Characteristics of sea reflection fading in maritime satellite communications

Abstract

MIURAAbstruct-The Japanese domestic experimental mobile satellite system (EMSS) has been studied to establish high qnality channels for small vessels with compact and low-gain antennas. The present international maritime satellite communication system (INMARSAT) has also been studied for the next generation to extend services for small ships, for which the present ship terminals inclnding the antenna systems are too large and too heavy. By using a low-gain antenna, however, mdtipath fading caused by sea reflections wiU become a serious problem in designing the new system. To take effective countermeasures to the fading effect, it is verg important to get a better knowledge of the fading phenomena caused by sea reflections.From a standpoint of maritime satellite communications, experiments measuring the amount of fading were performed nuder various sea conditions and in two frequency bands. The wave height, which is considered the most important experimental parameter, was measured objectively by a wave rider buoy. The experimental results show that the amonnt of fading depends on a wave height and radio frequency and, as the most interesting result, as a wave increases above a certain level, the amount of fading decreases. These results are also discussed theoretically.

Radio Channel Modeling in a Ship Hull: Path Loss at 868 MHz and 2.4, 5.25, and 60 GHz

“…Enabling wireless connectivity inside the ship allows for automatic monitoring and controlling of devices and improves safety on board. During the last decade, most research focused on offboard marine communication [2], [3], [4], [5], [6], and existing papers about in-vessel wireless communication seem to focus on higher-layer measurements, e.g. deploying a sensor network and investigating packet error rate [7], [8], [9].…”

Simulation of High-Altitude Electromagnetic Pulse (Hemp) Above Sea Surface

“…By substituting (9) into (7), we obtain The effects of rough sea surface on maritime communications were studied in [19][20][21][22][23]. Fig.…”

On combating deep fades due to ground reflection in point‐to‐point WiMAX communications

“…Elliptical, circular, hexagonal, and rectangular shaped UWB antennas with band notched characteristics have been proposed [4][5][6][7][8][9][10][11][12][13]. Band rejection characteristics are achieved by cutting a slot or a slit in radiating patch.…”

“…Other authors have focused their studies on formulating terrain propagation problems using deterministic and stochastic approaches [3,4]. Others have measured channel parameters-like the received power and the delay spread-and then introduced the resulting model into antenna patterns underlining by that the realistic effect of multipath fading on the communication system [5,6].…”