PULSE CODE MODULATION (PCM)
|
|
- Carol Norris
- 5 years ago
- Views:
Transcription
1 PULSE CODE MODULATION (PCM) 1. PCM quantization Techniques 2. PCM Transmission Bandwidth 3. PCM Coding Techniques 4. PCM Integrated Circuits 5. Advantages of PCM 6. Delta Modulation 7. Adaptive Delta Modulation 8. Differential PCM ECE 416 DIGITAL COMMUNICATION Friday, 09 March 2018
2 SYLLABUS
3 KEY POINTS ABOUT PCM 1. While PCM is a pulse modulation technique much like PWM, PAM or PPM. 2. PCM is digital while the others are either analogue in time or amplitude, i.e PCM pulses are discrete in time and amplitude unlike PAM, PWM or PPM. 3. Essential aspects of a PCM transmitter are sampling, quantizing and encoding. 4. PCM is not a modulation in the conventional sense because it does not rely on varying a characteristic of a carrier (amplitude, frequency or phase).
4 PCM TRANSMITTER Analogue signal x(t) PAM Signal X(nT s ) Analogue to Digital Converter ADC Quantized PAM X q (nt s ) Low-pass Filter Sample and Hold q-level quantizer Binary encoder Timer Parallel to serial converter Sampling clock signal f s 2f m PCM out r = uf s
5 BINARY EQUIVALENTS AND PULSE CODE WAVEFORMS
6 PCM TRANSMISSION PATH PCM transmission path refers to the path the the signal travels between the transmitter and the receiver. From Transmitter Regenerative Repeater Regenerative Repeater To Receiver Distorted PCM Signal Clean PCM Pulse Distorted PCM Signal Clean PCM Pulse
7 PCM REPEATER Compensates for the effects of amplitude and phase distortions Makes a decision on whether the equalized PCM wave is a zero or one Amplitude and Phase Equalizer Decision Making Circuit Distorted PCM Signal Timing Circuit Clean PCM Pulse The timing clock is extracted from the PCM pulsestream
8 PCM RECEIVER Distorted PCM Pulse Trainl Clean PCM Pulse train Analogue Signal x(t) Regenerative Repeater Serial to Parallel converter Digital to Analogue Converter Sample and Hold circuit Low pass filter, f m Timer
9 TYPES OF QUANTIZERS Quantization Uniform Quantization Non-Uniform Quantization Midtread Quantization Midrise Quantization Step size is the same throughout the input signal range Step size varies according the input signal values
10 MIDTREAD QUANTIZER 1. A midtread quantizer assumes values of the form H i where is the step size and H i = 0, ±1, ±2, ±3, It is called mid-tread because the origin lies in the middle of a tread of a staircaselike graph.
11 MIDRISER QUANTIZER 1. A mid-riser quantizer has output levels are given by 2 H i, where is the step size and H i = ±1, ±2, ±3, The origin lies in the middle of the rising part of the staircase-like characteristic graph.
12 PCM TRANSMISSION BANDWIDTH 1. Assume the a PCM encoder has q levels which are encoded to υ bits. 2. We can infer q = 2 υ 3. The number of bits per second can be expressed as: f pcm = υf s where f s 2f m (Nyquist criterion) 4. It therefore follows that the bandwidth, BW of a PCM channel is bounded by: BW pcm 2υf m
13 EXAMPLE 1 1. A TV signal with a bandwidth of 4.2 MHz is transmitted using binary PCM system using 512 quantization levels. Determine (a) Code word-length (b) The PCM bandwidth/bit rate SOLUTION (a) f m = 4.2 MHz q = 2 υ = 512 υ = log = 9 bits (b) Bandwidth, BW = 2υf m = 2 x9 4.2 = 75.6 Mb/s
14 WHY IT IS NECESSARY TO HAVE NON-UNIFORM QUANTIZATION? 1. Using linear quantization, the quantization error is given by: ε = 2 2. If q quantization levels of a bipolar signal are used, we can write: = 2x max q 3. Consider a PCM system with υ = 4 bits and x max = 16 Volt, then: q = 2 4 = 16 = 2 q = 2 16 = 1 8 The maximum quantization error is therefore ε max = 2 = At maximum, the relative error is 1 volt out of 16 volts or 6.25% 5. At lower levels, e.g. 2 volts, the relative error is 1 volt out of 2 volts or 50%. 6. To reduce this high relative error at low levels, PCM systems use nonuniform quantization.
15 COMPANDING 1. With uniform sampling, the quantization step is fixed thus resulting in uniform quantization noise power. 2. However signal power is not constant, it is proportional to the square of the signal amplitude. This means Quantization Noise is very significant at low amplitudes. 3. To reduce quantization noise at lower amplitudes, we use commanding: Companding = Compressing + Expanding Input Compressor Uniform Quantizer Expander Output Provides High Gain to Weak Signals and Low Gain to strong Signals Provides Low Gain to Weak Signals and High Gain to strong Signals
16 COMPRESSING WITH MIDRIZER QUANTIZER
17 COMPANDING IN COMMUNICATION SYSTEMS 1. The loudest sound that can be tolerated (120 db SPL) is about one-million times the amplitude of the weakest sound that can be detected (0 db SPL). 2. If the quantization levels are equally spaced (uniform quantization), 12 bits must be used to obtain telephone quality speech. 3. However, only 8 bits are required if the quantization levels are made unequal (companding) to match the characteristics of human hearing.
