Patent ID: 8285202
Filing Date: 2012-10-09
Classification: H04B

Abstract:
1. A satellite comprising: a power source; a plurality of amplifiers for generating a plurality of spot beams; and an antenna for transmitting the plurality of spot beams to illuminate a corresponding plurality of regions on Earth, the plurality of spot beams including a spot beam illuminating a region at least partially overlapping with regions illuminated by one or more neighboring spot beams to result in interference; wherein the spot beam services a first subscriber terminal located in a first area closer to the center of the region illuminated by spot beam and a second subscriber terminal located in a second area closer to the periphery of the region illuminated by the spot beam; wherein the spot beam comprises a signal having a first portion sent with a first modcode destined for the first subscriber terminal located in the first area closer to the center of the illuminated region, the signal having a second portion sent with a second modcode destined for the second subscriber terminal located in the second area closer to the periphery of the illuminated region, wherein the first modcode corresponds to a higher data rate than the second modcode; and wherein modcodes of signals sent to the first and second subscriber terminals are adjusted according to an adaptive modulation and coding (ACM) scheme based on link quality information collected from the first and second subscriber terminals, to mitigate effects of interference from the one or more neighboring spot beams.