Trans-filter/Detectors are extremely sensitive circuits that recover exponentially modulated signals buried in noise. They can be used wherever Matched Filter/Coherent Detectors are used and operate at negative input signal-to-noise ratios to recover RADAR, SONAR, communications, or data signals, as well as reduce phase noise of precision oscillators. Input signal and noise is split into two paths where complementary derivatives are extracted. Outputs of the two paths are equal in amplitude and 180 degrees relative to each other at the band center frequency. The outputs are summed, causing stationary in-band noise to be reduced by cancellation while exponentially modulated signals are undiminished. Trans-filters are Linear Time Invariant circuits, have no noise x noise threshold and can be cascaded, increasing output signal-to-noise ratio prior to detection. Trans-filters are most sensitive to all types of digital modulation, producing easily detected polarized pulses synchronous with data transitions. Trans-filters do not require coherent conversion oscillators and complex synchronizing circuits.

Trans-filter/Detectors are extremely sensitive circuits that recover exponentially modulated signals buried in noise. They can be used wherever Matched Filter/Coherent Detectors are used and operate at negative input signal-to-noise ratios to recover RADAR, SONAR, communications, or data signals, as well as reduce phase noise of precision oscillators. Input signal and noise is split into two paths where complementary derivatives are extracted. Outputs of the two paths are equal in amplitude and 180 degrees relative to each other at the band center frequency. The outputs are summed, causing stationary in-band noise to be reduced by cancellation while exponentially modulated signals are undiminished. Trans-filters are Linear Time Invariant circuits, have no noise x noise threshold and can be cascaded, increasing output signal-to-noise ratio prior to detection. Trans-filters are most sensitive to all types of digital modulation, producing easily detected polarized pulses synchronous with data transitions. Trans-filters do not require coherent conversion oscillators and complex synchronizing circuits.

An oversampling channelizer for processing overlapping data that includes a data storage unit, coupled to a data line that receives data values. The data storage unit includes a plurality of lanes, wherein each of the plurality of lanes includes dedicated memory locations and wires that store and transmit data values for a data vector of a data frame, and that store and transmit additional data values for a subsequent data vector of a subsequent data frame that includes a plurality of the data values from the data vector in the data frame. The oversampling channelizer includes a coefficient storage unit that stores a plurality of coefficient vectors for a plurality of coefficient frames. The oversampling channelizer includes a computation unit that computes a dot product of the data values for the data vectors of the data frame with coefficient values for coefficient vectors of a coefficient frame selected by a coefficient storage unit.

A filterbank, suitable for modifying audio signals with dynamic gains in each band, is constructed so that the perceived latency is small, while a larger group delay is applied at low frequencies to enable higher frequency resolution in the lower frequency bands. The higher group delay at low frequencies is achieved by inserting an all-pass filter into the reconstructed filter response.

This application relates to a signal filtering device. The device includes a memory and a processor. The processor may generate one or more matrices based on a size of a digital filter bank that generates an output signal by dividing an input signal into a plurality of channels and store in the memory each of the generated one or more matrices to which a plurality of digital filter bank coefficients or a plurality of input signals are assigned. The processor may also partially calculate the stored plurality of digital filter bank coefficients and the plurality of signals based on a number of at least some of the plurality of channels, and calculate the calculated digital filter bank coefficients and signals. The processor may further perform a discrete Fourier transform (DFT) on the calculated signal and compensate for a phase of the discrete Fourier transformed signal according to a preset reference.

A subchannel detection system for a wireless communication device is disclosed. The system includes an input interface arranged to receive digital data over a predetermined baseband having a plurality of subchannels a plurality of frequency translators arranged to shift the spectrum of the digital data within a subchannel to the center of the baseband, a plurality of low-pass filters arranged to filter frequencies in the middle of the baseband within a subchannel bandwidth, a plurality of correlators arranged to receive a filtered digital signal and correlate the received signal to a subchannel size, and a processing module arranged to receive data from the plurality of correlators and detect one or more active subchannels. The plurality of frequency translators shift the spectrum of all subchannels in the digital data to the center of the baseband; the shifted spectra are filtered by the plurality of low-pass filters and correlated to individual subchannels.

Methods and systems for finite impulse response filter under a constrained sampling rate. A method for constrained sampling rate filtering includes segmenting an input signal with a first rate into a defined number of streams, wherein the defined number of streams sets an effective sample rate of each stream to at least less than a second rate and the second rate is less than the first rate, determining filter coefficients for a finite impulse response filter, grouping the filter coefficients into subsets of filter coefficients to match the defined number of streams, applying in parallel, for each of the defined number of streams, a subset of filter coefficients to a corresponding stream, and combining at least some outputs from the defined number of streams conditionally based on the second rate.

A subchannel detection system for a wireless communication device is disclosed. The system includes an input interface arranged to receive digital data over a predetermined baseband having a plurality of subchannels a plurality of frequency translators arranged to shift the spectrum of the digital data within a subchannel to the center of the baseband, a plurality of low-pass filters arranged to filter frequencies in the middle of the baseband within a subchannel bandwidth, a plurality of correlators arranged to receive a filtered digital signal and correlate the received signal to a subchannel size, and a processing module arranged to receive data from the plurality of correlators and detect one or more active subchannels. The plurality of frequency translators shift the spectrum of all subchannels in the digital data to the center of the baseband; the shifted spectra are filtered by the plurality of low-pass filters and correlated to individual subchannels.

This application relates to a signal filtering device. The device includes a memory and a processor. The processor may generate one or more matrices based on a size of a digital filter bank that generates an output signal by dividing an input signal into a plurality of channels and store in the memory each of the generated one or more matrices to which a plurality of digital filter bank coefficients or a plurality of input signals are assigned. The processor may also partially calculate the stored plurality of digital filter bank coefficients and the plurality of signals based on a number of at least some of the plurality of channels, and calculate the calculated digital filter bank coefficients and signals. The processor may further perform a discrete Fourier transform (DFT) on the calculated signal and compensate for a phase of the discrete Fourier transformed signal according to a preset reference.

Trans-filter/Detectors are extremely sensitive circuits that recover exponentially modulated signals buried in noise. They can be used wherever Matched Filter/Coherent Detectors are used and operate at negative input signal-to-noise ratios to recover RADAR, SONAR, communications, or data signals, as well as reduce phase noise of precision oscillators. Input signal and noise is split into two paths where complementary derivatives are extracted. Outputs of the two paths are equal in amplitude and 180 degrees relative to each other at the band center frequency. The outputs are summed, causing stationary in-band noise to be reduced by cancellation while exponentially modulated signals are undiminished. Trans-filters are Linear Time Invariant circuits, have no noise×noise threshold and can be cascaded, increasing output signal-to-noise ratio prior to detection. Trans-filters are most sensitive to all types of digital modulation, producing easily detected polarized pulses synchronous with data transitions. Trans-filters do not require coherent conversion oscillators and complex synchronizing circuits.