ANALOG AND DIGITAL COMMUNICATION Prepared according to Anna university syllabus R-2017 (Common to III semester-CSE/IT ) G Elumalai, M.E.,(Ph.D) Assistant Professor (Grade I) Department of Electronics and Communication Engineering Panimalar Engineering College Chennai Er m JaiGanEsh, M.E., Assistant Professor Department of Electronics and Communication Engineering Panimalar Engineering College Chennai SREE KAMALAMANI PUBLICATIONS CHENNAI SREE KAMALAMANI PUBLICATIONS (P) Ltd Publised by SREE KAMALAMANI PUBLICATIONS New No AJ 21, old No AJ 52, Plot No 2614, 4th Cross, 9th Main Road, Anna Nagar -600 040, Chennai, Tamilnadu, India Landline: 91-044-42170813, Mobile: 91-9840795803 EMAil id: skmpulbicationsmumdad@gmail.com 1ST EdiTioN 2014 2Nd REViSEd EdiTioN 2016 Copyright © 2014, by Sree Kamalamani Publications No part of this publication may be reproduced or distributed in any form or by any means, electronic, mechanical, photocopying, recording or otherwise or stored in a database or retrieval system without the prior written permission of the publishers This edition can be exported from India only by the Publishers, Sree Kamalamani Publications ISBN (13 digits): 978-93-85449-12-3 Information contained in this work has been obtained by Sree Kamalamani Publications, from sources believed to be reliable However, neither Sree Kamalamani Publications nor its authors guarantee the accuracy or completeness of any information published herein, and neither; Sree Kamalamani nor its authors shall be responsible for any errors, omissions, or damages arising out of use of this information This work is published with the understanding that Sree kamalamani publications and its authors are supplying information but are not attempting to render engineering or other professional services if such services are required, the assistance of an appropriate professional should be sought Typeset & Coverpage : Sree Kamalamani Publications New No AJ 21, Old No AJ 52, Plot No 2614, 9th Main, 4th cross, Anna Nagar-600 040 Chennai, Tamilnadu, India Landline: 91-044-42170813, Mobile: 91-9840795803 About the Author G.Elumalai M.E., is working as an Assistant Professor (Grade – I) in the Department of Electronics and Communication Engineering, Panimalar Engineering College, Chennai He obtained his B.E in Electronics and Communication Engineering; M.E in Applied Electronics and Ph.D pursing in Wireless Sensor Network His areas of interests are Communication System, Digital communication, Digital signal processing and Wireless Sensor Network He has more than 13 years of experience M.Jaiganesh M.E., is working as an Assistant Professor in the Department of Electronics and Communication Engineering, Panimalar Engineering College, Chennai He obtained his B.E in Electronics and Communication Engineering; M.E in Computer and Communication His areas of interests are Communication System, Digital communication, Optical Communication and Embedded system He has more than years of experience PREFACE Dear Students, We are extremely happy to present the book “Analog and Digital Communication” for you This book has been written strictly as per the revised syllabus (R2013) of Anna University We have divided the subject into five units so that the topics can be arranged and understood properly The topics within the units have been arranged in a proper sequence to ensure smooth flow of the subject Unit I - Introduce the basic concepts of communication, need of modulation and different types of analog modulation (Amplitude modulation, Frequency modulation and Phase modulation) Unit II - Deals with basic concepts of digital communication which includes ASK, FSK, PSK, QPSK and QAM Unit III - Discuss about concept of data communication and various pulse modulation technique Unit IV - Concentrate on various techniques for error control coding Unit V – Describe about multiuser radio communication A large number of solved university examples and university questions have been included in each unit, so we are sure that this book will cater all your needs for this subject We have made every possible effort to eliminate all the errors in this book However if you find any, please let we know, because that will help for us to improve further G.Elumalai M.Jaiganesh EC8394 ANALOG AND DIGITAL COMMUNICATION L T P C 0 UNIT I