Other
Data transmission, digital transmission, or digital
communications is the physical transfer of data (a digital bit stream) over
a point-to-point or point-to-multipoint communication channel.
While analog transmission is the
transfer of a continuously varying analog signal, digital communications is the
transfer of discrete messages. The messages are either represented by a
sequence of pulses by means of a line code, or by a limited set of continuously
varying wave forms, using a digital modulation method. The passband modulation
and corresponding demodulation (also known as detection) is carried out by modem
equipment. According to the most common definition of digital signal, both
baseband and passband signals representing bit-streams are considered as
digital transmission, while an alternative definition only considers
数据传输
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