| 摘要 |
PROBLEM TO BE SOLVED: To reduce complicatedness of an equipment mounted on a satellite and a portable terminal equipment by decreasing number of required satellites and providing a high capacity with respect to a bit rate and to minimize a switching procedure of a portable terminal equipment by eliminating the need for switching between the satellites. SOLUTION: A radio signal is transmitted between a fixed ground station ST1 and mobile user terminal equipments T1 , T2 via a network of a satellite Sat1 with a tilted circular orbit whose radius is smaller than a radius of the earth stationary orbit in this method and system. In this case, an output beam is split into pencil beams p1 , p20 . and each of the pencil beams p1 , p20 has a sub frequency band where frequencies F1 , F20 are consecutive in the order of increasing or decreasing frequencies. An instantaneous transmission frequency is continuously offset for a call toward the frequency sub band F2 of the adjacent pencil beam at a speed proportional to a rotating speed so as to attain switching between the pencil beams p1 , p20 or between the satellites. |
