1026results about How to "Reduce the impact of interference" patented technology

A method and apparatus for de-noising weak bio-signals having a relatively low signal to noise ratio utilizes an iterative process of wavelet de-noising a data set comprised of a new set of frames of wavelet coefficients partially generated through a cyclic shift algorithm. The method preferably operates on a data set having 2N frames, and the iteration is performed N−1 times. The resultant wavelet coefficients are then linearly averaged and an inverse discrete wavelet transform is performed to arrive at the de-noised original signal. The method is preferably carried out in a digital processor.

A cellular wireless internet access system which operates in the 2.5 to 2.68 GHz band and which must comply with complex government regulations on power levels, subscriber equipment and interference levels yet which provides high data rates to users and cell sizes of 1½ miles radius or more from base stations with subscriber equipment and antennas mounted indoors. Such base stations are mounted low and use spread-spectrum transmission to comply with interference rules with respect to adjacent license areas. An unidirectional tear-drop coverage pattern is used at multiple cells to further reduce interference when required. Time division duplex is used to allow the system to operate on any single channel of varying bandwidth within the 2.5 to 2.68 GHz band. Backhaul transmission from base stations to the Internet is provided using base station radio equipment, operating either on a different frequency in the band or on the same frequency using a time-division peer-to-peer technique. Different effective data-rates are provided by a prioritization tiering technique.

A multi-protocol, multi-band array antenna system may be used in Radio Frequency Identification (RFID) system reader and sensory networks. The antenna array may include array elements with an integrated low noise amplifier. The system may employ digital beam forming techniques for transmission and steering of a beam to a specific sensor tag or group of tags in an cell. The receive beam forming network is optimized for detecting signals from each sensor tag. Narrow and wideband interferences may be excised by an interference nulling algorithm. Space division multiplexing may be used by the antenna system to enhance system processing capacity.

An optical improvement for angular position sensors, which may be used to determine the spatial coordinates of a small source of light (or other energy) in a 3-dimensional volume. Such sensors normally include a linear photosensitive image detector such as a photodiode array or a charge-coupled device (CCD). An irregular pattern of parallel slits is described which increases the amount of light gathered while avoiding the undesirable characteristics of lens optics for this application. One optimal type of irregular pattern is the uniformly redundant array. A mathematical correlation function together with a polynomial interpolation function can determine the displacement of the image on the detector and thereby the location of the source relative to one angular dimension. Given the locations and orientations of several sensors in a 3-dimensional coordinate system and given the angles measured by each, the location of the point source can be computed.

A mode-locked laser with intracavity frequency conversion is disclosed. In one embodiment the conversion frequency is improved by reducing the temporal, spatial, or polarization overlap between pulses at the fundamental frequency and pulses at a frequency-shifted frequency.

A wireless communication network may include a plurality of mobile nodes each including a wireless transceiver and a controller for controlling the wireless transceiver. The controller may also be for scheduling a respective semi-permanent time slot to establish a communication link with neighboring mobile nodes for transmitting data therebetween, where the data has different priority levels. The controller may also determine respective link utilization metrics for each data priority level for each communication link, and schedule demand assigned time slots for establishing additional communication links with the neighboring mobile nodes for transmitting data therebetween based upon the link utilization metrics and data priority levels. The wireless communication network may also provide enhanced interference avoidance and / or mitigation features in certain embodiments.

An illumination apparatus comprises:(a) at least one light source;(b) a light guide for accepting light from the at least one light source and for guiding the light using total internal reflection, the light guide having a top surface;(c) a light extracting film having an input surface optically coupled with the top surface and an output surface for providing light,wherein the input surface comprises a plurality of features which are optically coupled to the top surface of the light guide, each feature having:(i) a first side comprising two or more planar segments; and(ii) a second side comprising two or more planar segments, andwherein the first and second sides intersect at an apex.

A multi-protocol, multi-band array antenna system may be used in Radio Frequency Identification (RFID) system reader and sensory networks. The antenna array may include array elements with an integrated low noise amplifier. The system may employ digital beam forming techniques for transmission and steering of a beam to a specific sensor tag or group of tags in an cell. The receive beam forming network is optimized for detecting signals from each sensor tag. Narrow and wideband interferences may be excised by an interference nulling algorithm. Space division multiplexing may be used by the antenna system to enhance system processing capacity.

