Design Of Smart Antenna For Marine Mobile Communications

In recent years, marine ship to ship mobile communications are strongly required.By now, due to no specific knowledge of the users' whereabouts, a conventional antennaas omnidirectional have to be adopted, it radiates and receives information equally in alldirections. This equal distribution leads to power being transmitted to, but not received by,the user. This wasted power becomes potential interference to other users. Omnidirectionalantennas cannot selectively reject signals interfering in receive also.Because of the increasing demand for higher spectrum efficiency, the introduction ofsmart antennas has recently gained much attention. Based on an overview of recent marinemobile data communications and the basic principles in smart antennas, this paper gives adesign scheme using smart antennas for marine mobile communications to overcome theproblems associated with omnidirectional antennas. Smart antennas can estimate thedirection of arrival (DOA). By knowing the DOA, we can locate the mobile ship, focus alltransmitted power to the user and only "look" in the direction of the user for the receivedsignal. Finally, the implementation components associated with this design scheme arepresented.