An Efficient Utilization of Power Spectrum Density for Smart Cities
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Digital Transmission 01204325 Data Communications and Computer Networks
Digital Transmission 01204325 Data Communications and Computer Networks Chaiporn Jaikaeo Department of Computer Engineering Kasetsart University Based on lecture materials from Data Communications and Networking, 5th ed., Behrouz A. Forouzan, McGraw Hill, 2012. Revised 2021-05-07 Outline • Line coding • Encoding considerations • DC components in signals • Synchronization • Various line coding methods • Analog to digital conversion 2 Line Coding • Process of converting binary data to digital signal 3 Signal vs. Data Elements 1 data element = 1 symbol 4 Encoding Considerations • Signal spectrum ◦ Lack of DC components ◦ Lack of high frequency components • Clocking/synchronization • Error detection • Noise immunity • Cost and complexity 5 DC Components • DC components in signals are not desirable ◦ Cannot pass thru certain devices ◦ Leave extra (useless) energy on the line ◦ Voltage built up due to stray capacitance in long cables v Signal with t DC component v Signal without t DC component 6 Synchronization • To correctly decode a signal, receiver and sender must agree on bit interval 0 1 0 0 1 1 0 1 Sender sends: v 01001101 t 0 1 0 0 0 1 1 0 1 1 Receiver sees: v 0100011011 t 7 Providing Synchronization • Separate clock wire Sender data Receiver clock • Self-synchronization 0 1 0 0 1 1 0 1 v t 8 Line Coding Methods • Unipolar ◦ Uses only one voltage level (one side of time axis) • Polar ◦ Uses two voltage levels (negative and positive) ◦ E.g., NRZ, RZ, Manchester, Differential Manchester • Bipolar ◦ Uses three voltage levels (+, 0, and -
Criteria for Choosing Line Codes in Data Communication
ISTANBUL UNIVERSITY – YEAR : 2003 (843-857) JOURNAL OF ELECTRICAL & ELECTRONICS ENGINEERING VOLUME : 3 NUMBER : 2 CRITERIA FOR CHOOSING LINE CODES IN DATA COMMUNICATION Demir Öner Istanbul University, Engineering Faculty, Electrical and Electronics Engineering Department Avcılar, 34850, İstanbul, Turkey E-mail: [email protected] ABSTRACT In this paper, line codes used in data communication are investigated. The need for the line codes is emphasized, classification of line codes is presented, coding techniques of widely used line codes are explained with their advantages and disadvantages and criteria for chosing a line code are given. Keywords: Line codes, correlative coding, criteria for chosing line codes.. coding is either performed just before the 1. INTRODUCTION modulation or it is combined with the modulation process. The place of line coding in High-voltage-high-power pulse current The transmission systems is shown in Figure 1. purpose of applying line coding to digital signals before transmission is to reduce the undesirable The line coder at the transmitter and the effects of transmission medium such as noise, corresponding decoder at the receiver must attenuation, distortion and interference and to operate at the transmitted symbol rate. For this ensure reliable transmission by putting the signal reason, epecially for high-speed systems, a into a form that is suitable for the properties of reasonably simple design is usually essential. the transmission medium. For example, a sampled and quantized signal is not in a suitable form for transmission. Such a signal can be put 2. ISSUES TO BE CONSIDERED IN into a more suitable form by coding the LINE CODING quantized samples. -
One Twisted Pair Cable Or Equivalent) Capable of Transporting Analog Signals in the Frequency Range Ofapproximately 300 to 3000 Hertz (Voiceband)
APPENDIX UNE-SBCI3STATE PAGE 21 OF 51 SBC-13STATE/SPRINT COMMUNICATIONS COMPANY, L.P. 110802 8 .3 SBC-12STATE will offer the following subloop types: 8.3.1 2-Wire Analog Subloop provides a 2-wire (one twisted pair cable or equivalent) capable of transporting analog signals in the frequency range ofapproximately 300 to 3000 hertz (voiceband). 8.3.2 4-Wire Analog Subloop provides a 4-wire (two twisted pair cables or equivalent, with separate transmit and receive paths) capable of transporting analog signals in the frequency range of approximately 300 to 3000 hertz (voiceband). 8.3.3 4-Wire DS 1 Subloop provides a transmission path capable of supporting a 1 .544 Mbps service that utilizes AMI or B8ZS line code modulation. 8.3.4 DS3 Subloop provides DS3 service from the central office MDF to an Interconnection Panel at the RT. The loop facility used to transport the DS3 signal will be a fiber optical facility. 8 .3 .5 2-Wire / 4-Wire Analog DSL Capable Subloop that supports an analog signal based DSL technology (such as ADSL). It will have twisted copper cable that may be loaded, have more than 2,500 feet of bridged tap, and may contain repeaters. 8 .3.6 2-Wire / 4-Wire Digital DSL Capable Subloop that supports a digital signal based DSL technology (such as HDSL or IDSL). It will have twisted copper cable that may be loaded, have more than 2,500 feet of bridged tap, and may contain repeaters. 8.3 .7 ISDN Subloop is a 2-Wire digital offering which provides a transmission path capable of supporting a 160 Kbps, Basic Rate ISDN (BRI) service that utilizes 2BIQ line code modulation with end user capacity up to 144 Kbps . -
