52 results about "Nonlinear channel" patented technology

A method for processing a signal propagated through a nonlinear channel is disclosed. The method comprises modeling the channel characteristics to produce a linearized channel model, wherein the linearized channel model has a linearized transfer function that includes a plurality of first order polynomials and nonlinear operators. The method further comprises deriving an inverse linearized channel model from the linearized channel model and filtering the signal using the inverse linearized channel model.

A contact tip for a welding torch is provided. In one embodiment, the contact tip includes a body formed of an electrically conductive material and a non-linear passage that extends through the body. The non-linear passage of this embodiment is configured to receive a wire electrode and to facilitate electrical communication between the body and the wire electrode. Various contact tip assemblies and manufacturing techniques for forming contact tips are also provided.

A dielectric arrestor insert for use in a chamber wafer processing system having a gas input line, an arrestor housing and a wafer processing space. The input line is able to provide gas to the arrestor housing. The arrestor housing is able to house the dielectric arrestor insert. The dielectric arrestor insert comprises a gas entry portion, a non-linear channel and a gas exit portion. The gas entry portion is arranged to receive the gas from the input line. The non-linear channel is arranged to deliver the gas from the gas entry portion to the gas exit portion. The gas exit portion is arranged to deliver the gas from the non-linear channel to the wafer processing space.

A method for identifying and modeling nonlinearities in communications channels, particularly optical communication channels. A channel in general is modeled as a summation of linear and non linear terms having memory. The terms are functions of the input to the channel with respect to time, such as a sequence of input bits to the channel. In one embodiment the most recent input bits are used to access a value in a look up table. The value accessed is compared to an actual value received from the channel. The difference between the value in the table and the actual channel value may be used to correct the value in the table. When the look up table and the channel converge the look up table contains a model of the channel with memory that can model nonlinearities. A nonlinear channel having memory may also be modeled in terms of Volterra Kernels.

An adaptive coding scheme for nonlinear channels improves reliability and an efficiency in digital communication networks. The method monitors channel statistics to analyze an extrinsic information transfer chart of the channels. The channel statistics are fed back to the transmitter to adapt forward error correction coding. A parametric analysis method uses a Gaussian mixture model. The statistical information feedback can adapt an ARQ sheme by adding a weighted received signal to the original coded signals to reduce nonlinear distortion. Trellis shaping, can make the transmitting signal preferable for nonlinear channels.

A communications system (10) which utilizes an M-ary QAM signal constellation suitable for non-linear applications. The communications system includes a modulator (18) for utilizing the M-ary constellation to implement the modulation. The M-ary constellation is a circular constellation which provides a simplified amplitude predistortion by utilizing the subject M-ary constellations, enabling more efficient communications can then be achieved through a peak-power-limited non-linear channel (16). Such non-linear channels (16) are more power efficient at creating RF energy from DC energy.

A method and apparatus for intermodulation product (IMP) cancellation. In one embodiment, the method comprises: acquiring copies of source signals that create IMPs in a passband of interest; creating copies of the IMPs for use as IMP cancellation signals by either multiplying the source signals together as a series of digital samples such that the multiplied signals create a near real and continuous time copy of the IMPs or creating a sum of the source signals in near real and continuous time and convolving the sum of the source signals with a mathematical model to effectively multiply the signals together to create a copy of the IMPs; adjusting one or both of phase and amplitude of the copies; and using the copies to cancel the IMPs inband of the passband of interest.

An apparatus for cancelling a self-interference signal between a transmission antenna and a reception antenna is disclosed. The apparatus includes a first self-interference signal cancellation unit for cancelling a self-interference signal in consideration of a linear channel between the transmission antenna and the reception antenna, a second self-interference signal cancellation unit for cancelling a self-interference signal in consideration of nonlinear channel characteristic between the transmission antenna and the reception antenna or linear characteristic of a radio channel, and a controller for comparing a transmitted signal output from the transmission antenna and a received signal received by the reception antenna to provide a first coefficient to be applied to self-interference signal cancellation of a linear device in the first self-interference signal cancellation unit and a second coefficient to be applied to self-interference signal cancellation of a nonlinear device in the second self-interference signal cancellation unit.

