摘要:
A method for determining a frequency correction and a symbol rate correction for transmissions from a user terminal in a satellite communications system comprises determining a frequency of a signal received at the user terminal, and determining a symbol rate of the signal received at the user terminal. The method also comprises computing an error associated with an oscillator at an outdoor unit of the user terminal, and computing an error associated with an oscillator at an indoor unit of the user terminal. The method also comprises computing a transmit frequency correction for the user terminal based on the error of the oscillator at the outdoor unit and the error of the oscillator at the indoor unit, and computing a transmit symbol rate correction for the user terminal based on the error of the oscillator at the indoor unit.
摘要:
A method for determining a frequency correction and a symbol rate correction for transmissions from a user terminal in a satellite communications system comprises determining a frequency of a signal received at the user terminal, and determining a symbol rate of the signal received at the user terminal. The method also comprises computing an error associated with an oscillator at an outdoor unit of the user terminal, and computing an error associated with an oscillator at an indoor unit of the user terminal. The method also comprises computing a transmit frequency correction for the user terminal based on the error of the oscillator at the outdoor unit and the error of the oscillator at the indoor unit, and computing a transmit symbol rate correction for the user terminal based on the error of the oscillator at the indoor unit.
摘要:
A method for providing soft handoff between antennas in a multi-antenna system is provided according to some embodiments of the disclosure. A first packetized digital data stream may be received from a satellite using a first antenna and the data stream may include a plurality of packets that each include a header and data. The data may be provided, forwarded or stored in memory. In the meantime, a second packetized digital data stream is monitored. The second packetized digital data stream may be received from the satellite using a second antenna. The phase difference between the first packetized digital data stream and the second packetized digital data stream may be determined and added or subtracted from the second packetized digital data stream. The second packetized digital data stream may then be provided, forwarded or stored in memory.
摘要:
An apparatus for recovering heat from exhaust air received from a restaurant kitchen. Rotating backwards inclined fan blades draw exhaust air from the kitchen along a flow path and impel it against walls of a housing, such that grease is removed from the exhaust air. A fan motor is positioned out of the flow path. The exhaust air is pushed out of the housing to a heat recovery coil directly downstream that is formed from a heat conductive material. The coil has an internal conduit through which a heat transfer fluid is supplied at a temperature below the exhaust air temperature, such that the fluid in the conduit is heated by exhaust air passing over the conductive material. After leaving the conduit, heat energy is transferred from the fluid to makeup air for return to, or to water for use in, the restaurant.
摘要:
An apparatus for converting three phase AC supply line voltages to DC voltage on a DC bus, the apparatus including a master converter subsystem and at least one slave converter subsystem wherein each subsystem includes a current regulator, a PMW modulator and a converter, the master converter linked to the supply lines and the slave converter linked to the supply lines via intermediate lines, each regulator receiving a current command signal and generating modulating signals, each modulator using a carrier signal and modulating signals from a corresponding regulator to generate control signals to control a corresponding converter, the intermediate lines linked to a common mode choke for essentially eliminating common mode currents in the intermediate lines.
摘要:
A container holder adapted to releaseably retain a plurality of similarly configured containers and adapted to permit release of each container individually.The holder is comprised of a central panel portion and a plurality of retaining portions. Each of the retaining portions has a pull tab that corresponds to it. The pull tab is joined to its respective retaining portion along the margin. The pull tab has a scoreline of a selected length proximate the pull tab so that the pull tab can be operated to release the loop-like structure thus preventing wildlife from becoming entangled in unruptured rings of plastic containers once the package is discarded.
摘要:
Novel polyurethane formulations especially useful as membranes for the protection of bridge deckings. The polyurethane is prepared by mixing two components, A and B. Component A comprises castor oil, a low molecular weight polyol having a molecular wieght between 92 and about 200, preferably with an elastomer. Component B is a modified MDI, being either (i) a mix of 4,4'- and 2,4'-isomers of diphenylmethane diisocyanate or (ii) a diphenylmethane diisocyanate and its reaction product with a low molecular weight poly(oxyalkylene).
摘要:
A spray assembly for a milk tank, where there is an elongate water pipe positioned in the tank, and a plurality of spray nozzle assemblies mounted to the pipe. Each spray nozzle assembly comprises a nozzle member having radially inwardly directed openings leading to a middle impact chamber which in turn leads directly to an upper discharge opening. The water flows radially inwardly to the impact chamber to provide a random expanding spray pattern that washes upwardly against the interior surface of the tank. The nozzle member is retained by a member having an expanded head and a shank that extends downwardly through a second opening in the pipe. A releasable retaining member retains the connecting member in place. In operation, the water flows against substantially all of the surface portions of the nozzle assembly to provide a self-cleaning action. The assembly can be easily disassembled for maintenance or possibly further cleaning.
摘要:
An auxiliary handle attached to a main handle of a welding apparatus by means of a circumferential clamp which permits adjustment rotationally and pivotally of the auxiliary handle. A radiation and contact shield, made of a single piece of heat insulating flexible material, is attached to the auxiliary handle so as to provide a forward radiation shield to protect the user's hand from heat generated at the weld area, and a contact insulating portion which permits the user to place the heel of his hand against the work piece being welded, while protecting the user's hand from the heat of the work piece itself.
摘要:
Digital communications interleavers re-order the bits of a data coding block in a way that can be described by a table of indices that map the original order to the interleaved order. Conventional interleavers include index table interleavers, which store an index table ahead of operation and algorithmic Interleavers, which generate the indices during operation.Described herein are a new class of interleavers: Subset Transform Interleavers. A subset of generator outputs is selected and processed to create the interleaver indices. The selection is determined apriori and the selection results are stored in a Subset Usage Table. During operation, the generator is operated again and the Subset Usage Table entries determine which generator outputs are used. The generator may be a pseudo-random number generator. Implementations can use an Indexes Remaining Table, which can additionally be manipulated during operation such that it returns to an initialized state after each block interleaving process.