This document discusses various methods for digital transmission, including:
- Digital-to-digital conversion techniques like line coding, block coding, and scrambling.
- Analog-to-digital conversion techniques like pulse code modulation (PCM) which involves sampling, quantization, and encoding an analog signal into a digital bitstream.
- Different line coding schemes like bipolar, polar, and multilevel coding and their considerations for minimizing issues like baseline wandering and DC components.
- Transmission modes like parallel, asynchronous serial, and synchronous serial transmission and their relative advantages for speed and cost.
SDH (Synchronous Digital Hierarchy) & Its Architectureijsrd.com
The SDH (Synchronous Digital Hierarchy) tell us about transferring large amount of data over an same optical fiber and this document gives us the information about the structure and architecture of SDH.
SDH (Synchronous Digital Hierarchy) & Its Architectureijsrd.com
The SDH (Synchronous Digital Hierarchy) tell us about transferring large amount of data over an same optical fiber and this document gives us the information about the structure and architecture of SDH.
Description of the analog to digital convercion process (ADC).
It is becoming more and more widespread to imply progressive technologies into different aspect of both daily and business life. One of the most desired technology that is being implicated into numerous industries is speech–recognition software. In reality, it looks like an operator speaks to his computer/machine/device and sets commands which are performed subsequently. Special voice-recognition software ADC (Analog-to-digital converter) lies in the heart of this process. Its main role is to transform human speech to “computer” speech which set commands. To understand the principle of voice command working, we concentrate on the technology of ADC.
Digital
to
Digital
Encoding Lack of Synchronization
Unipolar encoding uses only one
voltage level.
In a unipolar scheme, all the
signal levels are on one side of
the time axis, either above
or below.
A general overview of signal encoding
You will learn why to use digital encoding, how signal is transmitted and received and how analog signals are converted to digital
Some digital encoding methods
A presentation prepared by my friend's friend. I have done no editing at all, I'm just uploading the presentation as it is.
Data Communication & Computer Networks : Unipolar & Polar codingDr Rajiv Srivastava
These slides cover the fundamentals of data communication & networking. It covers Unipolar and Polar coding which are used in communication of data over transmission medium. It is useful for engineering students & also for the candidates who want to master data communication & computer networking.
Exploiting Artificial Intelligence for Empowering Researchers and Faculty, In...Dr. Vinod Kumar Kanvaria
Exploiting Artificial Intelligence for Empowering Researchers and Faculty,
International FDP on Fundamentals of Research in Social Sciences
at Integral University, Lucknow, 06.06.2024
By Dr. Vinod Kumar Kanvaria
This presentation was provided by Steph Pollock of The American Psychological Association’s Journals Program, and Damita Snow, of The American Society of Civil Engineers (ASCE), for the initial session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session One: 'Setting Expectations: a DEIA Primer,' was held June 6, 2024.
The simplified electron and muon model, Oscillating Spacetime: The Foundation...RitikBhardwaj56
Discover the Simplified Electron and Muon Model: A New Wave-Based Approach to Understanding Particles delves into a groundbreaking theory that presents electrons and muons as rotating soliton waves within oscillating spacetime. Geared towards students, researchers, and science buffs, this book breaks down complex ideas into simple explanations. It covers topics such as electron waves, temporal dynamics, and the implications of this model on particle physics. With clear illustrations and easy-to-follow explanations, readers will gain a new outlook on the universe's fundamental nature.
Delivering Micro-Credentials in Technical and Vocational Education and TrainingAG2 Design
Explore how micro-credentials are transforming Technical and Vocational Education and Training (TVET) with this comprehensive slide deck. Discover what micro-credentials are, their importance in TVET, the advantages they offer, and the insights from industry experts. Additionally, learn about the top software applications available for creating and managing micro-credentials. This presentation also includes valuable resources and a discussion on the future of these specialised certifications.
