Now, I'm focus on the sigma-delta ADC, when I study the part of digital filtering, I found that the FIR filter uses convolution to implement decimation and digital filtering, I think the output must be a discrete signal (I simulated it under MATLAB), but the ADCs' output must be digital signal? who can tell me what happened? 3x.
hi.
the FIR filter is the digital filter which has a linear output phase.
Desimation and interpolation are the techniqes in multirate DSP.
you can reffer to HELP of MATLAB for give more details.
The output of the FIR filter is a discrete signal calculated by the convolution sum between the input and the filter impulse response.
You can design an FIR filter in MATLAB using the GUI of the filter design toolbox.
The conversion to digital signal is the work of the ADC because it is the normal output for its specifications
Now, I'm focus on the sigma-delta ADC, when I study the part of digital filtering, I found that the FIR filter uses convolution to implement decimation and digital filtering, I think the output must be a discrete signal (I simulated it under MATLAB), but the ADCs' output must be digital signal? who can tell me what happened? 3x.
sigma-delta ADC includes two parts,analog sigma-delta modulator, after the modulator, digital signal generates, then you decimate the digital output from the modulator using digital filter, finally improved quantized multibit digital signal generates.