18 THREE METHODS OF REALIZING COMPANDING IN COMMUNICATION SYSTEMS 1. Run the analog signal through a nonlinear circuit before reaching a linear 8 bit ADC, 2. Use an 8 bit ADC that internally has unequally spaced steps, or 3. Use a linear 12 bit ADC followed by a digital lookup table (12 bits in, 8 bits out). Each of these three options requires the same nonlinearity, just in a different place: at analog circuit, at the ADC, or a digital circuit after the ADC.
19 COMPANDING STANDARDS (1) μ255 law used in North America (2) "A" law, used in Europe. 19
20 "A" LAW COMPANDING Where A is the compression parameter 20
21 µ-law COMPANDING where µ is 255 for 8 bits. 21
22 BINARY ENCODING 1. Encoding converts the quantized samples into a form that is more convenient for the purpose of transmission. 2. It is a one-to-one mapping of the quantized samples by using code elements or symbols of the required length per sample.
23 FOLDED BINARY CODE The folded binary code (also called the signmagnitude representation) assigns the first (left most) digit to the sign and the remaining digits are used to code the magnitude. This code is superior to the natural code in masking transmission errors when encoding speech.
24 INVERTED FOLDED BINARY CODE 1. If only the amplitude digits of a folded binary code are complemented (1's changed to 0's and 0's to 1's), an inverted folded binary code results. 2. This code has the advantage of higher density of 1's for small amplitude signals, which are most probable for voice messages. 3. The higher density of 1's relieves some system timing errors.
25 GRAY CODE 1. With natural binary encoding, a number of codeword digits can change even when a change of only one quantization level occurs. For example, a change from level 7 to 8 entails every bit changing in the 4-bit code illustrated. 2. In some applications, this behavior is undesirable and a code is desired for which only one digit changes when any transition occurs between adjacent levels. 3. The Gray Code has this property
26 4-BIT PCM TRANSMITTER - CIRCUIT SCHEMATIC
27 PCM FOR BI-POLAR SIGNALS
28 PCM INTEGRATED CIRCUITS - MC14LC The MC14LC5480 is a general purpose per channel PCM Codec Filter with pin selectable µ Law or A Law companding, and is offered in 20 pin DIP, SOG, and SSOP packages. 2. MC14LC5480 performs voice digitization and reconstruction as well as the band limiting and smoothing required for PCM systems. 3. MC14LC5480 designed to operate in both synchronous and asynchronous applications and contains an on chip precision reference voltage.
29 MC14LC BLOCK DIAGRAM μ/a Law Select (Pin 16) This pin controls the compression for the encoder and the expansion for the decoder. Mu Law companding is selected when this pin is connected to VDD A Law companding is selected when this pin is connected to VSS.
30 MC14LC TYPICAL CONNECTION
31 MC14LC COST KSH 700/=
32 ADVANTAGES OF PCM 1. PCM provides high noise immunity 2. Allows regeneration of clean signal by using repeaters placed between the transmitter and the receiver. 3. PCM signals can be stored for later use or retransmission with high fidelity 4. PCM signals can be encrypted more easily and to very high standards.
33 DISADVANTAGES OF PCM 1. PCM requires complex circuitry to sample, quantize, code and decode. 2. PCM requires large bandwidth compared with that of the original analog signal.
34 DELTA MODULATION ECE 416 Thursday, 08 March 2018
35 DELTA MODULATION 1. Delta modulation seeks to overcome the problem of high bandwidth requirement in conventional PCM. 2. Instead of generating and transmitting many bits per sample, only one bit is transmitted. 3. During coding, the present sample is compared with the previous and a 0 or 1 transmitted depending on whether the sample is higher or lower than the previous. PCM code for each sample
36 SIGNALS IN A DELTA MODULATION SYSTEM Amplitude Original Analog Signal Output from Encoder Output from the receiver (decoder) Time
37 DELTA MODULATION TRANSMITTER x(nt s ) + - x (nt s ) error e(nt s ) One-bit Quantizer b(nt s ) + + Output Delay T s u(nt s ) Accumulator
38 DELTA MODULATION RECEIVER + + Low-pass filter Demodulated Signal Delay T s Accumulator
39 ADVANTAGES OF DELTA MODULATION Delta Modulation: 1. Requires very small bandwidth since it transmits only one bit per sample 2. Has very simple transmitter and receiver circuitry.
40 DISADVANTAGES OF DELTA MODULATION Delta modulation has: a) Slope and overload distortion b) Granular and Idle noise
41 Slope-overload occurs when the step size is too small to follow a steep segment of the input waveform x(t ). SLOPE OVERLOAD
42 GRANULARITY Granularity refers to a situation where the staircase function x(t) hunts around a relatively flat segment of the input function, with a step size that is too large relative to the local slope characteristic of the input.
