CTH15-3: Performance of Distributed Space-Time Cooperative Schemes for Underwater Acoustic Communications

In resource limited, large scale underwater sensor networks, cooperative communication over multiple hops offers opportunities to save power when intermediate nodes between source and destination act as cooperative relays. Herein, protocols coupled with space-time block code (STBC) strategies are analyzed for distributed cooperative communication in underwater channels. Amplify-and-forward type protocols are considered, in which the relays do not attempt to decode the information. The Alamouti-based cooperative scheme proposed by Hua et al (2003) for flat-fading channels is modified in order work in the presence of multipath. A time-reversal distributed space-time block code (TR-DSTBC) is employed, which extends the classical TR-STBC approach from Lindskog and Paulraj (2000) to a cooperative communication scenario. Furthermore, the performance of the scheme employing a DFE equalizer at the destination is analytically investigated in terms of bit error rate (BER) bounds and achievable spatial diversity.