摘要:
A method for encoding an OFDM signal includes pairing two adjacent subcarriers of an OFDM signal as a group, changing a modulated symbol set of the OFDM signal to a modified symbol set for coding the OFDM signal, and providing a modified baseband OFDM signal with an increased frequency separation between the subcarriers and reducing the total number of subcarriers being used for transmission over each OFDM symbol interval.
摘要:
A method for encoding an OFDM signal includes pairing two adjacent subcarriers of an OFDM signal as a group, changing a modulated symbol set of the OFDM signal to a modified symbol set for coding the OFDM signal, and providing a modified baseband OFDM signal with an increased frequency separation between the subcarriers and reducing the total number of subcarriers being used for transmission over each OFDM symbol interval.
摘要:
A modulation system includes a modulator configured to employ a modulation mechanism on data. The mechanism includes a signal constellation configured to map sub-carriers which include a signal to be modulated. The signal constellation has a plurality of points asymmetrically disposed on a circle about an origin and a point at the origin wherein a number of sub-carriers becomes variable over different symbol intervals. Corresponding demodulators and corresponding methods are also disclosed.
摘要:
FIG. 1 is a front view of a smart fish tank showing my new design; FIG. 2 is a rear view thereof; FIG. 3 is a right side view thereof; FIG. 4 is a left side view thereof; FIG. 5 is a top plan view thereof; FIG. 6 is a bottom plan view thereof; and, FIG. 7 is a perspective view thereof. The broken lines in the drawings depict portions of the smart fish tank and form no part of the claimed design.
摘要:
Provided is a leak-proof lubrication system for a power device, comprising an oil supply pump inlet pipe, an oil supply pump, an oil supply pressure gauge, an oil supply pump outlet pipe, an oil supply filter, a lubricating oil, an oil storage tank, an oil return pipe, an storage tank pressure gauge, a vacuum pump intake pipe, a vacuum pump inlet air filter, a vacuum pump and a vacuum pump exhaust pipe. The system employs a negative pressure operation method in which the pressure of the lubrication system is controlled to be lower than the outside ambient pressure, which allows a small amount of air to flow from the outside to the inside of the lubrication system along with the lubricant to return to the storage tank, preventing leakage of the lubricant from connection joints. It is suitable to be used for gas turbines or other high-speed power machines.
摘要:
An optical transport network based on multimode/multicore fibers includes a mode-multiplexer to multiplex independent data streams from one or more transmitters; a multimode erbium-doped fiber amplifier (MM EDFA) to compensate for MMF loss; a multimode optical add-drop multiplexer (MM OADM) to add and/or drop multimode channels in multimode networks; a multimode optical cross-connect; and a mode-demultiplexer to separate various mode streams to one or more receivers.
摘要:
A method for generating a 400 Gb/s single channel optical signal from multiple modulated subchannels includes carving respective modulated subchannels into return-to-zero RZ modulated subchannels having non-overlapping peaks with intensity modulators having a duty cycle less than 50%, and combining the subchannels into a single channel signal aggregating the bit rate of each of the subchannels. The subchannels are combined with a flat top optical component for increased subsequent receiver sensitivity.
摘要:
A method for optical layer traffic grooming includes receiving at least two optical input signals into respective optical receivers, each optical receiver having a photodetector for converting the respective optical input signal into a respective electrical signal; a grooming processor responsive to the electrical signals, the grooming processor being a radio frequency RF processor for processing the electrical signals at a subcarrier level to produce an RF orthogonal frequency division multiplexing signal OFDM signal; and modulating the groomed RF OFDM signal at a transmitter for conversion of the groomed RF OFDM into an optical signal.
摘要:
The present invention employs a look up table based implementation for the metric computations which eliminate redundancy and substantially reduce the number of multiplications. Moreover, inventive method exploits the fact that the un-normalized constellation symbols are complex integers so that the product of a real-number and an un-normalized constellation symbol can be implemented by only additions. The inventive method also enables a greater efficiency for whitening colored noise prior to demodulation, one of which involves no square-root operation. The invention results in less complexity, faster operation, lower power consumption, without sacrificing performance.