# Tag Info

1 vote

### Demodulate qpsk with gnu radio

Does anyone know what i'm doing wrong? Sad, honest answer: no. This could be incorrect assumptions on symbol rate or frequency offset, an incorrect receive filter, a lack of equalization, too much ...
• 26.3k
Accepted

### RRC filter has massive impulse response

After generating the pulse, you need to scale it to give it the energy you wish. Starting from the pulse RRC, find its energy ...
• 13.8k
Accepted

### Signal filtering with rrcos filter doesn't seem to work

The reason you're getting lots of zeros is because you're making the RRC filter way too long. If I plot it: ...
• 22.5k

### Kalman Filter EM Estimation of Covariances

I think there is a bug in your code. In KalmanFilter(), observation_matrices=H is probably not what we want. By the reference in ...
• 21
Accepted

### Reference for Wiener-Kolmogorov whitening procedure

There's some missing context, but I'm 99.44% sure that the authors are referring to part of the design process for the Wiener (AKA Wiener-Kolmogorov) filter. If they don't actually cite Weiner's and ...
• 8,285

### What are the problems with designing an FIR filter using FFT?

For method 1, by taking IFFT of desired $H[\omega]$, you will likely get a impulse response $h[n]$ in complex numbers, which means the output of the filter $y[n]$ will be complex numbers too.
Accepted

### Noise Reduction - noisy lines

I just used the method suggested in this older DSP.SE post and it seems to work: I did this manually by first loading the image: ...
• 22.5k
1 vote

### Is it ok to use MATLAB ''freqs" command for Digital filters?

You should use freqz to calculate frequency response of a digital filter and freqs for an analog filter. Given a transfer ...
• 2,493

### Is it ok to use MATLAB ''freqs" command for Digital filters?

For discrete-time filters, such as FIR and IIR filters, the appropriate Matlab function is freqz.m. You need to evaluate the frequency response on the unit circle of the complex plane; ...
• 80.2k

### A problem on FIR filter design given a difference equation

The filter order is the minimum number of (unit) delay elements necessary to implement the filter, or, equivalently, the order of the corresponding transfer function. In the case of causal FIR filters,...
• 80.2k
Let's see how DoG approximates LoG for the 2D case (for an image, e.g.). By derivative theorem of convolution (by associativity and commutativity), \nabla^2[f(x, y) \ast G(x, y)] = \nabla^2 G(x, y) \...