ANALOG COMMUNICATION Noise: Source of Noise - External Noise- Internal Noise- Noise Calculation Introduction to Communication Systems: Modulation – Types - Need for Modulation Theory of Amplitude Modulation - Evolution and Description of SSB Techniques - Theory of Frequency and Phase Modulation – Comparison of various Analog Communication System (AM – FM – PM) UNIT II DIGITAL COMMUNICATION Amplitude Shift Keying (ASK) – Frequency Shift Keying (FSK) Minimum Shift Keying (MSK) –Phase Shift Keying (PSK) – BPSK – QPSK – PSK – 16 PSK - Quadrature Amplitude Modulation (QAM) – QAM – 16 QAM – Bandwidth Efficiency– Comparison of various Digital Communication System (ASK– FSK – PSK – QAM) UNIT III DATA AND PULSE COMMUNICATION Data Communication: History of Data Communication - Standards Organizations for Data Communication- Data Communication Circuits - Data Communication Codes - Error Detection and Correction Techniques - Data communication Hardware serial and parallel interfaces Pulse Communication: Pulse Amplitude Modulation (PAM) – Pulse Time Modulation (PTM) – Pulse code Modulation (PCM) - Comparison of various Pulse Communication System (PAM – PTM – PCM) UNIT IV SOURCE AND ERROR CONTROL CODING Entropy, Source encoding theorem, Shannon fano coding, Huffman coding, mutual information, channel capacity, channel coding theorem, Error Control Coding, linear block codes, cyclic codes, convolution codes, viterbi decoding algorithm UNIT V MULTI-USER RADIO COMMUNICATION Advanced Mobile Phone System (AMPS) - Global System for Mobile Communications (GSM) - Code division multiple access (CDMA) – Cellular Concept and Frequency Reuse - Channel Assignment and Hand - Overview of Multiple Access Schemes - Satellite Communication - Bluetooth TABLE OF CONTENTS TABLE OF CONTENTS UNIT – I ANALOG COMMUNICATION 1.1-1.120 1.1 Introduction 1.2 1.2 Noise 1.5 1.3 Introduction to communication system 1.12 1.4 Modulation 1.16 1.5 Need for modulation 1.17 1.6 Classifications of modulation 1.7 Some important definitions related to 1.20 communication 1.21 1.8 Theory of Amplitude modulation 1.24 1.9 Generation of SSB 1.58 1.10 AM – Transmitters 1.65 1.11 AM Super heterodyne receiver with its characteristic Performance 1.68 1.12 Performance characteristics of a receiver 1.72 1.13 Theory of Frequency and Phase modulation 1.75 1.14 Comparison of various analog communication system 1.103 Solved two mark questions 1.106 Review Questions 1.117-1.120 UNIT – II DIGITAL COMMUNICATION 2.1-2.84 2.1 Introduction 2.2 2.2 Digital Transmission system 2.3 2.3 Digital Radio 2.4 2.4 Information capacity 2.5 2.5 Trade of between, Bandwidth and SNR 2.7 2.6 M-ary encoding 2.10 2.7 Digital Continuous wave modulation technique 2.10 Analog and Digital communication 2.8 Amplitude shift keying (or) Digital Amplitude Modulation (or) OOK – System 2.12 2.9 Frequency shift keying 2.18 2.10 Minimum shift keying (or) continuous phase frequency shift keying 2.26 2.11 Phase shift keying 2.27 2.12 Differential Phase shift keying 2.37 2.13 Quadrature Phase shift keying 2.41 2.14 PSK System 2.49 2.15 16 PSK System 2.56 2.16 Quadrature Amplitude modulation 2.57 2.17 16 - QAM 2.61 2.18 Carrier recovery (phase referencing) 2.66 2.19 Clock recovery circuit 2.70 2.20 Comparison of various digital communication system 2.72 Solved two mark questions 2.74 Review Questions UNIT – III DATA AND PULSE COMMUNICATION 2.83-2.84 3.1-3.128 3.1 Introduction 3.2 3.2 History of data communication 3.3 3.3 Components of Data communication systems 3.4 3.4 Standard organization for data communication 3.6 3.5 Data communication circuits 3.7 3.6 Data transmission 3.8 3.7 Configurations 3.13 3.8 Topologies 3.14 3.9 Transmission modes 3.15 3.10 Data communication codes 3.18 3.11 Introduction to error detection and correction techniques 3.25 3.12 Error detection techniques 3.28 3.13 Error correction techniques 3.45 TABLE OF CONTENTS 3.14 Data communication hardware 3.51 3.15 Serial interface 3.63 3.16 Centronics – Parallel interface 3.72 3.17 Introduction to Pulse modulation 3.76 3.18 Pulse Amplitude Modulation (PAM) 3.80 3.19 Pulse Width Modulation (PWM) 3.83 3.20 Pulse Position Modulation (PPM) 3.84 3.21 Pulse Code Modulation (PCM) 3.84 3.22 Differential Pulse Code Modulation (DPCM) 3.104 3.23 Delta Modulation (DM) 3.107 3.24 Adaptive Delta Modulation (ADM) 3.111 3.25 Comparison of various pulse communication system 3.115 3.26 Comparison of various source coding methods 3.117 Solved two mark questions 3.119 Review Questions 3.126-3.128 UNIT – IV SOURCE AND ERROR CONTROL CODING 4.1-4.138 4.1 Introduction 4.2 4.2 Entropy (or) average information (H) 4.6 4.3 Source coding to increase average information per bit 4.18 4.4 Data compaction 4.20 4.5 Shannon fano coding algorithm 4.20 4.6 Huffman coding algorithm 4.24 4.7 Mutual information 4.39 4.8 Channel capacity 4.45 4.9 Maximum entropy for continuous channel 4.46 4.10 Channel coding theorem 4.47 4.11 Error control codings 4.57 4.12 Linear Block codes 4.59 4.13 Hamming codes 4.61 4.14 Syndrome decoding for Linear block codes 4.69 4.15 Cyclic codes 4.88 4.16 Convolutional codes 4.100 4.17 Decoding methods of Convolutional codes 4.113 Analog and Digital communication Solved two mark questions Review Questions UNIT – V MULTI-USER RADIO COMMUNICATION 4.130 4.137-4.138 5.1-5.78 5.1 Introduction 5.2 5.2 Advanced Mobile Phone Systems (AMPS) 5.4 5.3 Global system for mobile - GSM (2G) 5.8 5.4 CDMA 5.19 5.5 Cellular network 5.25 5.6 Multiple access techniques for wireless Communication 5.37 5.7 Satellite communication 5.47 5.8 Satellite Link system Models 5.48 5.9 Earth station (or) ground station 5.52 5.10 Kepler’s laws 5.54 5.11 Satellite Orbits 5.56 5.12 5.58 Satellite Elevation categories 5.13 Satellite frequency plans and allocation 5.60 5.14 5.60 5.75-5.77 5.78 MULTI-USER RADIO COMMUNICATION Baseband Concerned with connection establishment within a piconet, addressing, packet format, timing, and power control Link manager protocol (LMP) Responsible for link setup between Bluetooth devices and ongoing link management This includes security aspects such as authentication and encryption, plus the control and negotiation of baseband packet sizes Logical link control and adaptation protocol (L2CAP) Adapts upper-layer protocols to the baseband layer L2CAP provides both connection less and connection-oriented services Service discovery protocol (SDP) Device information, services, and the characteristics of the services can be queried to enable the establishment of a connection between two or more Bluetooth devices AT Commands = core protocols vCard/vCal WAE =Cable WAP OBEX replacements protocol UDP/TCP =Telephony control IP protocols =Adopted protocols PPP TCS BIN SDP Control Audio Logical link control and Adaptation Protocol (L2CAP) Host-Controller Interface Link Manager Protocol (LMP) Baseband Bluetooth Radio Figure 5.36 Bluetooth Protocol Stack AT = attention sequence (modem prefix) ANALOG AND DIGITAL COMMUNICATION IP = Internet Protocol OBEX = Object Exchange Protocol PPP = Point-to-Point Protocol RFCOMM = Radio frequency communications SDP =Service Delivery Protocol TCP =Transmission Control Protocol TCS BIN = Telephony control specification-binary UDP = User Datagram Protocol vCal = virtual calendar vCard = virtual card WAE =Wireless application Environment WAP =Wireless Application Protocol Cable replacement protocol cc RFCOMM is the cable replacement protocol include in the Bluetooth specification RFCOMM presents a virtual serial port that is designed to make replacement of cable technologies as transparent as possible Serial ports are one of the most common types of communications interfaces used with computing and communications devices Hence, RFCOMM enables the replacement of serial port cables with the minimum of modification of existing devices RFCOMM provides for binary data transport and emulates EIA-232 control signals over the Bluetooth baseband layer EIA-232 (formerly known as RS-232) is a widely used serial port interface standard Telephony control protocol cc Telephony control specification – binary (TCS BIN) is a bit- oriented protocol that defines the call control signaling for MULTI-USER RADIO COMMUNICATION the establishment of speech and data calls between Bluetooth devices In addition, it defines mobility management procedures for handling groups of Bluetooth TCS devices Adopted protocols cc PPP: The point-to-point protocol is an Internet standard protocol for transporting IP datagram over a point-to-point link cc TCP/UDP/IP: These are the foundation protocols of the TCP/IP protocol suite cc OBEX: The object exchange protocol is a session-level