88 results about "Self noise" patented technology

Disclosed is a satellite communication timing synchronization error detection method based on full-digital receiving. In view of wide application of a Gardner algorithm in a timing synchronization loop and the limitation of the Gardner algorithm to band-limited signals, when polarity jump happens to two adjacent symbols, after two adjacent code elements are utilized for cosine roll-off forming filtering, the relation between samples of two best sampling points and the sample of a middle point of the two best sampling points is utilized, the effect of different adjacent symbols to the middle value is firstly taken into consideration and the effect value is calculated according to the minimum mean-square error criterion, and is then eliminated; when polarity jump does not happen to the adjacent symbols, how to reduce self noise generated by the situation that timing information can not be acquired is taken into consideration. A sign function sign (.) in an E-Gardner algorithm is utilized to solve the problem. Under the satellite channel environment, the enhancing algorithm is simple in structure, under the condition of a small roll-off coefficient, the performance of QPSK modulating signal clock capturing and error detection is improved, and the satellite communication timing synchronization error detection method based on full-digital receiving can effectively eliminate self-noise and reduce system resource consumption.

A simplified self noise-immunity controller formation method of PMSM (permanent magnet synchronous motor) is applicable to the high performance control of PMSM. It constructs the expanding voltage-controlled inverter (2) by the voltage control voltage source inverter (1) and space vector pulse width modulation; it constructs a composite controlled object (10) by the expanding voltage-controlled inverter and current controller (3), the coordinate transformation (4), the permanent magnet synchronous motor (7), the workload (8) and the photoelectric encoder (9); it constructs the second-order state observer (52) by compositing the input and output signals of the controlled object; It constructs the composite speed feedback (54) by the weighted sum of the two speed measurement value; it constructs the composite controller (53) by the superposition of the generalized rate error square controller (51) and the compensation value of the system perturbation (-z2 / b); it series connects the composite controller before the composite controlled object, and finally, it constructs the simplified self noise-immunity controller (5) by the composite controller and the expanding second-order state observer.

The invention relates to a flexible anti-interference projection-type capacitor touch screen which comprises three layers of high-transmittance optical PET, wherein the upper bottom surface of the upper layer of PET is a hard surface which is hardened and prevents from being scraped; two surfaces of the middle layer of PET are both provided with ITO, the ITO on the upper bottom surface is etched to be an X-axle or Y-axle diamond pattern and an upper bottom surface interface line, the ITO on the lower bottom surface is etched to be a Y-axle or X-axle diamond ITO pattern and a lower bottom surface interface line; the upper bottom surface of the bottom layer of PET is provided with integral ITO which is grounded; and the three layers of high-transmittance optical PET are sequentially adhered into an integral body through transparent optical cement. The invention has the advantages of being suitable to a curved surface and a plane and preventing the self-noise signal interference of a mobile phone as well as having low cost.

A diversity antenna for use with a portable host device such as a laptop computer, for example as part of a PCMCIA card pluggable into the laptop computer to enable wireless computer by the laptop computer, includes a main antenna and a diversity antenna. Various configurations for these antennas are possible, including the use of a balanced dipole as the main antenna element and a split diversity antenna for the diversity antenna element. The diversity antenna provides high isolation between the antenna elements and isolation from interfering self-noise generated by the host device.

The invention discloses a self-noise test system and level test method for a ship sonar platform and belongs to the field of underwater noise control engineering. According to the invention, three signal source generators are controlled through a computer to generate excitation signals, and so the three signal source generators generate simulated hydrodynamic noise, simulated mechanical noise andsimulated propeller noise. Then data is collected and analyzed through a signal acquisition and recording end. A sonar platform self-noise test under a single noise resource effect can be carried out,a platform self-noise test under the effects of multiple noise resources at the same time can be implemented, test data in a whole wide frequency band can be obtained at a time, tests in different frequency bands are avoided, the work efficiency is improved, and the self-noise characteristics of a sonar chamber under various working conditions are more realistically simulated, and the establishment of a self-noise test system for the ship sonar platform is achieved.