43 ADAPTIVE DELTA MODULATION ECE 416 Digital Communication Thursday, 08 March 2018
44 Amplitude THE PRINCIPLE OF ADAPATIVE DELTA MODULATION Adaptive Delta Modulation seeks to overcome quantization errors arising from slope overload and granular noise by varying the step size in accordance to the signal amplitude. n+1 n n Time
45 ADAPTIVE DELTA MODULATION TRANSMITTER Logic for step control x(nt s ) + - x (nt s ) error e(nt s ) One-bit Quantizer + + Output Delay T s Accumulator
46 ADAPTIVE DELTA MODULATION RECEIVER Receiver Input Low-pass filter Receiver Output Logic for step-size control Delay T s Accumulator
47 DIFFERENTIAL PULSE CODE MODULATION (DPCM) ECE 416 Digital Communication Thursday, 08 March 2018
48 DIFFERENTIAL PULSE CODE MODULATION 1. Some signals such as speech have high correlation between adjacent samples. 2. When such highly correlated samples are encoded using basic PCM, the resulting code contains a lot of redundant information. 3. In such cases, basic PCM scheme is not the preferred coding method. 4. By removing this redundancy before encoding an efficient coded signal can be obtained. 5. One method of removing redundancy is by using the Differential PCM (DPCM) method. 6. DPCM is based on the principle that by knowing the past behaviour of a signal up to a certain point in time, it is possible to predict future values.
49 DPCM TRANSMITTER Analogue Signal X(t) x(nt s ) e nt s = x nt s x (nt s ) b nt s = coded form of x nt s x nt s x (nt s ) x (nt s ) Quantized value of e nt s = x nt s x (nt s ) u nt s = x^(nt s ) Predictor uses x^(nt s ) and previous values to predict x (nt s )
50 DPCM RECEIVER e nt s = x nt s x (nt s ) y nt s = x(nt s ) b nt s = coded form of e nt s x (nt s ) Predictor uses x^(nt s ) and previous values to predict x (nt s )
51 COMPARISON OF PCM, DELTA MODULATION AND ADAPTIVE PULSE CODE MODULATION N0 PARAMETER PULSE CODE MODULATION (PCM) DELTA MODULATION ADAPTIVE DELTA MODULATION 1 Levels and Step Size Number of levels depend on number of bits Level size is fixed Step size is fixed Step size varies according to the rate at which the signal is varying 2 Number of Bits Can take 4, 8 or 16 bits per sample 3 Quantization errors Quantization noise is and distortion present One bit per sample Has lope overload and granular noise 4 Bandwidth Highest bandwidth Low bandwidth required 5 Feedback in No feedback Feedback in transmitter or transmitter receiver 6 Complexity in implementation High Simple Simple One bit per sample Quantization noise is present Least bandwidth required Feedback in transmitter
Time division multiplexing The block diagram for TDM is illustrated as shown in the figure
CHAPTER 2 Syllabus: 1) Pulse amplitude modulation 2) TDM 3) Wave form coding techniques 4) PCM 5) Quantization noise and SNR 6) Robust quantization Pulse amplitude modulation In pulse amplitude modulation,
More informationEEE 309 Communication Theory
EEE 309 Communication Theory Semester: January 2017 Dr. Md. Farhad Hossain Associate Professor Department of EEE, BUET Email: mfarhadhossain@eee.buet.ac.bd Office: ECE 331, ECE Building Types of Modulation
More informationEEE 309 Communication Theory
EEE 309 Communication Theory Semester: January 2016 Dr. Md. Farhad Hossain Associate Professor Department of EEE, BUET Email: mfarhadhossain@eee.buet.ac.bd Office: ECE 331, ECE Building Part 05 Pulse Code
More informationVoice Transmission --Basic Concepts--
Voice Transmission --Basic Concepts-- Voice---is analog in character and moves in the form of waves. 3-important wave-characteristics: Amplitude Frequency Phase Telephone Handset (has 2-parts) 2 1. Transmitter
More informationCHAPTER 3 Syllabus (2006 scheme syllabus) Differential pulse code modulation DPCM transmitter
CHAPTER 3 Syllabus 1) DPCM 2) DM 3) Base band shaping for data tranmission 4) Discrete PAM signals 5) Power spectra of discrete PAM signal. 6) Applications (2006 scheme syllabus) Differential pulse code
More informationDigital Communication (650533) CH 3 Pulse Modulation
Philadelphia University/Faculty of Engineering Communication and Electronics Engineering Digital Communication (650533) CH 3 Pulse Modulation Instructor: Eng. Nada Khatib Website: http://www.philadelphia.edu.jo/academics/nkhatib/
More informationUNIT III -- DATA AND PULSE COMMUNICATION PART-A 1. State the sampling theorem for band-limited signals of finite energy. If a finite energy signal g(t) contains no frequency higher than W Hz, it is completely
More informationCHAPTER 4. PULSE MODULATION Part 2
CHAPTER 4 PULSE MODULATION Part 2 Pulse Modulation Analog pulse modulation: Sampling, i.e., information is transmitted only at discrete time instants. e.g. PAM, PPM and PDM Digital pulse modulation: Sampling
More informationPulse Code Modulation
