Band-limited function

1. What is meant by a band-limited function?
2. What is band limitation?
3. What is band-limited channels?
4. Why is band limiting necessary?

What is meant by a band-limited function?

A signal is said to be band-limited if the amplitude of its spectrum goes to zero for all frequencies beyond some threshold called the cutoff frequency. For one such signal, G(f) in Figure 1, we see that the spectrum is zero for frequencies above α.

What is band limitation?

Bandlimiting is the limiting of a signal's frequency domain representation or spectral density to zero above a certain finite frequency.

What is band-limited channels?

band-limited channel A transmission channel with defined finite bandwidth. All physically realizable channels are band-limited by the constraints of the transmission medium and the drivers and receivers. The bandwidth may be deliberately constrained by filtering to limit the emission of or susceptibility to EMI.

Why is band limiting necessary?

For data communications, a signal, which is to be transmitted, has an infinite number of terms in its Fourier transform. However, when this signal needs to be transmitted through a channel of fixed bandwidth, band-limiting is required.