摘要:
The present invention provides a method for determining antenna pointing error of a satellite antenna (702-716) that produces at least one spot beam having a corresponding gain pattern. The method obtains from a first unique location (510) on the ground a first measurement of a spot beam strength for a first cell (502). Similar measurements are obtained at second and third unique locations (512, 514). Attitude component errors, for example the roll or pitch attitude component errors may then be determined. The method may further determine a yaw attitude component error based on fourth, fifth, and sixth measurements of spot beam strength made from unique locations (616-620) in a second cell (604) also generated by the antenna. Additional measurements may be collected in each beam at unique locations (510-514, 516-520, 610-614, 616-620) and averaged to reduce the temporary or zero means effects of rain, scintillation, or other atmospheric conditions on the spot beam strength. Furthermore, the method may transmit any of the measurements to a central processor (422) which determines the attitude component errors based on the measurements.
摘要:
A method for enhancing the performance of a communications system is disclosed. The system generally includes an originating ground station (300) which produces error-control coded uplink signals and transmits the coded uplink signals to a satellite (310). The system also includes a destination ground station (326) which receives a downlink beam from the satellite (310). The method includes the steps of receiving uplink signals transmitted by an originating ground station (300) at a destination ground station (326) and determining a downlink channel signal quality indication (504) at the destination ground station (326). The method also includes the steps of measuring an error rate associated with at least a portion of a downlink beam at said destination ground station (326) and determining an operating point (506) relative to a desired performance curve (502) based on the signal quality indication (504) and the error rate. At least one signal processing parameter of said originating ground station (300) is adjusted based on the operating point (506) when said operating point (506) lies in a predetermined region relative to the performance curve (502).
摘要:
The present disclosure relates to computer-implemented systems and methods for wireless communication in radar transmission channels. The method may include receiving, by a first computer comprising one or more processors from a second computer, a request to initiate wireless communication, the first computer in communication with a wireless access point. Additionally, the method may include determining, by the first computer, that the wireless access point is communicating in a radar transmission channel. Further still, the method may include establishing wireless peer-to-peer communication between the first computer and the second computer in the radar transmission channel.
摘要:
A platform to facilitate updating an equalizer in addition to other receiver functionality is disclosed. A transmitting entity transmits one or more pilot tones in each protocol data unit (PDU) such as a packet. A receiving entity is able to derive a sufficiently accurate channel response estimate with the pilot tones under most channel conditions. The method and apparatus rotates the pilot tones through each of the subcarriers over the packet. The pilot tones would be separated by some number of data subcarriers so that estimation of slope and intercept for subcarrier tracking could be maintained. As the pilot tones are swept across the subcarriers, the taps for the equalizer for the subcarriers for which the pilot tones currently populate would be updated as well. This approach allows the system to track channel changes over time.
摘要:
In a network that contains both new devices capable of using wide channels and legacy devices that can only use narrow channels, the network controller may define which devices are to use which narrow channels for concurrently transmitting uplink acknowledgements. Further, the network controller may schedule the devices to respond in groups based on the received signal strength of their transmissions at the network controller.
摘要:
Schemes are disclosed for efficiently training MIMO channels in wireless networks. In at least one embodiment, multiple STAs in a network may share a single channel sounding packet to develop corresponding beamforming matrices or CSI.
摘要:
A method including wirelessly receiving a packet at a wireless station belonging to a cell of a wireless network, the network for communicating according to a wireless network standard, each transmitting station of the cell able to transmit a packet that includes cell identification information; and ascertaining at the physical layer level whether or not the received packet is from another station of the cell by ascertaining whether or not the received packet includes the cell identification information of the cell.
摘要:
A method including wirelessly receiving a packet at a wireless station belonging to a cell of a wireless network, the network for communicating according to a wireless network standard, each transmitting station of the cell able to transmit a packet that includes cell identification information; and ascertaining at the physical layer level whether or not the received packet is from another station of the cell by ascertaining whether or not the received packet includes the cell identification information of the cell.
摘要:
A method and an apparatus in a first wireless station of a network transmitting to a second wireless station. The network uses multi-tone OFDM signals. The first station includes multiple antennas and a receive and a transmit signal path per antenna. Each receive signal path includes a discrete Fourier transformer determining the tones in a received signal, and each transmit signal path includes an inverse discrete Fourier transformer converting tones to a signal. The method includes determining channel estimates for each tone and each receive path while receiving from the second station, determining transmit weights to transmit to the second station, tone-by-tone weighting a signal for transmission to the second station to produce weighted tone sets for each transmit signal path, and transmitting the weighted tone sets. The first station is configured so that the weighting produces additive beamforming without the second station needing multiple antennas.
摘要:
The present invention provides a method for custom coding uplink signals and downlink beams in a satellite communications system. The method includes the step of applying, at a ground station (100), an outer code (102) to an uplink signal to produce an outer coded uplink signal. Next, the ground station (100) applies a selected reduced complexity inner code (104) to the outer coded uplink signal to produce a concatenated coded uplink signal. The ground station (100) transmits the concatenated coded uplink signal to a satellite (110). At the satellite (110), the inner code of the concatenated coded uplink signal is decoded (116) to produce an outer coded satellite data stream. Next, the satellite (110) applies a selected inner code (120) to a portion of the outer coded satellite data stream to produce a concatenated coded satellite data stream. The satellite (110) then transmits the concatenated coded satellite data stream in a downlink beam to a destination ground station (126).