Multilevel Sequences and Line Codes
COPYRIGHT AND CITATION CONSIDERATIONS FOR THIS THESIS/ DISSERTATION o Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use. o NonCommercial — You may not use the material for commercial purposes. o ShareAlike — If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the original. How to cite this thesis Surname, Initial(s). (2012) Title of the thesis or dissertation. PhD. (Chemistry)/ M.Sc. (Physics)/ M.A. (Philosophy)/M.Com. (Finance) etc. [Unpublished]: University of Johannesburg. Retrieved from: https://ujdigispace.uj.ac.za (Accessed: Date). MULTILEVEL SEQUENCES AND LINE CODES by LOUIS BOTHA Thesis submitted as partial fulfilment of the requirements for the degree MASTER OF ENGINEERING in ELECTRICAL AND ELECTRONIC ENGINEERING in the FACULTY OF ENGINEERING at the RAND AFRIKAANS UNIVERSITY SUPERVISOR: PROF HC FERREIRA MAY 1991 SUMMARY As the demand for high-speed data communications over conventional channels such as coaxial cables and twisted pairs grows, it becomes neccesary to optimize every aspect of the communication system at reasonable cost to meet this demand effectively. The choice of a line code is one of the most important aspects in the design of a communications system, as the line code determines the complexity, and thus also the cost, of several circuits in the system. It has become known in recent years that a multilevel line code is preferable to a binary code in cases where high-speed communications are desired. -
CODING for Transmission
CODING for Transmission Professor Izzat Darwazeh Head of Communicaons and Informaon System Group University College London [email protected] Acknowledgement: Dr A. Chorti, Princeton University for slides on FEC coding Dr P.Moreira, CERN, for slides on the CERN Gigabit Transmitter (GBT) Dr J. Mitchell, UCL, for the sampled music and voice. June 2011 Coding • Defini7ons and basic concepts • Source coding • Line coding • Error control coding Digital Line System Message Message source Distortion, sink interference Input Output signal and noise signal Encoder- Demodulator modulator -decoder Communication Transmitted channel Received signal signal Claude Shannon • Shannon’s Theorem predicts reliable communicaon in the presence of noise “Given a discrete, memoryless channel with capacity C, and a source with a posi8ve rate R (R<C), there exist a code such that the output of the source can be transmi@ed over the channel with an arbitrarily small probability of error.” • B is the channel bandwidth in Hz and S/N is the signal power to noise power rao ⎛⎞S CBc =+log2 ⎜⎟ 1 ⎝⎠N Types of Coding • Source Coding – Encoding the raw data • Line (or channel) Coding – Formang of the data stream to benefit transmission • Error Detec7on Coding – Detec7on of errors in the data seQuence • Error Correcon Coding – Detec7on and Correc7on of Errors • Spread Spectrum Coding – Used for wireless communicaons Signals and sources: Discrete - Con8nuous m(t) n Continuous Time and Amplitude n Discrete Time, continuous Amplitude – PAM signal n Discrete Time, and Amplitude -
Università Degli Studi Di Parma Architectural
UNIVERSITÀ DEGLI STUDI DI PARMA DIPARTIMENTO DI INGEGNERIA DELL’INFORMAZIONE PARMA (I) - VIALE DELLE SCIENZE TEL. 0521-905800 • FAX 0521-905758 Dottorato di Ricerca in Tecnologie dell’Informazione XIX Ciclo Giulia Papotti ARCHITECTURAL STUDIES OF A RADIATION-HARD TRANSCEIVER ASIC IN 0.13 um CMOS FOR DIGITAL OPTICAL LINKS IN HIGH ENERGY PHYSICS APPLICATIONS DISSERTAZIONE PRESENTATA PER IL CONSEGUIMENTO DEL TITOLO DI DOTTORE DI RICERCA GENNAIO 2007 CERN-THESIS-2007-111 //2007 εστω δε ο λογος υμων ναι ναι ου ου το δε περισσον τουτων εκ του πονηρου εστιν (Simply let your 'Yes' be 'Yes,' and your 'No,' 'No'; anything beyond this comes from the evil one.) (Matthew, 5:37) Acknowledgements I have always been concise, so all you get is a list. Here it goes… Paulo and Sandro for useful comments, critiques, discussions, explanations, feedback, questions, support… Apart from helping out in the completion of the PhD thesis in particular and PhD program in general, they have been role models who helped me in my personal professional growth. At my University in Parma, Prof. Ciampolini for being there every time I needed him, despite the amount of other engagements. I will not forget that he was the one who suggested CERN to me in the first place. Mike and all the Microelectronics group at CERN, for being such a stimulating working environment. In particular Bert, Ernest, Federico, Francois, Giovanni e Giovanni, Guido, Hugo, Kostas, Matthieu, and Rafael. Winnie needs to be specially thanked among them for reading and patiently correcting most of this thesis. Francois, Jan and Karl cannot be forgotten either, for having initiated me to CERN and the world of experimental measurements. -
