784 results about "Narrow bandwidth" patented technology

Organic vertical-cavity surface-emitting lasers ("OVCSELs"), in which a thin layer of organic material is disposed between highly reflective mirrors to thereby form a vertical cavity within a stacked arrangement. The lasers of the present invention each comprise a first mirror layer; a layer of active organic material over the first mirror layer; and a second mirror layer over the layer of first active organic material. The active organic material lases when pumped to thereby produce laser light. The present invention provides for optical semiconductor lasers with desired properties such as narrow bandwidth emission, the minimal use of active organic materials, and the facilitation of wavelength tuning and electrical pumping.

A circular-polarization dipole helical antenna is used for electronic device and satellite terminal and includes a base, and an antenna conductor arranged on surface of the base. The antenna conductor includes a plurality of metal conductors with high Q value and anti-oxidation property and continuously and helically coated on surface of the base. The base is made of low loss and high dielectric constant material. An unbalance-to-balance circuit module connects two signal-feeding ends to the base with phase difference of 180 degree. The problems of narrow bandwidth, low efficiency, complicated structure and precise manufacture can be solved.

Systems and/or methods for supporting communications at a reduced bandwidth with a full bandwidth network such as a long-term evolution (LTE) network may be disclosed. For example, inband assignments such as downlink assignments and/or uplink grants may be provided and/or received and transmissions may be monitored and/or decoded based on the inband assignment. Additionally, information (e.g. a definition or configuration) associated with an ePDCCH may be provided and/or received and ePDCCH resources may be monitored and/or decoded based on such information. An indication for support of a reduced bandwidth by the full bandwidth network may also be provided and/or received and control channels in the reduced or narrow bandwidth may be monitored and/or decoded based on the indication. A PRACH preamble and/or a multi-type sub frame definition may also be provided and/or used for support of such a reduced bandwidth.

A first irradiation portion that radiates white light onto a subject, a second irradiation portion that radiates narrow bandwidth light having a narrower wavelength bandwidth than the white light, and an observation window used to observe the subject are respectively disposed on a leading end surface of an endoscope insertion portion. Each of the first and second irradiation portions includes a pair of irradiation windows for emitting light therefrom. A straight line passing through a center point of the observation window and bisecting the leading end surface is defined as a boundary line. The pair of irradiation windows of the first irradiation portion are disposed on both sides of the boundary line. The pair of irradiation windows of the second irradiation portion are disposed on the both sides of the boundary line. Spectra of lights radiated from the irradiation windows of the second irradiation portion can be changed individually.

The device and method of the invention receives a digital speech signal, which is processed by an Acoustic Processor to produce a Mel-Cepstrum Vector and Pitch. This is recalibrated and encoded. The encoded signal is transmitted over a narrow-band Channel, then decoded, split and recalibrated. From the split signals, one signal feeds a Statistical Processor which produces Recognized Text. Another signal feeds a Regenerator, which produces Regenerated Speech. The device and method according to the invention achieve simultaneously very perceptive Automatic Speech Recognition and high quality VoCoding, using Speech communicated or stored via a Channel with narrow-bandwidth; very perceptive Automatic Speech Recognition on a Client & Server system without a need to store or to communicate wide-bandwidth Speech signals; very perceptive Automatic Speech Recognition with Deferred Review and Editing without storage of wide-bandwidth Speech signals; better feedback in a system for Automatic Speech Recognition particularly for Deferred Automatic Speech Recognition; and good usability for unified Automatic Speech Recognition and VoCoding.

A wireless communication device is implemented to include a communication interface and a processor. The processor is configured to process communications associated with the other wireless communication devices within the wireless communication system to determine one or more traffic characteristics of those communications as well as one or more class characteristics of the other wireless communication devices. The processor is configured to classify the communications into one or more access categories based on the one or more traffic characteristics and is configured to classify the other devices into one or more device class categories based on the one or more class characteristics. The processor is then configured to generate one or more channel access control signals based on these classifications. The communication interface of the device is configured to transmit the one or more channel access control signals to one or more of the other devices.

