51 results about "Signal Repression" patented technology

A system and method for suppressing radio frequency (“RF”) transmissions includes a transmitter for transmitting electronic signals that suppresses (e.g., prevents, disrupts, jams, interferes with or otherwise disables) RF transmissions. Some embodiments of the invention include a transmitter that suppresses one or more signals transmitted from a target transmitter in an RF transmission system to a target receiver in a wireless device operating in the RF transmission system to prevent, disrupt, jam, interfere with or otherwise disable an RF transmission between the target transmitter and the target receiver in the wireless device (i.e., target wireless device). These systems and methods may be used to interrupt communication, command and control of non-friendly combatant. These systems and methods may also be used to suppress RF transmissions to prevent the detonation of improvised explosive devices, or IEDs.

A system for processing radio frequency (RF) signals includes a searcher and a plurality of Cluster Path Processor (CPPs). The searcher detects a maximum signal energy level and position of at least one of a plurality of individual distinct path signals in a signal cluster of a first information signal, wherein at least a portion of the plurality of individual distinct path signals is received within a duration of a corresponding delay spread. The sampling position is used as a starting sampling location by the plurality of CPPs, including a first information signal CPP and a second information signal CPP. Fine sampling positions of the plurality of CPPs are based upon channel energy estimates for the plurality of individual distinct path signals. CPP outputs are employed to produce channel estimates, which are themselves used in subsequent equalization operations. Sampling positions may change over time in order to satisfy alignment criteria.

The invention discloses an anti-spoofing-attack method and system applied to a satellite navigation system. The method comprises the following steps: S1) capturing and processing satellite signals, and obtaining code Doppler information and carrier wave Doppler information of the satellite signals; S2) carrying out consistency detection on the code Doppler information and the carrier wave Doppler information to obtain a consistency comparison result; and S3) judging whether the satellite signals are spoofing signals, sending alarm information if the satellite signals are spoofing signals, and sending current code phase position and carrier wave frequency information to a preset tracking loop if the satellite signals are not spoofing signals. The method and system in the invention not only can judge whether the spoofing signals exist in the received signals, but also can judge which signals are the spoofing signals and which signals are real signals, that is, the second layer can be reached; and the method and system have spoofing signal suppression function and also have strong anti-spoofing capability.

A flip-angle calculating unit calculates a flip angle of a fat-suppression pulse by inputting scanning parameters read from a scanning-parameter storage unit based on scanning conditions set by a scan-condition setting unit and a desired fat-suppression level, into a predetermined computing program. A control unit suppresses fat signals to a desired level by performing irradiation of a fat-suppression pulse having the calculated flip angle and application of a spoiler gradient magnetic field onto a scan target portion of a subject by controlling a gradient magnetic-field generating unit and a transmitting-receiving unit, and further performs irradiation of an RF pulse and application of a gradient magnetic field in accordance with a predetermined pulse sequence, thereby detecting water signals and suppressed fat signals as MR signals. An image-data creating unit creates image data by reconstructing the MR signals.

A target object detection device is provided. The device includes a transmitter for transmitting at least one transmission wave in a predetermined azimuth, an echo signal receiver for receiving echo signals of the transmission waves, an echo signal suppressor for suppressing levels of the echo signals corresponding to sampling positions, a target object detector for detecting the target object(s) based on the level-suppressed echo signals, a first updater for comparing amplitude level(s) of echo signals of sampling positions, with the threshold that is set in association with the first distance, and determining to update the values with a new threshold and a new suppression value, and a second updater for comparing amplitude level(s) of echo signals of sampling positions, with the threshold that is set in association with the second distance, and determining to update the values with a new threshold and a new suppression value.

The present invention discloses a method and a system for noise reduction of a ground penetrating radar B-scan image based on EEMD and permutation entropy. First, a ground penetrating radar two-dimensional B-scan image signal is obtained, and then each obtained B-scan image signal is subjected to noise reduction to obtain the B-scan image signal of the channel after the noise suppression signal, and finally the signal after each channel is recombined to obtain a noise-suppressed two-dimensional B-scan image signal; for any one B-scan image signal, the method for denoising includes: performing EEMD decomposition on the B-scan image signal of the channel to obtain K IMF components arranged from high frequency to low frequency; calculating arrangement entropy values of each IMF component; and selecting an arrangement entropy value not greater than a preset value IMF components to reconstruct, and obtaining the signal after denoising. The invention solves the signal mode aliasing problem existing in the EMD decomposition and can effectively reduce the noise.

