A method and apparatus may include receiving a transmission. The method can also include determining a sparsifying dictionary that sparsely approximates a data vector of the transmission. The determining the sparsifying dictionary includes performing a fast Fourier transform and/or an inverse fast Fourier transform. The method also includes configuring a filter based on the determined sparsifying dictionary.

System and method of timing recovery for recovering a clock signal by using adaptive channel response estimation. The channel response estimation in the timing recovery loop is dynamically adapted to the current channel response that varies over time. More particularly, the channel estimation coefficients used in a channel estimator can be adapted based on an error signal representing the difference between a received signal at the timing recovery loop and an estimated signal output from a channel estimator. Further, to prevent undesirable interaction between the channel estimator and the overall timing recovery loop with respect to clock phase recovery, the adaptation of channel estimation can be controlled in terms of speed or time so as to reduce or eliminate the channel estimator's effect on clock phase correction.

Modulated optical signals are received in a coherent optical receiver employing both post digital filter and inter-symbol-interference (ISI) equalizer such as a maximum likelihood sequence estimation (MLSE) or Bahl-Cocke-Jelinek-Raviv (BCJR) algorithms. Some disclosed techniques are directed to adaptively adjusting the impulse response in time domain (or equivalently the frequency response in frequency domain) of the post digital filter and the corresponding structure of ISI equalizer in different spectrum-narrowing operation scenarios.

A signal processing method, a signal filtering apparatus, and a signal processing apparatus are provided. An input signal may be input into a filter having a passband, a superfluous signal of the passband may be output from the filter, and a target signal may be obtained by subtracting the superfluous signal from the input signal.

A Continuous Time Linear Equalizer (CTLE) and a method of operating a CTLE in a receiver for a Pulse Amplitude Modulation (PAM) signal are disclosed. The method includes initiating equalization using an initial equalization setting that is optimized to meet a first objective and responsive to a determination, shifting to a final equalization setting that is optimized to meet a second objective.

A Continuous Time Linear Equalizer (CTLE) and a method of operating a CTLE in a receiver for a Pulse Amplitude Modulation (PAM) signal are disclosed. The method includes initiating equalization using an initial equalization setting that is optimized to meet a first objective and responsive to a determination, shifting to a final equalization setting that is optimized to meet a second objective.

The present disclosure relates to control actuation smoothing, and more particularly, to a control actuation smoothing system that smoothes brake actuation. The smoothing may be determined in response to a filter. In various embodiments, the smoothing may enhance brake component performance.

Phase and amplitude error correction in a transmission circuit is provided. The transmission circuit includes a transceiver circuit, a power management integrated circuit (PMIC), and a power amplifier circuit(s). The transceiver circuit generates a radio frequency (RF) signal(s) from an input vector, the PMIC generates a modulated voltage, and the power amplifier circuit(s) amplifies the RF signal(s) based on the modulated voltage. In embodiments disclosed herein, the transceiver circuit is configured to equalize the input vector using multiple complex filters to thereby correct amplitude-amplitude (AM-AM) and amplitude-phase (AM-PM) errors. As a result, it is possible to reduce undesired instantaneous excessive compression and/or spectrum regrowth to thereby improve efficiency and linearity of the power amplifier circuit(s) across the modulation bandwidth.

A method for sending and receiving a signal is disclosed, and a corresponding device and system. The method includes performing constellation mapping on a data stream to obtain a mapped signal, and performing pre-filtering on the mapped signal to convert the mapped signal into a narrowband signal filtered signal. The pre-filtering is finite impulse response filtering. A bandwidth of the narrowband signal filtered signal is less than bandwidth of the mapped signal, and the narrowband signal filtered signal is a baud rate signal. The method also includes performing waveform forming according to the narrowband signal filtered signal to obtain a shaped signal, and performing digital-to-analog conversion on the shaped signal to convert a shaped second signal into an analog signal, and sending the analog signal.