Pulse Code Modulation Modulation is the process of varying one or more parameters of a carrier signal in accordance with the instantaneous values of the message signal. The message signal is the signal
More informationEXPERIMENT WISE VIVA QUESTIONS
EXPERIMENT WISE VIVA QUESTIONS Pulse Code Modulation: 1. Draw the block diagram of basic digital communication system. How it is different from analog communication system. 2. What are the advantages of
More informationCODING TECHNIQUES FOR ANALOG SOURCES
CODING TECHNIQUES FOR ANALOG SOURCES Prof.Pratik Tawde Lecturer, Electronics and Telecommunication Department, Vidyalankar Polytechnic, Wadala (India) ABSTRACT Image Compression is a process of removing
More informationEC 6501 DIGITAL COMMUNICATION UNIT - II PART A
EC 6501 DIGITAL COMMUNICATION 1.What is the need of prediction filtering? UNIT - II PART A [N/D-16] Prediction filtering is used mostly in audio signal processing and speech processing for representing
More informationDIGITAL COMMUNICATION
DEPARTMENT OF ELECTRICAL &ELECTRONICS ENGINEERING DIGITAL COMMUNICATION Spring 00 Yrd. Doç. Dr. Burak Kelleci OUTLINE Quantization Pulse-Code Modulation THE QUANTIZATION PROCESS A continuous signal has
More informationChapter-3 Waveform Coding Techniques
Chapter-3 Waveform Coding Techniques PCM [Pulse Code Modulation] PCM is an important method of analog to-digital conversion. In this modulation the analog signal is converted into an electrical waveform
More informationCommunications and Signals Processing
Communications and Signals Processing Dr. Ahmed Masri Department of Communications An Najah National University 2012/2013 1 Dr. Ahmed Masri Chapter 5 - Outlines 5.4 Completing the Transition from Analog
More informationQUESTION BANK. SUBJECT CODE / Name: EC2301 DIGITAL COMMUNICATION UNIT 2
QUESTION BANK DEPARTMENT: ECE SEMESTER: V SUBJECT CODE / Name: EC2301 DIGITAL COMMUNICATION UNIT 2 BASEBAND FORMATTING TECHNIQUES 1. Why prefilterring done before sampling [AUC NOV/DEC 2010] The signal
More information10 Speech and Audio Signals
0 Speech and Audio Signals Introduction Speech and audio signals are normally converted into PCM, which can be stored or transmitted as a PCM code, or compressed to reduce the number of bits used to code
More informationQUESTION BANK EC 1351 DIGITAL COMMUNICATION YEAR / SEM : III / VI UNIT I- PULSE MODULATION PART-A (2 Marks) 1. What is the purpose of sample and hold
QUESTION BANK EC 1351 DIGITAL COMMUNICATION YEAR / SEM : III / VI UNIT I- PULSE MODULATION PART-A (2 Marks) 1. What is the purpose of sample and hold circuit 2. What is the difference between natural sampling
More informationCommunications I (ELCN 306)
Communications I (ELCN 306) c Samy S. Soliman Electronics and Electrical Communications Engineering Department Cairo University, Egypt Email: samy.soliman@cu.edu.eg Website: http://scholar.cu.edu.eg/samysoliman
More informationDepartment of Electronics and Communication Engineering 1
UNIT I SAMPLING AND QUANTIZATION Pulse Modulation 1. Explain in detail the generation of PWM and PPM signals (16) (M/J 2011) 2. Explain in detail the concept of PWM and PAM (16) (N/D 2012) 3. What is the
More informationEC 2301 Digital communication Question bank
EC 2301 Digital communication Question bank UNIT I Digital communication system 2 marks 1.Draw block diagram of digital communication system. Information source and input transducer formatter Source encoder
More informationComm 502: Communication Theory. Lecture 4. Line Coding M-ary PCM-Delta Modulation
Comm 502: Communication Theory Lecture 4 Line Coding M-ary PCM-Delta Modulation PCM Decoder PCM Waveform Types (Line Coding) Representation of binary sequence into the electrical signals that enter the
More informationFundamentals of Digital Communication
Fundamentals of Digital Communication Network Infrastructures A.A. 2017/18 Digital communication system Analog Digital Input Signal Analog/ Digital Low Pass Filter Sampler Quantizer Source Encoder Channel
More informationPulse Code Modulation
Pulse Code Modulation EE 44 Spring Semester Lecture 9 Analog signal Pulse Amplitude Modulation Pulse Width Modulation Pulse Position Modulation Pulse Code Modulation (3-bit coding) 1 Advantages of Digital
More informationSEN366 Computer Networks
SEN366 Computer Networks Prof. Dr. Hasan Hüseyin BALIK (5 th Week) 5. Signal Encoding Techniques 5.Outline An overview of the basic methods of encoding digital data into a digital signal An overview of
More informationUnderstanding Digital Communication Principles.
s Understanding Digital Communication Principles Scientech TechBooks are compact and user friendly learning platforms to provide a modern, portable, comprehensive and practical way to learn Technology.
