Experimental Evaluation of the Generalized Cross-Correlation Method on Binary and Polyphase Sequences for Underwater Acoustic Communications

In communications, a spread-spectrum sequence can be used for frame synchronization in order to detect the packets arrival. This sequence is usually detected by means of a matched filter with the original code, which ideally provides a distinguishable peak among the correlation noise. The detection of this peak is crucial, since the information contained in the data packet will be lost if the peak is missed. Thus, choosing a good sequence and a robust detection method is an important first step, although sometimes overlooked, in an efficient communication system. In this work, the detection of binary and polyphase sequences for frame synchronization in underwater acoustic communications has been experimentally evaluated. This detection has been conducted by means of the matched filter and the Generalized Cross-Correlation (GCC) method. The results show that the GCC provides a slightly better performance than the matched filted in all cases, and that polyphase sequences provide similar results than binary sequences, outperforming them in some situations.