74 results about "Spectral mask" patented technology

Controlling margins in a DSL modem pair is based on collected operational data. The operational data is analyzed and at least one of the modems in the modem pair is instructed to use a margin-related parameter value to assist the modem pair in meeting a margin target, such as a margin limit imposed by a DSL standard or the like. A controller, such as a DSM Center, a “smart” modem unit and / or a computer system can collect and analyze the operational data and generate one or more margin-related parameter values. The margin-related parameter value may be a PSD-related value, such as the MAXNOMPSD, MAXNOMATP or PSDMASK parameter used by various ADSL systems, and may be a shaped spectral mask and / or caps or limits on bit loading for use in transmissions between the modems. In some cases, preference bands can be imposed to direct modems to favor and / or avoid certain frequencies in the modem's usable band(s). The operational data may include historical data relating to prior performance of the modem pair and prior margin compliance. A distribution of margins also may be based on operational data and may be estimated as a function of data rate. Using the estimated margin distribution, a distribution of performance parameters also is calculated, including the probabilities of line outages and probabilities of one or more error parameters exceeding minimum levels. Data rates and / or performance-related parameters may be set on the basis of the estimated performance of the system using various margin settings and levels.

Disclosed are: a variety of methods and apparatuses for aggregating a plurality of carriers and using the carrier aggregation in a wireless connection system; and a variety of methods and apparatuses for providing information on the structure of a carrier generated by aggregating a plurality of carriers. A method for transmitting and receiving carrier group information, according to one embodiment of the present invention, includes the steps of: a mobile terminal transmitting a first message containing multi-carrier performance information of the mobile terminal to a base station; and the mobile terminal receiving, from the base station, a second message containing allocation information on the wireless resource allocated on the basis of the multi-carrier information. Here, multi-carrier performance information includes a spectral mask-type parameter for the supportable multi-carrier of the mobile terminal.

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 novel and useful mechanism for reducing the required backoff and the peak to average power ratio (PAPR) needed for an OFDM transmitter whiles still meeting spectral mask and EVM specifications. The mechanism searches, for each packet to be transmitted, for several possible scrambler and encryption sequences that would yield the best spectral mask and EVM with lowest PAPR. The search can be performed using the existing transmitter and receiver PHY circuit chain to modulate and demodulate the candidate hypotheses. Once the scrambler sequence and / or encryption sequence is selected, the packet is transmitted using the selected scrambler and encryption sequences. In addition, the invention exploits the fact that even for very low backoff margins, a reduced number of candidate hypotheses may be tested while still yielding a high probability of meet the spectral mask and EVM specifications.

A transmitting unit (12) clips a communication signal (14) to form a threshold-responsive signal (36, 36′) which includes in-band distortion (40) and out-of-band distortion (38). A portion of the out-of-band distortion (38) is notched within rejection bands (48, 50) adjacent to the communication signal's bandwidth (24). But remaining portions of the out-of-band distortion (38) and portions of the in-band distortion (40) are included with the communication signal (14). The remaining portion of the out-of-band distortion (38) causes the communication signal (14) to be in violation of a spectral mask (30). The mask-violating communication signal 14 with out-of-band distortion (38) and in-band distortion (40) is amplified by an RF power amplifier (22). After amplification, a bandpass filter (92) exhibiting fast rolloff regions (110) attenuates the amplified out-of-band distortion (38) causing compliance with the spectral mask (30).

Methods and systems are provided for timing synchronization for reception of highly-spectrally efficient communications. An example method may include, mapping, in a transmitter, a plurality of transmit bits to a plurality of symbols at a symbol rate that is based on an oscillator signal. The plurality of symbols may be processed via a filter. The processing may result in an inter-symbol correlated (ISC) signal. The oscillator signal may be frequency divided to generate one or more pilot signals having a frequency that is a sub-harmonic of a frequency of the oscillator signal. The pilot signal may be injected into the ISC signal. The injecting may result in an ISC signal with timing carrier. The ISC signal with timing carrier may be transmitted. Gain of the one or more pilot signals may be adjusted based on a spectral mask value associated with the transmitting.

A configurable spectral mask for a channel for use in a wireless communication includes a channel pass region, a floor region, and a transition region. The channel pass region provides a first usable signal bandwidth of a plurality of usable signal bandwidths corresponding to a first channel width of a plurality of channel widths. The floor region provides a first floor attenuation value of a plurality of floor attenuation values corresponding to the first channel width. The transition region providing a first transition attenuation of a plurality of transition attenuations from the channel pass region to the floor region, wherein the first attenuation region corresponds to the first channel width.

