Communication Systems for Electrical Engineers (eBook)

Dr. Mohammad A Matin is currently working at the department of Electrical and Electronic Engineering, Universiti Teknologi Brunei (UTB), Brunei Darussalam as an Associate Professor. Before joining ITB, he was with the department of Electrical Engineering and Computer Science, North South University as an Associate Professor. He obtained his BSc. degree in Electrical and Electronic Engineering from BUET (Bangladesh), MSc degree in digital communication from Loughborough University, UK and PhD degree in wireless communication from Newcastle University, UK. He has taught several courses in communications, electronics and signal processing at KUET, Khulna University, and BRAC University during his career. He has published over 80 refereed journals and conference papers. He is the author of ten academic books and nine book chapters. He has presented invited talks in Bangladesh, and Malaysia and has served as a member of the program committee for more than 50 international conferences. He is currently serving as a member of editorial board of several international journals such as  IEEE Communications Magazine,  IET Wireless Sensor Systems (IET-WSS), etc. and Guest Editor of special issue of IJDSN, IJAPIJCNIS etc. Dr. Matin is a member of IEEE, IEEE Communications Society (IEEE ComSoc), and several other international organizations. He served as a counselor of IEEE North South University (2008-2011), and secretary of IEEE Communication Society, Bangladesh Chapter (2010-2011). He has received a number of Prizes and Scholarships including the Best student prize (Loughborough University), Commonwealth Scholarship and Overseas Research Scholarship (ORS).​

Contents 6
1 Introduction to Signals, Systems and Communication 10
1.1 Introduction 10
1.2 Signals 10
1.2.1 Representation of Signals 12
1.2.2 Bandwidth of Signals 12
1.2.3 Evaluation of Signal Power 13
1.2.4 Transform of Periodic Signals 14
1.2.5 Fourier Transform and Spectra 15
1.2.6 Signal Shapes in Communication 16
1.2.7 Some Useful Signal Operations 16
1.3 System 18
1.3.1 Baseband Systems 19
1.3.2 Passband Systems 20
1.4 Communication System 20
1.4.1 Analog Versus Digital Communication System 21
1.4.2 Modulation and Demodulation in Communication System 22
1.4.3 Performance of Communication Systems 22
1.5 Sample Questions 23
2 Transmission Media and Propagation Mechanisms 24
2.1 Introduction 24
2.2 Wired Media: Twisted Pair 24
2.3 Wired Media: Optical Fiber 25
2.3.1 Structure of an Fiber Optic Cable 25
2.3.2 Propagation Modes of Fiber Optic Cable 26
2.3.3 Calculation of Number of Modes in a Fiber 27
2.3.4 Optical Fiber Index Profile 28
2.3.5 Optical Fiber’s Numerical Aperture (NA) 29
2.4 Wireless Media 30
2.5 Transmission Impairments 30
2.6 Data Transmission 32
2.6.1 Nyquist Information Capacity 32
2.6.2 Shannon Capacity 33
2.7 Wireless Propagation 34
2.7.1 Ground Wave Propagation 34
2.7.2 Sky Wave Propagation 34
2.8 Propagation Mechanism 36
2.9 Sample Questions 37
Reference 37
3 Speech Digitization and Service Integration 38
3.1 Introduction 38
3.2 Speech Digitization 38
3.3 Pulse Code Modulation (PCM) 39
3.3.1 Sampling 39
3.3.2 Quantizing 40
3.3.2.1 Signal to Quantization Noise Ratio, (SNR)Q 41
3.3.3 Nonuniform Quantizing: Companding 44
3.3.4 Encoding 44
3.4 PCM Transmission Bandwidth and the Output SNR 45
3.5 Time Division Multiplexing of Digitized Speech Channels in PSTN 46
