Progressive intercarrier and co-channel interference mitigation for underwater acoustic multi-input multi-output orthogonal frequency-division multiplexing
Multi-input multi-output orthogonal frequency-division multiplexing (MIMO-OFDM) has been actively studied for high data rate communications over the bandwidth-limited underwater acoustic (UWA) channels. Unlike existing receivers that treat the intercarrier interference (ICI) as additive noise, in this paper, the proposed receiver considers ICI explicitly together with the co-channel interference (CCI) due to parallel transmissions in MIMO-OFDM. Using a recently developed progressive receiver framework, the proposed receiver starts with low-complexity ICI-ignorant processing and then progresses to ICI-aware processing with increasing ICI levels. The key components of the proposed receiver include the following: (1) compressed sensing-based sparse channel estimation, (2) soft-input soft-output minimum mean square error/Markov chain Monte Carlo detector for interference mitigation, and (3) soft nonbinary low-density parity check decoding. In addition to simulation, we use real data from the Surface Processes and Acoustic Communications Experiment 2008 (SPACE08) and the Mobile Acoustic Communications Experiment 2010 (MACE10) to verify the system performance, where the transmitter in SPACE08 was stationary and that in MACE10 was slowly moving. Simulation and experimental results show that explicitly addressing ICI and CCI significantly improves the performance of MIMO-OFDM in UWA systems. Copyright (c) 2012 John Wiley & Sons, Ltd.
co-channel interference intercarrier interference sparse channel estimation iterative receiver underwater acoustic communications