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Spatially Concatenated Channel-Network Code for Underwater Wireless Sensor Networks

Underwater environment monitoring is an important application of wireless sensor networks (WSNs). However, WSNs face challenges, such as erroneous communication, ensuring the lifetime and robustness of the network, and cost constraints. The underwater acoustic channel (UAC) is highly frequency-selective, and the channel response changes over time because of variations in the channel conditions. Therefore, designing a cooperative coded orthogonal frequency division multiplexing (COFDM) system that is suitable for the doubly selective UAC and has reduced power consumption is very challenging. We propose a cooperative spatial-domain coding scheme combined with the low-density parity-check-coded OFDM system, called spatially concatenated channel-network code, for underwater acoustic WSNs. The designed underwater acoustic WSN exhibits a significant advantage regarding the required number of sensors, bit error rate (BER), and power consumption over the non-cooperative COFDM communication system. We also analyze sensor deployment schemes and find out the area in which our proposed scheme can be beneficial in terms of reduced power consumption and enhanced BER.