A microphone includes a microelectromechanical system (MEMS) device, an amplifier, and an attenuation apparatus. The MEMS device converts acoustic energy into electrical signals. The amplifier is coupled to the MEMS device and receives an input signal from the MEMS device and performs amplification on the input signal to produce an output signal. The attenuation apparatus is coupled to the amplifier. Activation of the attenuation apparatus is effective to attenuate the output signal of the amplifier. A self-noise of the amplifier is attenuated and a sensitivity of the microphone is reduced such that a first signal-to-noise ratio is substantially the same as a second signal-to-noise ratio. The first signal-to-noise ratio occurs when the attenuation apparatus is not activated, and the second signal-to-noise ratio occurs when the attenuation apparatus is activated.

A diversity antenna for use with a portable host device such as a laptop computer, for example as part of a PCMCIA card pluggable into the laptop computer to enable wireless computer by the laptop computer, includes a main antenna and a diversity antenna. Various configurations for these antennas are possible, including the use of a balanced dipole as the main antenna element and a split diversity antenna for the diversity antenna element. The diversity antenna provides high isolation between the antenna elements and isolation from interfering self-noise generated by the host device.

The invention discloses an MEMS thermal acoustic particle sensor and relates to the field of microelectronic machining, and in particular relates to a design method for the MEMS thermal acoustic particle sensor. Currently, based on a principle of a two-wire flowmeter, conventional MEMS thermal acoustic particle sensors have large self-noise and poor high-frequency characteristics. To solve this problem, the present invention provides a MEMS three-wire thermal acoustic particle sensor structure that can be applied to sound source positioning. The sensor has a three-layer cantilever structure which is formed by bonding upper and lower polar plates and consists of two right and left measuring units having orthogonal planes. Two temperature sensing resistance cantilever beams are arranged on each of two upper and lower layers of each measuring unit, and a heating resistance cantilever beam from an upper plate or a lower plate is arranged on a middle layer. Four cantilever beams on the upper and lower layer form a rectangle, and the cantilever beam on the middle layer is located at the center of the rectangle. Processing steps include a step of making three cantilever beams on each of two front and back surfaces of the upper and lower polar plates of each measuring unit, a step of removing excessive cantilever beams in the upper and lower polar plates, and a step of bonding the upper and lower polar plates together.

A diversity antenna for use with a portable host device such as a laptop computer, for example as part of a PCMCIA card pluggable into the laptop computer to enable wireless computer by the laptop computer, includes a main antenna and a diversity antenna. Various configurations for these antennas are possible, including the use of a balanced dipole as the main antenna element and a split diversity antenna for the diversity antenna element. The diversity antenna provides high isolation between the antenna elements and isolation from interfering self-noise generated by the host device.

In a memory module, a plurality of memories are mounted on a module base plate, impedance between Vref and Vss near each memory is coupled to Vss by a decoupling capacitor and a Vref plane to achieve low impedance configuration in a wide frequency range, Vref planes are individually provided for the respective memories, and the Vref planes are connected to each other by using a high impedance wire, or a high impedance chip part. Accordingly, a wiring technique for a module which allows effective reduction of self noise and propagation noise can be provided.

The invention provides a calibration device and a calibration method for the equivalent self-noise acceleration spectrum level of a low-noise vector hydrophone. It is mainly composed of underwater acoustic tube, vacuum tube, electromagnetic shielding tube, vibration-damping base and upper cover. The noise self-spectrum measured by each vector hydrophone includes the self-noise spectrum and the environmental background noise spectrum, and the cross-correlation calculation of the noise signals of the two vector hydrophones can obtain the environmental background noise spectrum, and then through the known vector hydrophone The transfer function of the earphone can be calculated to obtain the equivalent self-noise acceleration spectrum level of the respective vector hydrophones. The present invention effectively reduces external vibration, electric, electromagnetic and acoustic interference, makes the background noise of the test environment extremely low, and thus better satisfies the calibration accuracy of the equivalent self-noise acceleration spectrum level parameters of the low-noise vector hydrophone It improves the evaluation effectiveness of the self-noise level of the low-noise vector hydrophone, and ensures the engineering application quality of the low-noise vector hydrophone.

