Index Modulated OFDM with ICI Self-Cancellation in Underwater Acoustic Communications

OFDM is promising for underwater acoustic (UWA) communications due to its potential to combat the large delay spread. However, the performance of the OFDM system is seriously deteriorated by the inter-carrier interference (ICI) caused by the transmitter/receiver motion and ocean waves. In this paper, we propose a novel ICI countermeasure. The key idea is to inactivate partial subcarriers according to index modulation and meanwhile transmit signals with opposite polarity on two adjacent active subcarriers for ICI self cancellation. Simulation results validate that the proposed scheme achieves much better bit error rate (BER) performance than many existing schemes in UWA communications.