A method for controlling an FIR filter includes generating, based on operation information, a first and second control data, generating a second amplitude characteristic, and setting filter coefficients of the FIR filter based on the second amplitude characteristic. The first control data indicates an amount of expansion/compression in a frequency axis direction of a first amplitude characteristic that corresponds to a predetermined transfer function that is expressed as a function of an angular frequency, and the amount of expansion/compression is an integer value or a non-integer value. The second control data indicates an amount of shift in the frequency axis direction of the first amplitude characteristic. The second amplitude characteristic is generated by expanding/compressing the first amplitude characteristic in the frequency axis direction in accordance with the first control data and shifting the first amplitude characteristic in the frequency axis direction in accordance with the second control data.

An active noise reduction device includes: a reference signal input terminal that receives a reference signal from a reference signal source attached to an automobile; a simulated vibration transfer characteristics filter unit that generates a second signal by correcting, using simulated vibration transfer characteristics, a first signal for outputting, from a loudspeaker attached to the automobile, a sound different from a canceling sound, the simulated vibration transfer characteristics simulating vibration transfer characteristics from the loudspeaker to the reference signal source; a first subtracter that outputs a corrected reference signal obtained by subtracting the second signal generated, from the reference signal received by the reference signal input terminal; and an adaptive filter unit that applies an adaptive filter to the corrected reference signal outputted from the first subtracter to generate a canceling signal to be used to output the canceling sound.

A method and an apparatus for signal processing: implementing step-by-step orthogonal decomposition of an original signal to be inputted; on the basis of the number of layers of orthogonal decomposition and the edge high frequency bandwidth of the original signal after orthogonal decomposition, generating a finite-length unit impulse response FIR filter; using the FIR filter to filter the edge high-frequency signal of the original signal; and, after passing the signal obtained after filtering and the low frequency signal obtained at each stage of orthogonal decomposition through an orthogonal filter bank, implementing signal synthesis processing.

Embodiments of the disclosure implement an application of an adaptive filter bank that is used to characterize the heat transfer of a volume in a thermal system, to estimate temperature and power consumption, and to improve performance characteristics in applications including optimal temperature control and diagnostics. In some embodiments, the adaptive filter bank is an iterative solution, comprised of a collection of adaptive filters defined to consume incident signals, produce an aggregate reference signal, estimate an error relative to an observed primary signal, and modify thermal coefficients to converge on a solution. For example, the incident signals are comprised of properties related to active, passive, solar irradiance, and unobserved heat transfer. A reference signal is an estimate of a primary signal, related to the rate of heat transfer or temperature change. Thereupon, the thermal coefficients are modified in an adaptive process to include gradient descent, which minimizes estimation error.

Methods, systems, and devices for wireless communications are described that provide a repeater for beamforming a received signal at a millimeter wave (mmW) radio frequency via one or more scan angles or beamforming directions and then retransmitting and beamforming the signal at the mmW radio frequency. Repeaters may include analog and digital components for downconverting on the received signal to reduce a frequency of the signal from the mmW frequency to an intermediate frequency (IF) or baseband frequency, and then filtering the downconverted signal to reduce interference. The filtering may include digital filtering or a combination of analog and digital filtering, in which a set of filter coefficients for the digital filtering is selected based on beamforming parameters used to receive the signal, retransmit the signal, or both. The repeater may then upconvert the filtered signal back to the mmW frequency for the retransmission of the signal.

Methods, systems, and devices for wireless communications are described that provide a repeater for beamforming a received signal at a millimeter wave (mmW) radio frequency via one or more scan angles or beamforming directions and then retransmitting and beamforming the signal at the mmW radio frequency. Repeaters may include analog and digital components for downconverting on the received signal to reduce a frequency of the signal from the mmW frequency to an intermediate frequency (IF) or baseband frequency, and then filtering the downconverted signal to reduce interference. The filtering may include digital filtering or a combination of analog and digital filtering, in which a set of filter coefficients for the digital filtering is selected based on beamforming parameters used to receive the signal, retransmit the signal, or both. The repeater may then upconvert the filtered signal back to the mmW frequency for the retransmission of the signal.

A method for controlling an FIR filter includes generating, based on operation information, a first and second control data, generating a second amplitude characteristic, and setting filter coefficients of the FIR filter based on the second amplitude characteristic. The first control data indicates an amount of expansion/compression in a frequency axis direction of a first amplitude characteristic that corresponds to a predetermined transfer function that is expressed as a function of an angular frequency, and the amount of expansion/compression is an integer value or a non-integer value. The second control data indicates an amount of shift in the frequency axis direction of the first amplitude characteristic. The second amplitude characteristic is generated by expanding/compressing the first amplitude characteristic in the frequency axis direction in accordance with the first control data and shifting the first amplitude characteristic in the frequency axis direction in accordance with the second control data.

A method for controlling an FIR filter includes generating, based on operation information, a first and second control data, generating a second amplitude characteristic, and setting filter coefficients of the FIR filter based on the second amplitude characteristic. The first control data indicates an amount of expansion/compression in a frequency axis direction of a first amplitude characteristic that corresponds to a predetermined transfer function that is expressed as a function of an angular frequency, and the amount of expansion/compression is an integer value or a non-integer value. The second control data indicates an amount of shift in the frequency axis direction of the first amplitude characteristic. The second amplitude characteristic is generated by expanding/compressing the first amplitude characteristic in the frequency axis direction in accordance with the first control data and shifting the first amplitude characteristic in the frequency axis direction in accordance with the second control data.

A radio frequency (RF) unit and a method for RF isolation. The RF unit includes first and second RF couplers, an RF filter, and an RF canceler connected in parallel with the RF filter. The first RF coupler is configured to receive an input signal. The RF filter is configured to receive a first portion of the input signal from the first RF coupler and attenuate frequencies outside of a passband of the RF filter from the first portion of the input signal. The RF canceler is configured to receive a second portion of the input signal from the first RF coupler and generate a cancellation signal from the second portion of the input signal based on a target frequency band of the RF canceler. The second RF coupler is configured to combine the cancellation signal with an output of the RF filter to generate an output signal.

An equalizer can connect with N receiving antennas that receive single carrier transmission signals transmitted from M transmitting antenna(s) in the same frequency band at the same time, and receives as input L signals sampled in a sampling period T from each of the N receiving antennas, the equalizer comprising, a first selection part that selects K signal(s) from the L signals for each of the N receiving antennas as signals to be multiplied by a first tap coefficient(s), and a second selection part selects L-K signal(s) to be multiplied by a second tap coefficient(s), from the L signals obtained by multiplying signals in the same sampling period for each of the N receiving antennas by the tap coefficient(s) and performing addition thereof.