24-12-2012, 01:31 PM
TERM PAPER CHANNEL BANDWIDTH
1CHANNEL BANDWIDTH.docx (Size: 48.62 KB / Downloads: 22)
What is Bandwidth?
Bandwidth is the difference between the upper and lower frequencies in a continuous set of frequencies. It is typically measured in hertz, and may sometimes refer to passband bandwidth, sometimes to baseband bandwidth, depending on context. Rate at which electronic signals can travel through a medium such as a wire, cable, or channel is called bandwidth. Bandwidth may be thought of as the width of the 'pipe' through which data travels: greater the width, larger the amount of data that can flow through it. Technically, it means the difference between two frequencies.
In analog transmission bandwidth is measured in cycles per second (or Hertz). In digital transmission bandwidth is measured in bits per second (BPS). For the same amount of data, digital transmission requires more bandwidth than the analog transmission, and different types of data require very different bandwidths. For example, full motion video normally requires about 10 million bits per second (10 Mbps) bandwidth which is sufficient to carry 1,200 simultaneous telephone conversations. A key characteristic of bandwidth is that a band of a given width can carry the same amount of information, regardless of where that band is located. For example, a 3 kHz band can carry a telephone conversation whether that band is at baseband or modulated to some higher frequency.
Bandwidth is a key concept in many telephony applications. In radio communications, for example, bandwidth is the frequency range occupied by a modulated carrier wave, whereas in optics it is the width of an individual spectral line or the entire spectral range.
For different applications there are different precise definitions. For example, one definition of bandwidth could be the range of frequencies beyond which the frequency function is zero. This would correspond to the mathematical notion of the support of a function
Bandwidth typically refers to baseband bandwidth in the context of, for example, sampling theorem and Nyquist sampling rate, while it refers to passband bandwidth in the context of Nyquist symbol rate or Shannon-Hartley channel capacity for communication systems.
SIGNAL BANDWIDTH -
We can divide signal into two categories:-
The pure tone signal consisting of one frequency signal for example: a sin wave of bandwidth 1 kHz, as shown below.