protocol developed by the Infrared Data Association (IrDA) for the exchange of objects OBEX provides functionality similar to that of HTTP, but in a simpler fashion It also provides a model for representing objects and operations Examples of content formats transferred by OBEX are vCard and vCalendar, which provide the format of an electronic business card and personal calendar entries and scheduling information, respectively cc WAE/WAP: Bluetooth incorporates the wireless application environment and the wireless application protocol into its architecture Usage Models A number of usage models are defined in Bluetooth profile documents In essence, a usage model is set of protocols that implement a particular Bluetooth-based application Each profile defines the protocols and protocol features supporting a particular usage model File transfer: The file transfer usage model supports the transfer of directories, files, documents, images, and streaming media formats This usage model also includes the capability to browse folders on a remote device ANALOG AND DIGITAL COMMUNICATION MULTI-USER RADIO COMMUNICATION Figure 5.37 Usage Models Internet Bridge: With this usage model, a PC is wirelessly connected to a mobile phone or cordless modern to provide dialup networking and fax capabilities For dial-up networking, AT commands are wed to control the mobile phone or modem, and another protocol stack (e.g., PPP over RFCOMM) is used for data transfer For fax transfer, the fax software op rates directly over RFCOMM LAN access: This usage model enables devices on a piconet to access a LAN Once connected, a device functions as if it were directly connected (wired) to the LAN Synchronization: This model provides a device-to-device synchronization of PIM (personal information management) information, such a phone book, calendar, message, and note information IrMC (Ir mobile communications) is an IrDA protocol that provides a client/server capability for transferring updated PIM information from one device to another Three-in-one phone: Telephone handsets that implement this usage ANALOG AND DIGITAL COMMUNICATION model may act as a cordless phone connecting to a voice base station, as an intercom device for connecting to other telephones, and as a cellular phone Headset: The headset can act as a remote device’s audio input and output interface 5.14.5 ‘Piconets and Scatternets Piconet • Basic unit of Bluetooth networking: a piconet, consisting of a master and from one to seven active slave devices The radio designated as the master makes the determination of the channel (frequency-hopping sequence) and phase (timing offset, i.e., when to transmit) that shall be used by all devices on this piconet The radio designated as master makes this determination using its own device address as a parameter, while the slave devices must tune to the same channel and phase A slave may only communicate with the master and may only communicate when granted permission by the master A device in one piconet may also exist as part of another piconet and may function as either a slave or master in each piconet Figure 5.38 Piconet and Scatternet MULTI-USER RADIO COMMUNICATION Scatternet cc Device in one piconet may exist as master or slave in another piconet This form of overlapping is called a Scatternet Fig 5.39 Master/Slave Relationships Figure 5.40 Wireless Network Configurations Advantage of the Piconet/Scatternet Scheme • It allows many devices to share same physical area • It makes efficient use of bandwidth ANALOG AND DIGITAL COMMUNICATION 5.14.7 Bluetooth Radio Specification The Bluetooth Radio (layer) is the lowest defined layer of the Bluetooth specification It defines the requirements of the Bluetooth transceiver device operating in the 2.4GHz ISM band The Bluetooth air interface is based on three power classes, • Power Class 1: designed for long range (~100m), max output power of 20 dBm, • Power Class 2: ordinary range devices (~10m), max output power of dBm, • Power Class 3: short range devices (~10cm), with a max output power of dBm The radio uses Frequency Hopping to spread the energy across the ISM spectrum in 79 hops displaced by 1MHz, starting at 2.402 GHz and stopping at 2.480GHz Some countries use the 79 RF channels whereas countries like Japan use 23 channels Currently, the