55 results about "Super-channel" patented technology

Consistent with the present disclosure, data, in digital form, is received by a transmit node of an optical communication, and converted to analog signal by a digital-to-analog converter (DAC) to drive a modulator. The modulator, in turn, modulates light at one of a plurality of wavelengths in accordance with the received data forming a plurality of corresponding carriers. The plurality of carriers are then optically combined with a fixed spacing combiner to form a superchannel of a fixed capacity. Accordingly, the number of carriers are selected according to a modulation format and symbol rate to realize the fixed capacity, for example. The superchannel is then transmitted over an optical communication path to a receive node. At the receive node, the superchannel is optically demultiplexed from a plurality of other superchannels. The plurality of carriers are then supplied to a photodetector circuit, which receives additional light at one of the optical signal carrier wavelengths from a local oscillator laser. An analog-to-digital converter (ADC) is provided in the receive node to convert the electrical signals output from the photodetector into digital form. The output from the ADC is then filtered in the electrical domain, such that optical demultiplexing of the carriers is unnecessary.

Consistent with the present disclosure, data, in digital form, is received by a transmit node of an optical communication system, is processed and then output to drive a modulator. The modulator, in turn, modulates light at one of a plurality of wavelengths in accordance with the received data, forming a plurality of corresponding carriers. The plurality of wavelengths used for the plurality of carriers are spectrally spaced apart by a common, periodic fixed spacing. The plurality of carriers are optically combined with a fixed spacing combiner to form a superchannel. A plurality of superchannels are generated and then multiplexed together onto an optical communication path and transmitted to a receive node. Each superchannel includes a plurality of carriers, each spectrally separated by the same fixed spacing. The plurality of superchannels are spectrally separated by an amount corresponding to the fixed spacing of the plurality of carriers. At the receive node, the superchannels are optically demultiplexed, and the plurality of carriers of a respective superchannel are then supplied to a photodetector circuit, which receives additional light at one of the optical signal carrier wavelengths from a local oscillator laser. The resultant signals are then processed electronically to separate the individual carriers and output data corresponding to the input data.

The present invention is directed to a method including determining an appropriate power level for a phase modulator for an optimum number of subcarriers; and applying the determined appropriate power level via a controller to produce the optimum number of subcarriers, wherein the optimum number of subcarriers enables an optical-orthogonal frequency division multiplex O-OFDM based variable rate transmitter with automatic control by a controller to produce an optimum setting based on a required rate.

The transmission of data from a transmitter to a receiver over an optical super-channel including a set of sub-channels of different frequencies includes partitioning the data into a set of data streams including one data stream for each sub-channel and partitioning each data stream into a set of sub-streams. Each sub-stream of each data stream is encoded with different forward error correction (FEC) codes to produce a set of encoded sub-streams for each data stream, and the set of encoded sub-streams of each data stream are superimposed with different powers to produce a set of encoded data streams. The set of encoded data streams is multiplexed to produce an optical signal transmitted over the set of sub-channels of the optical super-channel.

Consistent with the present disclosure, data, in digital form, is received by a transmit node of an optical communication system, and converted to an analog signal by a digital-to-analog converter (DAC) to drive a modulator. The modulator, in turn, modulates light at one of a plurality of wavelengths in accordance with the received data forming a plurality of corresponding carriers. The carriers are modulated according to one of a plurality of modulation formats and then optically combined to form a superchannel of a constant maximum capacity, for example. Accordingly, the number of carriers and the bit rate for each carrier remain constant for each modulation format to realize a constant maximum capacity. The superchannel is then transmitted over an optical communication path to a receive node. At the receive node, the superchannel is optically demultiplexed from a plurality of other superchannels. The plurality of carriers of the superchannel are then supplied to a photodetector circuit, which receives additional light at one of the optical signal carrier wavelengths from a local oscillator laser. An analog-to-digital converter (ADC) is provided in the receive node to convert the electrical signals output from the photodetector into digital form. The output from the ADC is then filtered in the electrical domain, such that optical demultiplexing of the carriers is unnecessary.

