What happens when to the spectrum of a signal when it is sampled?
One of the basic DSP principles states that a sampled time signal has a periodic spectrum with period equal to the sample rate. The derivation of can be found in textbooks [1,2]. You can also demonstrate this principle numerically using the Discrete Fourier Transform (DFT).
How can we retrieve original signal from sampled signal?
A continuous time signal can be processed by processing its samples through a discrete time system. For reconstructing the continuous time signal from its discrete time samples without any error, the signal should be sampled at a sufficient rate that is determined by the sampling theorem.
What is signal sampling and reconstruction?
In signal processing, sampling is the reduction of a continuous-time signal to a discrete-time signal. The original signal is retrievable from a sequence of samples, up to the Nyquist limit, by passing the sequence of samples through a type of low pass filter called a reconstruction filter.
How is signal reconstruction carried out for a discrete time signal?
A discrete-time signal is constructed by sampling a continuous-time signal, and a continuous-time signal is reconstructed by interpolating a discrete-time signal. Figure 11.1: Sampler. Recall that frequency can be given with any of various units. The units of the f in (11.3) and (11.4) are Hertz, or cycles/second.
What is meant by Nyquist rate?
The Nyquist rate or frequency is the minimum rate at which a finite bandwidth signal needs to be sampled to retain all of the information. If a time series is sampled at regular time intervals dt, then the Nyquist rate is just 1/(2 dt ).
What is the difference between convolution and multiplication?
Explanation: Convolution is defined as weighted superposition of time shifted responses where the whole of the signals is taken into account. But multiplication leads to loss of those signals which are after the limits.
What is meant by aliasing?
In signal processing and related disciplines, aliasing is an effect that causes different signals to become indistinguishable (or aliases of one another) when sampled. Aliasing can occur in signals sampled in time, for instance digital audio, and is referred to as temporal aliasing.
What is the best anti aliasing?
Which one is best for you?
- MSAA is best suited for midrange gaming computers.
- FXAA is perfect for low-end PCs because it is less demanding on your PC.
- If you have an old PC, do not choose Supersample Anti-Aliasing (SSAA).
- TXAA is an advanced anti-aliasing method that is found in new graphics cards.
Why 3dB is cut off?
It’s because decibels are logarithmic, and the log (base 10) of 3 is about 50% power. So the 3 decibel cutoff is where power drops off by a half. Generally speaking, a filter’s cutoff frequency is not necessarily defined at -3dB. In communication we wnat 100% frequency of the output.