3.5.1 Higher Order Multiplexing 47
3.6 Differential Pulse Code Modulation (DPCM) 48
3.7 Delta Modulation 49
3.8 Integrated Services Digital Network (ISDN) 50
3.9 Sample Questions 51
References 51
4 AM, Angle Modulation and Digital Modulation Systems 52
4.1 Introduction 52
4.2 Amplitude Modulation (AM) 52
4.2.1 AM Spectrum 52
4.2.2 Double Sideband Suppressed Carrier (DSB-SC) 54
4.2.3 AM Modulation Index 57
4.2.4 Power of an AM Signal 58
4.2.5 AM Signals Generation 60
4.2.6 Demodulation Methods of AM 61
4.2.6.1 Rectifier Detector 61
4.2.6.2 Envelope Detector 61
4.3 Angle Modulation (FM and PM) 63
4.3.1 Frequency Modulation (FM) 63
4.3.2 FM Signal Spectrum and Bandwidth 64
4.3.3 Power in FM Signal 66
4.3.4 FM Signal Generation 67
4.3.5 FM Demodulation-General Principles 68
4.3.5.1 Tuned Circuit 69
4.3.5.2 Phase-Locked Loop (PLL) 69
4.3.6 Frequency Modulation Versus Amplitude Modulation 70
4.3.7 Phase Modulation (PM) 70
4.3.8 Relation Between PM and FM 71
4.4 Generalized Receiver: Superheterodyne Receiver 71
4.5 Digital Modulation Techniques 72
4.5.1 Binary Modulated Bandpass Signaling 72
4.5.2 Multilevel Modulated Bandpass Signaling 75
4.6 Sample Questions 77
5 Telecommunication Systems 79
5.1 Introduction 79
5.2 Evolution of Modern Telecommunications 79
5.3 Simple Telephone Communication 80
5.3.1 Subscriber Loop Signaling 81
5.3.2 Signaling Tones to the Exchange from the Telephone 82
5.3.3 Telephone Numbering Plan 83
5.4 Telephone Call and Charging Plan 84
5.4.1 Telephone Call Set-up 84
5.4.2 Charging Plan 85
5.5 Telecommunication Network 85
5.5.1 Elements of Telecommunication Network 85
5.5.2 Technologies in Telecommunication Network 87
5.5.2.1 Transmission Systems 87
5.5.2.2 Switching Systems 88
5.5.2.3 Signalling System 89
5.6 Telecommunication Design and Implementation 90
5.6.1 Telecommunication Access Network Architecture: Fiber to the x 90
5.6.2 Metro (SONET/SDH, Metro Ethernet) and Core Network Architecture 90
5.7 Telecommunication Traffic Engineering 91
5.7.1 Trunking and Grade of Service 92
5.7.1.1 Traffic Model 93
5.7.1.2 Congestion 93
5.7.1.3 Erlang B formula 93
5.8 Sample Questions 95
References 95
6 Cellular Telephony System 96
6.1 Introduction 96
6.2 Basic Cellular Telephony 96
6.3 Cellular Telephony Evolution 97
6.4 Cellular Concept 98
6.4.1 Frequency Reuse 99
6.5 Hierarchical Cell Structure 101
6.6 Handoff in Cellular System 101
6.6.1 Types of Handoffs 103
6.6.2 Practical Handoff Scenarios 104
6.6.2.1 Umbrella Cell Approach 104
6.6.2.2 Cell Dragging 104
6.7 Interference and System Capacity 105
6.8 Techniques for Improving Coverage and Capacity 109
6.8.1 Cell Splitting 109
6.8.2 Sectoring 110
6.8.3 Microcell Zone Concept 111
6.9 Sample Questions 112
References 113
7 Satellite Communication Systems 114
7.1 Introduction 114
7.2 Active and Passive Satellites 115
7.3 Satellite Communications Spectrum 116
7.4 Orbits for Communication Satellites 116
7.5 Elements of Satellite Communications System 119
7.5.1 Space Segment 119
7.5.1.1 Satellite Payload 121
7.5.1.2 Satellite Subsystems 122
7.5.2 Ground Segment 123
7.6 “Link Budget” for Satellite Communication 125
7.6.1 Carrier-to-Noise Ratio 128
7.7 Launch Vehicles and Satellite Installation 128
7.7.1 Launch Vehicle 129
7.7.2 Satellite Installation 129
7.7.3 Launch of Communication Satellites 130
7.7.4 Launch Failure 130
7.8 Sample Questions 131
References 131
Index 132