1214 results about "Wideband signal" patented technology

A waveform adaptive transmitter that conditions and / or modulates the phase, frequency, bandwidth, amplitude and / or attenuation of ultra-wideband (UWB) pulses. The transmitter confines or band-limits UWB signals within spectral limits for use in communication, positioning, and / or radar applications. One embodiment comprises a low-level UWB source (e.g., an impulse generator or time-gated oscillator (fixed or voltage-controlled)), a waveform adapter (e.g., digital or analog filter, pulse shaper, and / or voltage variable attenuator), a power amplifier, and an antenna to radiate a band-limited and / or modulated UWB or wideband signals. In a special case where the oscillator has zero frequency and outputs a DC bias, a low-level impulse generator impulse-excites a bandpass filter to produce an UWB signal having an adjustable center frequency and desired bandwidth based on a characteristic of the filter. In another embodiment, a low-level impulse signal is approximated by a time-gated continuous-wave oscillator to produce an extremely wide bandwidth pulse with deterministic center frequency and bandwidth characteristics. The UWB signal may be modulated to carry multi-megabit per second digital data, or may be used in object detection or for ranging applications. Activation of the power amplifier may be time-gated in cadence with the UWB source thereby to reduce inter-pulse power consumption. The UWB transmitter is capable of extremely high pulse repetition frequencies (PRFs) and data rates in the hundreds of megabits per second or more, frequency agility on a pulse-to-pulse basis allowing frequency hopping if desired, and extensibility from below HF to millimeter wave frequencies.

A system and method are disclosed for extending the bandwidth of a narrowband signal such as a speech signal. The method applies a parametric approach to bandwidth extension but does not require training. The parametric representation relates to a discrete acoustic tube model (DATM). The method comprises computing narrowband linear predictive coefficients (LPCs) from a received narrowband speech signal, computing narrowband partial correlation coefficients (parcors) using recursion, computing Mnb area coefficients from the partial correlation coefficient, and extracting Mwb area coefficients using interpolation. Wideband parcors are computed from the Mwb area coefficients and wideband LPCs are computed from the wideband parcors. The method further comprises synthesizing a wideband signal using the wideband LPCs and a wideband excitation signal, highpass filtering the synthesized wideband signal to produce a highband signal, and combining the highband signal with the original narrowband signal to generate a wideband signal. In a preferred variation of the invention, the Mnb area coefficients are converted to log-area coefficients for the purpose of extracting, through shifted-interpolation, Mwb log-area coefficients. The Mwb log-area coefficients are then converted to Mwb area coefficients before generating the wideband parcors.

A typical data acquisition system takes periodic samples of a signal, image, or other data, often at the so-called Nyquist / Shannon sampling rate of two times the data bandwidth in order to ensure that no information is lost. In applications involving wideband signals, the Nyquist / Shannon sampling rate is very high, even though the signals may have a simple underlying structure. Recent developments in mathematics and signal processing have uncovered a solution to this Nyquist / Shannon sampling rate bottlenck for signals that are sparse or compressible in some representation. We demonstrate and reduce to practice methods to extract information directly from an analog or digital signal based on altering our notion of sampling to replace uniform time samples with more general linear functionals. One embodiment of our invention is a low-rate analog-to-information converter that can replace the high-rate analog-to-digital converter in certain applications involving wideband signals. Another embodiment is an encoding scheme for wideband discrete-time signals that condenses their information content.

A method and apparatus are disclosed for a wireless communication device to simultaneously receive at least two signals. Two receiver portions are provided in the wireless communication device. A first receiver portion is configured to receive a first communication signal. A second receiver portion is configured to receive a second communication signal. The two receiver portions are configured to convert the first and second communication signals to a common frequency band. The common frequency band may be an intermediate frequency band or baseband frequency band. The converted first and second communication signals are combined in the common frequency band using an adder or other signal combiner. The combined signal is processed in a single signal processor. The communication device is able to resolve each of the received signals when the first communication signal is a narrowband signal and the second communication signal is a wideband signal, such as a spread spectrum signal.