A technique of reducing the Peak-to-Average Power Ratio (PAPR) of Multi-Carrier (MC) modulated signals in which peaks in the baseband signal that lie above a threshold amplitude are detected and used to generate a pulse sequence signal which, after shaping, is subtracted from the baseband signal to reduce its PAPR. The method is spectrally efficient, has a low degree of implementation complexity and hence it is also suitable for low-power, portable implementation. Moreover, it is compatible with existing standard-based Orthogonal Frequency Division Multiplex (OFDM) systems. As an example of the performance of the proposed scheme, the amplifier back-off requirement in a Terrestrial Digital Video Broadcast (DVB-T) system can be reduced from 12 to 6 dB, while satisfying the of out-of-band emission specifications imposed by the Federal Communications Commission (FCC) spectral mask.

Method for designing transmission pulses for ultra-wideband communications systems. A preferred embodiment comprises specifying a spectral description for the pulse. After a spectral description is created, then an approximation of the pulse can be created and well known optimization techniques, such as the least squares technique, can be used to minimize the difference between the approximation and the pulse. If the communications system is operating in the presence of interferers, then the spectral mask can be modified to ensure that the approximation carries no signal information in frequencies corresponding to the interferers.

An adaptive echo cancellation system and method employing an algorithm suitable for a digital repeater with sub-band filtering is disclosed. Cross- and auto-correlation measurements used to estimate the residual coupling are computed from normalized cross and power spectrums which avoid the problems associated with narrow bandwidth signal components. The normalized cross- and power spectra are additionally masked in frequency to reduce the influence of interfering spectral components outside of the passband of the sub-band filter. Regularization of the iterative estimation process is applied to maintain stability and compensate for the bandwidth reduction associated with the sub-band filter and the spectral mask.

A DC—DC converter includes a variable frequency oscillator, a control system and a power train. The DC—DC converter is well suited for use in a cell phone. The control system uses the output of the oscillator to control the power train. The oscillator varies its frequency as a function of a pseudo random number generator, thereby reducing electromagnetic interference caused by ripple in the output of the DC—DC converter.

A transmit processor that includes a transmit frequency domain equalizer (TX FEQ) that pre-compensates packets in the frequency domain to flatten transmit filter response to improve spectral mask and reduce PER. The TX FEQ taps may be selected so that the average power at output equals the average power applied to the input. The TX FEQ may be designed to yield 64 QAM packets with no quantization distortion at the input of an Inverse Fast Fourier Transform (IFFT) processor. The 64 QAM constellation map points and TX FEQ gain values are selected to avoid exceeding the bit resolution of the IFFT processor. The tones may be bound together into zones to reduce implementation complexity by reducing the number of TX FEQ taps.

A transmitting unit (12) clips a communication signal (14) to form a threshold-responsive signal (36, 36′) which includes in-band distortion (40) and out-of-band distortion (38). A portion of the out-of-band distortion (38) is notched within rejection bands (48, 50) adjacent to the communication signal's bandwidth (24). But remaining portions of the out-of-band distortion (38) and portions of the in-band distortion (40) are included with the communication signal (14). The remaining portion of the out-of-band distortion (38) causes the communication signal (14) to be in violation of a spectral mask (30). The mask-violating communication signal 14 with out-of-band distortion (38) and in-band distortion (40) is amplified by an RF power amplifier (22). After amplification, a bandpass filter (92) exhibiting fast rolloff regions (110) attenuates the amplified out-of-band distortion (38) causing compliance with the spectral mask (30).

Disclosed is an acoustic communication method that includes filtering an audio signal to attenuate a high frequency section of the audio signal; generating a residual signal which corresponds to a difference between the audio signal and the filtered signal; generating a psychoacoustic mask for the audio signal based on a predetermined psychoacoustic model; generating a psychoacoustic spectrum mask by combining the residual signal with the psychoacoustic mask; generating an acoustic communication signal by modulating digital data according to the acoustic signal spectrum mask; and combining the acoustic communication signal with the filtered signal.

A system and method communicates and generates a Coded Orthogonal Frequency Division Multiplexed (COFDM) communications signal as a plurality of subcarriers. Selected subcarriers are turned ON and OFF while also frequency hopping and spreading the selected ON subcarriers over the frequency domain based on a fixed or variable sample rate to reduce average power for enhanced Low Probability of Interception / Low Probability of Detection (LPI / LPD) and also allow for more transmit power within a spectral mask.

