405 results about "Modulation pattern" patented technology

The invention relates to methods and systems for accurate ranging and geo-locationing using coherent multicarrier (CM) signals and based on a high-resolution estimation of a receiver timing offset in a signal receiver that receives ranging CM signals. A transmitter transmits a ranging CM signal having a known subcarrier modulation pattern. The receiver samples the ranging CM signal it receives reflected back from an object or from the remote transmitter, and processes the sampled signal that preserves relative subcarrier phases using a high-resolution model channel response function to determine the receiver timing offset with resolution much better than the receiver sampling period. The receiver timing offset is used to determine a flight time for the ranging CM signal with high accuracy.

Wavefront measuring systems and methods are disclosed which may be employed, for example, in detecting phase aberrations in a spectacle lens and in an eye. Various embodiments include disposing a modulation pattern in the path of a return beam from the spectacle lens or the eye, and imaging a diffraction pattern at a self-imaging plane relative to the modulation pattern with a detector. The diffraction pattern is analyzed and the results are used to produce a representation of the wavefront phase characteristics that describe aberrations in the lens or eye being measured. Illumination and processing techniques for improving the measurement results are dislcosed. Various embodiments comprise systems adaptable to both measure aberrations in lenses in spectacles as well as in a patient's eyes.

A method for photon counting including the steps of collecting light emitted or reflected / scattered from an object; imaging the object onto a spatial light modulator, applying a series of pseudo-random modulation patterns to the SLM according to standard compressive-sensing theory, collecting the modulated light onto a photon-counting detector, recording the number of photons received for each pattern (by photon counting) and optionally the time of arrival of the received photons, and recovering the spatial distribution of the received photons by the algorithms of compressive sensing (CS).

An optical detection system according to the present invention includes: a spatial light modulator for modulating the phase of incoming light; a photodetector having a plurality of photosensitive areas to receive the light of which the phase has been modulated by the spatial light modulator; a photosensor selecting section for selecting at least one of the photosensitive areas and activating the selected photosensitive area effectively; and a modulation control section for providing a modulation pattern, associated with the photosensitive area that has been selected by the photosensor selecting section, for the spatial light modulator.

An object of the present invention is to provide a detection device which does not cause the false detection by receiving laser light from an oncoming car. The pulse laser light modulated with a modulation pattern set every target position is irradiated at the target position from a laser irradiation portion. DSP (Digital Signal Processor) decides that there is an obstacle at the target position only when the modulation pattern of the pulse laser light emitted from the laser emitting portion matches with the modulation pattern of the pulse laser light received by the laser receiving portion. It is suppressed that the detection device misdetects the conditions of the target position when receiving laser light from an oncoming car or the like because modulation pattern of laser light from own does not match with modulation pattern of laser light from the oncoming car or the like.

A color balanced solid-state backlight provides feedback control of each color using a single photodetector by imposing a modulation pattern on the solid-state lamps revealing individual colors to the photodetector. The photodetector signal provides feedback controlling color balance over a small range of instantaneous brightness less than larger range of average brightness of the display to provide for accurate color balance throughout a large range of average brightnesses.

A circuit and a method for reducing output noise when a pulse width modulation mode is started. A pulse width modulation circuit generates a first pulse signal having a duty cycle that is in accordance with an output voltage of a regulator circuit. A drive circuit generates the output voltage from an input voltage in response to the first pulse signal provided from the pulse width modulation circuit. A feed forward circuit controls the pulse width modulation circuit in a manner to generate the first pulse signal having a duty cycle that maintains the output voltage at a desired level before the pulse width modulation circuit provides the first pulse signal to the drive circuit.

A system is provided for transmitting information through a speech codec (in-band) such as found in a wireless communication network. A modulator transforms the data into a spectrally noise-like signal based on the mapping of a shaped pulse to predetermined positions within a modulation frame, and the signal is efficiently encoded by a speech codec. A synchronization sequence provides modulation frame timing at the receiver and is detected based on analysis of a correlation peak pattern. A request / response protocol provides reliable transfer of data using message redundancy, retransmission, and / or robust modulation modes dependent on the communication channel conditions.