An intelligent gain controller operates to control the gain in each one of wideband uplink and downlink signal paths. Weak desired signals, within each wideband signal path, are detected using a narrowband down converter and detector, and these desired signals monitored by the micro controller. Based on the monitored signals, the micro controller operates, under control of suitable software implementing an Adaptive Control Algorithm, to adjust the gain in each of the uplink and downlink paths in order to dynamically optimize performance.

A wideband signal generator according to one embodiment of the invention includes a variable frequency source and a direct digital synthesizer. Local oscillators, signal analyzers, modulators, demodulators, and other equipment including one or more such generators are also disclosed.

A system and method are disclosed for extending the bandwidth of a narrowband signal such as a speech signal. The method applies a parametric approach to bandwidth extension but does not require training. The parametric representation relates to a discrete acoustic tube model (DATM). The method comprises computing narrowband linear predictive coefficients (LPCs) from a received narrowband speech signal, computing narrowband partial correlation coefficients (parcors) using recursion, computing Mnb area coefficients from the partial correlation coefficient, and extracting Mwb area coefficients using interpolation. Wideband parcors are computed from the Mwb area coefficients and wideband LPCs are computed from the wideband parcors. The method further comprises synthesizing a wideband signal using the wideband LPCs and a wideband excitation signal, highpass filtering the synthesized wideband signal to produce a highband signal, and combining the highband signal with the original narrowband signal to generate a wideband signal. In a preferred variation of the invention, the Mnb area coefficients are converted to log-area coefficients for the purpose of extracting, through shifted-interpolation, Mwb log-area coefficients. The Mwb log-area coefficients are then converted to Mwb area coefficients before generating the wideband parcors.

Occurrence of interference is detected using sampled amplitude data obtained by oversampling a beat signal. It is detected by comparing the absolute value (|VD|) of variation in the sampled data with a threshold value (TH). When interference occurs, a wideband signal is superposed on the beat signal, and this disturbs the signal waveform of the beat signal to drastically varies its amplitude. Therefore, occurrence of interference can be detected without fail regardless of the scheme on which a radar as the source of an interference wave is based and even when the amplitude of the interference wave is low. In addition, when low-frequency noise is superposed on the beat signal, erroneous detection of occurrence of interference can be prevented.

There is disclosed an encoding device capable of improving similarity between the high frequency band spectrum of the original signal and a new spectrum to be generated while realizing a low bit rate when encoding a wide-band signal spectrum. The encoding device has sub-band amplitude calculation units (122, 128) for calculating the amplitude of the respective sub-bands for the high frequency band spectrum obtained from the wide-band signal. A search unit (124) and a gain codebook (125) select some sub-bands from a plurality of sub-bands and only the gain of the selected sub-bands is subjected to encoding. An interpolation unit (126) expresses the gain of the sub-band not selected, by mutually interpolating the selected gains.

Various apparatuses and methods are described to reduce interference in signals subject to intermodulation products and high power narrow band interfering signals on lower power wideband signals. Apparatuses and methods described herein also provide the capability for supporting multi-standards, multi-modes and multi-bands in wireless and wired applications with a single receiver or a receiver with minor variations. The receiver described herein samples the entire band in which there can be signals of interest or signals that can generate interference. All of these signals are sampled in one bit stream and the bit stream is processed to isolate signals of interest and interfering signals. The isolated interfering signals are then cancelled out of the signals of interest.