A system and method communicates and generates a Coded Orthogonal Frequency Division Multiplexed (COFDM) communications signal as a plurality of subcarriers. Selected subcarriers are turned ON and OFF while also frequency hopping and spreading the selected ON subcarriers over the frequency domain based on a fixed or variable sample rate to reduce average power for enhanced Low Probability of Interception / Low Probability of Detection (LPI / LPD) and also allow for more transmit power within a spectral mask.

A configurable spectral mask for a channel for use in a wireless communication includes a channel pass region, a floor region, and a transition region. The channel pass region provides a first usable signal bandwidth of a plurality of usable signal bandwidths corresponding to a first channel width of a plurality of channel widths. The floor region provides a first floor attenuation value of a plurality of floor attenuation values corresponding to the first channel width. The transition region providing a first transition attenuation of a plurality of transition attenuations from the channel pass region to the floor region, wherein the first attenuation region corresponds to the first channel width.

Controlling margins in a DSL modem pair is based on collected operational data. The operational data is analyzed and at least one of the modems in the modem pair is instructed to use a margin-related parameter value to assist the modem pair in meeting a margin target, such as a margin limit imposed by a DSL standard or the like. A controller, such as a DSM Center, a 'smart' modem unit and / or a computer system can collect and analyze the operational data and generate one or more margin-related parameter values. The margin-related parameter value may be a PSD-related value, such as the MAXNOMPSD, MAXNOMATP or PSDMASK parameter used by various ADSL systems, and may be a shaped spectral mask and / or caps or limits on bit loading for use in transmissions between the modems. In some cases, preference bands can be imposed to direct modems to favor and / or avoid certain frequencies in the modem's usable band(s). The operational data may include historical data relating to prior performance of the modem pair and prior margin compliance. A distribution of margins also may be based on operational data and may be estimated as a function of data rate. Using the estimated margin distribution, a distribution of performance parameters also is calculated, including the probabilities of line outages and probabilities of one or more error parameters exceeding minimum levels. Data rates and / or performance-related parameters may be set on the basis of the estimated performance of the system using various margin settings and levels.

A low-power digital communications transmitter (20) includes a programmable digital-processing circuit (22), which may be provided by a digital signal processor (DSP), a programmable direct digital synthesizer (DDS), and a constant-envelope, high power amplifier (32). The DDS (24) is programmed to provide pulse-shaping and IF / RF signal modulation functions. The digital-processing circuit (22) produces only one sample per unit interval (134) and is programmed so that the one sample per unit interval (134) is a frequency-profile index symbol (52″) produced from a I,Q baseband symbol (52′). The DDS (24) converts each frequency-profile index symbol (52″) into a frequency profile (130) that controls the frequency of a synthesizer (56) to induce modulation into a periodic output (68) of the synthesizer. Moreover, the frequency profile (130) is configured to confine spectral emissions within a spectral mask (140).

A transmit processor that includes a transmit frequency domain equalizer (TX FEQ) that pre-compensates packets in the frequency domain to flatten transmit filter response to improve the spectral mask and reduce packet error rate (PER). The TX FEQ taps may be selected so that the average power at the output equalize the average power applied to the input. The TX FEQ may be designed to yield 64 QAM packets with no quantization distortion at the input of the an Inverse Fast Fourier Transform (IFFT) processor. The 64 QAM constellation map points and TX FEQ gain values are selected to avoid exceeding the bit resolution of the IFFT processor. The tones may be bound together into zones to reduce implementation complexity by reducing the number of TX FEQ taps.

An adaptive echo cancellation system and method employing an algorithm suitable for a digital repeater with sub-band filtering is disclosed. Cross- and auto-correlation measurements used to estimate the residual coupling are computed from normalized cross and power spectrums which avoid the problems associated with narrow bandwidth signal components. The normalized cross- and power spectra are additionally masked in frequency to reduce the influence of interfering spectral components outside of the passband of the sub-band filter. Regularization of the iterative estimation process is applied to maintain stability and compensate for the bandwidth reduction associated with the sub-band filter and the spectral mask.

The embodiment of the invention discloses an audio noise reduction method and a training method of an audio noise reduction model. According to the scheme, the method comprises the steps: acquiring the audio signal to be denoised, processing the audio signal to be denoised to obtain the spectrum feature, inputting the spectrum feature into the convolutional network model to be processed to obtainthe spectrum convolutional feature, and inputting the spectrum convolutional feature into the cyclic network model to be processed to obtain the target spectrum or the target spectrum mask; processingthe target spectrum to obtain a target audio signal; or processing the audio signal to be denoised by using the target spectrum mask to obtain a target audio signal. According to the embodiment of the invention, the neural network structure is applied to singing noise reduction of karaoke recording, so the original signal structure of the singing can be well maintained while the noisy singing issubjected to effective noise reduction, and the obvious hearing distortion after noise reduction is avoided.