Cathodic protection voltages are used to resist the damage to pipes or cables from electrolytic effects. However, localized fields can lead to stray currents and may result in corrosion and it is therefore desirable to detect and analyse those stray currents. Frequently there are several pipes in the area of interest and so it is necessary to distinguish between those pipes. Therefore the cathodic voltage on the pipes is modulated, with different pipes having different modulations. This modulation may be applied using an interrupter. Orthogonal modulations with non-unitary aspect ratios improve the discrimination between the pipes while maximizing the energy content of the modulation pattern. The analysis is improved when the interrupters are synchronized with each other and so repeating on the same time-base. This synchronization may be achieved using an external time signal such as GPS. An interrupter which can be used in this regard is also proposed, and may be powered from the cathodic voltage itself.

The present invention discloses an optical system for 3D printing and a control method thereof. The system comprises a laser device, a beam expanding system, a beam splitter, a spatial light modulator and a focusing system. The spatial light modulator is connected with a computer and configured to generate a modulation pattern after receiving the target modulation pattern generated by the computer. A light beam emitted by the laser device is expanded into a parallel light beam by the beam expanding system and then irradiates on the beam splitter. A part of the expanded light beam reaches the spatial light modulator for modulation after passing through the beam splitter, then the modulated light beam is reflected to the beam splitter, and a part of the modulated light beam is focused by the focusing system and then irradiates on a target plane for 3D printing.

A MIMO FMCW radar sensor and a MIMO time multiplexing method for localizing a radar target, in which an FMCW radar measurement is performed with a transmitted signal whose modulation pattern encompasses, for different transmission switching states that differ in terms of the selection of antenna elements used for transmission, mutually temporally interleaved sequences of ramps; ambiguous values for the relative velocity of the radar target are determined from a position of a peak in a two-dimensional spectrum; phase relationships between spectral values of spectra are checked for agreement with phase relationships expected for several of the determined values of the relative velocity; on the basis thereof, an estimated value for the relative velocity of the radar target is selected from the determined periodic values of the relative velocity; and the angle of the radar target is determined on the basis of amplitudes and / or phase relationships between obtained baseband signals.

Methods and systems consistent with the present invention provide a method for dynamically controlling power consumption in a digital demodulator circuit by varying clock rates and bit widths of demodulator components including an analog to digital converter, decimation filter, OFDM operating engine, FEC decoder, and MPE-FEC processor, according to parameters and conditions of the received signal including modulation mode, signal to noise ratio, effective bit transmission rate, bit error rate, packet error rate, adjacent channel interference, and co-channel interference.

The invention relates to measuring the mobility spectra of ions with ion mobility spectrometers (IMS). The invention provides an analog modulation of the ion current of an IMS ion source with a continuous modulation function, the instantaneous frequency of which temporally varies across a large frequency range, and a generation of the mobility spectrum from the measured ion current by a correlation analysis with the modulation pattern. The modulation can, for example, be produced by the gating grid, which is usually present. The analog modulation removes many of the difficulties which occur with square-wave modulation and leads to a surprisingly stable evaluation which is relatively insensitive to noisy signals and produces a high mobility resolution at very low noise.

Disclosed herein is an illumination system including an array of LED light sources for emitting light encoded with a modulation pattern, an array of sensors and a space characterization unit. The array of sensors receives emitted light scattered by an object. Each sensor determines a distance between the corresponding light source and the object using the modulation pattern. The space characterization unit uses the distance from each sensor to generate an elevation map indicating a presence of the object.

A system is provided for transmitting information through a speech codec (in-band) such as found in a wireless communication network. A modulator transforms the data into a spectrally noise-like signal based on the mapping of a shaped pulse to predetermined positions within a modulation frame, and the signal is efficiently encoded by a speech codec. A synchronization sequence provides modulation frame timing at the receiver and is detected based on analysis of a correlation peak pattern. A request / response protocol provides reliable transfer of data using message redundancy, retransmission, and / or robust modulation modes dependent on the communication channel conditions.

