## Top new questions this week:

### Impulse response of a time scaling system

Assume a bandlimited signal $X(t)$. Given that the output for this signal is $X(t/2)$, what will be the impulse response $h(t)$ of such a system? \begin{array}{l} X( \omega ) \ =\ \int ^{\infty ...

fourier-transform impulse-response scaling
 answered by Matt L. 1 vote

### Friendliest python library for fixed point algorithm simulation

My primary programming language is python. Is anyone aware of solid python libraries to simulate fixed point algorithms in python? A quick google search revealed this: ...

python fixed-point

### Using a low pass filter to interpolate signal

In my DSP university textbook, the interpolation process is described as follows: In order to represent a baseband signal $x[k]$ at an increased sampling rate with the same shapes of its ...

lowpass-filter interpolation

### Response of a system using DFT

Let's say that we have two sequences, input sequence $x(n) = [0121]$ and impulse response of a given system $h(n) = [0, 1, -1, 1]$. I need to find response of this system to given input sequence. ...

dft convolution

### Find a LTI system such that $\mathcal{T}\{\frac{\sin t}{t}\} = \frac{\sin 2t}{t}$

Let $x(t) = \frac{\sin t}{t}$ and $y(t) = \frac{\sin 2t}{t}$. Is it possible to find a LTI system such that $\mathcal{T}\{x(t)\} = y(t)$? If not, what's the reason for that? My try: Assuming ...

continuous-signals linear-systems frequency-response impulse-response

### Calculate the difference of the magnitude of discrete fourier transform - help inimplementing the formula

I have a time-series of length N generated by the following equation: x(1) = 0.1; for jj =1 : 500 x(jj+1) = 4*x(jj)*(1-x(jj)); end The functional form of the equation is x[n+1] = ...

image-processing matlab fft fourier-transform ifft

### Degrees of freedom in coding (for a communication channel)

I was reading on my lecture slides about how to achieve diversity (i.e. transmit more copies of the same message in order to avoid its corruption; this technique may be realized by repeating the ...

## Greatest hits from previous weeks:

### How can I generate a sine wave with time varying frequency that is continuous, in C?

How can I generate a sine wave with time varying frequency that is continuous? How can I resolve the following problem? I want a continuous graph. I'm generating this simply like this: for(int i = ...

c

### Gaussian Blur - Standard Deviation, Radius and Kernel Size

I've implemented a gaussian blur fragment shader in GLSL. I understand the main concepts behind all of it: convolution, separation of x and y using linearity, multiple passes to increase radius... I ...

image-processing gaussian blur

### How to Remove a Glare / Clipped Brightness from an Image?

I have an image Is there any way of removing the bright white spots ? Please help thanks Edit: After operating with gaussian and then displaying using imagesc get the following output which ...

image-processing matlab image-restoration

### Calculate symbol rate for QAM modulation

Not sure if this is the right place to ask, feel free to move it if any other site suits this better. Anyway I am referring to QAM modulation used in US Cable TV. I know it comes under Annex B which ...

modulation channelcoding

### What does frequency domain denote in case of images?

I was just learning about the frequency domain in images. I can understand the frequency spectrum in case of waves. It denotes what frequencies are present in a wave. If we draw the frequency ...

image-processing frequency-spectrum dft

### Is a notch filter for 50 Hz without delay possible?

I am processing an EEG signal (2 kHz sampling frequency) from hardware and the built-in filter doesn't work as intended. FIR gives a delay, and IIR is unstable. The signal of interest is from ...

filter-design delay

### Kalman filter - understanding the noise covariance matrix

What is the significance of the noise covariance matrices in the Kalman Filter framework? I am referring to: process noise covariance matrix Q, and measurement noise covariance matrix R at any ...

filters noise kalman-filters tracking

## Can you answer these questions?

### Finding the system output by convolution

pretty new to this concept, so do bear with me. A linear dynamic system is described by the following differential equation: Transfer function H(s) is calculated to be = I've already found the ...

convolution linear-systems laplace-transform math differential-equation

### symbol synchronization

PLL is typically used in carrier synchronization and its diagram is well known, consisting of a multiplier, a low pass filter, and a VCO. In "Phase-locked Loop" at wiki ...

digital-communications demodulation pll symbol-timing