More informationDigital Communication Prof. Bikash Kumar Dey Department of Electrical Engineering Indian Institute of Technology, Bombay
Digital Communication Prof. Bikash Kumar Dey Department of Electrical Engineering Indian Institute of Technology, Bombay Lecture - 03 Quantization, PCM and Delta Modulation Hello everyone, today we will
More informationPractical Approach of Producing Delta Modulation and Demodulation
IOSR Journal of Electronics and Communication Engineering (IOSR-JECE) e-issn: 2278-2834,p- ISSN: 2278-8735.Volume 11, Issue 3, Ver. II (May-Jun.2016), PP 87-94 www.iosrjournals.org Practical Approach of
More informationChapter 3 Pulse Modulation
Chapter 3 Pulse Modulation Outline Sampling Process: Sampling Theory, Anti-Aliasing Pulse Modulation Analog Pulse Modulation: PAM, PDM, PWM, PPM Digital Pulse Modulation: PCM, DM, DPCM Quantization Process:
More informationWaveform Encoding - PCM. BY: Dr.AHMED ALKHAYYAT. Chapter Two
Chapter Two Layout: 1. Introduction. 2. Pulse Code Modulation (PCM). 3. Differential Pulse Code Modulation (DPCM). 4. Delta modulation. 5. Adaptive delta modulation. 6. Sigma Delta Modulation (SDM). 7.
More informationTelecommunication Electronics
Politecnico di Torino ICT School Telecommunication Electronics C5 - Special A/D converters» Logarithmic conversion» Approximation, A and µ laws» Differential converters» Oversampling, noise shaping Logarithmic
More informationANALOGUE AND DIGITAL COMMUNICATION
ANALOGUE AND DIGITAL COMMUNICATION Syed M. Zafi S. Shah Umair M. Qureshi Lecture xxx: Analogue to Digital Conversion Topics Pulse Modulation Systems Advantages & Disadvantages Pulse Code Modulation Pulse
More informationDownloaded from 1
VII SEMESTER FINAL EXAMINATION-2004 Attempt ALL questions. Q. [1] How does Digital communication System differ from Analog systems? Draw functional block diagram of DCS and explain the significance of
More informationClass 4 ((Communication and Computer Networks))
Class 4 ((Communication and Computer Networks)) Lesson 5... SIGNAL ENCODING TECHNIQUES Abstract Both analog and digital information can be encoded as either analog or digital signals. The particular encoding
More informationEC6501 Digital Communication
EC6501 Digital Communication UNIT -1 DIGITAL COMMUNICATION SYSTEMS Digital Communication system 1) Write the advantages and disadvantages of digital communication. [A/M 11] The advantages of digital communication
More informationData Encoding g(p (part 2)
Data Encoding g(p (part 2) CSE 3213 Instructor: U.T. Nguyen 10/11/2007 12:44 PM 1 Analog Data, Digital Signals (5.3) 2 1 Analog Data, Digital Signals Digitization Conversion of analog data into digital
More informationSyllabus. osmania university UNIT - I UNIT - II UNIT - III CHAPTER - 1 : INTRODUCTION TO DIGITAL COMMUNICATION CHAPTER - 3 : INFORMATION THEORY
i Syllabus osmania university UNIT - I CHAPTER - 1 : INTRODUCTION TO Elements of Digital Communication System, Comparison of Digital and Analog Communication Systems. CHAPTER - 2 : DIGITAL TRANSMISSION
More informationCommunication Systems Lecture-12: Delta Modulation and PTM
Communication Systems Lecture-12: Delta Modulation and PTM Department of Electrical and Computer Engineering Lebanese American University chadi.abourjeily@lau.edu.lb October 26, 2017 Delta Modulation (1)
More informationDIGITAL COMMUNICATION
DIGITAL COMMUNICATION TRAINING LAB Digital communication has emerged to augment or replace the conventional analog systems, which had been used widely a few decades back. Digital communication has demonstrated
More informationDigital Communication - Analog to Digital
Unit 26. Digital Communication Digital Communication - Analog to Digital The communication that occurs in our day-to-day life is in the form of signals. These signals, such as sound signals, generally,
More informationDIGITAL COMMUNICATIONS LAB
DIGITAL COMMUNICATIONS LAB List of Experiments: 1. PCM Generation and Detection. 2. Differential Pulse Code modulation. 3. Delta modulation. 4. Time Division Multiplexing of 2band Limited Signals. 5. Frequency
More informationAnalog and Telecommunication Electronics
Politecnico di Torino - ICT School Analog and Telecommunication Electronics D5 - Special A/D converters» Differential converters» Oversampling, noise shaping» Logarithmic conversion» Approximation, A and
More informationML PCM Codec Filter Mono Circuit
PCM Codec Filter Mono Circuit Legacy Device: Motorola MC145506 The ML145506 is a per channel codec filter PCM mono circuit. This device performs the voice digitization and reconstruction, as well as the
More informationCommunications IB Paper 6 Handout 3: Digitisation and Digital Signals
Communications IB Paper 6 Handout 3: Digitisation and Digital Signals Jossy Sayir Signal Processing and Communications Lab Department of Engineering University of Cambridge jossy.sayir@eng.cam.ac.uk Lent
More information7.1 Introduction 7.2 Why Digitize Analog Sources? 7.3 The Sampling Process 7.4 Pulse-Amplitude Modulation Time-Division i i Modulation 7.
