## Top new questions this week:

### What are some promising areas of research in digital signal processing?

I intend to pursue a PhD program in digital signal processing (DSP). However, it seems nowadays that research has saturated in DSP and it's all about machine learning and deep learning. Are there are ...

reference-request

### Importance of Phase in FFT of an image

While processing digital images in the Fourier domain, mostly we exploit the amplitude and not the phase. This could be because the amplitude is much more structured and the amplitude spectrum reveals ...

image-processing fourier-transform dft computer-vision

### Creating a PAM function with Matlab

So I need to make a function that will be called as function [t, pulse] = PAM (array). My function should have a result like this when I use ...

matlab amplitude-modulation

### transfer function of a sampler in the s domain

I would like to modelize my whole system into the S-domain. This is a mixed system, there a numerical part (corrector, ADC, DAC) and an analogic part (plant transfer function, sensors, etc...). I know ...

discrete-signals z-transform laplace-transform analog-to-digital

### Under what conditions is there a one-to-one mapping between continuous-time and discrete-time signals?

As the sampling theorem dictates that the uniform sampling frequency must be at least twice the maximum frequency present in the bandlimited signal (Nyquist rate), a question arises about the ...

sampling random-process nonuniform discretization

### Is spectral density conserved after aliasing?

Will the integral of the PSD of a down-sampled signal still equal the variance in all cases

power-spectral-density downsampling aliasing

### How can an audio segment report an integrated loudness (LUFS) greater than 0

According to my very rudimentary understanding of the ITU-R BS.1770 standard, I thought that the LUFS (LKFS) value for any audio signals should not ever go positive. However, there is a 5-second ...

audio
 asked by Tony Wu 1 vote

## Greatest hits from previous weeks:

### What are characteristics of shadows in an image given an outdoor setting from an image processing point of view?

I'm wondering what basic characteristics of shadows are. I'm looking from a camera image/video processing point of view. I'm considering the case of an outside scene in direct sunlight. These are the ...

image-processing classification camera

### Intuitive explanation of cross-correlation in frequency domain

According to the cross-correlation theorem : the cross-correlation between two signals is equal to the product of fourier transform of one signal multiplied by complex conjugate of fourier transform ...

fft fourier-transform dsp-core ifft

### What is the distinction between ergodic and stationary?

I have trouble distinguishing between these two concepts. This is my understanding so far. A stationary process is a stochastic process whose statistical properties do not change with time. For a ...

random ergodic

### Converting frequency from $\textrm{Hz}$ to radians-per-sample

In MATLAB I have to pass cut-off frequency for designing a filter. But this Cut-off frequency is in radians-per-sample. How do I convert my analog Cut off frequency in $\textrm{Hz}$, into the required ...

matlab sampling

### When are two signals orthogonal?

The classical definition of orthogonality in linear algebra is that two vectors are orthogonal, if their inner product is zero. I thought this definition might be applied to signals as well, but then ...

orthogonal-signals

### What is the physical significance of negative frequencies?

This has been one of the holes in my cheddar cheese block of understanding DSP, so what is the physical interpretation of having a negative frequency? If you have a physical tone at some frequency ...

frequency

### How to compute magnitude and phase response from transfer function in Z-domain?

I have a transfer function $$H(z)=\frac{1+1.2z^{-1}+0.8z^{z^-2}}{1-0.9z^{-1}}$$ from which I'm supposed to sketch the magnitude and phase response. I know that you can transform $z=e^{j\omega}$ to get ...

phase infinite-impulse-response transfer-function z-transform magnitude

## Can you answer these questions?

### Correlation estimation by the Blackman-Tukey method

Problem statement: Assume that the spectral estimation for an unknown signal is given by the Blackman-Tukey method as follows: $$S_x(\omega) = 5+8\cos(\omega)-6\cos(2\omega)+2\cos(3\omega).$$ Assume ...

frequency-spectrum power-spectral-density autocorrelation estimation spectrum-estimation

### Implementation of IIR filter

Suppose we have a discrete input waveform (with sampling frequency Fs = 32*56e9). We want to filter this waveform with a filter that has two complex conjugate poles (at 22 GHz) and one zero (at 17GHz) ...

filters filter-design lowpass-filter poles-zeros