Interfering signals coming at random timings from different radio stations are identified. In order to attain this, a method for storing the characterizing quantity of an interfering signal included in a received signal includes calculating the characterizing quantity of the received signal, determining a probability that a desired signal is included in the received signal, determining that the received signal is an interfering signal when determining that there is no probability that the desired signal is included in the received signal, and storing the characterizing quantity of the received signal as an interfering signal characterizing quantity when it is determined at the received signal determination step that there is no probability that the desired signal is included in the received signal.

An electroimpedance tomograph with a plurality of electrodes (1) is provided, which can be placed on the body of a patient and are connected via a selector switch (60) with a control and evaluating unit (20). The control and evaluating unit (20) cooperates with the selector switch (60) such that two electrodes each are supplied with an alternating current from an AC power source (22) and the detected analog voltage signals of the other electrodes are processed in order to reconstruct therefrom the impedance distribution of the body in the plane of the electrodes, wherein a symmetrical AC power source is used to reduce common-mode signals. To further suppress interferences due to common-mode signals, provisions are made for the control and evaluating unit (20) to be set up, furthermore, for detuning the common-mode signal of the alternating current on the body against the ground by means of a common-mode signal measuring electrode (4) and, based on this, the symmetry of the symmetrical AC power source such that the common-mode signal on the body is minimized, and the corresponding detuning parameters are stored for each electrode pair.

In an echo suppressing apparatus suppressing from a near-end input signal acoustic echo signals caused by a far-end signal, an estimated-echo path characteristic is multiplied by a far-end signal to produce an estimated-echo signal for each frame, and frames of the estimated-echo signals thus obtained are stored in an estimated-echo signal storage. A delay amount estimator calculates the total of differences between the near-end input signal and each estimated-echo signal thus stored, and determines the amount of frame delay having its total of differences minimal. A delay estimated-echo signal calculator uses the amount of frame delay to read out an optimum frame and near frames respectively preceding and following the optimum frame and to calculate a corrected, delay estimated-echo signal. An echo suppressor uses the estimated-echo signal thus corrected to suppress the acoustic echo signals from the near-end input signal.

Provided are an image signal rejection method capable of avoiding demodulation of an image signal along with a real signal in a radio frequency (RF) signal and a low IF receiver of rejecting an image signal by using the method. The low IF receiver of rejecting an image signal includes a low noise amplifier, a quadrature I / Q mixer, a signal complex filter, and a phase and gain control block. The low noise amplifier amplifies a radio frequency (RF) signal. The quadrature I / Q mixer generates an I signal and a Q signal by down-converting the amplified RF signal into an IF signal. The phase and gain control block generates an I′ signal and a Q′ signal which are obtained by changing phases and amplitudes of the I signal and the Q signal by using a real signal. The signal complex filter minimizing the image signal in the IF signal and passing the real signal by performing filtering on the I′ signal and the Q′ signal.

The invention discloses a crossroad non-motor vehicle and pedestrian position detection method based on special-purpose short-distance communication. The method comprises the following steps: disposing a road side special-purpose short-distance communication unit and a roadbed computer unit at a crossroad turning area, wherein the road side special-purpose short-distance communication unit and the roadbed computer unit are connected; the road side special-purpose short-distance communication unit obtaining crossroad area wireless signal data frames; and by taking the data frames as input signals, performing real-time signal spectrum analysis, window function weighing and multipath signal inhibition processing through the roadbed computer unit such that time sequence based non-motor vehicle and pedestrian position detection in the crossroad turning area is realized. The method provided by the invention has the advantages of being free of space-time change influences, effectively utilizing the wireless signal resources of the crossroad area, and improving the safety grade of a crossroad.

A radio frequency (RF) transceiver includes an RF transmitter that generates an outbound RF signal at a carrier frequency that is based on a transmitter local oscillation. An RF front-end receives an inbound RF signal that includes a desired signal component that is based on the outbound RF signal and that includes an undesired signal component. The RF front-end includes a first RF combiner module that attenuates the undesired signal component to produce a desired RF signal. A down conversion module generates a down converted signal from the desired RF signal based on a receiver local oscillation. A receiver processing module generates inbound data from the down converted signal. A frequency control module controls a frequency of the transmitter local oscillation and a frequency of the receiver local oscillation, based on an interference rejection signal, to control the attenuation of the undesired signal component.

In a magnetic resonance measurement sequence, an inversion pulse is applied that acts on a longitudinal magnetization of a first spin species and a second spin species, for example on a water portion and a fat portion. An excitation pulse is applied after a predetermined time period. At least one manipulation pulse is subsequently applied, respectively with associated gradient pulse.

