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Topic: Unipolar encoding


  
  Network Signal Transmission: Physical Layer
Unipolar and polar RZ encoding is illustrated in Figure 3.3.
Manchester encoding is a synchronous clock encoding technique used by the OSI physical layer to encode the clock and data of a synchronous bit stream.
In the Manchester encoding shown, a logic 1 is indicated by a 0 to 1 transition at the centre of the bit and a logic 0 is indicated by a 1 to 0 transition at the centre of the bit.
www.ists.pwr.wroc.pl /~kano/mirrors/net/node4.html   (6719 words)

  
 Line code - Wikipedia, the free encyclopedia
Line coding consists of representing the digital signal to be transported, by an amplitude- and time-discrete signal, that is optimally tuned for the specific properties of the physical channel (and of the receiving equipment).
The waveform pattern of voltage or current used to represent the 1s and 0s of a digital signal on a transmission link is called line encoding.
The common types of line encoding are unipolar, polar, bipolar and Manchester encoding.
en.wikipedia.org /wiki/Line_code   (332 words)

  
 21. Line Encoding   (Site not responding. Last check: 2007-11-04)
Unipolar encoding has 2 voltage states with one of the states being 0 volts.
A common example of Unipolar line encoding is the TTL logic levels used in computers and digital logic.
Unipolar line encoding works well for inside machines where the signal path is short but is unsuitable for long distances due to the presence of stray capacitance in the transmission medium.
www.techbooksforfree.com /intro_to_data_com/page65.html   (326 words)

  
 Bipolar encoding - Wikipedia, the free encyclopedia   (Site not responding. Last check: 2007-11-04)
In telecommunication, bipolar encoding is a type of line code -- a method of encoding digital information to make it resistant to certain forms of signal loss during transmission.
The main difference is that instead of a binary 0 resulting in a flat line for one period, a binary 0 is encoded as -1 V (binary 1 is still +1 V).
Using the probability that a 0 is just as likely as a 1, the resulting DC-component will be close to 0.
en.wikipedia.org /wiki/Bipolar_encoding   (127 words)

  
 Patent 4078159: Modified duobinary repeatered span line
The receiving-end office repeater equalizes and regenerates the modified duobinary signal, decodes the signal to obtain a unipolar signal, descrambles the unipolar signal, and converts the unipolar signal into a bipolar signal.Detection of errors in the modified duobinary signal may be obtained without adding redundant digits.
This unipolar pulse train is descrambled in descrambler 46, which provides an inverse function to the scrambler 36 of the transmit section.
Except for errors which may have occurred in transmission, the unipolar signal appearing at the output of descrambler 46 would be that of the transmitted signal output from the bipolar-to-unipolar converter 32 of the transmitting section.
www.freepatentsonline.com /4078159.html   (6101 words)

  
 TCM 250
Although unipolar is inexpensive, it carries a dc component and lacks good synchronization.
The average amplitude of a unipolar signal is nonzero.
A unipolar signal is unvarying (change from + to -) so the receiver cannot determine the beginning and ending of each bit.
www.atl.devry.edu /cjensen/Docs-Notes-TCM246/TCM250forouzan-chapter4.htm   (931 words)

  
 Line Encoding   (Site not responding. Last check: 2007-11-04)
Unipolar line encoding works well for inside machines--where the signal path is short-- but is unsuitable for long distances, due to the presence of stray capacitance in the transmission medium.
Polar line encoding is the simplest pattern that eliminates most of the residual DC problem.
Polar and Unipolar line encoding both share the same synchronization problem: if there is a long string of logical 1s or 0s, the receive oscillator may drift and become unsynchronized.
www.thelinuxreview.com /howto/intro_to_networking/c2161.htm   (682 words)

  
 Telco Basics
Data is encoded in current-state strategies by the presence or absence of a signal characteristic or state.
State-transition encoding methods differ from current-state encoding methods in that they use a transition in the signal to represent data, as opposed to encoding data by means of a particular voltage level or state.
Phase shift keying, on the other hand, is a state-transition encoding scheme because it relies on the presence or absence of a transition from one phase to another.
networking.ringofsaturn.com /Telecommunications/telco.php   (7452 words)

  
 [No title]   (Site not responding. Last check: 2007-11-04)
With unipolar signaling, the voltage is always positive or negative (like a dc current).
Manchester encoding is a special type of unipolar signaling in which the signal is changed from a high to low or from low to high in the middle of the signal.
Manchester encoding is less susceptible to having errors go undetected, because if there is no transition in mid-signal the receive knows that an error must have occurred.
www.25cubed.com /utd/myprogs/chapter_3.doc   (1477 words)

