundancy; yet the receiver only selectively receives those cooperative blocks depending on its own decoding conditions. The S-DCC scheme can utilize the retransmission mechanism adequately to eliminate the waiting time and drastically shorten the overall transmission time, the gain of which increases linearly with the number of hops. Concerning the transmission delay and energy consumption, we evaluated the performances with the different maximum number of retransmissions and different data burst sizes for the proposed S-DCC scheme and other compared schemes. The simulation results showed that the proposed S-DCC scheme could achieve decent outage performance and reduce the end-to-end delay effectively without extra energy consumption compared with other existing schemes, especially for the cases with low transmission signal to noise ratio. Sea test data were also adopted to further verify the conclusions.