Line Coding: Polar 7
Polar Line Coding – uses two non-zero voltage level for represent.
of two data levels - one positive & one negative
Polar Line Coding – uses two non-zero voltage level for represent.
of two data levels - one positive & one negative
- • “DC-problem” alleviated
- • 4 main types of polar coding:
in NRZ there are two types :NRZ-level NRZ-invert
(1) Nonreturn to Zero
(NRZ)
(1) Nonreturn to Zero
(NRZ)
- • NRZ-level: signal level represents particular
- bit, (e.g.) 0 = positive volt. , 1 = negative volt.
- poor synchronizat. for long series of 1-s & 0-s
- • NRZ-invert: inversion of voltage level = bit 1,
no voltage = bit 0 - 1s in data streams enable synchronization
- long sequence of 0-s still a problem
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