BASEBAND TRANSMISSION SYSTEM
In digital communication, formatting is the first and most
important signal processing step. Formatting ensures that the message or source
signal may be processed digitally. The method of transforming source data to
digital symbols is known as transmit formatting. Source coding is the term used
when data compression and formatting are used together.
The binary ones and zeros logical structure is used to
represent digital communications. Baseband processors convert these messages
into baseband waveforms via pulse modulation. Waveforms of this nature can then
be sent through a cable.
BASEBAND SYSTEMS
The Figure represents the functional diagram of baseband signal formatting and transmission (Baseband Systems).
Figure: Formatting and Transmission of baseband signals (Baseband Systems)
Analog and discrete information sources are available.
As a result, a data source's output might be digital, textual, or analogue. The
formatting function would not be used if the data was already in digital
format. With the help of a coder, textual data is converted to binary digits.
If the data is in the form of alphanumeric text, it will be encoded using one
of many common formats, including ASCII, EBCDIC, Baudot, and Hollerith.
The three independent procedures of sampling, quantization,
and coding are used to format analogue data. The formatting phase produces a
series of binary numbers for all sorts of information sources.
The bit stream is converted into a series of pulse waveforms
by the pulse modulator. The digits being transmitted correspond to the features
of this series of pulses. These pulse waveforms are then sent across a baseband
channel, which might be a pair of wires or a coaxial cable.
The pulse waveforms are recovered (demodulated) and detected
after transmission over the channel to generate an approximation of the
transmitted digits. The reverse formatting is the final stage, which retrieves
an estimate of the source data.