Implementation of Multiple Access Techniques Applicable for Maritime Satellite Communications

• Main Author: Stojce Dimov Ilcev
• Format: Article
• Language: English
• Published: Gdynia Maritime University 2013-12-01
• Series: TransNav: International Journal on Marine Navigation and Safety of Sea Transportation
• Subjects: Global Maritime Distress and Safety System (GMDSS); Maritime Mobile Satellite Communications (MMSC); Multiple Access (MA); Multiple Access Techniques; Code Division Multiple Access (CDMA); Time Division Multiple Access (TDMA); Frequency Division Multiple Access (FDMA); Random (Packet) Division Multiple Access (RDMA)
• Online Access: http://www.transnav.eu/files/Implementation of Multiple Access Techniques Applicable for Maritime Satellite Communications,464.pdf

In this paper are introduced fundamentals, characteristics, advantages and disadvantages of Multiple Access (MA) employed as transmission techniques in the Maritime Mobile Satellite Communications (MMSC) between ships and Coast Earth Station (CES) via Geostationary Earth Orbit (GEO) or Not-GEO satellite constellations. In fixed satellite communication, as a rule, especially in MMSC many users are active at the same time. The problem of simultaneous communications between many single or multipoint mobile satellite users can be solved by using MA technique, such as Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Code Division Multiple Access (CDMA), Space Division Multiple Access (SDMA) and Random (Packet) Division Multiple Access (RDMA). Since the resources of the systems such as the transmitting power and the bandwidth are limited, it is advisable to use the channels with complete charge and to create a different MA to the channel. This generates a problem of summation and separation of signals in the transmission and reception parts, respectively. Deciding this problem consists in the development of orthogonal channels of transmission in order to divide signals from various users unambiguously on the reception part.