We introduce a new Periodic micro coaxial transmission line (PMTL) that is capable of sustaining a TEM propagation mode up to THz band. The PMTL can be manufactured using the current photolithographic processes. This transmission line can be embedded in microscopic layers that allow many new applications. We use the PMTL to develop a wideband highly scalable connector that is then used in a Probe that can be used for connecting to microscopic scale Integrated Circuits with picoseconds High Speed Digital and near THz Analogue performance in various stages of development from R&D to production testing. These probes, in one embodiment, provide a thin pen-like vertical probe tip that matches the die pad pattern precisely that can be as agile as a high speed plotter pen, connecting on the fly to any die pattern on a wafer. This approach allows the most valuable part of the test, namely the wafer to remain stationary and safe, and the least costly part of the test, namely the probe to take most of the wear and tear. We further use the embedded PMTL to develop a modular, scaleable and fully automated Universal Test Fixture for testing chips in various stages of development mainly for digital IC chips that can be utilized in production lines with pick and place of chips on tape to test every chip before insertion into circuits. One embodiment includes a low profile wideband Signal Launcher and an alligator type RF Clip that can be used at the edge of PCB's directly for validation broads. The Signal Launcher is used to develop a new versatile Flush Top Test Fixtures for individual device testing in various stages of development from die, to packaged, to Module, to Circuit Boards. The PMTL can also provide Confined Field Interconnects (CFI) between various elements on semiconductor wafers to reduce parasitic and radiation losses and practically eliminating cross talk, thus, increasing the speed of digital IC's. The PMTL is also used to develop a Universal Test Socket, and a Hand Probe with performance up to 220 GHz.

Systems, methods and apparatus for automatic signal detection with temporal feature extraction in an RF environment are disclosed. An apparatus learns the RF environment in a predetermined period based on statistical learning techniques, thereby creating learning data. A knowledge map is formed based on the learning data. The apparatus automatically extracts temporal features of the RF environment from the knowledge map. A real-time spectral sweep is scrubbed against the knowledge map. The apparatus is operable to detect a signal in the RF environment, which has a low power level or is a narrowband signal buried in a wideband signal, and which cannot be identified otherwise.

A system, computer-readable medium and generated signal are disclosed for extending the bandwidth of a first signal (i.e., a narrowband signal) such as a speech signal. The system produces a second signal from a first signal by computing first area coefficients from a first signal, generating second area coefficients from the first area coefficients and generating a second signal using the second area coefficients. The first signal may be a narrowband signal and second signal may be a wideband signal. The first area coefficients may be narrowband coefficients and the second area coefficients may be wideband area coefficients.

The gain smoothing method and device modify the amplitude of an innovative codevector in relation to background noise present in a previously sampled wideband signal. The gain smoothing device comprises a gain smoothing calculator for calculating a smoothing gain in response to a factor representative of voicing in the sampled wideband signal, a factor representative of the stability of a set of linear prediction filter coefficients, and an innovative codebook gain. The gain smoothing device also comprises an amplifier for amplifying the innovative codevector with the smoothing gain to thereby produce a gain-smoothed innovative codevector. The function of the gain-smoothing device improves the perceived synthesized signal when background noise is present in the sampled wideband signal.

A method and system of reconstructing data signals from one of incomplete measurements comprising a receiver for receiving data signals, an ADC system operatively connected to the receiver that digitizes the received data signal at a slower rate than the Nyquist rate to obtain sparse measurements; first and second dictionaries comprising a plurality of time shifted responses recovered from the data signal; the first dictionary comprising time shifted versions of the previously observed data signals which are sampled at or above the Nyquist minimum sample rate; the second dictionary comprising time shifted versions are sampled below the Nyquist minimum, and at least one processor for reconstruction of the waveform signals by transforming the sub-Nyquist digitized output using the first and second dictionaries to produce the data signal.

The present invention provides an adaptive, intelligent transform based Analog to Information Converter (AIC) for wideband signals by directly converting an analog signal to information (e.g., features, decisions). This direct conversion is achieved by (i) capturing most of the information of a wideband signal via hardware / software implemented mathematical transformations, (ii) effectively removing unwanted signals such as jammer and interfere from the input signal, and (iii) using novel algorithms for highly accurate decision making and feature extraction (e.g., high probability of detection with low probability of false alarm). The jump in the improvement over today's state-of-the-art is in terms of effective and optimum signal information extraction at high-speed.

