Robust Underwater Acoustic Communication Using the Overlapped Chirp Spread Carrier Technique in Doubly Spread Environments

The performance of underwater acoustic communication is significantly affected by multipath propagation and Doppler spread. In this paper, we propose a new technique called overlapped chirp spread carrier (OCSC) modifying the existing sweep (SSC) technique, which robust in environment. Our proposed OCSC uses repeated wave combining up-chirp down-chirp signals estimates corrects shift frequency received signal utilizing characteristics correlation function each down-chirp. To demonstrate provide results simulation using an channel simulator sea trial conducted East Sea. As result trial, when demodulating only estimated frequency, uncoded bit error rate reached 0.135. However, our correction method was applied to decreased 0.001.