Chapter 7 Digital Representation of Analog Signals Wireless Information Transmission System Lab. Institute of Communications Engineering g National Sun Yat-sen University Contents 7.1 Introduction 7.2
More informationAPPLICATIONS OF DSP OBJECTIVES
APPLICATIONS OF DSP OBJECTIVES This lecture will discuss the following: Introduce analog and digital waveform coding Introduce Pulse Coded Modulation Consider speech-coding principles Introduce the channel
More informationUNIT TEST I Digital Communication
Time: 1 Hour Class: T.E. I & II Max. Marks: 30 Q.1) (a) A compact disc (CD) records audio signals digitally by using PCM. Assume the audio signal B.W. to be 15 khz. (I) Find Nyquist rate. (II) If the Nyquist
More informationCourse 2-3 Fundamental notions of digital telephony. The primary PCM multiplex.
Course 2-3 Fundamental notions of digital telephony. The primary PCM multiplex. Zsolt Polgar Communications Department Faculty of Electronics and Telecommunications, Technical University of Cluj-Napoca
More informationIn this lecture. System Model Power Penalty Analog transmission Digital transmission
System Model Power Penalty Analog transmission Digital transmission In this lecture Analog Data Transmission vs. Digital Data Transmission Analog to Digital (A/D) Conversion Digital to Analog (D/A) Conversion
More informationYear : TYEJ Sub: Digital Communication (17535) Assignment No. 1. Introduction of Digital Communication. Question Exam Marks
Assignment 1 Introduction of Digital Communication Sr. Question Exam Marks 1 Draw the block diagram of the basic digital communication system. State the function of each block in detail. W 2015 6 2 State
More informationMultiplexing Concepts and Introduction to BISDN. Professor Richard Harris
Multiplexing Concepts and Introduction to BISDN Professor Richard Harris Objectives Define what is meant by multiplexing and demultiplexing Identify the main types of multiplexing Space Division Time Division
More informationUNIT-1. Basic signal processing operations in digital communication
UNIT-1 Lecture-1 Basic signal processing operations in digital communication The three basic elements of every communication systems are Transmitter, Receiver and Channel. The Overall purpose of this system
More informationUNIT I Source Coding Systems
SIDDHARTH GROUP OF INSTITUTIONS: PUTTUR Siddharth Nagar, Narayanavanam Road 517583 QUESTION BANK (DESCRIPTIVE) Subject with Code: DC (16EC421) Year & Sem: III-B. Tech & II-Sem Course & Branch: B. Tech
More informationȘ.l. dr. ing. Lucian-Florentin Bărbulescu
Ș.l. dr. ing. Lucian-Florentin Bărbulescu 1 Data: entities that convey meaning within a computer system Signals: are the electric or electromagnetic impulses used to encode and transmit data Characteristics
More informationLecture 3 Concepts for the Data Communications and Computer Interconnection
Lecture 3 Concepts for the Data Communications and Computer Interconnection Aim: overview of existing methods and techniques Terms used: -Data entities conveying meaning (of information) -Signals data
More information3.6 Intersymbol interference. 1 Your site here
3.6 Intersymbol intererence 1 3.6 Intersymbol intererence what is intersymbol intererence and what cause ISI 1. The absolute bandwidth o rectangular multilevel pulses is ininite. The channels bandwidth
More informationChapter-1: Introduction
Chapter-1: Introduction The purpose of a Communication System is to transport an information bearing signal from a source to a user destination via a communication channel. MODEL OF A COMMUNICATION SYSTEM
More informationCHAPTER 2. Instructor: Mr. Abhijit Parmar Course: Mobile Computing and Wireless Communication ( )
CHAPTER 2 Instructor: Mr. Abhijit Parmar Course: Mobile Computing and Wireless Communication (2170710) Syllabus Chapter-2.3 Modulation Techniques Reasons for Choosing Encoding Techniques Digital data,
More informationSixth Semester B.E. Degree Examination, May/June 2010 Digital Communication Note: Answer any FIVEfull questions, selecting at least TWO questionsfrom each part. PART-A a. With a block diagram, explain
More informationCommunication Theory II
Communication Theory II Lecture 18: Pulse Code Modulation Ahmed Elnakib, PhD Assistant Professor, Mansoura University, Egypt April 19 th, 2015 1 Lecture Outlines opulse Code Modulation (PCM) Sampling and
More informationEEE482F: Problem Set 1
EEE482F: Problem Set 1 1. A digital source emits 1.0 and 0.0V levels with a probability of 0.2 each, and +3.0 and +4.0V levels with a probability of 0.3 each. Evaluate the average information of the source.
More informationAMSEC/ECE
EC6501 -DIGITAL COMMUNICATION UNIT-I SAMPLING & QUANTIZATION 1. Define Dirac comb or ideal sampling function. What is its Fourier Transform? Dirac comb is nothing but a periodic impulse train in which
More informationChapter 4 Digital Transmission 4.1
Chapter 4 Digital Transmission 4.1 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 4-2 ANALOG-TO-DIGITAL CONVERSION We have seen in Chapter 3 that a digital signal
More informationPulse Code Modulation (PCM)
Pulse Code Modulation (PCM) PCM in the Bell System Multiplexing PCM Asynchronous PCM Extensions to PCM Differential PCM (DPCM) Adaptive DPCM (ADPCM) Delta-Sigma Modulation (DM) Vocoders PCM in the Bell
More informationAdvantages of Analog Representation. Varies continuously, like the property being measured. Represents continuous values. See Figure 12.
