The ocean monitoring sensor network is a typically energy-limited and bandwidth-limited system, and the technical bottleneck of which is the asymmetry between the demand for large-scale and high-resolution information acquisition and the limited network resources. The newly arising compressed sensing theory provides a chance for breaking through the bottleneck. In view of this and considering the potential advantages of the emerging interleave-division multiple access (IDMA) technology in underwater channels, this paper proposes an IDMA-based compressed sensing scheme in underwater sensor networks with applications to environmental monitoring information acquisition. Exploiting the sparse property of the monitored objects, only a subset of sensors is required to measure and transmit the measurements to the monitoring center for accurate information reconstruction, reducing the requirements for channel bandwidth and energy consumption significantly. Furthermore, with the aid of the semianalytical technique of IDMA, the optimal sensing probability of each sensor is determined to minimize the reconstruction error of the information map. Simulation results with real oceanic monitoring data validate the efficiency of the proposed scheme. 1. Introduction With the ever-increasing demand for marine exploitation and the rapid development of network communication technologies, underwater sensor network (UWSN)  has become a new research hotspot in recent years. As the extension of wireless sensor networks (WSN) into ocean, UWSN has potential values in the wide application fields, such as oceanographic information collection, hydrological and environmental monitoring, resources exploration, disaster forecast, underwater navigation, and military defense. This paper focuses on the ocean environmental monitoring application. In this kind of UWSN, a large number of underwater sensor nodes are deployed in the concerned area, which measure the required physical, chemical, or biological phenomena and transmit the measurements to the monitoring center. Then, the monitoring center forms the information map of the monitoring area according to the measurements it received. Due to the particularity of underwater environments , wireless acoustic communication is believed as the most suitable physical layer transmission technology in underwater networks. However, wireless acoustic communication has some distinct disadvantages in the following aspects: low carrier frequency leads to limited available bandwidth; low propagation speed of sound leads to long end-to-end delay.
J. Heidemann, U. Mitra, J. Preisig, M. Stojanovic, M. Zorzi, and L. Cimini, “Underwater wireless communication networks,” IEEE Journal on Selected Areas in Communications, vol. 26, no. 9, pp. 1617–1619, 2008.