A communication system is provided which allows video and audio / video transmissions over unloaded, twisted pairs of telephone wires. The system provides for automatic compensation of attenuation of a broadband video signal by measuring the attenuation of the low frequency components of the signal to determine the length of the unloaded, twisted pair through which the signal has been transmitted. This calculation is performed by comparing the attunated signal with the known signal level of transmission. Based upon the calculated length, the signal is amplified nonlinearly, since a greater loss occurs in the high frequency portions of a broadband signal than in the low frequency portions in transmission over twisted pairs of telephone wires. The signal is thereupon reconstructed. Also, the system allows transmission of a broadband frequency spectrum much wider than has heretofore been obtained. A broadband signal of at least 10.7 MHz can be transmitted over the system. The system also provides for left and right audio inputs and outputs, as well as auxiliary inputs and outputs. The transmission system can be utilized so that persons with a video camera and a personal computer can communicate with each other, transmitting full-motion, color video over unloaded, twisted pairs of telephone wires.

The invention provides audio bandwidth expansion coding and decoding devices which can reconstruct a high frequency signal by using the lower code rate so as to improve the quality of the output audio signal. The audio bandwidth expansion coding device comprises a frequency division module, a core coder module, a linear prediction analysis module, a spectrum envelope quantization module, a high and low frequency correlation computation module and a gain computation module; and the audio bandwidth expansion decoding device comprises a core decoder module, a high-frequency spectrum envelope reconstruction module, a high-frequency residual error reconstruction module, a high-frequency gain adjustment module, a high-frequency signal synthesis module and a wideband signal reconstruction module.

The present invention relates to an ultra wideband internal antenna, which is provided in a mobile communication terminal to cut off frequencies in a certain frequency band while processing ultra wideband signals. The ultra wideband internal antenna includes a first radiation part, a second radiation part, a feeding part and a ground part. The first radiation part is made of a metal plate on a top surface of a dielectric substrate and is provided with at least one cut part, formed by cutting out a lower corner portion thereof, and an internal slot. The second radiation part is formed in the slot of the first radiation part while being connected to the first radiation part, the second radiation part being conductive. In this case, the first and second radiation parts form an ultra wide band due to electromagnetic coupling therebetween using individual currents flowing into the first and second radiation parts.

An integrated swept wavelength tunable optical source uses a narrowband filtered broadband signal with an optical amplifier and self-tracking filter. This source comprises a micro optical bench, a source for generating broadband light, a tunable Fabry Perot filter, installed on the bench, for spectrally filtering the broadband light from the broadband source to generate a narrowband tunable signal, an amplifier, installed on the bench, for amplifying the tunable signal. The self-tracking arrangement is used where a single tunable filter both generates the narrowband signal and spectrally filters the amplified signal. In some examples, two-stage amplification is provided. The use of a single bench implementation yields a low cost high performance system. For example, polarization control between components is no longer necessary.

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 system and a method for medium wide band communications using impulse radio techniques. The method of transmitting medium wide band signals includes the steps of producing a sinusoidal signal and a train of preferably Gaussian shaped pulses. The method also includes the steps of multiplying the sinusoidal signal by the train of pulses to produce a train of sinusoidal bursts, and transmitting the train of sinusoidal bursts. The center frequency of the transmitted signal consisting of the train of sinusoidal bursts can be controlled by selecting an appropriate frequency of the sinusoidal signal. The bandwidth of the transmitted signal can be controlled by selecting an appropriate width of the pulses in the train of pulses. Information and / or coding modulation can be accomplished by adjusting the time position and / or phase of the sinusoidal bursts.

A frequency agile cable modem termination system which is configured to receive cable TV or other broadband signals on a frequency allocated basis. Cable TV headend may receive cable TV modem or other signals via optical / electrical converters and other links, and route those signals through a frequency multiplexer to divide individual feeds into separated frequency slots. The cable modem termination system may then have receivers tuned to individual slots allocated to data feeds, such as Internet, video, telephony or other sources, and route those sources over the Internet. Upon a failure condition within any given receiver or other component, a backup cable modem termination system, connected to the same common bus as the main or active system, may be rapidly activated by having backup receivers contained in that unit tuned to appropriate frequencies to pick up the signals within the corresponding band. Reliability and robustness is increased, and cabling requirements are decreased.