Abstract: A communication satellite in a satellite communication system has multiple communication signal transmit horns or other transmit antenna (e.g., phased arrays) that transmit communication downlink signals to multiple corresponding terrestrial communication cells. The satellite includes first and second contiguous, high aspect ratio arrangements of the transmit horns. The first and second arrangements of transmit horns have allocated to them respective first and second orthogonal communication band segments. The first communication band segment is shared and fully allocable among the transmit horns of the first arrangement, and the second communication band segment is shared and fully allocable among the transmit horns of the second arrangement. The high aspect ratios of the first and second transmit horn arrangements result in corresponding high aspect ratios for terrestrial communication cell arrangements that can utilize well the allocable bandwidth of each communication band segment.
Abstract: A communication satellite transmitting system includes communication signal amplifiers (e.g., traveling wave tube (TWT) amplifiers) with outputs that are multiplexed among multiple transmit horns, each of which transmits a downlink communication signal to a corresponding geographic cells. In one implementation, each TWT amplifier is multiplexed among at least three transmit horns.
Abstract: A communication satellite system dynamically allocates additional downlink resources on the satellite to selected downlink signals to compensate for signal degradation. A typical cause of such degradation is rain where the downlink station is located. Another cause of such degradation is increased communication traffic or bandwidth demand within a particular region.
Abstract: A multi-symbol analysis process compensates for inter-symbol interference in communication signals. The multi-symbol analysis process determines a digital value for a symbol represented by a selected symbol period by correlating a digitized sample within the selected symbol period with a sum of weighted signal components. The sum of weighted signal components includes contributions from the selected symbol period and symbols from a number of other symbol periods that occur before and after the selected symbol period. The multi-symbol analysis process allows more extensive digital filtering, which reduces the bandwidth required to achieve the signal to noise ratio necessary to determine correctly a digital symbol represented by an analog signal. As a result, the multi-symbol analysis process can markedly increase the capacity of communications channels, including satellite communication channels.