4.1 DIGITAL-TO-DIGITAL CONVERSION in Chapter 3, We Discussed Data and Signals
A computer network is designed to send information from one point to another. This information needs to be converted to either a digital signal or an analog signal for trans• mission. In this chapter, we discuss the first choice, conversion to digital signals; in Chapter 5, we discuss the second choice, conversion to analog signals. We discussed the advantages and disadvantages of digital transmission over analog transmission in Chapter 3. In this chapter, we show the schemes and techniques that we use to transmit data digitally. First, we discuss digital-to-digital conversion tech• niques, methods which convert digital data to digital signals. Second, we discuss analog- to-digital conversion techniques, methods which change an analog signal to a digital signal. Finally, we discuss transmission modes. 4.1 DIGITAL-TO-DIGITAL CONVERSION In Chapter 3, we discussed data and signals. We said that data can be either digital or analog. We also said that signals that represent data can also be digital or analog. In this section, we see how we can represent digital data by using digital signals. The conver• sion involves three techniques: line coding, block coding, and scrambling. Line coding is always needed; block coding and scrambling may or may not be needed. Line Coding Line coding is the process of converting digital data to digital signals. We assume that data, in the form of text, numbers, graphical images, audio, or video, are stored in com• puter memory as sequences of bits (see Chapter 1). Line coding converts a sequence of bits to a digital signal. At the sender, digital data are encoded into a digital signal; at the receiver, the digital data are recreated by decoding the digital signal. -
Adv. Communication Lab 6Th Sem E&C
TH ADV. COMMUNICATION LAB 6 SEM E&C • the line-coded signal can directly be put on a transmission line, in the form of variations of the voltage or current (often using differential signaling). • the line-coded signal (the "base-band signal") undergoes further pulse shaping (to reduce its frequency bandwidth) LINE CODING and then modulated (to shift its frequency bandwidth) to create the "RF signal" that can be sent through free space. Line coding consists of representing the digital signal to be • the line-coded signal can be used to turn on and off a light transported by an amplitude- and time-discrete signal that is in Free Space Optics, most commonly infrared remote optimally tuned for the specific properties of the physical channel control. (and of the receiving equipment). The waveform pattern of • the line-coded signal can be printed on paper to create a voltage or current used to represent the 1s and 0s of a digital bar code. data on a transmission link is called line encoding. The common • the line-coded signal can be converted to a magnetized types of line encoding are unipolar, polar, bipolar and spots on a hard drive or tape drive. Manchester encoding. • the line-coded signal can be converted to a pits on optical For reliable clock recovery at the receiver, one usually imposes a disc. maximum run length constraint on the generated channel Unfortunately, most long-distance communication sequence, i.e. the maximum number of consecutive ones or channels cannot transport a DC component. The DC zeros is bounded to a reasonable number. -
UNIT: 3 Digital and Analog Transmission
UNIT: 3 Digital and Analog Transmission DIGITAL-TO-ANALOG CONVERSION Digital-to-analog conversion is the process of changing one of the characteristics of an analog signal based on the information in digital data. Figure 5.1 shows the relationship between the digital information, the digital-to-analog modulating process, and the resultant analog signal. A sine wave is defined by three characteristics: amplitude, frequency, and phase. When we vary anyone of these characteristics, we create a different version of that wave. So, by changing one characteristic of a simple electric signal, we can use it to represent digital data. Before we discuss specific methods of digital-to-analog modulation, two basic issues must be reviewed: bit and baud rates and the carrier signal. Aspects of Digital-to-Analog Conversion Before we discuss specific methods of digital-to-analog modulation, two basic issues must be reviewed: bit and baud rates and the carrier signal. Data Element Versus Signal Element Data element is the smallest piece of information to be exchanged, the bit. We also defined a signal element as the smallest unit of a signal that is constant. Data Rate Versus Signal Rate We can define the data rate (bit rate) and the signal rate (baud rate). The relationship between them is S= N/r baud where N is the data rate (bps) and r is the number of data elements carried in one signal element. The value of r in analog transmission is r =log2 L, where L is the type of signal element, not the level. Carrier Signal In analog transmission, the sending device produces a high-frequency signal that acts as a base for the information signal. -