The invention discloses a digital self-interference cancellation method of an asynchronous simultaneous same-frequency full-duplex underwater acoustic communication system. The asynchronous full-duplex underwater acoustic communication has the characteristics that there is a delay difference between a self-interference signal and a desired signal to arrive at a receiving end. According to the method provided by the invention, a self-interference channel is estimated by using a non-overlapping area of the self-interference signal and the desired signal, thus avoiding the influence of the desired signal on the estimation accuracy of the self-interference channel and further improving the self-interference cancellation performance. To counteract a nonlinear component in the self-interferencesignal, the invention proposes a parameterized recursive least squares algorithm to estimate a nonlinear channel to counteract the nonlinear component in the self-interference signal. By adoption of the method disclosed by the invention, the self-interference signal generated by simultaneous same-frequency full-duplex underwater acoustic communication can be effectively canceled, so that the system can demodulate the desired signal under strong self-interference conditions.

Embodiments of the present invention provide a system and method for forming a non-linear channel through a molded component. The system includes a forming device having a molding chamber, and a malleable core-out pin positioned within the molding chamber. The malleable core-out pin includes at least one curve. Liquid plastic is injected into the molding chamber and flows around the malleable core-out pin to form the molded component. After the plastic solidifies and cools, the malleable core-out pin is removed from the molded component to form the non-linear channel through the molded component.

A particulate filter and a method for reducing pollutants are provided. The particulate filter comprises at least one first piece, said first piece comprising non-linear channels, and at least one second piece adjacent to the at least one first piece. The particulate filter is configured such that either the at least one first piece or the at least one second piece comprise either sintered metal fibers or porous metallic foam. The method comprises the steps of providing a particulate filter, said filter comprising, at least one first piece, said first piece comprising non-linear channels and at least one second piece adjacent to the at least one first piece, catalyzing the particulate filter with a catalyst, passing exhaust stream through the filter, filtering at least some soot from the exhaust stream, and chemically converting at least some NOx from the exhaust stream with the catalyst.

The invention discloses a digital pre-distortion processing system with sample rate conversion and a method thereof. The system comprises: a power-amplifier anti-model solution module and a digital pre-distortion module. The power-amplifier anti-model solution module and the digital pre-distortion module both comprise a sample rate conversion apparatus. The sample rate conversion apparatus is used to convert a sequence with 1 times sample rate into the sequence with the multiple times sample rate and extract the sequence with the 1 times sample rate from the sequence with the multiple times sample rate. According to the invention, a spectrum aliasing phenomenon can be eliminated through a sample rate conversion method. A pre-distortion effect of transmitting a broadband or multiband signal through a non-linear channel can be effectively improved.

The present disclosure relates to devices and methods for creating channels within bone. One method for treating bone generally includes traversing an elongated member through cancellous bone of a vertebral body along a first generally non-linear path and then retracting the elongated member, thereby leaving a generally non-linear channel. The elongated member then is traversed through the cancellous bone along a second generally non-linear path, which second path does not completely coincide with the first path and then retracted along the second generally nonlinear path, thereby leaving a second generally non-linear channel. Optionally, bone filler material is deployed into the channels.

The invention discloses an interstage gain mismatch correction method for a pipelined ADC, and belongs to the technical field of analog integrated circuits. Based on the theoretical basis that an ideal ADC input and output characteristic curve is a linear relation, correction signals with opposite injection symbols are used for enabling residual transfer characteristic curves of two channels to beinconsistent, and therefore gain correction of a nonlinear channel is completed through a linear channel. When the pipelined ADC is a split or time-interleaved pipelined ADC, two channels in the split or time-interleaved pipelined ADC can be used as a reference channel and a correction channel respectively; in addition, the same input signal can be quantized twice, one quantization channel is used as a reference channel, the other quantization channel is used as a correction channel, and two virtual channels are realized. According to the invention, the problem of gain mismatch in a pipelinedADC is solved; a mode of solving the slope based on at least three points is provided, and the accuracy is improved compared with a traditional two-point slope method; the method can work in a digital background and has high real-time performance.

The present invention is suitable for communication field, and provides a digital repeater, a self-excitation counteracting method and a device thereof, wherein the device comprises the following components: a digital baseband signal collecting unit which is used for collecting and combining a first digital baseband signal and a second digital baseband signal to obtain an exercise reference digital baseband signal; an estimator which executes the nonlinear model estimation of transceiver coupling channel according to the exercise reference digital baseband signal to obtain each parameter of a nonlinear filter; the nonlinear filter which is used for executing self-adapting real-time operation to the input first digital baseband signal according to each obtained nonlinear filter parameter to obtain a baseband counteracting signal which reflects the nonlinear channel characteristic of the transceiver feedback channel; and a self-excitation counteracting unit which is used for executing signal counteracting according to the first baseband signal and the baseband counteracting signal. The method and device according to the invention estimate the nonlinear characteristic in the transceiver feedback channel thereby effectively reducing the effect of interfering signal and obtaining a better self-excitation counteracting effect.