The invention relates to an observation system variable-layout design evaluation method and an observation system variable-layout design evaluation device based on actual seismic data. The method comprises the following steps: the shot-geophone distance distribution of each surface element is calculated according to a variable-layout observation system of an obstacle in an exploration area; seismic channel set data representing the features of a target layer of the exploration area is selected from actual seismic data of the exploration area, the selected seismic channel set data forms a model super channel set, and the shot-geophone distance of the super channel set is distributed uniformly; a seismic channel with smallest offset distance is extracted from the model super channel set according to the shot-geophone distance for each surface element to obtain channel set data of the surface element; the channel set data of the surface elements is superimposed to obtain a seismic data body of the exploration area; and a seismic profile or horizontal slice is extracted from the seismic data body to analyze shallow seismic data loss and remedy, thus realizing observation system variable-layout design evaluation.

A method for transmitting data over an optical super-channel partitions the data unequally into a set of data streams for transmission over the set of sub-channels of the super-channel, such that a size of a first data stream for transmission over a first sub-channel is different than a size of a second data stream of the data for transmission over a second sub-channel. The method encodes each data stream of the data with an error correction code (ECC) having different ECC rates to produce a set of encoded data streams and transmits concurrently the set of encoded data streams over the set of sub-channels of the super-channel. Accordingly, the method uses an adaptive ECC for optical super-channels, such that a first ECC rate for encoding the first data stream is different than a second ECC rate for encoding the second data stream.

Consistent with the present disclosure, a coherent detector is provided that includes an optical hybrid that supplies optical signals including local oscillator light to a balanced detector. The amount of imbalance or “balance error” in the balanced detector is identified by comparing an output of the balanced detector and an output of a photodiode that receives a portion of an input optical signal provided to the optical hybrid. Based on the balance error, electrical signals generated by the balanced detector or the power of optical signals passing through (or output from) the optical hybrid circuit can be adjusted so that the balance error is minimized or reduced to zero. As a result, imbalance associated with the balanced detector is corrected so that unwanted currents and/or related electrical signals are cancelled out or substantially cancelled out. Such unwanted currents and/or related electrical signals are generated in response to noise in the local oscillator light as well as intensity noise associated with non-selected optical signals in a superchannel.

The invention provides an optical signal-to-noise ratio (OSNR) test method. The method includes: determining the number of subcarriers in multi-subcarrier multiplexing super channels and measuring central wavelength and effective bandwidth of the subcarriers; subjecting each subcarrier to OSNR measurement which includes that the OSNR of the subcarrier is measured in the effective bandwidth at the central wavelength location, and the effective bandwidth is the effective bandwidth acquired during performing the effective bandwidth measurement on the subcarrier; acquiring the multi-subcarrier multiplexing super channels according to the OSNRs of the subcarriers and the number of the subcarriers acquired in measurement. On the basis of the method, the invention further provides an OSNR test device. By the method and the device, the reliable OSNRs of the multi-subcarrier multiplexing super channels can be acquired.

The disclosure relates to technology for constructing an optical network. A central node is selected among a plurality of nodes in the optical network, and each of the nodes is connected to the central node via a set of superchannels, wherein each of the superchannels includes sub-carriers and has a same data rate. The network resources between the central node and each of the plurality of nodes are managed by dynamically allocating the sub-carrier bandwidths to support communication among the plurality of nodes via the superchannels, and wavelength selective switching is performed among the superchannels at the central node.

A photonic cross-connect arrangement is presented which is able to cope with the transmission of super-channels, wherein complete super-channels are dropped and added to change a direction of transport. At least a cyclic filter is used in a drop-branch of a cross-connect for dividing a super-channel into sub-channels and/or at least a further cyclic filter is used in an add-branch to configure a super-channel.

