A statistical approach to the interference reduction of a class of satellite transmission systems

It is shown that the statistical characteristics of the intersystem interference power of the satellite communication system under consideration can be divided into two independent parts, one reflecting the statistical nature of the Single Channel Per Carrier (SCPC) carrier assignment procedure and the other reflecting the statistical nature of the sidelobe gain of the receiving antenna. It is assumed that the statistical behavior of the antenna sidelobe gain follows a Rayleigh distribution. It is shown that for a typical set of interference conditions (5-deg satellite spacing) between a wideband transmission system and a multiple SCPC system the interference power is less, by 6 dB with a confidence level 99%, than the worst-case power assumed in intersystem interference calculations. The interference is found to be extremely sensitive to orbital spacing. If at a 4-deg separation the same confidence level for the interference power is desired, the interference power must be 2.5 dB higher than at a 5-deg separation. This power, however, is still 3.5 dB lower than the worst-case power.