A method and a device for updating a coefficient vector of a finite impulse response filter are provided. The update method includes: obtaining an updated step-size diagonal matrix for a coefficient vector of the FIR filter; and obtaining an updated coefficient vector of the FIR filter based on the updated step-size diagonal matrix.

A digital signal processor is designed to channelize an input signal, and includes a channelizer circuit and a plurality of tuning modules. The channelizer circuit is designed to receive an input signal having a first bandwidth and to channelize the input signal into a first set of channels each having a bandwidth smaller than the first bandwidth as a first output signal and to channelize the input signal into a second set of channels having a bandwidth smaller than the first bandwidth as a second output signal. The plurality of tuning modules are designed to receive one or more channels from the first output signal or the second output signal and to further downsample the one or more channels to a user-defined bandwidth at a user-defined center frequency. Each of the plurality of tuning modules include a plurality of FIR filter blocks and a memory having a plurality of FIR filter coefficients.

A method and a device for updating a coefficient vector of a finite impulse response filter are provided. The update method includes: obtaining an updated step-size diagonal matrix for a coefficient vector of the FIR filter; and obtaining an updated coefficient vector of the FIR filter based on the updated step-size diagonal matrix.

A digital signal processor is designed to channelize an input signal, and includes a channelizer circuit and a plurality of tuning modules. The channelizer circuit is designed to receive an input signal having a first bandwidth and to channelize the input signal into a first set of channels each having a bandwidth smaller than the first bandwidth as a first output signal and to channelize the input signal into a second set of channels having a bandwidth smaller than the first bandwidth as a second output signal. The plurality of tuning modules are designed to receive one or more channels from the first output signal or the second output signal and to further downsample the one or more channels to a user-defined bandwidth at a user-defined center frequency. Each of the plurality of tuning modules include a plurality of FIR filter blocks and a memory having a plurality of FIR filter coefficients.

The present disclosure provides a resampling apparatus and a resampling method. The resampling apparatus includes a control unit, a memory device, a resolution identifier, a phase rate generator, a coefficient generator, and a resample filter. The control unit controls reading and writing operations of the resampling apparatus according to a control signal. The memory device transmits the control signal to the control unit. The resolution identifier sets a resolution bandwidth identity according to an interpolation/decimation (I/D) value of the control signal. The phase rate generator generates a phase select signal and a counter enable signal according to the resolution bandwidth identity. The coefficient generator generates a coefficient select signal according to the resolution bandwidth identity. The resample filter generates a resampled output data according to the phase select signal, the coefficient select signal, and an input data.

Methods, systems, and devices for wireless communication are described. A wireless device may use a sampling rate that is less than a default sampling rate associated with a wireless carrier. The device may operate in a narrowband portion of a system bandwidth, and the sampling rate may be less than that used by devices monitoring the whole bandwidth. Multiple sampling rates may be used so that a portion of signal processing may be associated with one sampling rate and another portion of the signal processing may be associated with another sampling rate. The size of a cyclic prefix (CP) may be adjusted based on the sampling rate to align subframe timing boundaries for signals of different sampling rates. In some cases, each symbol of a signal may include both a CP and a postfix such that the postfix for each symbol overlaps the prefix of the next symbol.

Methods, systems, and devices for wireless communication are described. A wireless device may use a sampling rate that is less than a default sampling rate associated with a wireless carrier. The device may operate in a narrowband portion of a system bandwidth, and the sampling rate may be less than that used by devices monitoring the whole bandwidth. Multiple sampling rates may be used so that a portion of signal processing may be associated with one sampling rate and another portion of the signal processing may be associated with another sampling rate. The size of a cyclic prefix (CP) may be adjusted based on the sampling rate to align subframe timing boundaries for signals of different sampling rates. In some cases, each symbol of a signal may include both a CP and a postfix such that the postfix for each symbol overlaps the prefix of the next symbol.