Abstract: Method and system for reducing a temperature differential across a flight vehicle. The system includes an exterior of the flight vehicle. The exterior of the flight vehicle includes a first exterior panel being at a first initial temperature and a second exterior panel being at a second initial temperature to define an initial temperature differential. A fluid loop, containing a working fluid, is coupled to the first exterior panel and the second exterior panel such that heat is transferred from the first exterior panel to the working fluid to decrease the first initial temperature of the first exterior panel to a first altered temperature, and to heat the working fluid. The heated working fluid is circulated from the first exterior panel and used to heat the second exterior panel to a second altered temperature greater than the second initial temperature.

Abstract: An aircraft cooling system comprises an evaporator, condenser, an accumulator, and a pump system. The evaporator is configured to cool a set of heat loads in an aircraft using a liquid. The liquid forms a vapor in response to cooling the set of heat loads. The condenser is configured to receive the vapor from the evaporator and cool the vapor in which cooling the vapor forms the liquid. The accumulator is configured to receive the liquid from the condenser and store the liquid. The pump system is configured to pump the liquid stored in the accumulator to the evaporator.

Abstract: Embodiments of the present invention provide a signal processing method, including: dividing a frequency band used to send a downlink synchronization symbol into at least two parts of frequency bands that do not overlap, where the two parts of frequency bands are a first frequency band and a second frequency band; alternately allocating frequencies in the first frequency band to a probe tone and a flag tone; and allocating all frequencies in the second frequency band to a probe tone; and modulating a downlink pilot sequence to probe tones in the first frequency band and the second frequency band, and sending the downlink pilot sequence to a peer device. The embodiments of the present invention further provide a signal processing apparatus and a network system.

Abstract: A line synchronization method in an overlapped spectrum duplex (OSD) system having K pairs of communications lines. Each pair of communications lines includes an uplink and a downlink. The method includes synchronizing downstream synchronization symbols of downlinks in the pairs of communications lines, and separately synchronizing an upstream synchronization symbol of an uplink of each pair of communications lines with a downstream synchronization symbol of a downlink of each pair of communications lines. The method may be applied to crosstalk channel estimation to distinguish near-end crosstalk (NEXT) and far-end crosstalk (FEXT) crosstalk channels when upstream and downstream spectrums are overlapped.

Abstract: A digital subscriber line (DSL) network device for coupling to DSL communication lines, the network device comprising: multiplexing circuitry that transmits signals to vector-compliant consumer premises equipment (CPE) and legacy CPE via the DSL communication lines; and processing circuitry configured to: initiate transmission of a predetermined set of orthogonal pilot sequences to a plurality of vector-compliant CPEs; initiate transmission of data symbols corresponding to the set of orthogonal pilot sequences to one or more legacy CPEs; pre-process line errors of a victim vector-compliant CPE to remove far-end crosstalk due to the vector compliant disturber lines and perform the same pre-processing for the transmitted data symbols; determine far-end channel crosstalk information using a correlation of the pre-processed line errors and the pre-processed transmitted data symbols; and reduce far-end channel crosstalk of the victim vector-compliant CPE using the determined far-end channel crosstalk information.

Abstract: A line synchronization method in an overlapped spectrum duplex (OSD) system having K pairs of communications lines. Each pair of communications lines includes an uplink and a downlink. The method includes synchronizing downstream synchronization symbols of downlinks in the pairs of communications lines, and separately synchronizing an upstream synchronization symbol of an uplink of each pair of communications lines with a downstream synchronization symbol of a downlink of each pair of communications lines. The method may be applied to crosstalk channel estimation to distinguish near-end crosstalk (NEXT) and far-end crosstalk (FEXT) crosstalk channels when upstream and downstream spectrums are overlapped.

Abstract: A line synchronization method in an overlapped spectrum duplex OSD system having K pairs of communications lines. Each pair of communications lines includes an uplink and a downlink. The method includes synchronizing downstream synchronization symbols of downlinks in all of the pairs of communications lines, and separately synchronizing an upstream synchronization symbol of an uplink of each pair of communications lines with a downstream synchronization symbol of a downlink of each pair of communications lines. The method may be applied to crosstalk channel estimation to distinguish NEXT and FEXT crosstalk channels when upstream and downstream spectrums are overlapped.