Quadrature modulation systems, circuits and methods are provided to support various modulation modes including ASK (amplitude shift key), FSK (frequency shift key) and PSK (phase shift key) modulation at high data rates (e.g., gigabit data rates). For example, a modulation circuit includes a mixer circuit including an integrated sign modulation control circuit and a plurality of mixer ports. The mixer ports include a first input port, a second input port, an output port and a sign modulation control port. The modulation circuit generates a modulated signal by operation of the mixer circuit multiplying a modulating signal applied to the first input port with a carrier signal applied to the second input port to generate a mixed signal output from the output port, and by operation of the integrated sign modulation control circuit controlling polarity switching of a signal at one of the mixer ports in response to a sign modulation control signal input to the sign modulation control port. The sign modulation control signal can be a digital data signal having binary data encoded into the modulated signal.

An optical information recording apparatus includes a light source that emits an irradiation beam; a spatial light modulator that converts the irradiation beam to an information beam, the information beam having a two-dimensional modulation pattern that carries information and is formed with a plurality of first regions in which each of boundaries is formed with OFF pixels; a phase modulator that includes a plurality of second regions, and that imparts the phases to the irradiation beam or the information beam to modulate phases of the irradiation beam or the information beam; and a light collector that collects the information beam and a reference beam on an optical information recording medium that can record the information as hologram, by using interference fringes produced due to interference between the information beam and the reference beam.

In one embodiment, an acoustic distance measurement system can use a modulation pattern to modulate a carrier wave. The modulated carrier wave may be transmitted to an acoustic transducer. An echo of the transmitted signal can be detected by correlating the received signal with the modulation pattern. Subsequent to detecting sufficient correlation between the received signal and modulation pattern, a distance determination can be made to determine the distance to the object that produced the received echo.

Embodiments of the invention are concerned with improvements to Doppler radar systems, and are suitable for use with frequency scanning radar systems.In one arrangement the improvements are embodied in a frequency scanning radar controller for use in controlling a frequency generator; the frequency generator is arranged to generate a plurality of sets of signals, each set of signals having a different characteristic frequency and comprising a plurality of signals transmitted at a selected rate, and the radar controller is arranged to select the rate in dependence on the characteristic frequency.The invention can be embodied in a pulsed radar, for which each set of signals comprises a set of pulsed signals and each pulsed signal is repeated at a selected repetition rate. The radar controller is then arranged to modify the repetition rate in dependence on the characteristic frequency of the pulsed signal. The invention can alternatively be embodied in a frequency modulated radar system, for which each set of signals comprises a sequence of modulation patterns. The radar controller is then arranged to modify a given modulation pattern in dependence on the characteristic frequency of the signal being modulated.

To suppress an unbalance of a dwell period in a changeover of phases in which switching is dwelled in an inverter controller. A PWM operation unit 5 includes a modulation-wave generating unit 11 that generates a modulation wave as a voltage command value to an inverter main circuit 2, a carrier-wave generating unit 12 that generates a carrier wave used as a reference for a switching command, and a comparing unit 13 that compares the modulation wave generated by the modulation-wave generating unit 11 and the carrier wave generated by the carrier-wave generating unit 12. During an operation in a two-phase modulation mode in which switching of any one of three phases configuring the inverter main circuit 2 is dwelled, the PWM operation unit 5 controls the carrier-wave generating unit 12 to set a carrier wave frequency to an integral multiple of a modulation wave frequency.

A system and method for THz imaging utilizing a single THz detector that detects an image of a large area and provides good spatial details (high resolution). In one aspect, the THz beam passes through an object to be imaged, and a THz fiber bundle having a plurality of THz fibers collect the THz beam on the other side of the object and transmit the beams to a single THz detector. Each THz fiber imparts a different time delay to the beam traveling therein. Therefore, the spatial information is converted into time information in the form of time delays. Knowing the distance each part of the imaging area must travel (hence the time it takes) before reaching the THz detector, one can recover the spatial information from the time data. In another aspect, the THz fiber bundle is replaced with a mask having an array of holes with each hole having a different depth or a different refractive index. In still another aspect, the THz fiber array is replaced with a plate holding different masks. Each mask may include holes that may be turned on / off with a distinct pattern from all of the other holes. Once the data for each mask has been received, the data for each hole may be extracted according to its modulation pattern.