The embodiment of the invention provides a vehicle-mounted voice recognition method. The method comprises the following steps: carrying out voice area signal separation on vehicle-mounted space by using a plurality of microphones, so that the vehicle-mounted space is at least separated into a plurality of voice areas, and forming a distributed microphone network according to the microphones in thevoice areas; collecting audio under the vehicle-mounted environment in real time through the distributed microphone network, and inhibiting vehicle-mounted environment self noise in the audio according to the echo cancellation algorithm; separating voices of a plurality of speakers in the inhibited audio through a blind source separation algorithm; and locating the voice area of each speaker through the distributed microphone network, when no voice made by the speakers is available, collecting the voice as noise estimation, when voice made by the speakers is available, carrying out denoisingaccording to the noise estimation collected by a previous frame, determining clean voice, and carrying out voice recognition. The embodiment of the invention further provides a vehicle-mounted voice recognition system. According to the embodiment of the invention, in the vehicle-mounted noise environment, the relatively high awakening rate and recognition rate are available.

The invention discloses a voice processing method applied to a smart loudspeaker box. The method comprises: when a smart loudspeaker box is switched to be in a voice collection accessory mode, a soundaccompaniment signal sent by a preset intelligent household device is set to be an echo cancellation self-noise reference signal; according to a preset buffer area setting algorithm, a buffer area isset to store the echo cancellation self-noise reference signal of the corresponding retardation time length; and on the basis of the echo cancellation self-noise reference signal stored in the bufferarea, echo cancellation self-noise processing is carried out a voice signal collected by the smart loudspeaker box. In addition, the invention also discloses a smart loudspeaker box and a readable storage medium. Therefore, the awakening rate and recognition rate for the far-field voice by the smart loudspeaker box serving as the voice collection accessory of the intelligent household device areincreased.

Removal of extraneous magnetic measurement components from magnetic anomaly detection (MAD) tends to increase its accuracy. Conventional removal accounts for anomalous magnetism manifested by the MAD vehicle (typically, unmanned), but assumes that the magnetic field applied to the MAD vehicle is the earth's magnetic field, i.e., is non-anomalous and known. In contrast, the present invention accounts not only for anomalous magnetism manifested by the MAD vehicle, but also for anomalous magnetism manifested in the MAD vehicle's vicinity, such as by a manned control vehicle. The present invention's mathematical characterization of vehicular “self-noise” due to induced and permanent magnetization is more refined, especially insofar as treating the vehicle's ambient magnetic field as an unknown (empirical) quantity, rather than a known (non-empirical) quantity. A typical inventive system for vehicular magnetic self-noise-reduced magnetic anomaly detection includes magnetic and other sensors, and a computer implementing the inventive mathematical characterization in processing the signals.

In a memory module, a plurality of memories are mounted on a module base plate, impedance between Vref and Vss near each memory is coupled to Vss by a decoupling capacitor and a Vref plane to achieve low impedance configuration in a wide frequency range, Vref planes are individually provided for the respective memories, and the Vref planes are connected to each other by using a high impedance wire, or a high impedance chip part. Accordingly, a wiring technique for a module which allows effective reduction of self noise and propagation noise can be provided.