For more detailed information on delivering micro-credentials in TVET, visit this https://tvettrainer.com/delivering-micro-credentials-in-tvet/
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
Normal Labour/ Stages of Labour/ Mechanism of LabourWasim Ak
Normal labor is also termed spontaneous labor, defined as the natural physiological process through which the fetus, placenta, and membranes are expelled from the uterus through the birth canal at term (37 to 42 weeks
How to Build a Module in Odoo 17 Using the Scaffold MethodCeline George
Odoo provides an option for creating a module by using a single line command. By using this command the user can make a whole structure of a module. It is very easy for a beginner to make a module. There is no need to make each file manually. This slide will show how to create a module using the scaffold method.
3. Signal Element and Data ElementSignal Element and Data Element
4-3
• Data elements are what we need to send; signal elements are what we
can send
3-3
4. Data Rate Versus Signal RateData Rate Versus Signal Rate
4-4
• Data rate defines the number of data elements (bits) sent in 1s: bps
• Signal rate is the number of signal elements sent in 1s: baud
• Data rate = bit rate, signal rate = pulse rate, modulation rate, baud
rate
• S = c x N x 1/r, where N is the date rate; c is the case factor, S is the
number of signal elements; r is the number of data elements carried
by each signal element
• Although the actual bandwidth of a digital signal is infinite, the
effective bandwidth is finite
• The bandwidth is proportional to the signal rate (baud rate)
• The minimum bandwidth: Bmin = c x N x 1/r
• The maximum data rate: Nmax = 1/c x B x r
3-4
5. Design Consideration for Line CodingDesign Consideration for Line Coding
SchemeScheme
Baseline wandering
Long string of 0s and 1s can cause a drift in the
baseline
DC components
DC or low frequencies cannot pass a transformer or
telephone line (below 200 Hz)
Self-synchronization
Built-in error detection
Immunity to noise and interference
Complexity
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8. Unipolar SchemeUnipolar Scheme
One polarity: one level of signal voltage
Unipolar NRZ (None-Return-to-Zero) is simple, but
DC component : Cannot travel through microwave or transformer
Synchronization : Consecutive 0’s and 1’s are hard to be synchronized →
Separate line for a clock pulse
Normalized power is double that for polar NRZ
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3-8
9. Polar SchemePolar Scheme
Two polarity: two levels of voltage
Problem of DC component is alleviated
(NRZ,RZ) or eliminated (Biphaze)
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10. Polar NRZPolar NRZ
NRZ-L (Non Return to Zero-Level)
Level of the voltage determines the value of the bit
NRZ-I (Non Return to Zero-Invert)
Inversion or the lack of inversion determines the value of the bit
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11. Polar NRZ: NRZ-L and NRZ-IPolar NRZ: NRZ-L and NRZ-I
Baseline wandering problem
Both, but NRZ-L is twice severe
Synchronization Problem
Both, but NRZ-L is more serious
NRZ-L and NRZ-I both have an average
signal rate of N/2 Bd
Both have a DC component problem
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3-11
12. RZRZ
Provides synchronization for consecutive 0s/1s
Signal changes during each bit
Three values (+, -, 0) are used
Bit 1: positive-to-zero transition, bit 0: negative-to-zero transition
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13. BiphaseBiphase
Combination of RZ and NRZ-L ideas
Signal transition at the middle of the bit is used for
synchronization
Manchester
Used for Ethernet LAN
Bit 1: negative-to-positive transition
Bit 0: positive-to-negative transition
Differential Manchester
Used for Token-ring LAN
Bit 1: no transition at the beginning of a bit
Bit 0: transition at the beginning of a bit
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15. Bipolar SchemeBipolar Scheme
Three levels of voltage, called “multilevel binary”
Bit 0: zero voltage, bit 1: alternating +1/-1
(Note) In RZ, zero voltage has no meaning
AMI (Alternate Mark Inversion) and pseudoternary
Alternative to NRZ with the same signal rate and no DC
component problem
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16. Multilevel SchemeMultilevel Scheme