A method and system shapes a spectrum of an impulse radio signal, such as an UWB signal. First, basis pulses at various frequencies and pseudo-random delays are generated. The generated set of basis pulses are then weighted and delayed, and combined linearly to conform the spectrum of the transmitted basis pulses to a spectral mask. The spectral mask can be predetermined, or the conforming can be adaptive. Furthermore, the basis pulses can be frequency-shifted before the combining.

A method of masking a residual echo signal by an echo canceller is provided. The method comprises receiving a far-end signal, adjusting filter coefficients of an adaptive filter in response to the far-end signal, generating an echo model signal based on the far-end signal using the adaptive filter, receiving a near-end signal, subtracting the echo model signal from the near-end signal to generate an output signal, defining a spectral mask based on the near-end signal, wherein the spectral mask is indicative of near-end spectral peaks and near-end spectral valleys, de-emphasizing the output signal in spectral regions of the near-end spectral peaks, and emphasizing the output signal in spectral regions of the near-end spectral valleys, wherein the de-emphasizing occurs during filter coefficients determination for the adaptive filter. A weighted filter may perform the de-emphasizing and the emphasizing operations, where the weighted filter uses medium term spectral characteristics of the near-end signal.

A "Smart DSL System" for addressing the performance objectives of LDSL and examples of smart systems for LDSL are disclosed. In accordance with embodiments of the invention, there is disclosed a method for implementing smart DSL for LDSL systems. Embodiments of the method may comprise presenting a number of spectral masks that are available on the LDSL system, and selecting from the number of spectral masks an upstream mask and a downstream mask wherein the upstream mask and the downstream mask exhibit complimentary features.

The invention relates to a method, and a device for performing said method, for allocating power levels to a transmission in a DSL network, the method comprising the steps of: identifying a first and second geographical region as being associated with a subscriber line in the DSL network; defining a first spectral mask having a first set of power levels over a range of frequencies, wherein the first set of power levels are tailored according to a Radio Frequency, RF, environment of the first geographical region; defining a second spectral mask having a second set of power levels over the range of frequencies, wherein the second set of power levels are tailored according to an RF environment of the second geographical region; and constructing a transmit spectral mask for the subscriber line, the transmit spectral mask based on a combination of the first and second spectral masks, including, for each frequency in the range of frequencies, using the minimum power level for that frequency from the first and second spectral masks.

Embodiments relate to a method, and a device for performing the method, for allocating power levels to a transmission in a DSL network, the method including: identifying a first and second geographical region as being associated with a subscriber line in the DSL network; defining a first spectral mask having a first set of power levels over a range of frequencies, wherein the first set of power levels are tailored according to a Radio Frequency, RF, environment of the first geographical region; defining a second spectral mask having a second set of power levels over the range of frequencies, wherein the second set of power levels are tailored according to an RF environment of the second geographical region; and constructing a transmit spectral mask for the subscriber line, the transmit spectral mask based on a combination of the first and second spectral masks, including, for each frequency in the range of frequencies, using the minimum power level for that frequency from the first and second spectral masks.

Methods, systems, and devices are described for wireless communications. A wireless station includes a transmitter to generate a wideband contiguous waveform in a band. The transmitter transmits the waveform that conforms to spectral masking attributes and spectral flatness attributes. The wireless station, or another device supporting spectrum analysis functions, detects a wideband contiguous waveform and performs spectrum analysis of the waveform. The wireless station includes a resolution bandwidth of 25 KHz and a video bandwidth of 7.5 KHz.

The invention relates to the field of terminal artificial intelligence (AI), in particular, relates to the field of voice recognition, and provides an audio processing method and device, terminal equipment and a computer storage medium, wherein the method comprises the steps: obtaining a to-be-processed face image set and a to-be-denoised audio signal; extracting mouth features of each face imagein the to-be-processed face image set, and extracting frequency spectrum features of the to-be-denoised audio signal; inputting the mouth features of each face image and the frequency spectrum featureof the to-be-denoised audio signal into a preset neural network model to obtain a frequency spectrum mask; and processing the to-be-denoised audio signal by using the spectrum mask to obtain a targetaudio signal. The method can solve the problems that an existing face-based auxiliary noise reduction algorithm has high requirements for the computing power of terminal equipment, is difficult to operate on low-computing-power terminal equipment and is limited in application scene.