In order to reduce mutual interferences between POLMUX and signals, the signals are transmitted with differed to each other carrying signals, thereby making it possible to obtain the circular polarization of each resulting POLMUX signal. Each second POLMUX signal is transmissible with an opposite circular polarization. In order to reduce also interferences when only one modulated data signal is transmitted through a POLMUX channel, a polarization plane of modulated data signals of each second POLMUX channel is turned at 45°. In a variant, polarization multiplex signals are produces and the resulting polarizations thereof in adjacent channels are perpendicular to each other.

Described are an apparatus and method for routing packets through a multiple-hop wireless communications network. Interference with packet switched communications carried by radio frequency (RF) over the multiple-hop wireless communications network is detected. In response to information related to the detected interference, a route is adaptively determined for transmitting packets through the multiple-hop wireless communications network that mitigates the effect of the interference on the packets.

A beamforming method in a communication system having a transmitter for transmitting signals to users on a plurality of transmit antennas, and spatially identifying the users and a plurality of receivers for receiving the signals discriminately. A beamforming weight is determined based on channel information received from each of the receivers, based on whether the each receiver uses a single antenna or a plurality of antennas. A transmission signal is multiplied by the beamforming weight and transmitted.

Frequency modification circuitry may be employed as part of a crystal oscillator circuit to generate a reference signal with adjustable frequency. The frequency modification circuitry may be implemented as part of a crystal oscillator circuit that includes digitally controlled crystal oscillator (“DCXO”) circuitry and a crystal. The frequency modification circuitry may adjust the frequency of the reference signal in response to one or more frequency control signals. In one example, the frequency modification circuitry may include variable capacitors such as one or more continuously variable and / or discretely variable capacitors for providing coarse and / or fine adjustment of the reference signal frequency.

Fractional frequency reuse systems and methods for assigning physical resource units of an available frequency band to sectors of cells are disclosed. In particular, the systems and methods permit adaptation of frequency configuration partitions to mobile station or throughput distribution within cells while at the same time ensuring mitigation of interference between neighboring sectors of different cells.

Communication quality is prevented from being deteriorated due to interference caused by low accuracy of channel information or interference from another base station or another wireless communication system. A wireless communication system includes a first wireless station including a plurality of antenna elements, transmission units corresponding to the plurality of antenna elements, and a transmission directivity control unit that controls transmission directivity of the plurality of antenna elements, and a plurality of second wireless stations each including a reception power measurement unit that measures a reception power. The transmission directivity control unit determines the transmission directivity of each of the plurality of antenna elements so that a signal does not reach a particular second wireless station among the plurality of second wireless stations. The transmission units generate wireless signals using the transmission directivity. The plurality of antenna elements transmit the generated wireless signals. The reception power measurement unit measures the reception power in a period that is set so that a signal does not reach the particular second wireless station, and detect the presence or absence of interference.

A wireless communication network may include a plurality of mobile nodes each including at least one wireless transceiver, a directional antenna and an omni-directional antenna connected to the at least one wireless transceiver, and a controller for controlling the at least one wireless transceiver. The controller may also be for controlling the at least one wireless transceiver, establishing an omni-directional communication link with another mobile node, and determining a link quality value for the omni-directional communication link. The controller may also establish a directional communication link with the other mobile node if the link quality value for the omni-directional communication link is greater than a quality threshold.

A method is disclosed that is performed in an apparatus having a receiver including a number of modules. The method includes receiving information in a reception frequency band. Responsive to a notification from a transmitter of a transmission in a predetermined transmission frequency band, at least one countermeasure is performed by at least one of modules. The at least one countermeasure is predetermined to reduce an effect of interference caused by transmission on reception of the information in the reception frequency band. Exemplary countermeasures include freezing an automatic gain control loop, freezing a synchronization loop, discarding channel estimation data, and blanking received information. Certain criteria, such as transmission power and transmission mode may also be used to determine whether and how many countermeasures are to be used. Additionally, handover is improved by waiting until transmission is complete to determine receiver signal strength of signals from potential transmitters for handover.

