102 results about "Quiet zone" patented technology

An active noise control system generates an anti-noise signal to drive a speaker to produce sound waves to destructively interfere with an undesired sound in a quiet zone. The anti-noise signal is generated with an adaptive filter having filter coefficients. The coefficients of the adaptive filter may be adjusted based on a first filter adjustment from a first listening region, and a second filter adjustment from a second listening region. A first weighting factor may be applied to the first filter adjustment, and a second weighting factor may be applied to the second filter adjustment. The first and second weighting factors may dictate the location and size of the quiet zone as being outside or partially within at least one of the first listening region and the second listening region.

In an IP-based cellular wireless communication system, systems and methods for spatially controlling cellular phone usage are provided. Entry of a cellular phone device into an area of restricted phone access (“quiet zone”) is detected and an IP message identifying the phone sent to a central facility. In one embodiment, an IP message is sent to the phone causing it to change behavior, for example turning off the volume on the ringer. Alternatively, the central facility can process an incoming call for a phone that is determined to be in a quiet zone to reduce intrusion in the quiet zone; for example, it can send the call to a phone mailbox or give the caller a busy signal.

A two-dimensional, high-density, damage-tolerant printed code suitable for encoding multiple biometrics and text for positive off-line identity verification comprises a horizontal header section; a vertical header section; a start pattern; a left row address pattern; an encoded data portion; a right two address pattern; and stop pattern. The horizontal header section encodes the number of bit areas in a transverse row of the encoded data portion; and the vertical header section encodes the vertical height of each bit area. The start and stop patterns of the code demarcate the lateral extent of the code (i.e., the beginning and end) from the adjacent quiet zone. Information is encoded into the ended information portion in bit areas that may be printed or blank. The information is encoded sequentially in the information portion from the top of the encoded information portion along each transverse row of bit areas to the next row of bit areas until the end of the encoded information portion. Error correction is applied to subunits of information from the encoded information portion by dividing the user messages and applying error correction to subunits of the user message. The two-dimensional, high-density, damage-tolerant printed code is suitable for printed on a conventionally sized ISO cord or other papers used in verifying identity. An ISO-sized cord or other identity paper bearing a two-dimensional, high-density, damage-tolerant printed code encoding multiple biometrics, e.g., encoded image likeness and multiple finger print templates, maybe used with an off-line integrated positive identity verification apparatus that is capable of decoding the image and fingerprint samples taken from an individual whose identity is sought to be verified.

The present invention discloses a solution that establishes an emergency contact list, which includes at least one contact. The emergency contact list can be associated with a mobile device capable of wireless communications. The mobile device can be placed within a quiet zone that restricts wireless communications capabilities of the mobile deice while the mobile device is within the quiet zone. A communication attempt can be detected that involves the mobile device and a second device used by a communication participant. When the communication participant is included within the emergency contact list, at least one emergency communication action can be automatically performed. The emergency communication action can provide a communication capability for a communication conducted responsive to the communication attempt that is a capability denied for communications where the communication participant is not included in the emergency contact list. For example, the emergency contact action can enable an otherwise prohibited communication.

A mechanism is provided for detecting when a wireless device is entering a quiet zone. An out-of-range condition is created in an entryway to a quiet zone. When a wireless device is in a transition zone, the device transmits a re-scan message with a unit identification in an attempt to reestablish communication with the communication tower. A re-scan receiver is provided in the entryway to receive re-scan messages and notify a mobile telephone switching office that the device is entering a quiet zone. The switching office then sends a ring type modifier property to the device when the device leaves the transition zone and reestablishes communications with the communication tower.

A parametric sound system for creating an acoustical column along an axis of propagation having a quiet zone an audible zone is disclosed. The system comprises a parametric electro-acoustic emitter configured for emitting a plurality of focalized parametric ultrasonic waves. A plurality of decoupled acoustic waves are maximized at a focalizing area within the audible zone. The system also includes a signal source for applying a parametric ultrasonic signal to the parametric electroacoustic emitter. The signal includes an ultrasonic carrier signal and one or more sideband signals corresponding to an audio input signal. The system further comprises a signal processor for controlling phases of the parametric ultrasonic signal so that the plurality of focalized parametric ultrasonic waves emitted by the parametric electro-acoustic emitter will create a quiet zone along the same direction of propagation as the audible zone. The plurality of decoupled audio waves are substantially in phase within the audible zone while the plurality of decoupled audio waves are largely out-of-phase within the quiet zone.

