MATLAB Simulation Program to implement TRELLIS CODE m file
Trellis modulation (also known as trellis coded modulation, or simply TCM) is a modulation scheme that transmits information with high efficiency over band-limited channels such as telephone lines. Gottfried Ungerboeck
invented trellis modulation while working for IBM in the 1970s, and
first described it in a conference paper in 1976. It went largely
unnoticed, however, until he published a new, detailed exposition in
1982 that achieved sudden and widespread recognition.
In the late 1980s, modems operating over plain old telephone service (POTS) typically achieved 9.6 kbit/s by employing four bits per symbol QAM
modulation at 2,400 baud (symbols/second). This bit rate ceiling
existed despite the best efforts of many researchers, and some engineers
predicted that without a major upgrade of the public phone
infrastructure, the maximum achievable rate for a POTS modem might be
14 kbit/s for two-way communication (3,429 baud × 4 bits/symbol, using
QAM).
.jpg)
Posts
No comments