Analog Signals Signals that vary continuously throughout a defined range. Representative of many physical quantities, such as temperature and velocity. Usually a voltage or current level. Digital Signals
More informationSUMMER 14 EXAMINATION Model Answer
SUMMER 14 EXAMINATION Model Answer Subject Code: 12188 Important Instructions to examiners: 1) The answers should be examined by key words and not as word-to-word as given in the model answer scheme. 2)
More informationDigital to Digital Encoding
MODULATION AND ENCODING Data must be transformed into signals to send them from one place to another Conversion Schemes Digital-to-Digital Analog-to-Digital Digital-to-Analog Analog-to-Analog Digital to
More informationtechniques are means of reducing the bandwidth needed to represent the human voice. In mobile
8 2. LITERATURE SURVEY The available radio spectrum for the wireless radio communication is very limited hence to accommodate maximum number of users the speech is compressed. The speech compression techniques
More informationChapter 4 Digital Transmission 4.1
Chapter 4 Digital Transmission 4.1 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 4-1 DIGITAL-TO-DIGITAL CONVERSION In this section, we see how we can represent
More informationDEPARTMENT OF COMPUTER GCE@Bodi_ SCIENCE GCE@Bodi_ AND ENIGNEERING GCE@Bodi_ GCE@Bodi_ GCE@Bodi_ Analog and Digital Communication GCE@Bodi_ DEPARTMENT OF CsE Subject Name: Analog and Digital Communication
More informationDIGITAL COMMUNICATION. In this experiment you will integrate blocks representing communication system
OBJECTIVES EXPERIMENT 7 DIGITAL COMMUNICATION In this experiment you will integrate blocks representing communication system elements into a larger framework that will serve as a model for digital communication
More informationECE 556 BASICS OF DIGITAL SPEECH PROCESSING. Assıst.Prof.Dr. Selma ÖZAYDIN Spring Term-2017 Lecture 2
ECE 556 BASICS OF DIGITAL SPEECH PROCESSING Assıst.Prof.Dr. Selma ÖZAYDIN Spring Term-2017 Lecture 2 Analog Sound to Digital Sound Characteristics of Sound Amplitude Wavelength (w) Frequency ( ) Timbre
More informationOverview of Digital Mobile Communications
Overview of Digital Mobile Communications Dong In Kim (dikim@ece.skku.ac.kr) Wireless Communications Lab 1 Outline Digital Communications Multiple Access Techniques Power Control for CDMA IMT-2000 System
More informationCOMPUTER COMMUNICATION AND NETWORKS ENCODING TECHNIQUES
COMPUTER COMMUNICATION AND NETWORKS ENCODING TECHNIQUES Encoding Coding is the process of embedding clocks into a given data stream and producing a signal that can be transmitted over a selected medium.
More informationChapter 2: Fundamentals of Data and Signals
Chapter 2: Fundamentals of Data and Signals TRUE/FALSE 1. The terms data and signal mean the same thing. F PTS: 1 REF: 30 2. By convention, the minimum and maximum values of analog data and signals are
More informationLab.3. Tutorial : (draft) Introduction to CODECs
Lab.3. Tutorial : (draft) Introduction to CODECs Fig. Basic digital signal processing system Definition A codec is a device or computer program capable of encoding or decoding a digital data stream or
More informationReal-Time Application of DPCM and ADM Systems
8th IEEE, IET International Symposium on Communication Systems, Networks and Digital Signal Processing Real-Time Application of DPCM and ADM Systems Roger Achkar, Ph.D, Member, IEEE. Department of Computer
More informationDhanalakshmi College of Engineering Manimangalam, Tambaram, Chennai
Dhanalakshmi College of Engineering Manimangalam, Tambaram, Chennai 601 301 DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING V SEMESTER - R 2013 EC6512 COMMUNICATION SYSTEMS LABORATORY LABORATORY
More informationQUESTION BANK SUBJECT: DIGITAL COMMUNICATION (15EC61)
QUESTION BANK SUBJECT: DIGITAL COMMUNICATION (15EC61) Module 1 1. Explain Digital communication system with a neat block diagram. 2. What are the differences between digital and analog communication systems?
More informationNEAR EAST UNIVERSITY FA CUL TY OF ENGINEERING. Waveform Encoding Techniques Based on Differential and Adaptive Quantizing. Wael Sulaiman Mashawekh
NEAR EAST UNIVERSITY FA CUL TY OF ENGINEERING Waveform Encoding Techniques Based on Differential and Adaptive Quantizing Wael Sulaiman Mashawekh Master Thesis Department of Electrical and Electronic Engineering
More information17. Delta Modulation
7. Delta Modulation Introduction So far, we have seen that the pulse-code-modulation (PCM) technique converts analogue signals to digital format for transmission. For speech signals of 3.2kHz bandwidth,
More informationDigital transmission has several advantages over analog transmission:
DIGITAL TRANSMISSION Pulse Modulation, Pulse code Modulation, Dynamic Range, Signal Voltage to-quantization Noise Voltage Ration, Linear Versus Nonlinear PCM Codes, Companding, PCM Line Speed, Delta Modulation
More information2. By convention, the minimum and maximum values of analog data and signals are presented as voltages.
