Abstract:
A network for providing high speed data communications may include multiple terrestrial transmission stations that are located within overlapping communications range and a mobile receiver station. The terrestrial transmission stations provide a continuous and uninterrupted high speed data communications link with the mobile receiver station employing a wireless radio access network protocol.
Abstract:
A satellite broadcasting system is achieved in which remote beam forming processors located among distributed ground stations are used to control downlink beam footprints and pointing directions. Digital beam forming techniques allow a single satellite downlink broadcast antenna array to generate multiple simultaneous downlinks that can be pointed independently and that may contain distinct information content. By allocating some of the uplink back-channel elements as null channels, continuous calibration of the uplink channel can be performed, improving the performance of the downlink broadcast array and the quality of the broadcast for users. By wavefront multiplexing, all of the uplink channel elements propagate through the all of the available propagation channels simultaneously, eliminating the need for complex and costly individual array-element calibration equipment using on-board or ground-based references.
Abstract:
Methods of reducing interference in a satellite communications system may include receiving a plurality of feeder link signals and time aligning the plurality of feeder link signals to provide time aligned feeder link signals. At least two of the time aligned feeder link signals may be combined to provide reduced interference of at least one of the feeder link signals. Related systems are also discussed.
Abstract:
Systems and methods are presented for measuring power levels of primary and interfering signals as well as noise, particularly for satellite transmitted signals. A typical method comprises the steps of receiving a signal comprising a primary signal, an interference signal and noise, demodulating the primary signal to remove a carrier frequency, decoding the primary signal to obtain symbols, estimating a power level of the primary signal based upon the demodulated and decoded primary signal. Additionally, an ideal primary signal can be generated from the carrier power and frequency and the symbols and subtracted from the received signal to produce the noise and interference signal. The noise and interference power is then estimated from the noise and interference signal.
Abstract:
A system and method are disclosed which may include providing at least one satellite having a plurality of beamformers configured to provide a plurality of respective beams having a plurality of different respective fixed pitch angles about an axis of the satellite; causing the at least one satellite to move around the earth along a non-geostationary orbit; establishing a data communication path between a first of the beamformers on the satellite and a communication target, the data communication path having a satellite end at the first beamformer and an target end at the communication target; shifting the satellite end of the data communication path through a succession of the beamformers as the satellite moves along its orbit; and at least substantially reducing an amount of RF wave energy directed to beamformers of the plurality of beamformers not forming part of the data communication path.
Abstract:
Methods of reducing interference in a satellite communications system may include receiving a plurality of feeder link signals and time aligning the plurality of feeder link signals to provide time aligned feeder link signals. At least two of the time aligned feeder link signals may be combined to provide reduced interference of at least one of the feeder link signals. Related systems are also discussed.
Abstract:
A communication systems providing a fault-tolerant communications path for narrow and broad band communication comprising one or more self-powered satellite units each providing signal information to at least one command console through a segmented cable assembly system in operable communication with a central station that receives signal information from the at least one command console and relays signal information back to the command console wirelessly and via the segmented cable assembly system.
Abstract:
An improved satellite communication device and system are provided. The satellite communication device uses yaw or roll-yaw steering to linearize angular track of uplink cells; one-dimensional linear “ratcheting” in an uplink antenna to maintain resource allocation of uplink cells along antenna columns; phased-array downlink antennas which can track earth-fixed downlink cells while compensating for the yaw (or roll-yaw) satellite steering; and variable rate TDMA service among downlink cells in a footprint. As a result, system overhead for performing new resource allocations between satellite handovers is minimized, thereby reducing resource management and increasing system capacity. Flexible bandwidth/capacity assignment of both uplink and downlink resources to earth locations via linear cell ratcheting, uplink RF peaking switch, and data-driven variable-TDMA downlink phased-arrays, is provided.
Abstract:
Methods of reducing interference in a satellite communications system may include receiving a plurality of feeder link signals and time aligning the plurality of feeder link signals to provide time aligned feeder link signals. At least two of the time aligned feeder link signals may be combined to provide reduced interference of at least one of the feeder link signals. Related systems are also discussed.
Abstract:
A first radio signal is received via a first satellite reception path, for example, an antenna or spot beam, which serves a satellite cell. The received first radio signal includes a desired satellite uplink signal transmitted from a first source using a frequency assigned to the satellite cell and an interfering signal transmitted from at least one second source using the frequency assigned to the satellite cell. A second radio signal is received via a second satellite reception path, for example, via another antenna or spot beam of the system and/or via a satellite antenna beam of another system. The second radio signal includes a measure of the interfering signal. The first and second radio signals are processed to recover the desired satellite uplink signal.