The invention provides a sensor noise signal inhibition method in a three-point-method rotation error separation process. The method comprises steps that firstly, a sensor mounting angle is reasonably designed to carry out signal acquisition, and a sensor combination signal frequency domain expression in a three point method after noise signal interference is constructed; secondly, an error model of a real rotor contour signal and a contour signal acquired through separation after noise interference is established, and a transfer function of a noise signal in a separation process is acquired through analysis; lastly, an optimization target function is constructed according to the acquired transfer function, a harmony search algorithm based on coordinate rotation is further utilized to carry out optimization solution. According to the method, a sensor noise signal inhibition problem in the three-point-method rotation error separation process is converted into a target function optimization problem, each-order frequency components of the noise signal are effectively inhibited through optimizing the transfer function of the noise signal, and rotation error separation precision is improved.

Modular gain control based on blocker signal detection is disclosed herein. In a multi-stage gain control scheme for a receiver, the input stage gain or the pre-mixing stage gain can be controlled for effective blocker rejection based on detecting a blocker signal at a mixer, and the output stage gain or the post-mixing stage gain can be controlled to restore and maintain an appropriate output level after pre-mixing gain reduction performed for blocker rejection. Accordingly, the RF communication systems herein can include multiple loops for providing AGC. In particular, an RF communication system can include a main loop and a blocker loop used to override the main loop when the blocker signal is detected. In certain configurations, the blocker loop reduces the gain of an RF VGA, while the main loop will increase the gain of an IF VGA to restore the output power.

The present invention provides a cell which comprises; (i) a chimeric antigen receptor (CAR) which comprises an antigen binding domain and an intracellular signalling domain; (ii) a membrane tethering component (MTC) which comprises a first dimerization domain; and (Hi) a signal-dampening component (SDC) comprising a signal-dampening domain (SDD) and a second dimerization domain which specifically binds the first dimerisation domain of the membrane-tethering component. Dimerisation between the MTC and SDC may be controllable with an agent, meaning that the agent can be used to control CAR-mediated cell signalling.

In a receptive system of a base station according to the communication system of a PDMA, CDMA and the like, the reception signals from a plurality of users received on a plurality of antennas are frequency-converted by a frequency conversion circuit, and then converted into digital signals by an A / D converter to be applied to a DSP. The signal of a particular user is extracted from the input signal by an adaptive array. Also, the interference user signal component is removed by an interference canceller. Accordingly, the signal component of a desired user having the interference component caused by an unrequired user signal suppressed is output. Thus, the communication quality in a radio communication system such as a mobile communication system can be improved.

The invention provides a photoelastic modulation measurement system. A reference signal is introduced into the photoelastic modulation measurement system; the reference signal contains information of demodulation deviation of a photoelastic modulator on a polarization state; and data noise caused by the deviation of a modulation state of the photoelastic modulator is curbed through the reference signal.

A signal processing system, such as a hearing aid system, adapted to enhance binaural input signals is provided. The signal processing system is essentially a system with a first signal channel having a first filter and a second signal channel having a second filter for processing first and second channel inputs and producing first and second channel outputs, respectively. Filter coefficients of at least one of the first and second filters are adjusted to minimize the difference between the first channel input and the second channel input in producing the first and second channel outputs. The resultant signal match processing of the signal processing system gives broader regions of signal suppression than using the Wiener filters alone for frequency regions where the interaural correlation is low, and may be more effective in reducing the effects of interference on the desired speech signal. Modifications to the algorithms can be made to accommodate sound sources located to the sides as well as the front of the listener. Processing artifacts can be reduced by using longer averaging time constants for estimating the signal power and cross-spectra as the signal-to-noise ratio decreases. A stability constant can also be incorporated in the transfer functions of the first and second filters to increase the stability of the signal processing system.

The invention provides a clutter map principle-based radar clutter signal suppression method and a radar detection system. The method comprises the following steps of S100, dividing a radar space detection range into a plurality of space units along radar detection distance, direction and pitching direction; and S200, counting numbers of target signals detected in each space unit in one time by taking each N radar scanning periods as a batch, judging attribute of the target signal detected in each space unit in current batch according to the situation whether the numbers of the target signal detected in each space unit in previous batch conform to a given condition or not, judging whether the target signal is output or not according to the attribute of the target signal, and rejecting thesystem to output the target signal so as to prevent interference of a clutter signal if the target signal belongs to the clutter signal.