Methods and systems for adding optical signals, such as superchannels, to an optical transport network include using a spread tree wavelength allocation in order to reduce cross-phase modulation (XPM). The spread tree wavelength allocation may result in an overall reduction in operating costs for the optical transport network as compared to a first fit wavelength allocation, for example due to reduced equipment costs for a given level of network loading.

The invention provides a main optical channel power test method. The method includes the following steps that: WDM optical signals to be tested are scanned, so that the central wavelengths of optical signals in the WDM optical signals can be obtained; effective spectral widths occupied by the optical signals can be determined according to the central wavelengths of the optical signals in the WDM optical signals; and the main optical channel power of the WDM optical signals is tested according to the central wavelengths of the optical signals in the WDM optical signals and the determined effective spectral widths. Based on the same conception as above, the invention also provides a main optical channel power test apparatus. With the main optical channel power test apparatus adopted, main optical channel power measurement of multi-sub-carrier multiplexed super channel spectra of flexible spectrum intervals can be performed flexibly.

Disclosed herein is a method of transmitting a data stream from a first location to a second location through an optical network, as well as a corresponding performance monitoring unit, a transmitting arrangement and a receiving arrangement. The method comprises the steps of transmitting said data stream from said first location to said second location along a working path, wherein said data stream is transmitted in the form of a super channel comprising a number of n wavelengths within a predefined reserved wavelength range, monitoring the performance of the transmission based on the super channel signal received at said second location, and in case the performance is observed to drop below a predetermined performance threshold, unburdening the super channel from a part of said data stream while maintaining the reserved wavelength range for said super channel, by redirecting said part of the data stream for transmittal along at least one restoration path connecting said first and second locations, and transmitting the remainder of said data stream within the super channel on a number of wavelengths that is less than n, and/or with a reduced transmission rate for at least some of the wavelengths in said super channel.

The invention belongs to the field of seismic data processing for oil-gas exploration, and particularly relates to a seismic wave imaging method based on particle swarm optimization CRS (Common Reflection Surface) super gather. The method comprises the following steps of: step 1, optimizing distributed CRS superposition on pre-stack data, and updating three wave field parameters of a CRS superimposed surface of the superimposed final output by using a particle swarm optimization algorithm; step 2, performing curvature and inclination correction on the pre-stack data under the guidance of an optimal value of the CRS wave field parameter; step 3, inputting the optimal value of the CRS wave field parameters as a standard parameter, performing partial CRS superposition on the pre-stack data, and outputting a CRS optimized super-channel set; and step 4, performing CRS superposition and time offset on the output CRS optimized super gather to obtain an optimal CRS superposition profile and anoffset profile. The seismic wave imaging method based on the particle swarm optimization CRS super gather can effectively solve a problem that the inclination and curvature correction of the data arenot performed in the CRS superposition process in the prior art, so that the influence of the curvature and the inclination angle is amplified together with effective signals in a superposition process, thereby seriously affecting the imaging quality.

The invention provides a residual static correction method and device. The method includes the steps that according to obtained super-channel data, shot point list data and demodulator probe list dataare generated, wherein the super-channel data includes seismic channel data of a combination of seismic waveforms within the same time window; shot point super-channel data in the shot point list data is distributed into one or more first task processing threads respectively, and the first task processing threads are used for working out a residual static correction value corresponding to a shotpoint according to the distributed shot point super-channel data; demodulator probe super-channel data in the demodulator probe list data is distributed into one or more second task processing threadsrespectively, and the second task processing threads are used for working out a residual static correction value corresponding to a demodulator probe according to the distributed demodulator probe super-channel data. According to all embodiments of the residual static correction method and device, resources of a large-scale computer cluster are fully utilized, the run time for super-channel disintegration operation on mass data is shortened substantially, and the calculating efficiency of the residual static correction value is improved.

A device and method are provided for allocating an E1 channel between a mobile switching center (“MSC”) and an interworking function (“IWF ”) unit in a CDMA mobile communication system are provided. The method results in an E1 super channel being variably allocated to support both IS-95A service for low speed calls and IS95B service for high speed calls.