| 主权项 |
1. A broadband multibeam satellite radio communication system, configured for fractional reuse of frequencies of a total band BT allocated to a forward channel, comprising:
a satellite having a multibeam transmission antenna system, configured to cover a geographical service area that is broken down into a plurality of transmission spots, having a first grid G1 of spots and a second grid G2 of transmission spots, the transmission spots of the first grid G1 and the transmission spots of the second grid G2 being positioned and their radiation patterns being configured such that there are points of intersection between the roll-off isocontours of an integral number m, greater than or equal to three, of partially overlapping adjacent spots, the number m denoting the order of multiplicity of the points of intersection; and a set of receiving terminals that are distributed over all of the transmission spots, each receiving terminal comprising a geographical positioning means and a reception means according to an allocated transmission resource; a forward channel transmission resource planner and allocator, which is implemented in the form of one or more electronic computers and configured to assign to a receiving terminal, when it so demands, a forward channel transmission resource in terms of a frequency sub-band of the total band BT and of a polarization state taken from among a first polarization state P1 and a second polarization state P2 on the basis of the geographical position of the receiving terminal and a forward channel transmission resource allocation plan according to which each transmission spot is made up of a central internal area and a peripheral area surrounding the central internal area; and the first polarization state and the second polarization state are respectively allocated to the spots of the first grid G1 and to the spots of the second grid G2, and one and the same main band BP of frequencies in one piece or in multiple pieces, forming a dominant part of the total band BT in terms of occupied band, is allocated wholly to each central internal area of the spots of the first and second grids; and the frequencies of the total band BT that are not part of the main band BP form a secondary band BS in one piece or in multiple pieces that is broken down into an integral number n, greater than or equal to 2, of secondary sub-bands in one piece that are each, separately or adjacently, distributed over all of the peripheral areas of the transmission spots according to a multicoloured scheme with n colours of secondary sub-bands, wherein the points of intersection between the spots of the first and second grids are quadruple points of intersection, having an order of multiplicity equal to 4. |