SIG (Special Interest Group) is working to harmonize this 79-channel radio to work globally and has instigated changes within Japan, Spain, and other countries Also, the Bluetooth radio module uses GFSK (Gaussian Frequency Shift Keying) where a binary one is represented by a positive frequency deviation and a binary zero by a negative frequency deviation BT is set to 0.5 and the modulation index must be between 0.28 and 0.35 The receiver must have a sensitivity level for which the bit error rate (BER) 0.1% is met For Bluetooth this means an actual sensitivity level of -70 dBm or better 5.14.8 Baseband Specification The Baseband is the physical layer of the Bluetooth It manages physical channels and links apart from other services like error correction, data whitening, hop selection and Bluetooth security As mentioned previously, the basic radio is a hybrid spread spectrum radio Typically, the radio operates in a frequency-hopping manner in which the 2.4 GHz ISM band is broken into 79 channels 1MHz that the radio randomly hops through while transmitting and receiving MULTI-USER RADIO COMMUNICATION data A piconet is formed when one Bluetooth radio connects to another Bluetooth radio Both radios then hop together through the 79 channels The Bluetooth radio system supports a large number of piconets by providing each piconet with its own set of random hopping patterns Occasionally, piconets will end up on the same channel When this occurs, the radios will hop to a free channel and the data are retransmitted (if lost) The Bluetooth frame consists of a transmit packet followed by a receive packet Each packet can be composed of multiple slots (1, 3, or 5) of 625us A typical single slot frame typically hops at 1,600hops/second Multi-slot frames allow higher data rates because of the elimination of the turn-around time between packets and the reduction in header overhead ADVANTAGES hh Low Power Consumption hh Works in noisy environments hh No line of sight restriction hh Reliable and secure hh The 2.45 GHz ensures universal compatibility Also complies with airline regulations hh The qualification and logo program ensure higher quality hh Very Robust as the radio hops faster and uses shorter packets DISADVANTAGES • Too many unfeasible applications so we really need it? • No handoff / handover capability • Initial stages so it needs to prove its worth • Few analog or FH cordless phones have designed to operate at the ANALOG AND DIGITAL COMMUNICATION 2.4 GHz band Certainly interference exists in between, but more serious effects would be exerted on analog 2.4 GHz cordless phone TECHNICAL SPECIFICATIONS Table 5.2 Technical Specifications MULTI-USER RADIO COMMUNICATION Comparison of 802.11 and Bluetooth 802.11 Bluetooth Represents Internet Already proved itself Widespread Connectivity Represents faux internet Still to prove Connect at close proximity ANALOG AND DIGITAL COMMUNICATION Solved Two Marks Part-A What is AMPS and in what way it differs from D-Amps? AMPS is a purely analog cellular telephone system developed by Bells Labs and use North America and other countries On the other hand D-Amps is a backward compatible digital version of AMPS What is IG and 2G? First generation use analog FM for speech transmission (i) AMPS→Advanced mobile phone system (ii) ETACS→European Total Access Communication System (iii) NTT→Nippon Telephone and Telegraph Second generation use digital system (i) GSM→Global System for Mobile (ii) IS-136→Interim Standard 136 (iii) PDC→Pacific Digital Cellular (iv) IS-95→Interim Standard 95 code Division Multiple Access Define MS,BS and MSC MS→Mobile Station – A Station in the Cellular radio service intended for use (e g) Hand held units (portables), installed in vehicles (mobiles) BS→Base Station –A fixed Station in a mobile radio system used for r+++++ audio communication with MS MSC→Mobile switching centre-co ordinates the routing of calls in a service area What is meant by frequency reuse? Physical Separation of two cells is sufficiently wide means the same subset of frequencies can be used in both cells So the spectrum is efficiently utilized MULTI-USER RADIO COMMUNICATION Define Hand off and mode of Hand-off The process of transferring as MS from one BS to another BS is known as simply Hand-off (or) Hand-over Mode of Hand-off MCHO-Mobile