  
 Bandwidth Market, Ltd   (Site not responding. Last check: 2007-11-04)
Interposed between the regeneration circuit 30 and the line driver circuit 34 is a bipolar to unipolar data conversion circuit 36, which converts data from bipolar coding to unipolar coding and passes the signal to data framer circuitry 38.
A bipolar signal is in fact two unipolar signals, one representing positive bits and one representing negative bits, both aligned by a local clock.
The conversion from bipolar to unipolar encoding in the preferred embodiment of the present invention is accomplished in two stages.
www.bandwidthnews.com /resources/patents/data7/5521977.html   (6994 words)

  
 Contents
When we transmit data from your computer to your printer, both the original data and the transmitted data are digital, the binary 1s and 0s generated by a computer are translated into a sequence of voltage pulses that can be propagated over a wire.
In NRZ encoding, the level of the signal is always either positive or negative.
Manchester encoding uses the inversion at the middle of each bit interval for both synchronization and bit representation.
www.mcs4u.netfirms.com /datacomlec06.htm   (1923 words)

  
 [No title]   (Site not responding. Last check: 2007-11-04)
\par \par Unipolar encoding is so named because it uses only one polarity.
See figure 5.4 \par \par Advantages of unipolar: inexpensive \par \par Diadvantages of unipolar: on DC Component and Synchronization problem.
Manchester \par \par }\pard\plain \s3\ql \li0\ri0\keepn\widctlpar\aspalpha\aspnum\faauto\outlinelevel2\adjustright\rin0\lin0\itap0 \b\fs32\lang1033\langfe1033\cgrid\langnp1033\langfenp1033 {Manchester \par }\pard\plain \ql \li0\ri0\widctlpar\aspalpha\aspnum\faauto\adjustright\rin0\lin0\itap0 \fs24\lang1033\langfe1033\cgrid\langnp1033\langfenp1033 {\fs32 Manchester encoding uses the in version at the middle of each bit interval for both synchronization and bit representation.
www.fsktm.upm.edu.my /~hakim/skr3200/encoding1.rtf   (698 words)

  
 ' + pPage + '   (Site not responding. Last check: 2007-11-04)
The problem with this kind of encoding (called unipolar) is that there is no "return to zero" between positive pulses.
As Figure 16.2 shows, bipolar encoding still uses no voltage to represent a digital zero, but uses alternative positive and negative voltages to represent digital ones.
The primary purpose of the DSU is to convert the standard unipolar digital signal from the multiplexer into a bipolar signal.
www.codestorm.org /books/Networking/high_perf_network/ch16.htm   (4133 words)

  
 Examen 2   (Site not responding. Last check: 2007-11-04)
In _______ encoding one amplitude represents a 1 bit and zero amplitude represents a 0 bit (or vice versa).
Unipolar encoding has a DC component because the average _______ of the signal is nonzero.
In _______ encoding the transition between a positive and a negative voltage represents a 1 bit.
coqui.metro.inter.edu.ms /malsaadi/classes/network/exams/exam2.html   (3087 words)

  
 Encoding
Data Encoding à Electrical Signals before information can be transported across communication media
Binary data are transmitted by encoding each data bit into signal elements
Unipolar signal elements all have the same algebraic sign
www.etcs.ipfw.edu /~lin/cpet355/S2000/Lectures/SigEncodehtml.htm   (1033 words)

  
 Encoding & Modulation - HOME
This is called digital-to-digital conversion or encoding digital data into a digital signal.
Sometimes, we need to convert an analog signal such as voice in a telephone conversation into a digital signal for several reasons, such as to decrease the effect of noise.
Categories of digital-to-digital encoding include Unipolar, which one voltage level is used, Polar which two voltage levels are used and Bipolar, which the ones are represented by alternating positive and negative voltages: AMI (alternate mark inversion), B8ZS(bipolar 8-zero substitution) and HDB3(high-density bipolar 3).
www.geocities.com /tuanhui/home.htm   (326 words)

  
 CSIS 625 Week 2
The significant bandwidth of a digital bit rate must fit within the limited bandwidth of the medium that carries it.
0’s are encoded by absence of a signal
Allows for 2 bits per baud to be encoded.
personal1.stthomas.edu /droelke/Fall2002/Week2Notes.htm   (1398 words)