ETRI PHY Proposal on VLC Line Code for Illumination
September 2009 doc.: IEEE 802.15-09-0675-00-0007 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [ETRI PHY Proposal on VLC Line Code for Illumination] Date Submitted: [23 September, 2009] Source: [Dae Ho Kim, Tae-Gyu Kang, Sang-Kyu Lim, Ill Soon Jang, Dong Won Han] Company [ETRI] Address [138 Gajeongno, Yuseong-gu, Daejeon, 305-700] Voice:[+82-42-860-5648], FAX: [+82-42-860-5218], E-Mail:[[email protected]] Re: [Response to call for proposals] Abstract: [This document describes a proposal of PHY line code for LED illumination ] Purpose: [Proposal to IEEE 802.15.7 VLC TG]] Notice: This document has been prepared to assist the IEEE P802.15. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15. TG VLC Submission Slide 1 Dae-Ho Kim, ETRI September 2009 doc.: IEEE 802.15-09-0675-00-0007 ETRI PHY Proposal on VLC Line code for Illumination Dae Ho Kim [email protected] ETRI TG VLC Submission Slide 2 Dae-Ho Kim, ETRI September 2009 doc.: IEEE 802.15-09-0675-00-0007 Contents • ETRI PHY Considerations and Scope • Summary of ETRI PHY Proposal • Flickering issue at LED illumination • Proposed Line Code – Modified-4B5B -
Experiment Three: Line Coding
Experiment Three: Line Coding Modified from original TIMS Manual experiment by Mr. Faisel Tubbal. Objectives 1) Learn about line coding techniques by generating the codes using the LINE-CODE ENCODER and DECODER modules in the lab. 2) Display line coding techniques on oscilloscope in time and frequency domains (Spectrum) and make a comparison among these different techniques using TTL as a reference signal. 3) Using snap shot method to display line coding techniques. 4) Link the theory that you studied in lecture with the practical. 5) Observe the effect of the 180 phase shift of these techniques. Equipment Required Sequence Generator (01), Line-code Encoder (01), Buffer Amplifier (01), and Line-code Decoder. Essential Reading 1) Watch the video, read the introduction, read the tutorial questions, and read any necessary data sheets Introduction This ‘experiment’ is tutorial in nature, and serves to introduce two new modules (Line-code Encoder and Line-code Decoder). In your course work you should have covered the topic of line coding at whatever level is appropriate for you. TIMS has a pair of modules, one of which can perform a number of line code transformations on a binary TTL sequence. The other performs decoding. A- Why line coding? There are many reasons for using line coding. Each of the line codes you will be examining offers one or more of the following advantages: Spectrum shaping and relocation without modulation or filtering. This is important in telephone line applications, for example, where the transfer characteristic has heavy attenuation below 300 Hz. Bit clock recovery can be simplified. -
Design of Return to Zero (RZ) Bipolar Digital to Digital Encoding Data Transmission
IOSR Journal of Engineering (IOSRJEN) www.iosrjen.org ISSN (e): 2250-3021, ISSN (p): 2278-8719 Vol. 05, Issue 02 (February. 2015), ||V4|| PP 33-36 Design of Return to Zero (RZ) Bipolar Digital to Digital Encoding Data Transmission Amna mohammed Elzain1,Abdelrasoul Jabar Alzubaidi2 Alazhery University- Engineering college Sudan University of Science and technology –Engineering College- Electronics Engineering School Abstract: - Line encoding is the method used to represent the digital information on the media. A pattern, that uses either voltage or current, is used to represent the 1s and 0s of the digital signal on the transmission link. Common types of line encoding methods used in data communications are: Unipolar line encoding, Polar line encoding, Bipolar line encoding and Manchester line encoding. This paper deals with the design of bipolar digital to digital encoding (RZ) data transmission using latch SN 74373, darlington amplifier ULN 2003-500 m A, solid state relay, personnel computer and Turbo C++ programming language ). Keywords: - Bipolar, Encoding, Digital to Digital, Latch SN 74373, Darlington Amplifier ULN 2003-500 m A, Solid State Relay (SSR) ,Turbo C++ , Computer. I. INTRODUCTION A computer network is used for communication of data from one station to another station in the network [1]. Data and signals are two of the basic building blocks of any computer network. Data must be encoded into signals before it can be transported across communication media [2]. Encoding means conversion of data into bit stream [3]. There are different encoding schemes available: Analog-to-Digital Digital-to-Analog Analog-to-Analog Digital-to-Digital Digital-to-Digital Digital-to-Digital encoding is the representation of digital information by a digital signal .