Tutorials, Electronics made EASY, Williamson Labs. Baseband. Spectrum of a baseband signal, energy E per unit frequency as a function of frequency f. The total energy is the area under the line. In telecommunications and signal processing, baseband is an adjective that describes signals and systems whose range of frequencies is measured from close to 0 hertz to a cut-off frequency (a maximum bandwidth or highest signal frequency); it is sometimes used as a noun for a band of frequencies starting close to zero. Baseband can often be considered a synonym to lowpass or non-modulated, and antonym to passband, bandpass, carrier-modulated, intermediate frequency, or radio frequency (RF).
The term is often used in contrast to passband, which refers to a signal which has been translated to a higher frequency, often for transmission by frequency division multiplexing. Various uses[edit] Baseband bandwidth[edit] Baseband channel[edit] Digital baseband transmission[edit] Baseband transmission in Ethernet [edit] Baseband processor[edit] Baseband signal[edit] where. Broadband. Different criteria for "broad" have been applied in different contexts and at different times. Its origin is in physics, acoustics and radio systems engineering, where it had been used with a meaning similar to wideband.[2][3] Later, with the advent of digital telecommunications, the term was mainly used for transmission over multiple channels.
Whereas a passband signal is also modulated so that it occupies higher frequencies (compared to a baseband signal which is bound to lowest end of spectrum, see line coding), it is still occupying a single channel. The key difference is that what is typically considered a broadband signal in this sense is a signal that occupies multiple (non-masking, orthogonal) passbands thus allowing for much higher throughput over a single medium, but with additional complexity in the transmitter/receiver circuitry. In computer networks[edit] Power lines have also been used for various types of data communication. In video[edit] Internet access[edit] Modulation. In electronics and telecommunications, modulation is the process of varying one or more properties of a periodic waveform, called the carrier signal (high frequency signal), with a modulating signal that typically contains information to be transmitted. In telecommunications, modulation is the process of conveying a message signal, for example a digital bit stream or an analog audio signal, inside another signal that can be physically transmitted.
Modulation of a sine waveform transforms a baseband message signal into a passband signal. A modulator is a device that performs modulation. A demodulator (sometimes detector or demod) is a device that performs demodulation, the inverse of modulation. A modem (from modulator–demodulator) can perform both operations. The aim of digital baseband modulation methods, also known as line coding, is to transfer a digital bit stream over a baseband channel, typically a non-filtered copper wire such as a serial bus or a wired local area network.
How Does a Computer Modem Work?: Computer Basics. Characters and encodings.