  
 [No title]
Unipolar¡  ª ðࢠð Ó ðN€”p …‡¿¿ Ëÿ?¿ÿðd w ðbŸ *¡ØªðH ð ƒ ð0ƒ“ŽŸ‹”Þ½h¿ÿ ?ð ÿÿ̀€€Ì™33ÌÌÌÿ²²²î•ï€ùÿÿÿ -ð%pð ð½ð( ð¿ ð ðXB ð ƒ ð0…‡¿Ë8cÎÿ?ð   ÔðXB ð ƒ ð0…‡¿Ë8cÎÿ?ð 0 0 ÔðXB ð ƒ ð0…‡¿Ë8cÎÿ?ð à à ÔðX ð ƒ ð0…‡ƒ¿Ëœ1ÿ?ð`°`€ð^ ð “ ð6…‡™Ìÿ¿ÀËœ1ÿ?ð p ðü ð à ðH€$y xa‚¢­ƒxa„¢­¿ƒ¿Ëœ1ÿ?ðN]#¶  ð„Ÿ¨ð 2.
Transition at the middle of the bit interval is used for synchronization.
AMI: 1 = alternating positive and negative voltages 0 = 0 voltage DC component is eliminated.
faculty.chi.devry.edu /rmelton/modulation.ppt   (906 words)

  
 [No title]
Specially, every 4 bits of actual data are encoded in a 5 bit code that is then transmitted to the receiver; hence the name 4B/5B.
Problem of Having a Separate Clock Line A solution developed to control the synchronization of unipolar transmission is to use a separate, parallel line that carries a clock pulse and allows the receiving device to resynchronize its timer to that of the signals.
If a sender attempts to transmit changes faster than the bandwidth, the hardware will not be able to keep up because it will not have sufficient time to complete one change before the sender attempts to make another.
www.utdallas.edu /~mkalam/EE4367/CodingI.ppt   (950 words)

  
 21. Line Encoding (cont'd)   (Site not responding. Last check: 2007-11-04)
When the digital encoding is symmetrical around 0 Volts, it is called a Polar Code.
Polar encoding has an added benefit in that it reduces the power required to transmit the signal by one-half compared with unipolar.
Polar line encoding has the same synchronization problem as Unipolar line encoding.
www.techbooksforfree.com /intro_to_data_com/page66.html   (131 words)

  
 Signal/Clock Encoding   (Site not responding. Last check: 2007-11-04)
Unipolar encoding uses 0 and +5 volts DC
Bipolar encoding uses +6 and -6 volts DC
We can apply differential encoding to derive variations in the preceding
www.samconline.com /samc/613/Chap-3/tsld012.htm   (39 words)

  
 Professor Yu -- Publications
Tai, F.T.S. Yu and H. Chen, "White-Light Pseudocolor Encoding," Journal of the Optical Society of America, Vol.
Palmer, K. Shung and F.T.S. Yu, "Pseudocolor Encoding of Medical Images with White-Light," IEEE Proceedings of 12th Annual Northeast Bioengineering Conference, pp.
F.T.S. Yu, G. Lu and C. Uang, (Invited) "Unipolar Neural Networks Using Redundant Interconnections," Proceedings of the International Conference on Optical Memory and Neural Networks, SPIE, Vol.
www.ee.psu.edu /faculty/yu/yu2.html   (14322 words)

  
 Encoding   (Site not responding. Last check: 2007-11-04)
Unipolar: uses one polarity, only encode the 1(typically)
transform binary data into digital signal using one of the digital-to-digital encoding techniques.
The information is encoded by modulating the carrier signal
www.buoy.com /~bobh/sccc/cm68/notes/chapter5.html   (461 words)

  
 Data Comm - Week 3, Day 2   (Site not responding. Last check: 2007-11-04)
Nyquist Theorm: If a signal is sampled at reqular intervals of time and at a rate higher, at least twice the significant signal frequency, the samples contain sufficient information to ensure accurate reproduction of the original signal
The phase of the carrier signal is modulated to follow the changing amplitude of the modulating signal
Data encoding and decoding technique to represent data using the properties of analog waves.
www.rit.edu /~cmd3187/notes/200402/datacomm/w3d2.htm   (592 words)

  
 encoding   (Site not responding. Last check: 2007-11-04)
Therefore, encoding of data into signals falls into four categories:
Encoding is unipolar, polar, or bipolar (polarity means positive or negative)
Can generate by: applying unipolar digital signal to one carrier, inverse digital to other, then summing the result
www.otterbein.edu /home/fac/DPTSNDR/csc465/notes/spring00/encoding.html   (503 words)

  
 [No title]   (Site not responding. Last check: 2007-11-04)
Two methods for line-encoding are shown below for 1-0 binary message sequence.
Figure 8(a) shows Unipolar encoding and Figure 8(b) shows Polar encoding.
What is the minimum size of the replicator memory buffer required to store the information encoded in a typical large pizza?
users.rowan.edu /~shreek/spring05/ecomms/midterm_s04.doc   (854 words)

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