An OFDM transmitter and a signal processing method thereof are provided. An OFDM transmitter includes a FEC unit for coding data of transmitting stream(TS); a frame format unit inserts pilot signal or transmitting parameter signal (TPS) or null signal into coding TS data and inserts pilot signal or TPS into coding TS data; an inverse discrete Fourier transformer inverse-discrete-Fourier-transforms the coded data which the null signal has been inserted into OFDM signal of time domain; a GI (guide interval) inserting unit inserts a GI into an OFDM symbol outputing from the IDFT unit; a synchronous insertion unit inserts PN sequence into each OFDM signal of GI which having GI inserting unit; a PAL suppression filter removes PAL component from OFDM symbol outputing from the synchronous insertion unit, or transmits the OFDM symbol without filtering; a pulse shaping filter for filtering OFDM signal outputing from the PAL suppression filter, or filtering OFDM signal outputing from the synchronous insertion unit; a RF upconversing unit for upconversing OFDM signal after filtering into radio frequency.

Provided are an RFID reader and a method for suppressing transmission leakage signals thereof. The RFID reader includes a first loop, a second loop, and a digital signal processor. The first loop suppresses a first transmission leakage signal of an RX signal in response to a first leakage control signal. The second loop suppresses a second transmission leakage signal of the RX signal, received through the first loop, in response to a second leakage control signal. The digital signal processor generates the first leakage control signal and the second leakage control signal. The digital signal processor generates the first leakage control signal until the level of the first transmission leakage signal becomes equal to or lower than the level of a first reference transmission leakage signal.

A target object detection device is provided. The device includes a transmitter for transmitting at least one transmission wave in a predetermined azimuth, an echo signal receiver for receiving echo signals of the transmission waves, an echo signal suppressor for suppressing levels of the echo signals corresponding to sampling positions, a target object detector for detecting the target object(s) based on the level-suppressed echo signals, a first updater for comparing amplitude level(s) of echo signals of sampling positions, with the threshold that is set in association with the first distance, and determining to update the values with a new threshold and a new suppression value, and a second updater for comparing amplitude level(s) of echo signals of sampling positions, with the threshold that is set in association with the second distance, and determining to update the values with a new threshold and a new suppression value.

A method and apparatus for suppressing a transmit leakage signal of a radio frequency identification (RFID) reader is provided. The apparatus includes: a first power distributor distributing a transmission signal to output a first transmission signal and a second transmission signal; a second power distributor distributing the second transmission signal to output a third transmission signal and a fourth transmission signal; a first amplitude / phase converter converting an amplitude and a phase of the first transmission signal to generate a first converted signal; a second amplitude / phase converter converting an amplitude and a phase of the third transmission signal to generate a second converted signal; a first power combiner combining the first converted signal with a first leakage signal generated in association with the fourth transmission signal; and a second power combiner combining the second converted signal with a second leakage signal generated in association with the fourth transmission signal.

The invention discloses a near-field sound source signal pickup system based on a microphone array, which is applied to a voice application system. The near-field sound source signal pickup system comprises a microphone array, a pre-amplification module, a phase tracking module and a sound source distance recognition module, wherein the microphone array comprises a first microphone, a second microphone and a third microphone which are linearly distributed at equal intervals and is used for picking up sound source signals in multiple channels, and the sound source signals comprise near-field sound source signals and far-field sound source signals; the pre-amplification module is used for performing pre-amplification on output signals of the first microphone, the second microphone and the third microphone; the phase tracking module forms and provides a tracking signal according to output signals of the pre-amplification module, and is used for tracking the far-field sound source signalspicked up by the second microphone and outputting the amplitude and phase of the signals after the pre-amplification; and the sound source distance recognition module forms a recognition signal according to the tracking signal, and the recognition signal suppresses the far-field sound source signals picked up by the microphone array. The sensitivity of the system decreases along with the increaseof the sound source distance, so that the system can effectively suppress the far-field sound source signals, and thus the signal-to-noise ratio of the picked up near-field source signals is improved.

The invention provides a single-excitation micro-discharge radio frequency noise signal suppression method and device. The device includes a microwave device and a filter. The rear end of the microwave device is connected in series with the filter. A frequency parameter of the filter is determined according to frequency of a radio frequency noise signal generated by the microwave device under single excitation so as to suppress the radio frequency noise signal. Since the frequency of the radio frequency noise signal generated by the microwave device under single excitation is within a passingforbidding frequency range defined by the frequency parameter of the filter, the filter can accurately suppress the radio frequency noise signal. Therefore, the single-excitation micro-discharge radiofrequency noise signal suppression method and device have a good radio frequency noise signal suppression effect.