Joint linear precoding and nonbinary LDPC coding for underwater acoustic OFDM

Both channel coding over a finite field and linear precoding over a complex field can improve the system performance in wireless fading channels. In this paper, we investigate the potential benefit of linear precoding in a nonbinary LDPC coded underwater acoustic OFDM system. Real precoders of small sizes are selected in different setups, in order to avoid any complexity increase at the receiver. Simulations and emulated experimental results demonstrate the benefits of linear precoding, particularly when the receiver has a small number of hydrophones.