The invention relates to the field of the underwater structure noise control engineering, and specifically relates to a noise reduction effect detection method of a ship bow acoustic platform sound-absorption / insulation material. The method comprises the following steps: establishing a test system in a ship bow acoustic platform, measuring self-noise by directly utilizing a self-array hydrophone installed at an array location through the adoption of a platform self-noise horizontal detection processing method, describing the distribution of the whole sound field in the acoustic platform through thought of average sound energy, computing mean-square sound pressure level at each measurement point in the ship bow acoustic platform by adopting the mean-square sound pressure method, and obtaining the mean-square sound pressure level of the whole sound field in the ship bow acoustic platform by using a formula so as to be used as a data result of the self-noise level in the ship bow acousticplatform. Noise reduction control effects on the ship bow acoustic platform self-noise by different sound-absorption / insulation materials can be directly evaluated, thereby realizing the detection onthe noise reduction effects on the ship bow acoustic platform self-noise by different sound-absorption / insulation materials

A plurality of sensors and a digital adaptive tuning filter bank are used in extracting a desired emitted signal embedded in a noisy environment. By monitoring noise statistics of the sensor signals, the digital adaptive tuning filter bank automatically adjusts its upper (to eliminate strong tonals) and lower (to eliminate background noise) thresholds to obtain a discovery frequency band. The filter bank is designed by examining the discovery band across the sensors and over a predefined period of time. The method described significantly reduces the possibilities of matching self-noise transients (unwanted signals) and thus minimizes the false alarm rate in emitted signal recognition.

The embodiment of the invention discloses an application awakening method and device, a storage medium and electronic equipment. The electronic equipment comprises two microphones and can collect twochannels of audio data and obtain data of background audio played during audio collecting through the two microphones; then the two channels of audio data are subjected to echo cancellation processingaccording to the background audio data so as to cancel self-noise; then the two channels of audio data subjected to echo cancellation are subjected to beam forming processing so as to cancel externalnoise, and the enhanced audio data are obtained; and then text features and voiceprint features of the enhanced audio data are subjected to two-stage verification, when two-stage verification is passed, voice interaction application is awakened, and thus voice interaction between the electronic equipment and a user is achieved. Thus, interference of the self-noise and the external noise can be removed, verification accuracy is guaranteed through two-stage verification, and the purpose of increasing the awakening rate of the voice interaction application is achieved.

The invention belongs to the technical field of communication signal processing and relates to a symbol synchronization method based on particle filtering, in particular to a high speed satellite communication system symbol synchronization method based on the particle filtering. An input analog baseband signal is turned into a digital signal after being subjected to analog digital (AD) sampling; the digital signal first passes through an interpolation filter; the interpolation filter calculates an optimal sampling instant value according to the input signal and a timing deviation estimated value which is provided by a particle filter; the output value of the interpolation filter is sent into a timing error calculation module to obtain a measured timing error; the measured timing error is subjected to the particle filtering to obtain the timing deviation estimated value, and then the timing deviation estimated value is sent into the interpolation filter to control an interpolation moment; and the output value x' (rTs) of the interpolation filter contains the optimal sampling instant value x' (rT) so that the symbol synchronization can be finished through direct output of the output value x' (rTs). By means of the symbol synchronization method based on the particle filtering, timing error estimated accuracy is improved on the premise that the sampling rate is not increased, the particle filtering is utilized for adjusting timing deviation, and compared with a traditional scheme, the influence of self noise is lowered.

This invention provides a system apparatus and method for ship-towed deployment of a non-linear volumetric array of hydrophones, allowing line-intersect or line-transect sampling of marine mammal populations through passive acoustic monitoring, enabling unambiguous real-time three-dimensional localization of single sounds received through a low-cost, modular, robust, stable, small, light, neutrally to slightly negatively buoyant volumetric array having low self-noise and low flow noise, that avoids putting high tension on the tow cable and that is compatible with standard hydrophones, instrumentation, cabling, and analytical software.