The invention discloses a method and a system for notifying layer mapping information under a multi-user multiple input multiple output (MU-MIMO) mode. The method comprises that: a transmitting party allocates orthogonal DMRS for a group of receiving parties which are paired to perform MU-MIMO transmission under an MU-MIMO transmission mode, wherein the port number of the used DMRS on resources which are allocated to the group of receiving parties is the sum of layers respectively used by each receiving party; or, the transmitting party shares the DMRS for the group of receiving parties which are paired to perform MU-MIMO transmission, and determines the port number of the DMRS according to the layer number of the receiving party with the most using layers; and for each receiving party in the group of receiving parties, the transmitting party notifies the mapping mode information from the code word stream to the layer of the receiving party to the receiving party. The method and the system for notifying layer mapping information under the MU-MIMO mode can solve the problem of data solution mapping problem because of UE does not know the presence of pilot frequency of other layers, and improve the user data detection performance.

The present invention is directed to an improved meter that utilizes a method of reducing the effects of interfering compounds in the measurement of analytes and more particularly to a method of reducing the effects of interfering compounds in a system wherein the test strip utilizes two or more working electrodes. In one embodiment of the present invention, a meter is described which applies a first potential to a first working electrode and a second potential, having the same polarity but a greater magnitude than the first potential, is applied to a second working electrode. The meter then measures the generated current and utilizes a predetermined algorithm to correct the measured current to compensate for the presence of interfering compounds in the sample.

The invention provides a refrigeration system with a compressing unit, and a method of controlling a refrigeration system. To facilitate a better control, the capacity of the compressing unit is controlled based on a predicted future cooling demand rather than an actually determined cooling demand. The invention further provides a system wherein a cost value for changing the cooling capacity of the system is taken into consideration.

The RF communications system of the present invention wirelessly communicates data without encountering undue interference problems with other devices and complies with rules governing unlicensed, spectrum-sharing devices. In an example embodiment, a transmitter device includes a digital subsystem powered by a power supply that processes data from another device and a radio frequency (RF) sub-system that transmits the processed data using a frequency hopping scheme. The RF sub-system includes a microprocessor arrangement that ON-OFF keys a voltage controlled oscillator (VCO) and provides a frequency-hopping scheme. The VCO is coupled to a signal frequency spreading arrangement that spreads the signal to a predetermined transmission bandwidth, wherein the frequency spreading occurs during an ON state of the ON-OFF keying and the transmission bandwidth exceeds a reception bandwidth at which the signal will be decoded.

A method and system are presented for providing satellite communications coverage for a geographical area involving operating a plurality of gateways including a first gateway and a second gateway, wherein the first gateway is configured to utilize at least one first spot beam associated with at least one first coverage area within the geographic area to provide relayed satellite communications to a plurality of first subscriber terminals located in the at least one first coverage area, wherein the second gateway is configured to utilize at least one second spot beam associated with at least one second coverage area within the geographic area to provide relayed satellite communications to a plurality of second subscriber terminals located in the at least one second coverage area, and upon a failure condition associated with the at least one first spot beam, expanding the at least one second coverage area to include a portion of the at least one first coverage area, to provide relayed satellite communications to at least some of the first subscriber terminals without utilizing the at least one first spot beam.

An arrangement and method in a communication system such as an Orthogonal Frequency Division Multiplexing (OFDM) radio receiver for reducing the impact of interference from an intermittent interfering signal transmitted by an interfering system which may be co-located with the OFDM system or may be remotely located. Each OFDM symbol in a received OFDM signal includes a guard interval (GI), a middle portion, and a last portion identical to the GI. The arrangement determines which portion of each OFDM symbol is contemporaneous with the interfering signal and time-shifts a fast Fourier transform (FFT) window in the OFDM receiver to minimize or eliminate FFT processing of samples of the OFDM symbol that are contemporaneous with the interfering signal, thereby minimizing the impact of the interfering signal.

A cable detection apparatus is disclosed having a filter, the filter transmitting components of a signal detected substantially at certain harmonics of a first frequency. The filter may also attenuate the signal at certain even harmonics thereof. A method of detecting and / or locating cables in the same manner is also disclosed.

Information is transmitted over selected, Orthogonal Frequency Division Multiplexed (OFDM) sub-channels to avoid frequencies with unacceptable congestion, noise or interference levels. Using frequency hopping, selected non-contiguous OFDM sub-channels used for transmission may vary with time. Once a group of OFDM sub-channels is selected, a power level and modulation technique may also be selected based on channel quality.