234results about How to "Compensation Distortion" patented technology

Methods and apparatus are disclosed for applying acoustic energy to the skin. Acoustic waveguides with elements of varying thickness or shape are disclosed which deliver energy to more than one depth below a surface of the skin substantially simultaneously. The invention is especially useful with devices that focus ultrasound energy by condensing a propagating wavefront. The invention compensates for the mismatch in acoustic properties of the device's waveguide and the biological tissue that typically cause portions of the collapsing wavefront to lag behind other portions and, thereby, limit the focusing capabilities of acoustic treatment devices.

The invention relates to a method and system for wideband digital pre-distortion linearization, which is used to overcome the influence of memory effect in radio frequency power amplifier, to expand digital pre-distortion linearization bandwidth, and to improve digital pre-distortion linearization performance. The method and system can get an in-band pre-distortion signal and an out-of-band pre-distortion signal according to the characteristic parameter of the amplifier; the in-band pre-distortion signal is up-converted and the up-converted signal is added to the out-of-band pre-distortion signal, which is not up-converted, then the combined signal is inputted to the power amplifier as an input signal; a part of the output signal from the power amplifier, serving as a feedback signal, can be compared with the original input signal, and the characteristic parameter of the amplifier for generating the in-band pre-distortion signal and the out-of-band pre-distortion signal is adaptively regulated according to the comparison result, so that the waveform of time domain or the frequency domain of the feedback signal can be close to that of the original input signal as much as possible.

A hybrid laser source including a solid state laser driven by an array of fiber laser amplifiers, the inputs of which are controllable in phase and polarization, to compensate for distortions that arise in the solid state laser, or to achieve desired output beam properties relating to direction or focus. The output beam is sampled and compared with a reference beam to obtain phase and polarization difference signals across the output beam cross section, at spatial positions corresponding with the positions of the fiber laser amplifiers providing input to the solid state laser. Therefore, phase and polarization properties of the output beam may be independently controlled by predistortion of these properties in the fiber laser amplifier inputs.

A digital communications transmitter (100) includes a digital linear-and-nonlinear predistortion section (200, 1800, 2800) to compensate for linear and nonlinear distortion introduced by transmitter-analog components (120). A direct-digital-downconversion section (300) generates a complex digital return-data stream (254) from the analog components (120) without introducing quadrature imbalance. A relatively low resolution exhibited by the return-data stream (254) is effectively increased through arithmetic processing. Distortion introduced by an analog-to-digital converter (304) may be compensated using a variety of adaptive techniques. Linear distortion is compensated using adaptive techniques with an equalizer (246) positioned in the forward-data stream (112). Nonlinear distortion is then compensated using adaptive techniques with a plurality of equalizers (226) that filter a plurality of orthogonal, higher-ordered-basis functions (214) generated from the forward-data stream (112). The filtered-basis functions are combined together and subtracted from the forward-data stream (112).

Systems, methods, and devices relating to the provision of deliberate predistortion to an input signal to compensate for distortions introduced by an amplifier subsystem. An input signal is received by a signal processing system which includes a predistortion subsystem. The input signal is decomposed and the fragments are then predistorted by the predistortion subsystem by applying a deliberate predistortion to the fragments. The predistorted fragments are then separately processed and recombined to arrive at the system output signal. The predistortion subsystem adaptively adjusts based on characteristics of the system output signal. Also, the predistortion subsystem is equipped with a control system that is state based—the state of the predistortion subsystem is dependent upon the prevailing conditions and, when required, the control system switches the state of the predistortion subsystem. A feedback signal, a replica of the system output signal, is used in updating lookup table entries used to determine the predistortion.

Nonlinearity-induced signal distortions are compensated by processing an input communications signal, in the electrical domain prior to Electrical-to-optical conversion and transmission through an optical link of a communications system. According to the invention, a compensation operator is determined that substantially mitigates the nonlinearity-induced signal distortions imparted to an optical signal traversing the communications system. The input communications signal is then input to the compensation operator to generate a predistorted electrical signal. This predistorted electrical signal is then used to modulate an optical source to generate a corresponding predistorted optical signal for transmission through the optical communications system. With this arrangement, arbitrary nonlinearity-induced signal distortions imparted by the optical link can be compensated in such a manner that a comparatively undistorted optical signal is obtained at the receiving end of the optical link.

A multi-beam apparatus for observing a sample with high resolution and high throughput and in flexibly varying observing conditions is proposed. The apparatus uses a movable collimating lens to flexibly vary the currents of the plural probe spots without influencing the intervals thereof, a new source-conversion unit to form the plural images of the single electron source and compensate off-axis aberrations of the plural probe spots with respect to observing conditions, and a pre-beamlet-forming means to reduce the strong Coulomb effect due to the primary-electron beam.