A method and system for a Radio Frequency (RF)-based identification, tracking and locating of objects. The method and system use a narrow bandwidth signal in VHF of lower frequency range, which minimizes propagation loss and loss of accuracy of the RF locating signals. The signal is sent from a Master Unit(s) to a Tag. The signal traveling time is recorded and the distance between the Master(s) and the Tag is calculated. The method and system allow achieving a longer distance of the RF signal penetration and an increased accuracy by using VHF bands. The techniques of Digital Signal Processing and Software-Defined Radio are used. The actual waveforms transmitted and received by the radios are defined by the software. The roles of the Master Unit(s) and the Tag can be reversed.

A method and system for a long range Radio Frequency (RF)-based identification, tracking and locating of objects. The method and system use a narrow bandwidth ranging signal(s), including VHF of lower frequency bands, which minimizes propagation loss and loss of accuracy of the RF locating signals. The method and system includes narrow bandwidth ranging signal multi-path mitigations processor, which further improves the track-locate accuracy. The signal is sent from a Master Unit(s) to a Tag. The signal traveling time is recorded and the distance between the Master(s) and the Tag is calculated. The method and system allow achieving a longer distance of the RF narrow bandwidth ranging signal penetration and an increased accuracy by using VHF bands in conjunction with the narrow bandwidth ranging signal multi-path mitigations processor. The techniques of Digital Signal Processing and Software-Defined Radio are used. The actual waveforms transmitted and received by the radios are defined by the software. The roles of the Master Unit(s) and the Tag can be reversed.

A novel apparatus and method of reduced power consumption for battery backup operation of a communication device such as a cable modem. When the cable modem senses a failure of the external power source it requests from the cable head-end to switch from multi-channel DOCSIS 3.0 operation to single-channel DOCSIS 2.0 operation. In response to approval by the cable head-end, the cable modem shuts down multi-channel circuits in the PHY such as the wideband analog to digital converter (ADC) which is normally used during multi-channel operation. In its place, it activates narrowband circuitry such as a narrowband ADC which consumes far less power. Tuner filter circuits are also swapped to match the reduced bandwidth requirements of battery backup operation. To further reduce power, the narrower bandwidth requirements during battery backup operation permit the linearity of a programmable gain amplifier (PGA) in the upstream path to be reduced.

Wideband signal generation systems and methods are provided which employ frequency interleaving for generating wideband signals. A general method increases a digitally synthesized signal's bandwidth by frequency interleaving multiple digitally synthesized signal sources of narrower bandwidth. Frequency interleaving creates a continuous wideband signal by summing multiple narrower band signals that overlap in frequency. According to certain embodiments, digital signal processing (DSP) and analog mixing are used to create the multiple narrower band signals such that a high fidelity, continuous wideband signal is produced when the multiple narrower band signals are summed.

A lidar system capable of remotely identifying calibrated absolute aerosol backscatter coefficients of atmospheric aerosol particles by transmitting a beam of light and spectrally separating the intensity of Rayleigh and Mie backscattering is disclosed. The transmitter features high pulse energy to generate sufficient Rayleigh backscattering, enabling atmospheric scanning in a timely manner. The transmitter employs a seeded Nd:YAG laser and a seeded stimulated Raman scattering wavelength shifter to achieve narrow bandwidth, eye-safe laser pulses. The receiver employs a telescope, collimating lens, beam splitter, molecular absorption filter, focusing lenses, and avalanche photodiodes. Mie backscattering is blocked by the molecular absorption filter to provide a Rayleigh signal, which is used with knowledge of atmospheric density to calibrate the Mie signal. The system is intended for atmospheric research and aerosol monitoring applications where calibrated Mie scattering intensity is necessary to measure the optical depths of aerosol structures such as plumes, clouds, and layers.

The present patent application comprises a transmitting method and apparatus 240. A signal source 241 provides an input signal to a low-pass filter 242 which filters the input signal to produce a filtered signal. The filter 242 is selectively operable in a first mode in which the input signal is filtered within a narrower bandwidth; and in a second mode in which the input signal is filtered within a broader bandwidth. The filtered signal is output to a modulator 243 which modulates the filtered signal to produce a modulated signal. The modulated signal is output to a transmitter 244 which transmits the modulated signal.

