Channel sounding over sea surface environment

Abstract

Big tankers and cargo ships anchored off the Southern coast of Singapore act as a blockage for a line-of-sight (LOS) propagation for wireless link between the shore and sea. This results in Non-line-of-sight (NLOS) propagation, affecting sea-to-land wireless transmission. For military and commercial applications in particular, it is crucial for the wireless link used to be reliable. Space diversity will be studied and analyzed in this paper to characterize the sea-to-land wireless communication link at 5.5 GHz using experimental data obtained from sea trials. Space diversity reduces multipath fading caused by these NLOS blockage by using multiple transmitting and receiving antennas. Multiple Pseudo-random Noise (PN) sequences, modulated by Binary Phase Shift Keying (BPSK), are transmitted to ensure signals reaching the receivers have uncorrelated fading. Selective Combining technique is then used to select the highest instantaneous Signal-to-Noise Ratio (SNR) values so as to improve overall SNR values by mitigating multipath, thus improving the wireless link.