The invention discloses a permanent magnet brushless DC motor provided with a self anti-interference speed control circuit. The structure of the invention comprises a stator, a rotor and the speed control circuit, wherein, the speed control circuit consists of a tachogenerator, an A / D converting circuit, a digital pulse-width modulation circuit, a logic time delay circuit, a power amplifier drive circuit, an inverter circuit and a digital control circuit; the input end of the digital control circuit is orderly connected with the A / D converting circuit and the tachogenerator in series, and then to the rotor end of the permanent magnet brushless DC motor; the output end of the digital control circuit is orderly connected with digital pulse-width modulation circuit, the logic time delay circuit, the power amplifier drive circuit and the inverter circuit in series, and then to the stator end of the permanent magnet brushless DC motor. The invention has the advantages that: the invention can estimate external disturbance and compensate through feedback, reduce the effect of the external disturbance to the permanent magnet brushless DC motor, improve the dynamic performance of the motor, and reinforce the stability and reliability.

An improved hearing protection device intended to be inserted into an external auditory meatus of a user, having a housing structure, a passive tuning element, and a passive, nonlinear acoustic filter. The tuning element and the acoustic filter may be supported in series by the housing structure. The tuning element may be or include a diaphragm, a resonator, or both. The housing structure may support a diaphragm of the tuning element at its circumference, and may provide cavities on both sides of the diaphragm. In some embodiments electronic components are included in the hearing protection device to counteract insertion loss provided by the passive element, and restore natural hearing for low to moderate sound pressure levels, Communications devices may also be incorporated into the hearing protection device. The combination of a simple, low cost amplifier circuit, passive tuning element and nonlinear acoustic filter of some embodiments of the present invention achieve a low cost yet sophisticated ability to react to impulse noise without the need for a microprocessor or complex electronics. Furthermore, the configuration reduces power consumption and, therefore, increases service life or decreases battery size / capacity, and results in low electronic self-noise allowing the user to maintain situational awareness,

An apparatus having an array plate and an isolation section joined to the perimetrical edge of the plate. The isolation section has a plurality of isolation layers and a plurality of intermediate layers alternately arranged wherein an intermediate layer is positioned between consecutive isolation layers. An innermost isolation layer is joined to the perimetrical edge of the array plate and an outermost isolation layer is adapted to be joined to a hull structure of an underwater vehicle. Each isolation layer is made from energy absorbing material and each intermediate layer is made from generally rigid material. The isolation section substantially reduces vehicle self-noise from traveling to the array plate. Interchangeable depth stop members having various geometries are used to adjust the stiffness of the isolation section so as to maximize the isolation characteristics of the isolation section at particular water depths at which the underwater vehicle operates.

The invention discloses a quick and stable echo eliminating method of intelligent voice interaction equipment. The method comprises the steps of playing a preset voice content by the intelligent voiceinteraction equipment after first starting; suppressing self noise of the played preset voice content after first starting by the intelligent voice interaction equipment through adaptive filtering technology, when the self noise reaches a preset attenuation value, storing a filter coefficient at this time point, and obtaining a stored filter coefficient; in using the intelligent voice interactionequipment, using the stored filter coefficient as an initial coefficient of the adaptive filtering technology; and furthermore in a tracking process, limiting the increment of the filter coefficientto a preset range. According to the quick and stable echo eliminating method, through setting the specific initial coefficient of a filter, convergence speed of the adaptive filter can be increased; and furthermore in the tracking process, the increment range of the filter coefficient is limited, thereby preventing divergence of the adaptive filter.

The invention relates to a weak signal detection technology, aims to overcome the defects of narrow frequency band and high noise of a detection circuit for outputting weak signals by a marine sensor,and aims to provide a broadband and low-noise amplification circuit whichCan effectively amplify Nanoscale (nV) weak signals in a 0.1Hz-10MHz broadband range, and is low in the self noise level. Therefore, the technical scheme adopted by the invention is as follows: the broadband and low-noise differential amplification circuit for weak signal measurement comprises three stages of amplification circuits, the first stage amplification circuit adopts a proportional differential amplification circuit, the second stage amplification circuit adopts a high-pass filtering amplification circuit, andthe third stage amplification circuit adopts a proportional amplification circuit; And two paths of differential output of the first-stage amplifier respectively enter the in-phase input end and the inverted input end of the second-stage amplifier. The method is mainly applied to weak signal detection occasions.