A technique for noise reduction in a wireless communication system uses controllable bandwidth filters (120) to filter a received signal. In a typical implementation, the filters (120) are used at baseband frequencies. A measurement (RSSI) is indicative of the strength of the received signal. A control circuit (144) generates a control signal (146) to control the bandwidth of the filters (120). If the received signal strength is above a first threshold, a wider bandwidth may be used for the filters (120). If the received signal is below a second threshold, the control circuit (144) generates the control signal (146) to set the filters (120) to a more narrow bandwidth. The system (100) may also be used with digital filters (150, 152) following digitization by analog to digital converters (ADCs) (130, 132). The system (100) is particularly well-suited for operation with noise-shaped ADCs (130, 132), such as Delta-Sigma converters.

A high frequency signal receiver comprising a variable gain amplifier, a first filter for restricting a bandwidth of an analog baseband signal, an AD converter connected to the first filter, a second filter for restricting the bandwidth of an output of the AD converter, an interference wave detection circuit for detecting the level of an interference wave in the received signal, and a controller for controlling the first filter to have a wide bandwidth when the level of the interference wave is lower than a threshold level, and switching the first filter to have a narrow bandwidth while changing the characteristics of the second filter so as to compensate deterioration of the pass-band of the first filter when the level of the interference wave is equal to or greater than the threshold level.

An encoder comprising an input for inputting frames of an audio signal in a frequency band, at least a first excitation block for performing a first excitation for a speech like audio signal, and a second excitation block for performing a second excitation for a non-speech like audio signal. The encoder further comprises a filter for dividing the frequency band into a plurality of sub bands each having a narrower bandwidth than the frequency band. The encoder also comprises an excitation selection block for selecting one excitation block among the at least first excitation block and the second excitation block for performing the excitation for a frame of the audio signal on the basis of the properties of the audio signal at least at one of the sub bands. The invention also relates to a device, a system, a method and a storage medium for a computer program.

Objects of the present invention are to reduce the number of optical filters, and to improve crosstalk characteristics of periodic optical filters. WDM signals are converted into vestigial-side-band signals collectively using a periodic optical filter. As an example, light signals having odd number wavelengths (wavelengths lambda1, lambda3, lambda5) and light signals having even number wavelengths (wavelengths lambda2, lambda4, lambda6) are wavelength-multiplexed in the first optical wavelength multiplexer, and are then filtered by a periodic narrow band-pass optical filter to convert the light signals into vestigial-side-band (VSB) signals. Then, the vestigial-side-band signals are combined by the second optical wavelength multiplexer. Such an interleave configuration enables suppression of crosstalk caused by adjacent channels.

The invention provides a decoding method of an audio signal. The encoding method includes the following steps: when the audio signal corresponding to the received coding stream switched from the relatively wide bandwidth to the relatively narrow bandwidth, low band signal component of the audio signal is obtained and high band information is extended; the time-varying fade-out treatment is carried out to extended high band information to obtain processed high band information component; the processed high band information component and the low band signal component are combined. By the method provided by the embodiment of the invention, when the audio signal switches from the wide band to narrow band, a series of treatments, such as bandwidth detection, manual band spreading, time-varying fade-out treatment and bandwidth combination are available to realize smoothing switch from a wide band signal to a narrow band signal, thus achieving a more comfortable auditory feeling of human ears.

The present invention discloses a simple, low cost method to fabricate light emitting source using luminescent colloid nanoparticles. It uses monodispersed colloid light emitting nanoparticles of oxides, semiconductors, and polymers to fabricate high quality, narrow bandwidth light emitting source. The colloid particles can be dispersed homogeneously in liquid that can be coated easily on a substrate using a simple coating method such as spray, dip coating or spin coating. There is no restriction on the size or shape of the substrate. Therefore, a low cost, large area, high efficiency and reproducible light emitting source can be made easily.

A method and apparatus is disclosed for measurement and monitoring of in-band optical signal to noise ratio (OSNR). A two channel optical spectrum analyzer (OSA) is advantageously applied in acquiring wavelength division multiplex (WDM) signal data after it has been split according to polarization, then deriving the in-band OSNR from acquired data due to its narrow bandwidth, selective spectral shape, and capability to analyze two components of a polarized signal simultaneously. The in-band OSNR can be measured without interrupting optical transmission traffic in the network.

A grating pulse compressor configuration is introduced for increasing the optical dispersion for a given footprint and to make practical the application for chirped pulse amplification (CPA) to quasi-narrow bandwidth materials, such as Nd:YAG. The grating configurations often use cascaded pairs of gratings to increase angular dispersion an order of magnitude or more. Increased angular dispersion allows for decreased grating separation and a smaller compressor footprint.