Patent ID: 8102313

Claim:
A method for transmitting signals from transmitters into areas surrounding these transmitters via a satellite, comprising the steps of providing a satellite having a retrodirective antenna array comprising an array of receiving antenna elements defining a pattern of positions of the receiving antenna elements, and an array of transmitting antenna elements defining a pattern of positions of the transmitting antenna elements, receiving, by the array of receiving antenna elements of the retrodirective antenna array, a plurality of first signals each having an uplink frequency and being transmitted from individual transmitters, processing the received first signals for obtaining transformed signals by: A/D converting the received first signals from analog to digital signals at individual sampling times, performing a Fourier transformation on the digital signals from space domain into space spectral domain for each sampling time, performing a digital frequency conversion from an uplink frequency band to a downlink frequency band, digital phase shifting of the space spectral domain components according to the frequency difference between the uplink and downlink frequency bands by complex multiplication, performing an inverse Fourier transformation to phase-shifted space spectral domain components from the space spectral domain to space domain, center-symmetrical mirroring the pattern of the positions of the receiving antenna elements, and D/A converting the transformed signals, and applying the transformed signals to the transmitting antenna elements of the retrodirective antenna array in accordance with the center-symmetrical mirrored pattern of the positions of the transmitting antenna elements.