# Tag Info

Accepted

### The difference between convolution and cross-correlation from a signal-analysis point of view

In signal processing, two problems are common: What is the output of this filter when its input is $x(t)$? The answer is given by $x(t)\ast h(t)$, where $h(t)$ is a signal called the "impulse ...
• 13.8k
Accepted

### Stationary vs non-stationary signals?

There is no stationary signal. Stationary and non-stationary are characterisations of the process that generated the signal. A signal is an observation. A recording of something that has happened. A ...
• 10.1k
Accepted

### What are advantages of having higher sampling rate of a signal?

Sampling at a higher frequency will give you more effective number of bits (ENOB), up to the limits of the spurious free dynamic range of the Analog to Digital Converter (ADC) you are using (as well ...
• 37.7k

### Difference between discrete time fourier transform and discrete fourier transform

alright, i'm gonna answer this with an argument that "opponents" to my rigid nazi-like position regarding the DFT have. first of all, my rigid, nazi-like position: the DFT and Discrete ...
Accepted

### Difference between discrete time fourier transform and discrete fourier transform

The discrete-time Fourier transform (DTFT) is the (conventional) Fourier transform of a discrete-time signal. Its output is continous in frequency and periodic. Example: to find the spectrum of the ...
• 4,051
Accepted

### Why doesn't sampling a periodic continuous-time signal yield a periodic discrete-time signal?

If the ratio between your sampling frequency and the frequency of your signal is irrational, you will not have a periodic discrete signal. Assuming you have a 1-kHz sine wave and you sample at 3000*...
• 3,620
Accepted

### Why do we need DFT when we already have DTFT/DTFS?

The answer is the same to the question: "Why do we need computers to process data when we have paper and pencil?" DTFT as well as the continuous-time Fourier Transform is a theoretical tool ...
Accepted

• 80.4k

### How do I explain a complex exponential intuitively?

From a graphical point-of view, it is an infinite spring, whose distance between adjacent coils reflects the frequency of the complex exponential: If you have a 1D time x-axis, you may be used to ...
• 30.2k

### Digital filter coefficients from low-pass to high-pass

You can apply a so-called all-pass transformation to a discrete-time low-pass prototype filter in order to convert it to other standard filters (such as high-pass, band-pass, and band-stop). This is ...
• 80.4k
Accepted

### This is how my professor is finding the frequency response of an LTI system when given the impulse response. Is this wrong?

Your professor is right, and you're almost right too. The filter is clearly an FIR filter, but because its frequency response can be expressed as a geometric series, a recursive implementation is ...
• 80.4k