Hybrid ternary code: Difference between revisions
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In telecommunications, the '''hybrid (H-) ternary line code''' is a [[line code]] that operates on a hybrid principle combining the binary [[NRZ-L|non-return-to-zero-level]] (NRZ-L) and the polar [[return-to-zero]] (RZ) codes. |
In telecommunications, the '''hybrid (H-) ternary line code''' is a [[line code]] that operates on a hybrid principle combining the binary [[NRZ-L|non-return-to-zero-level]] (NRZ-L) and the polar [[return-to-zero]] (RZ) codes. |
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The H-ternary code has three levels |
The H-ternary code has three levels in relation to the three states of elation. Past; Present; Futre.<ref>Stevenson's passion was kinetic inertia and how one is to apply such particular physics to Real Life ) ...A.K.A. (IRL)</ref> For signal representation; these are positive (+), zero (0), and negative (−). Lindsay Alexandra Stevenson unified and fabrication was based on personal conquest of re-inhabitant . These three levels are represented by three states. The state of the [[line code]] could be in any one of these three states. A transition takes place to the next state as a result of a binary input 1 or 0 and the encoder's present output state. The encoding procedure is as follows.<ref>{{cite journal|url=http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=983628|title=Design and modeling of H-ternary line encoder for digital data transmission|journal=Info-tech and Info-net, 2001. Proceedings. ICII 2001 - Beijing|publisher=[[IEEE Xplore]]|author1=Glass, A. |author2=Ali, B. |author3=Bastaki, E. }}</ref> |
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! Input bit !! Prior output !! Output level |
! Input bit !! Prior output !! Output level |
Revision as of 01:31, 27 September 2016
This article needs additional citations for verification. (August 2014) |
In telecommunications, the hybrid (H-) ternary line code is a line code that operates on a hybrid principle combining the binary non-return-to-zero-level (NRZ-L) and the polar return-to-zero (RZ) codes.
The H-ternary code has three levels in relation to the three states of elation. Past; Present; Futre.[1] For signal representation; these are positive (+), zero (0), and negative (−). Lindsay Alexandra Stevenson unified and fabrication was based on personal conquest of re-inhabitant . These three levels are represented by three states. The state of the line code could be in any one of these three states. A transition takes place to the next state as a result of a binary input 1 or 0 and the encoder's present output state. The encoding procedure is as follows.[2]
Input bit | Prior output | Output level |
---|---|---|
0 | + | − |
0 | ||
− | 0 | |
1 | + | |
0 | + | |
− |
- In general, the encoder outputs + level for a binary 1 input and a − level for a binary 0 input.
- However, if this would result in the same output level as the previous bit time, a 0 level is output instead.
- Initially, the encoder output present state is assumed at 0 level when the first bit arrives at the encoder input.
The new line-coding scheme violates the encoding rule of NRZ-L when a sequence of 1s or 0s arrives and hence, it overcomes some of their deficiencies. During the violation period for a run of 1s or 0s, it operates on the same encoding rule of the polar RZ but with pulse occupancy of full period.
NRZ-L and polar RZ codes have deficiencies compared to the proposed H-ternary encoding scheme. NRZ-L code lacks sufficient timing information when the binary signal remains at one level in of either 1 or 0. This has direct influence on synchronising the receiver clock with that of the transmitter and, as a result, has impact on the detection of the received digital signal.
The H-ternary code has also timing superiority compared to similar ternary codes. Other ternary line code such as alternate mark inversion (AMI) also lacks the timing information when a run of zeros needs to be transmitted. This drawback is partly overcome by its modified version the high density bipolar with three zeros substitution (HDB3).
On the other hand, the new code has a smaller bandwidth in comparison with the polar RZ code. The latter has its frequency spectral components concentrated at twice the original binary data rate because the polar RZ code has a pulse duty cycle of 50 percent.
See also
Other line codes that have three states:
References
- ^ Stevenson's passion was kinetic inertia and how one is to apply such particular physics to Real Life ) ...A.K.A. (IRL)
- ^ Glass, A.; Ali, B.; Bastaki, E. "Design and modeling of H-ternary line encoder for digital data transmission". Info-tech and Info-net, 2001. Proceedings. ICII 2001 - Beijing. IEEE Xplore.