Code Division Multiple Access (CDMA) applicable for Mobile Satellite Communications

This paper describes in particular Code Division Multiple Access (CDMA) applicable in Mobile Satellite Communications (MSC) connecting Mobile Earth Stations (MES) via Land Earth Stations (LES). However, in satellite communication systems, as a rule, especially in MSC many users are active at the same time. The problem of simultaneous communications between many single or multipoint mobile satellite users, however, can be solved by using Multiple Access (MA) technique. 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, such as example of the described CDMA. This generates a problem of summation and separation of Radio Frequency (RF) 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.