Abstract: A method for canceling crosstalk between lines in a DSL system is presented. The method includes obtaining an upstream signal that is sent by corresponding customer premises equipment (CPE) and that is received by each central office (CO), forming an upstream signal sequence including upstream signals of all COs, obtaining a downstream signal that is sent by each CO to the CPE corresponding to each CO, and forming a downstream signal sequence including downstream signals of all the COs; performing FEXT cancellation processing on the upstream signal sequence to obtain a first signal sequence, and processing the downstream signal sequence to determine NEXT signals in the upstream signals of all the COs; and performing NEXT cancellation processing on the first signal sequence using the determined NEXT signals, to obtain a second signal sequence, and sending upstream signals in the second signal sequence to all the COs.

Abstract: A digital subscriber line (DSL) network device for coupling to DSL communication lines, the network device comprising: multiplexing circuitry that transmits signals to vector-compliant consumer premises equipment (CPE) and legacy CPE via the DSL communication lines; and processing circuitry configured to: initiate transmission of a predetermined set of orthogonal pilot sequences to a plurality of vector-compliant CPEs; initiate transmission of data symbols corresponding to the set of orthogonal pilot sequences to one or more legacy CPEs; pre-process line errors of a victim vector-compliant CPE to remove far-end crosstalk due to the vector compliant disturber lines and perform the same pre-processing for the transmitted data symbols; determine far-end channel crosstalk information using a correlation of the pre-processed line errors and the pre-processed transmitted data symbols; and reduce far-end channel crosstalk of the victim vector-compliant CPE using the determined far-end channel crosstalk information.

Abstract: A method comprising allocating one or more detection tones of a sync symbol for crosstalk-free feedback data estimation, wherein the one or more detection tones are a quiet signal; transmitting the one or more detection tones to a computing device, receiving the crosstalk-free feedback data from the computing device, wherein the crosstalk-free feedback data comprises data associated with a background noise detected during the detection tones; determining an optimized PSD based at least in part on the crosstalk-free feedback data; and adjusting a transmission PSD of a plurality of tones based at least in part on the optimized PSD.

Abstract: Embodiments of the present invention provide a signal processing method, including: dividing a frequency band used to send a downlink synchronization symbol into at least two parts of frequency bands that do not overlap, where the two parts of frequency bands are a first frequency band and a second frequency band; alternately allocating frequencies in the first frequency band to a probe tone and a flag tone; and allocating all frequencies in the second frequency band to a probe tone; and modulating a downlink pilot sequence to probe tones in the first frequency band and the second frequency band, and sending the downlink pilot sequence to a peer device. The embodiments of the present invention further provide a signal processing apparatus and a network system.

Abstract: A crosstalk processing method, an apparatus, and a system comprise a transceiver of a line that generates, respectively according to pilot sequences allocated by a vectoring control entity, pilot training signals that are within different spectral ranges and that satisfy a preset relationship with a pilot training signal of another line such that a receiver of the line can determine sample errors respectively according to the different pilot training signals. A vectoring control entity then determines crosstalk channel coefficients from the other line into an inband spectrum and an out-of-band spectrum of the line, and performs precoding processing on a to-be-sent data signal of the line to eliminate impact of crosstalk from the other line to the inband and out-of-band spectrums of the line.

Abstract: The present invention provides a method and an apparatus for training a Vector coefficient of a vectored digital subscriber line, where the method includes: after a handshake phase is executed for a joining line, calculating, by using a pilot estimation method, an initial precoding coefficient and an initial cancellation coefficient that represent interference from the joining line to a normal working line; and after a channel discovery phase is executed for the joining line, compensating the initial precoding coefficient and the initial cancellation coefficient by using a compensation factor, to obtain a precoding coefficient and a cancellation coefficient that represent the interference from the joining line to the normal working line, wherein the compensation factor is obtained according to a signal power change or a signal phase change of the joining line. The present invention improves efficiency of Vector coefficient training.