An active noise control system generates an anti-noise signal to drive a first speaker group including at least one speaker to produce sound waves to destructively interfere with an undesired sound in at least one quiet zone. The active noise control system receives error signals representative of a combination of undesired sound and destructively interfering sound waves produced by the first speaker group. The active noise control system may select a second speaker group to replace the first speaker group based on the error signals.

A transmitting controller is connected to a powerline and on command places a reference signal and a series of signal pulses in the powerline at a series of signal timing positions related to zero voltage crossing points so that the signals pulses are substantially in the powerline temporal quiet zone near zero crossing. The signal pulses are produced from a pair of capacitors and switches which are each sequentially charged a first polarity from the powerline and is discharged in the powerline at the opposite polarity so that the powerline voltage at the time of the pulse is additive to the pulse voltage. The receiving controller is connected to the powerline and has a filter circuit therein which filters away the powerline AC signal and noise to leave the reference and signal pulses. The signal pulses are compared to the position of starting reference pulses to determine in which signal timing position the pulses have occurred.

A method for measuring a compact range antenna by three reflectors comprises the following steps of: determining a system mapping function according to the distribution of a feed source field and the distribution of a system outlet field; tracking and analyzing the electromagnetic wave emitted by the feed source by adopting a dynamic waveband tracking theory; and determining all mirror surface parameters of a first forming auxiliary reflector and a second forming auxiliary reflector by the system mapping function, the feed source field wavefront parameters and the main reflector surface parameters. The embodiment of the invention also discloses a system for measuring compact range antenna by three reflectors. The system and the method can be applicable to the feed source higher than 300GHz, and lead the system outlet field to have large quiet zone utilization coefficient (achieving more than 70%), high cross polarization isolation degree, compact structure and wide measurement frequency bands.

An active noise cancellation fault detector (NCFD) is presented that is configured to cancel normal machine noise in an operator cabin, while allowing noise associated with a machine failure mode to remain so that an operator can hear when a machine component is beginning to fail or is in a failure mode. An NCFD can generate a model waveform of normal noise scaled to machine operating parameters. The model waveform can be inverted and adjusted in gain and phase to provide a cancellation waveform. The invention can be configured to determine operator location within a machine cab so that cancellation signals can be configured with the proper phases to destructively interfere with normal machine noise within a quiet zone or noise suppression envelope around an operator. Noise within the quiet zone can be detected and compared to various fault waveforms to determine whether a machine component is beginning to fail.

A quiet zone generation technique is proposed for interference mitigation for a receive antenna by injecting the very interference signals via iterative processing, generating quiet zones dynamically for receive (RCV) antennas. The receive antenna may feature multiple receiving apertures distributed over a finite area. Optimization loops consist of four cascaded functional blocks; (1) a pick-up array to obtain the interference signals, (2) element weighting and/or repositioning processors, (3) an auxiliary transmit (XMIT) array with optimized element positions, (4) a diagnostic network with strategically located probes, and (5) an optimization processor with cost minimization algorithms.

To minimize interferences between transmit (Tx) and receiving (Rx) apertures in limited space of an antenna farm for communications and/or radar applications are very tough problems. Among the tools for solving the problems are many conventional techniques listed in the references [1,2,3]. However, solutions for co-site interference mitigation may not be generic ones but more specific to geometries of antenna farms, Tx apertures and Rx antenna locations, and beam positions of the Tx beams.

The present invention provides a system to create a quiet zone by suppressing background noise near a user's head. The present invention utilizes two microphones; one microphone receives environmental noise and the other one is located close to a person's head. A parabolic dish loudspeaker creates a uniform sound field near a user's head. A high performance frequency-domain filtered-x least mean square with band selection (FD-FX-LMS-BS) algorithm is utilized to generate the anti-phase noise signals. The algorithm has high noise reduction performance and also allows selection of specific frequency bands for noise reduction. The FD-FX-LMS-BS algorithm is performed by a field programmable gate array (FPGA) chip, which has minimal delay in algorithm processing.