The controller controls the amplifier and a modulated power supply, supplying power to the amplifier, by detecting an RF envelope of a signal input to the amplifier. Predistortion of the amplifier synchronous with changes of bias is provided using a look-up table. Specifically, amplitude predistortion, phase predistortion and DC voltage level adjustments are made to the RF signal. Adjustments for gain and phase variation are applied synchronously with bias changes.

Neural networks provide efficient, robust and precise filtering techniques for compensating linear and non-linear distortion of an audio transducer such as a speaker, amplified broadcast antenna or perhaps a microphone. These techniques include both a method of characterizing the audio transducer to compute the inverse transfer functions and a method of implementing those inverse transfer functions for reproduction. The inverse transfer functions are preferably extracted using time domain calculations such as provided by linear and non-linear neural networks, which more accurately represent the properties of audio signals and the audio transducer than conventional frequency domain or modeling based approaches. Although the preferred approach is to compensate for both linear and non-linear distortion, the neural network filtering techniques may be applied independently.

An image generating device, a 3D image display system having the same and control methods thereof are disclosed. The image generating device includes: a first camera configured to photograph a depth image of a subject using a first light; a second camera configured to photograph a color image of the subject by converting a second light into an image signal; a view angle extender configured to change a view angle, wherein the view angle is an angle at which the first camera and the second camera are operable to photograph the subject; and a controller configured to control the view angle extender to change the view angle of the first camera and the second camera and to form a single depth image and a single color image by respectively synthesizing a plurality of depth images and a plurality of color images, photographed by the first camera and the second camera.

A system and method for compensating for angular distortion of a received waveform is disclosed. One embodiment measures the angular position of a current symbol, the preceding symbol and the succeeding symbol, calculates the phase shift between the current symbol and a preceding symbol and the phase shift between the current symbol and a succeeding symbol, uses the phase shifts to enter a 2-D lookup table to extract a phase correction factor, then uses the phase correction factor to modify the angular position of the current symbol.

The invention relates to a display device for displaying visual information, comprising: at least one image-forming element; at least one light source for generating a light beam, which in cooperation with the image-forming element produces an illuminated image; optical means for processing the light beam and/or illuminated image; and a projection surface for receiving the illuminated image, wherein the image-forming element is flat and the projection surface forms at least a part of a cylinder wall.

A steganographic digital watermark signal is decoded from host imagery without requiring a domain transformation for signal synchronization, thereby speeding and simplifying the decoding operation. In time-limited applications, such as in supermarket point-of-sale scanners that attempt watermark decode operations on dozens of video frames every second, the speed improvement allows a greater percentage of each image frame to be analyzed for watermark data. In battery-powered mobile devices, avoidance of repeated domain transformations extends battery life. A great variety of other features and arrangements, including machine learning aspects, are also detailed.

Systems and methods for compensating for visual distortion caused by surface features on a display are disclosed. For example, one disclosed system includes: a display including one ore more surface features; a processor configured to: receive a display signal including graphical data; determine a location of the surface feature; transform the display signal based at least in part on the location of the surface feature; and cause the transformed display signal to be displayed.

There is provided a liquid ejecting apparatus including: a liquid ejecting head capable of ejecting liquid; and a plurality of cap units each having a cap for individually capping a plurality of head areas of the liquid ejecting head. The plurality of cap units is constructed such that the shift position of each cap that is shifted from a retracted position toward the head area can be varied according to the distortion of the liquid ejecting head.

Provided are a multi-display supporting multi-view video object-based encoding apparatus and method, and an object-based transmission/reception system and method using the encoding apparatus and method. The encoding apparatus includes: a shape abstracting means for receiving right/left-eye image object video and abstracting right/ left object image, respectively, to abstract the shape information of a multi-view video; a data separating means for receiving the right/left-eye image object video, and the right/left shape information, and separating them into odd-field objects and even field objects to transmit only the essential bit streams for a user display mode; a shape compensation means for compensating for the distortion of the shape information separated into odd and even fields; and an object-based encoding means for receiving the object-based information from the shape compensation means and the object-based information from the data separating means, forming four layers, and performing motion and disparity estimation to encode object-based data that are separated into odd and even lines.

A method and system are disclosed for radiosurgical treatment of moving tissues of the heart, including acquiring at least one volume of the tissue and acquiring at least one ultrasound data set, image or volume of the tissue using an ultrasound transducer disposed at a position. A similarity measure is computed between the ultrasound image or volume and the acquired volume or a simulated ultrasound data set, image or volume. A robot is configured in response to the similarity measure and the position of the transducer, and a radiation beam is fired from the configured robot.