Abstract: The invention relates to active interference suppression in a satellite communication system, particularly but not exclusively to an apparatus and method for using active interference suppression in order to suppress co-channel interference between user signals in the communication system. The communication system includes a receive or transmit antenna having a plurality of antenna elements, each antenna element associated with a respective antenna element signal. The method includes the steps of calculating complex weighting values for one or more of a plurality of beam signals, adjusting the beam signals in accordance with the calculated complex weighting values and cancelling co-channel interference in at least one of the beam signals using the one or more adjusted derived beam signals to provide an interference suppressed output signal. The complex weighting values can be calculated based on a constant modulus algorithm.

Abstract: A telecommunications satellite having a phased array antenna, wherein the beam-forming function within the phased array is simplified by partitioning it into two stages, in which the sub-array stage relates to a fixed, or infrequently changed, set of overlapping sub-arrays and the main stage provides the main pattern reconfiguration, typically in the form of multiple reconfigurable spot beams within a defined coverage region. The key advantage lies in the significant reduction in number of second stage beam-forming control points (at which independent amplitude and phase is applied) when compared with a conventional phased array (where amplitude and phase control is applied for each element of the array). The sub-array stage beam-forming may be implemented in analogue technology. The main beam-former may be implemented in digital technology, where the key processing functions of A/D or D/A conversion, frequency (de)multiplexing and digital beam-forming all scale with the number of control points.

Abstract: The invention relates to active interference suppression in a satellite communication system, particularly but not exclusively to an apparatus and method for using active interference suppression in order to suppress co-channel interference between user signals in the communication system. The communication system includes a receive or transmit antenna having a plurality of antenna elements, each antenna element associated with a respective antenna element signal. The method includes the steps of calculating complex weighting values for one or more of a plurality of beam signals, adjusting the beam signals in accordance with the calculated complex weighting values and cancelling co-channel interference in at least one of the beam signals using the one or more adjusted derived beam signals to provide an interference suppressed output signal. The complex weighting values can be calculated based on a constant modulus algorithm.

Abstract: A telecommunications satellite having a phased array antenna, wherein the beam-forming function within the phased array is simplified by partitioning it into two stages, in which the sub-array stage relates to a fixed, or infrequently changed, set of overlapping sub-arrays and the main stage provides the main pattern reconfiguration, typically in the form of multiple reconfigurable spot beams within a defined coverage region. The key advantage lies in the significant reduction in number of second stage beam-forming control points (at which independent amplitude and phase is applied) when compared with a conventional phased array (where amplitude and phase control is applied for each element of the array). The sub-array stage beam-forming may be implemented in analogue technology. The main beam-former may be implemented in digital technology, where the key processing functions of A/D or D/A conversion, frequency (de)multiplexing and digital beam-forming all scale with the number of control points.

Abstract: The invention relates to active interference suppression in a satellite communication system, particularly but not exclusively to an apparatus and method for using active interference suppression in order to suppress co-channel interference between user signals in the communication system. The communication system includes a receive or transmit antenna having a plurality of antenna elements, each antenna element associated with a respective antenna element signal. The method includes the steps of calculating complex weighting values for one or more of a plurality of beam signals, adjusting the beam signals in accordance with the calculated complex weighting values and cancelling co-channel interference in at least one of the beam signals using the one or more adjusted derived beam signals to provide an interference suppressed output signal. The complex weighting values can be calculated based on a constant modulus algorithm.