controlled Hand-off NCHO-network Controlled Hand-off MAHO-Mobile Assisted Hand-off What are the types of Hand-off? Hard HO→Mobile monitors BS and new cell is allocated to a call with strong signal Soft HO→MS with or more calls at the same time and find which one is the strongest signal BS, then MSC automatically transfers the calls to that BS Advantages: Fast and loss less Efficient use of spectrum Write the principles of cellular network If a given set of frequencies (or) radio channels can be reused without increasing the interference , then the large geographical area is covered by a single high power transmitter The Large cell is divided into smaller cells; each allocated a subset of frequencies For small area, low power transmitter with lower antennas is used Define cell, cluster Each cellular base station is allocated a group of radio channels to be used with a small geographical area called a cell A group of cells that use a different set of frequencies in each cell is called a cluster What you mean by foot print, dwell time? The actual radio coverage of a cell is known as the foot print The time over which a call may be maintained within a cell without hand-off is called the dwell time ANALOG AND DIGITAL COMMUNICATION 10 Define Frequency reuse ratio Distance between centre of the nearest to channel cells Q=D/R= Radius of the cell 11 Define FDMA, TDMA and CDMA FDMA→ The total bandwidth is divided into non-overlapping frequency sub-bands TDMA→Divides the radio spectrum into time slots and in each slot only one user is allowed to either transmit or receive CDMA→Many users share the same frequency same time with different coding 12 State the principle of CDMA? * Many users share the same frequency * Each user is assigned a different spreading code 13 Write the goal of GSM-Standard *Better and more efficient technical solution for wireless communication *Single Standard was to be realized all over Europe enabling roaming across borders 14 What is mobility management ? Mobility management deals with two important aspects; Hand-off management and location management Hand-off management maintains service continuity when an MS migrates out of its current BS into the footprint of another BS To this it is necessary to keep track of the user’s current location The procedure performs for this purpose is known as location management 15 What is the maximum number of callers in each cell in a GSM? In multi-frame 8-users can transmit in 8-slots As there are 124 such channels are sent simultaneously using TDMA , total number of callers in a clusters is 124 x As reuse factor is in GSM, maximum number of callers in a cell is (124x8)%7=141 MULTI-USER RADIO COMMUNICATION Review Question Part-A What is AMPS and in what way it differs from D-Amps? What is IG and 2G? Define MS,BS and MSC What is meant by frequency reuse? Define Hand off and mode of Hand-off What are the types of Hand-off? Write the principles of cellular network Define cell, cluster What you mean by foot print, dwell time? 10 Define Frequency reuse ratio 11 Define FDMA, TDMA and CDMA 12 State the principle of CDMA? 13 Write the goal of GSM-Standard 14 What is mobility management ? 15 What is the maximum number of callers in each cell in a GSM? PART-B Explain briefly the principle of cellular networks Compare TDMA, FDMA and CDMA Discuss on 1G of mobile network (or) AMPS Discuss the effects of multipath propagation on CDMA-technique Enumerate on (i) GSM architecture (ii) GSM-Channels Explain code division multiple Access (CDMA) and compare its performance with TDMA Explain in detail about the GSM-logical channels Write short notes on (i) Frequency reuse (ii) Channel alignment (iii) Hand-off Write short notes on Bluetooth technology 10 Discuss various multiple access techniques ... Digital (or) analog signal Carrier - continuous signal (analog) ANALOG AND DIGITAL COMMUNICATION 1.6 CLASSIFICATIONS OF MODULATION Modulation Analog modulation Digital modulation Continuous Analog. . .ANALOG AND DIGITAL COMMUNICATION Prepared according to Anna university syllabus R-2017 (Common to III semester-CSE/IT ) G Elumalai, M.E.,(Ph.D)... consists of the electronic circuits such as modulator, amplifier, mixer, oscillator and power amplifier ANALOG AND DIGITAL COMMUNICATION In addition to that it increases the power level of the