Chapter 2: Fundamentals of Data and Signals Data Communications and Computer Networks A Business Users Approach 8th Edition White TEST BANK Full clear download (no formatting errors) at: https://testbankreal.com/download/data-communications-computer-networksbusiness-users-approach-8th-edition-white-test-bank/
More informationSignal Encoding Techniques
2 Techniques ITS323: to Data Communications CSS331: Fundamentals of Data Communications Sirindhorn International Institute of Technology Thammasat University Prepared by Steven Gordon on 3 August 2015
More informationLecture Outline. Data and Signals. Analogue Data on Analogue Signals. OSI Protocol Model
Lecture Outline Data and Signals COMP312 Richard Nelson richardn@cs.waikato.ac.nz http://www.cs.waikato.ac.nz Analogue Data on Analogue Signals Digital Data on Analogue Signals Analogue Data on Digital
More informationKINGS COLLEGE OF ENGINEERING DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING QUESTION BANK. Subject Name: Digital Communication Techniques
KINGS COLLEGE OF ENGINEERING DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING QUESTION BANK Subject Code: EC1351 Year/Sem: III/IV Subject Name: Digital Communication Techniques UNIT I PULSE MODULATION
More informationElectronics Interview Questions
Electronics Interview Questions 1. What is Electronic? The study and use of electrical devices that operate by controlling the flow of electrons or other electrically charged particles. 2. What is communication?
More informationData Encoding. Two devices are used for producing the signals: CODECs produce DIGITAL signals MODEMs produce ANALOGUE signals
Data Encoding Data are propagated from point to point by encoding data into signals The data may be analogue or digital Likewise the signals may be analogue or digital Two devices are used for producing
More information9.4. Synchronization:
9.4. Synchronization: It is the process of timing the serial transmission to properly identify the data being sent. There are two most common modes: Synchronous transmission: Synchronous transmission relies
More informationWaveform Coding Algorithms: An Overview
August 24, 2012 Waveform Coding Algorithms: An Overview RWTH Aachen University Compression Algorithms Seminar Report Summer Semester 2012 Adel Zaalouk - 300374 Aachen, Germany Contents 1 An Introduction
More informationEE390 Final Exam Fall Term 2002 Friday, December 13, 2002
Name Page 1 of 11 EE390 Final Exam Fall Term 2002 Friday, December 13, 2002 Notes 1. This is a 2 hour exam, starting at 9:00 am and ending at 11:00 am. The exam is worth a total of 50 marks, broken down
More informationCT111 Introduction to Communication Systems Lecture 9: Digital Communications
CT111 Introduction to Communication Systems Lecture 9: Digital Communications Yash M. Vasavada Associate Professor, DA-IICT, Gandhinagar 31st January 2018 Yash M. Vasavada (DA-IICT) CT111: Intro to Comm.
More informationAnalog Communication.
Analog Communication Vishnu N V Tele is Greek for at a distance, and Communicare is latin for to make common. Telecommunication is the process of long distance communications. Early telecommunications
More informationDepartment of Electronics & Telecommunication Engg. LAB MANUAL. B.Tech V Semester [ ] (Branch: ETE)
Department of Electronics & Telecommunication Engg. LAB MANUAL SUBJECT:-DIGITAL COMMUNICATION SYSTEM [BTEC-501] B.Tech V Semester [2013-14] (Branch: ETE) KCT COLLEGE OF ENGG & TECH., FATEHGARH PUNJAB TECHNICAL
More informationQUESTION BANK. Staff In-Charge: M.MAHARAJA, AP / ECE
FATIMA MICHAEL COLLEGE OF ENGINEERING & TECHNOLOGY Senkottai Village, Madurai Sivagangai Main Road, Madurai -625 020 An ISO 9001:2008 Certified Institution QUESTION BANK Sub. Code : EC 2301 Class : III
More informationSUMMER 15 EXAMINATION. 1) The answers should be examined by key words and not as word-to-word as given in the
SUMMER 15 EXAMINATION Subject Code: 17535 Model Answer Important Instructions to examiners: 1) The answers should be examined by key words and not as word-to-word as given in the model answer scheme. 2)
More informationDELTA MODULATION. PREPARATION principle of operation slope overload and granularity...124
DELTA MODULATION PREPARATION...122 principle of operation...122 block diagram...122 step size calculation...124 slope overload and granularity...124 slope overload...124 granular noise...125 noise and
More informationSignal Encoding Techniques
Signal Encoding Techniques Overview Have already noted previous chapters that both analog and digital information can be encoded as either analog or digital signals: Digital data, digital signals: simplest
More informationChapter 2: Digitization of Sound
Chapter 2: Digitization of Sound Acoustics pressure waves are converted to electrical signals by use of a microphone. The output signal from the microphone is an analog signal, i.e., a continuous-valued
More informationBAPATLA ENGINEERING COLLEGE DIGITAL COMMUNICATIONS LAB EC-451. PREPARED BY S. Pallaviram, Lecturer
BAPATLA ENGINEERING COLLEGE DIGITAL COMMUNICATIONS LAB EC-451 PREPARED BY S. Pallaviram, Lecturer Department of Electronics and Communications Engineering Bapatla Engineering College (Affiliated to Acharya
More information