A wireless terminal measures the received power of a tone corresponding to an intention base station null output, measures the received power of pilot signals, and determines a signal to noise ratio of the received pilot signal. The wireless terminal calculates a downlink signal to noise ratio saturation level representative of the SNR of a received downlink signal that the wireless terminal would measure on a received signal transmitted by the base station at infinite power. The calculated downlink signal to noise ratio saturation level is a function of the determined interference power, the measured received pilot signal power, and the determined pilot signal SNR. A report is generated corresponding to one of a plurality of quantized levels, the selected quantized level being the closest representation to the calculated downlink signal to noise ratio saturation level. The generated report is communicated using a dedicated control channel segment in a predetermined uplink timing structure.

The invention discloses a real-time evaluation method for a small number of measuring points of underwater radiation noise of a ship, which belongs to the field of real-time evaluation of radiation noise and comprises the following steps of: arranging a self-noise sensor and a vibration sensor for the ship to be evaluated, and arranging a radiation noise hydrophone outside the ship; operating common working conditions such as a highest speed, a lowest speed, starting all common equipment, starting as few equipment as possible and the like, and recording sound pressure measurement values and vibration responses obtained by the self-noise sensor, the vibration sensor and a radiation noise sensor of the ship under various working conditions; selecting a plurality of combination working conditions, calculating and storing transfer matrixes under different combinations; and measuring self-noise and vibration signals in an actual navigation process of the ship, selecting a corresponding transmission matrix according to a navigation working condition, and evaluating far-field radiation noise of the ship in a current navigation state according to the transmission matrix. The real-time evaluation method for the small number of the measuring points of the underwater radiation noise of the ship can more accurately evaluate the far-field radiation noise, and has the advantages of convenient operation and control, small numerical calculation amount and few measuring points.

An apparatus that automatically adjusts self-noise and can lower the lower limit value of a measurement range by reducing the effects of self-noise on measured values. This apparatus corrects self-noise when amplifying an output signal from a sensor so as to conform to a sensor sensitivity G, further processing the amplified signal, and then outputting the processed signal as a measured value. This apparatus includes a sensor sensitivity adjusting circuit that adjusts an amplification factor so as to conform to the sensor sensitivity G, a self-noise value calculating circuit 4 that calculates a self-noise component F·N from the amplification factor adjusted by the sensor sensitivity adjusting circuit so as to conform to the sensor sensitivity G, and a measured value correcting circuit that calculates a true measured value F·S from the self-noise component F·N calculated by the self-noise value calculating circuit 4 as well as a measured value L containing the self-noise component F·N.

PURPOSE: A base station scheduling method in a mobile communication system is provided to be applied to an uplink base station scheduling function of terminals which are soft handed over with plural base stations, thereby preventing performance deterioration while more effectively controlling an uplink noise rise in each base station. CONSTITUTION: A BSC determines proper weights of each terminal which is soft handed over, based on uplink related information(S10), and periodically informs a scheduling base station of the determined weights(S11). The scheduling base station analyzes a self noise rise to calculate a 'current tolerable noise rise', and determines transmit powers of the terminals, then applies the weights when determining a final transmit power(S12). The base station performs a scheduling process by directly informing each terminal of the determined final transmit power or by increasing / decreasing a current transmit power(S13).

This invention provides a system apparatus and method for ship-towed deployment of a non-linear volumetric array of hydrophones, allowing line-intersect or line-transect sampling of marine mammal populations through passive acoustic monitoring, enabling unambiguous real-time three-dimensional localization of single sounds received through a low-cost, modular, robust, stable, small, light, neutrally to slightly negatively buoyant volumetric array having low self-noise and low flow noise, that avoids putting high tension on the tow cable and that is compatible with standard hydrophones, instrumentation, cabling, and analytical software.