Abstract: A crosstalk processing method, an apparatus, and a system comprise a transceiver of a line that generates, respectively according to pilot sequences allocated by a vectoring control entity, pilot training signals that are within different spectral ranges and that satisfy a preset relationship with a pilot training signal of another line such that a receiver of the line can determine sample errors respectively according to the different pilot training signals. A vectoring control entity then determines crosstalk channel coefficients from the other line into an inband spectrum and an out-of-band spectrum of the line, and performs precoding processing on a to-be-sent data signal of the line to eliminate impact of crosstalk from the other line to the inband and out-of-band spectrums of the line.

Abstract: Embodiments of the present invention relate to a method and an apparatus for sending a single-ended loop testing SELT measurement signal, and a control device. The method for sending a SELT measurement signal includes: aligning a synchronization symbol of a digital subscriber line on which a SELT diagnosis needs to be performed with a synchronization symbol of at least one DSL line for data transmission, where the synchronization symbol of the digital subscriber line on which a SELT diagnosis needs to be performed and the synchronization symbol of the at least one digital subscriber line for data transmission are uplink or downlink synchronization symbols; and carrying a SELT measurement signal over the aligned synchronization symbol of the DSL line on which a SELT diagnosis needs to be performed, where the SELT measurement signal is used to detect transmission quality or a line fault of the DSL line.

Abstract: A method for canceling crosstalk between lines in a DSL system is presented. The method includes obtaining an upstream signal that is sent by corresponding customer premises equipment (CPE) and that is received by each central office (CO), forming an upstream signal sequence including upstream signals of all COs, obtaining a downstream signal that is sent by each CO to the CPE corresponding to each CO, and forming a downstream signal sequence including downstream signals of all the COs; performing FEXT cancellation processing on the upstream signal sequence to obtain a first signal sequence, and processing the downstream signal sequence to determine NEXT signals in the upstream signals of all the COs; and performing NEXT cancellation processing on the first signal sequence using the determined NEXT signals, to obtain a second signal sequence, and sending upstream signals in the second signal sequence to all the COs.

Abstract: A line synchronization method in an overlapped spectrum duplex OSD system having K pairs of communications lines. Each pair of communications lines includes an uplink and a downlink. The method includes synchronizing downstream synchronization symbols of downlinks in all of the pairs of communications lines, and separately synchronizing an upstream synchronization symbol of an uplink of each pair of communications lines with a downstream synchronization symbol of a downlink of each pair of communications lines. The method may be applied to crosstalk channel estimation to distinguish NEXT and FEXT crosstalk channels when upstream and downstream spectrums are overlapped.

Abstract: A method comprising allocating one or more detection tones of a sync symbol for crosstalk-free feedback data estimation, wherein the one or more detection tones are a quiet signal; transmitting the one or more detection tones to a computing device, receiving the crosstalk-free feedback data from the computing device, wherein the crosstalk-free feedback data comprises data associated with a background noise detected during the detection tones; determining an optimized PSD based at least in part on the crosstalk-free feedback data; and adjusting a transmission PSD of a plurality of tones based at least in part on the optimized PSD.

Abstract: Embodiments of the present invention relate to a method and an apparatus for sending a single-ended loop testing SELT measurement signal, and a control device. The method for sending a SELT measurement signal includes: aligning a synchronization symbol of a digital subscriber line on which a SELT diagnosis needs to be performed with a synchronization symbol of at least one DSL line for data transmission, where the synchronization symbol of the digital subscriber line on which a SELT diagnosis needs to be performed and the synchronization symbol of the at least one digital subscriber line for data transmission are uplink or downlink synchronization symbols; and carrying a SELT measurement signal over the aligned synchronization symbol of the DSL line on which a SELT diagnosis needs to be performed, where the SELT measurement signal is used to detect transmission quality or a line fault of the DSL line.

Abstract: The present invention provides a method and an apparatus for training a Vector coefficient of a vectored digital subscriber line, where the method includes: after a handshake phase is executed for a joining line, calculating, by using a pilot estimation method, an initial precoding coefficient and an initial cancellation coefficient that represent interference from the joining line to a normal working line; and after a channel discovery phase is executed for the joining line, compensating the initial precoding coefficient and the initial cancellation coefficient by using a compensation factor, to obtain a precoding coefficient and a cancellation coefficient that represent the interference from the joining line to the normal working line, wherein the compensation factor is obtained according to a signal power change or a signal phase change of the joining line. The present invention improves efficiency of Vector coefficient training.