For transmitting data, a receiving / backscattering arrangement receives, modulates and reflects or backscatters electromagnetic waves emitted by a base station. The modulation corresponds to the data to be transmitted and is carried out selectively using first and / or second different modulation methods depending on the received field strength of the received electromagnetic waves. Preferably, phase shift keying is used especially or at least at low field strengths at far range, while amplitude shift keying is used additionally or alternatively for high field strengths at close range. The two modulation methods can be superimposed. A circuit arrangement includes two different modulator arrangements to perform the two modulation methods depending on the received field strength. The second modulator arrangement preferably comprises a multi-stage voltage multiplier circuit with a modulated switching device intervening in one of the stages to achieve the modulation.

In a dispersion compensation quantity setting technique for use in a WDM transmission system, a transmitting terminal node transmits CW light and modulated light obtained by modulation using a modulation pattern signal, while a receiving terminal node detects a physical quantity stemming from cross phase modulation occurring between the transmitting terminal node and the receiving terminal node on the basis of a variation of an intensity of the transmitted CW light and sets a dispersion compensation quantity on the basis of a variation of the detected physical quantity. Moreover, this optimizes the crosstalk, suppresses the output power of transmitted light, eliminates the nonlinear optical effect of the transmitted light, and carries out dispersion compensation superior in cost performance.

A method and apparatus for providing a universal transmitter that can detect and emulate a transmission signal of a transmitter, the transmission signal having a corresponding transmission frequency and a corresponding modulation pattern. The universal transmitter comprises: a detection circuit that detects a frequency and a modulation pattern of a transmitted signal of a separate transmitter and a memory. A processor coupled to the detection circuit and the memory, stores a frequency value representative of the detected frequency and a plurality of value representative of the detected modulation pattern, in the memory. A transmitting circuit coupled to the processor, is operable to transmit an output signal having the frequency and the modulation pattern of the transmission signal.

The invention relates to a MIMO-FMCW radar sensor and to a MIMO-time-division multiplexing method for locating a radar target (18), wherein a FMCW radar measurement is carried out using a transmission signal, of which the modulation patterns for different transmission switching states (m), which differ in the selection of antenna elements (12) used for transmitting, comprise time-interleaved sequences (22; 26; 32; 36) of ramps (24; 28; 34; 38); ambiguous values for the relative speed (v) of the radar target (18) are determined from a position (k, l) of a peak in a two-dimensional spectrum (56); phase relationships between spectral values of spectra (X) are checked for conformity with the phase relationships (a (v,m)) expected for a plurality of the determined values of the relative speed (v); based on said phase relationships, from the determined periodic values of the relative speed (v), an estimated value for the relative speed (v) of the radar target (18) is selected; and based on amplitudes and / or phase relationships between obtained base band signals (b), the angle of the radar target (18) is determined.

Method for determining distances and relative velocities of simultaneously located objects using an FMCW radar, in which the frequency of a transmission signal is modulated in the form of periodically recurring ramps, the transmission signal is mixed with a received signal to form an intermediate frequency signal and, for determining the distance and / or the relative velocity of the objects, the change in the phase of the intermediate frequency signal is evaluated from one ramp to the next characterized in that the modulation pattern includes at least two ramps, which differ only by a fixed frequency offset and follow one another in a certain time interval, and an unambiguous approximate value is calculated for the object distance on the basis of the phase difference φ1−φ2 of the intermediate frequency signals for these two ramps.

[Problems] To provide an X-ray CT apparatus capable of easily comparing image quality supposed to be obtained when not using a X-ray dose optimization function and image quality supposed to be obtained when using the X-ray dose optimization function at the stage of scan planning.[Means for Solving Problems] A 3-dimensional model of an object to be examined (17) is generated from scanogram projection data (S170). An image noise dispersion value corresponding to an imaging region of the object is predicted from the 3-dimensional model.The predicted image noise dispersion value is compared to a desired value of the image index value inputted by a user so as to calculate a modulation pattern of the irradiation X-ray amount (S200).By predicting the image quality supposed to be obtained when using and not using the X-ray dose optimization function, each of the predicted results is displayed so as to be compared on a display device (5) (S230).