Embodiments relate to method for authenticating timepiece comprising measuring acoustic vibrations emitted by timepiece to obtain electrical signal, which indicates variation of magnitude of measured acoustic vibrations as function of time. The method includes processing electrical signal to attenuate plurality of acoustic events in said electrical signal, performing transform of processed electrical signal into a frequency domain to obtain frequency-domain power spectrum indicating variation of power of processed electrical signal as a function of frequency, identifying at least one narrow peak in frequency-domain power spectrum corresponding to at least one resonance frequency of a part of timepiece resonating in a quiet zone. The method also includes extracting at least one resonance frequency corresponding to at least one narrow peak, comparing extracted at least one resonance frequency with at least one reference resonance frequency, and deriving information on an authenticity of said timepiece based on the comparing.

A magnetic reader of the present invention comprises an MR sensor shielded by a magnetic shield including single domain soft magnetic materials. The domain wall free magnetic shield includes an unbiased soft magnetic layer and a biased soft magnetic layer separated by a non-magnetic layer. The easy axis of the biased layer is oriented to create a path for magnetic flux through the biased and unbiased layers thereby reducing the demagnetization field of the shield. A biasing layer maintains the first and second magnetic layers as single domain magnets. The biasing layer is further shaped to define a quiet zone where the biasing layer does not overlay the MR sensor.

A method and system for scheduling and protecting quiet periods (QP) in a quiet zone (105) for incumbent signal (121) detection in a wireless communications system. The communication system includes a plurality of wireless networks (103, 104), each of the plurality of wireless networks contains at least a master device (101, 401 ) and a client device (111, 411). In each of the plurality of wireless networks, the master device (101, 401) transmits a beacon (402) that contains a QP schedule (500) and a reservation of a time slot (405) for the client device (411 ). The client device (111, 411) transmits a request-to-quiet (RTQ) message (412) during the time slot, wherein the RTQ message (412) includes the client device's QP schedule information. The master and client devices within the quiet zone (105) keep quiet during scheduled quiet periods according to the QP schedule information contained in the received beacons and RTQ messages.

A compact range antenna test system provided by the present invention comprises a microwave anechoic chamber, and a first manipulator, a second manipulator, a reflector and a feed source which are all arranged in the microwave anechoic chamber, the reflector is arranged on the first manipulator, the feed source is arranged on the second manipulator and faces the reflector, the reflector is used for focusing emergent waves emitted by the feed source into plane waves and reflecting the plane waves to a to-be-tested piece to form a quiet zone, the first manipulator can drive the reflector to move, and the second manipulator can drive the feed source to move according to the moving position of the reflector so as to translate the quiet zone. According to the compact range antenna test system provided by the invention, the reflector and the feed source are respectively driven by the first manipulator and the second manipulator to move, and translation of the quiet zones can be realized by combining real-time matching and alignment of the reflector and the feed source, so that a plurality of quiet zones which can be mutually spliced are formed, the space of the quiet zones is multiplied, and the test performance is improved.

A device for shielding at least one sub-wavelength-scale object from an electromagnetic wave, which is incident on said device, comprises at least one layer of a dielectric material, a surface of which having at least one abrupt change of level forming a step. At least a lower and lateral part of the surface with respect to the step is in contact with a medium having a refractive index lower than that of the dielectric material. The at least one sub-wavelength-scale object is located within the device in a quiet zone where an electromagnetic field intensity is below a threshold, the quiet zone extending above said surface, in the vicinity of the step, in a direction of incidence of said electromagnetic wave.

The invention discloses a hybrid compact, near-field-to-far-field and direct-far-field test system in an anechoic chamber. It comprises a curved reflector with its primary feed antenna set situated on a lateral side and pointing towards it, a secondary feed antenna set pierced to the reflector or in front of it, and one or several sets of antennas or devices under test (AUT/DUT), and their 3D turntable tower placed at a quiet zone, for which roll, elevation and azimuth can change. In a receive process, the primary antenna set transmits several signals towards the reflector, which reflects these signals towards the quiet zone in the form of planar wavefronts. The secondary antenna set also transmits several signals, but directly towards the quiet zone in spherical wavefronts. The AUT/DUT receives all these signals simultaneously. Through reciprocity, a similar measurement process for transmission can be performed.