To increase the number of bits per baud by encoding a
pattern of m data elements into a pattern of n signal
elements
In mBnL schemes, a pattern of m data elements is
encoded as a pattern of n signal elements in which 2m
≤ Ln
2B1Q (two binary, one quaternary)
8B6T (eight binary, six ternary)
4D-PAM5 (four-dimensional five-level pulse amplitude
modulation)
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18. 8B6T8B6T
Used with 100Base-4T cable
Encode a pattern of 8 bits as a pattern of 6 (three-levels) signal
elements
222 redundant signal element = 36
(478 among 729) - 28
(256)
The average signal rate is theoretically, Save = 1/2 x N x 6/8; in practice
the minimum bandwidth is very close to 6N/8
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20. Multiline Transmission: MLT-3Multiline Transmission: MLT-3
The signal rate for MLT-3 is one-fourth the bit rate
MLT-3 when we need to send 100Mbps on a
copper wire that cannot support more than 32MHz
The MLT-3 uses three different voltage levels (+v,
0, -v) and three transition rules to move between
the levels:
If the next bit is 0, there is no transition
If the next bit is 1 and the current level is not 0, the next
level is 0.
If the next bit is 1 and the current level is 0, the next
level is the opposite of last nonzero level.
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22. Summary of Line CodingSummary of Line Coding
SchemesSchemes
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23. Block CodingBlock Coding
Block coding is normally referred to as mB/nB coding; it
replaces each m-bit group with an n-bit group
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24. 4B/5B4B/5B
Solve the synchronization problem of NRZ-I
20% increase the signal rate of NRZ-I (Biphase scheme has the signal
rate of 2 times that of NRZ-I
Still DC component problem
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27. ScramblingScrambling
Biphase : not suitable for long distance communication due
to its wide bandwidth requirement
Combination of block coding and NRZ: not suitable for
long distance encoding due to its DC component problem
Bipolar AMI: synchronization problem Scrambling
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28. B8ZSB8ZS
Commonly used in North America
Updated version of AMI with synchronization
Substitutes eight consecutive zeros with 000VB0VB
V denotes “violation”, B denotes “bipolar”
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29. HDB3HDB3
High-density bipolar 3-zero
Commonly used outside of North America
HDB3 substitutes four consecutive zeros with 000V or B00V depending
on the number of nonzero pulses after the last substitution
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31. PCMPCM
Pulse Code Modulation
Three processes
The analog signal is sampled
The sampled signal is quantized
The quantized values are encoded as streams of bits
Sampling: PAM (Pulse amplitude Modulation)
According to the Nyquist theorem, the sampling rate
must be at least 2 times the highest frequency contained
in the signal.
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39. PCM BandwidthPCM Bandwidth
The min. bandwidth of a line-encoded
signal
Bmin = c x N x 1/r = c x nb x fs x 1/r
= c x nb x 2 x Banalog x 1/r
= nb x Banalog where 1/r = 1, c = 1/2
Max. data rate of a channel
Nmax = 2 x B x log2L bps
Min. required bandwidth
Bmin = N/(2 x log2L) Hz
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3-39
45. Serial TransmissionSerial Transmission
On communication channel
Advantage: reduced cost
Parallel/serial converter is required
Three ways: asynchronous, synchronous, or isochronous
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3-45
46. Asynchronous TransmissionAsynchronous Transmission
Use start bit (0) and stop bits (1s)
A gap between two bytes: idle state or stop bits
It means asynchronous at byte level
Must still be synchronized at bit level
Good for low-speed communications (terminal)
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47. Synchronous TransmissionSynchronous Transmission
Bit stream is combined into “frames”
Special sequence of 1/0 between frames: No gap
Timing is important in midstream
Byte synchronization in the data link layer
Advantage: speed ⇒ high-speed transmission
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