Described is an all-optical switch that is significantly insensitive to polarization instabilities. The optical switch can be configured as an ultrafast logic gate, a switch for ultrafast communication systems or a key component of an all-optical regenerator. Performance is independent of the statistical characteristics of the data controlling the switch. The switch includes a birefringent optical channel in communication with one end of a nonlinear optical channel through a coupler and a polarization rotation mirror in communication with the other end of the nonlinear channel. An optical data pulse for controlling the switching function is provided to one port of the coupler.

A steering lock assembly an assembly housing includes a non-linear passage that receives a cam shaft and / or cam pin. The non-linear passage provides a steering lock assembly that is shorter than steering lock assemblies having an assembly housing with a linear passage for receiving the cam shaft and cam pin.

An apparatus for treating air from an exhaust port of a building. The apparatus includes an enclosed pathway having an inlet for communication with an exhaust port, a discharge outlet, and a non-linear pathway portion between the inlet and discharge outlet. The non-linear pathway includes air treatment material positioned in communication with a portion of the pathway to expose the air to the air treatment material as it moves through the pathway. The apparatus includes an irrigation system for maintaining the moisture content of the air treatment material.

Gear pumps are disclosed having a gear-assembly section, a drive-assembly section, and at least one passage fluidly connecting the gear-assembly and drive-assembly sections, wherein the passage includes substantially non-movable walls defining a non-linear fluid-flow path. A particular example is a magnetic gear pump having a gear-assembly section; a section that includes a magnet assembly received in a cup cavity; and a third section located between the gear-assembly and magnet-assembly sections, wherein the third section includes a fluid-input port, a fluid-output port, and at least one conduit for fluidly interconnecting the gear-assembly and magnet-assembly sections; and a member defining at least one non-linear passage in fluid connection with the third section conduit and the cup cavity.

The present disclosure provides methods and apparatuses for nonlinear channel identification and estimation of the distorted signals in digital data transmission systems that include signals traversing a dispersive nonlinear channel that produces noisy distorted signals. The identification and estimation are accomplished with an amplitude-based signal expansion and are adapted for changing nonlinear distortion effects using a Least-Means Square direct solution that includes a precomputed matrix.

The present invention is a machine or method used in digital communications. Symbols are selected in periodic fashion from at least two different symbol constellations. At least one of the symbol constellations has a non-conjugated second moment not equal to zero. The non-conjugated second moment is a second-order statistic. Symbol selection leads to second-order input statistics having cyclostationary phase, and thus to second-order output statistics having cyclostationary phase. These statistics can be used for low-complexity identification and equalization of both linear and nonlinear channels. The invention allows for low-complexity identification and equalization of linear channels and of nonlinear channels without requiring constant-modulus constellations.

A signal transmission apparatus and multicarrier communication system that includes: a first receiving unit configured to receive a probe signal transmitted by transmitting end; wherein, the signal is generated according to characteristics of recommended signal configuration obtained by previous signal to noise ratio (SNR) probings; a first processing unit configured to probe a channel SNR according to the signal; a first determining unit configured to determine transmission signal configuration and signal transmission performance according to a final channel SNR obtained by multiple times of SNR probing; and a first transmitting unit configured to transmit the configuration and the performance to the transmitting end, so that the transmitting end transmits an actual transmission signal according to the configuration and the performance. With the embodiments, accuracy of probing a nonlinear channel SNR is improved, and reliability and stability of the communication system are guaranteed.

A pump assembly is configured to fit to a predefined pipe layout defined by supply and discharge interfaces that are positioned in a predefined relation to supply and discharged centerlines, respectively. The pump assembly includes a multistage pump having a plurality of pumping stages mounted along a pump shaft rotating along a rotation axis. The multistage pump has an inlet port and a discharge port, and the multistage pump is aligned horizontally such that the rotation axis is oriented parallel to the supply centerline. The pump assembly also includes an adaptor having a pump interface and a pipe interface, wherein the adaptor has an internal fluid channel extending along a non-linear passageway between the pump and pipe interfaces. The pump interface is coupled to one of the inlet and discharge ports of the multistage pump, and the pipe interface is located proximate one of the supply and discharge interfaces.