A New Time Domain Channel Estimation Method for Digital Acoustic Communication System Using CDMA Technique

The paper proposes a time-domain channel estimation method for digital underwater acoustic communication systems employing Code Division Multiple Access (CDMA) technology. The proposed method does not require the transmitter to send any pilot signals. Experimental results demonstrate that CDMA-based underwater communication systems have the advantage of enabling long-distance transmission even with very low transmit power. In the experiments, with a transmit power of approximately 10 mW and a transmission distance of 100 m, the system performed well under Binary Phase Shift Keying (BPSK) modulation. Nevertheless, the method can also be extended to higher-order modulation schemes.