Abstract: The present invention relates to a satellite communications system comprising a satellite with a spatial digital modulator for transmitting an incoming bit stream in multiple beams, wherein the spatial digital modulator is configured to generate transmit symbols by dividing the incoming bit stream into symbols of a symbol alphabet and to allocate each transmit symbol to a specific beam. The invention further relates to a method for transmitting a bit stream by such a satellite communications system.

Abstract: The invention relates to a method for operating a communication system, the communication system comprising at least two separate transmitting antennas located on Earth and at least two receive antennas located with a distance from Earth, the receive antennas having directional receiving patterns which cover a common region on Earth, the method comprising the following steps: —precoding the symbol sequences before transmission from the transmitting antennas to the receive antennas in order to reduce spatial interference between the symbol sequences, and —simultaneously transmitting symbol sequences from the transmitting antennas to the receive antennas by spatial and frequency multiplexing in a time and phase synchronized fashion, the symbol sequences being transmitted from different transmitting antennas being different from each other but being transmitted on the same frequency.

Abstract: Operating a communication system comprises providing N transmitting antennas (TA) for transmitting symbol streams (SST) and K ground receivers (GR) which may be provided with symbol streams (SST) transmitted by transmitting antennas (TA). Transmitting antennas (TA) are located with a distance from Earth (E). Ground receivers (GR) are spatially separated from each other, wherein the constraint K>N applies. The method includes: simultaneously transmitting N symbol streams (SST) by N transmitting antennas (TA), receiving a linear combination of N simultaneously transmitted symbol streams (SST) by each ground receiver (GR), respectively, determining the respective linear combination for N transmitting antennas (TA) and each of the K ground receivers (GR), respectively, deciding on the basis of the determined linear combinations which of the K ground receivers (GR) is assigned to a respective common receiver group in order to be simultaneously and with the same frequency provided with symbol streams (SST).