i wirelesss communications and networks FOR m.tech (jntu - h) i year Ii semester (COMMON TO EMBEDDED SYSTEMS, ECE, DECE AND DECS) CONTENTS UNIT - I [THE CELLULAR CONCEPT-SYSTEM DESIGN FUNDAMENT AMENTALS ALS]... 1.1-1.32 1.1 INTRODUCTION... 1.2 1.2 FUNDAMENT AMENTAL AL DEFINITIONS... 1.2 1.3 FREQUENCY REUSE... 1.3 1.3.1 Method of Locating Co-channel Cells... 1.6 1.3.2 Advantages of Cellular Concept in Communication Systems.. 1.7 1.4 CHANNEL ASSIGNMENT STRATEGIES TEGIES... 1.7 1.4.1 Fixed Channel Assignment Strategy... 1.7 1.4.2 Dynamic Channel Assignment Strategy... 1.8 1.5 HANDOFF STRATEGIES TEGIES... 1.8 1.5.1 Prioritizing Handoffs... 1.10 1.5.2 Practical Handoff Considerations... 1.11 1.6 INTERFERENCE AND SYSTEM CAPACITY CITY... 1.12 1.6.1 Co-channel Interference and System Capacity... 1.12 1.6.2 Channel Planning for Wireless System... 1.16 1.6.3 Adjacent-Channel Interference... 1.16 1.6.4 Power Control for Reducing Interference... 1.17
ii 1.7 TRUNKING AND GRADE OF SERVICE... 1.17 1.7.1 Types of Truncked Systems... 1.19 1.7.1.1 Blocked Calls Cleared... 1.19 1.7.1.2 Blocked Calls Delayed... 1.20 1.8 IMPROVING COVERA VERAGE AND CAPACITY CITY IN CELLULAR SYSTEMS... 1.22 1.8.1 Cell Splitting... 1.22 1.8.2 Sectoring... 1.25 1.8.3 Repeaters for Range Extension... 1.27 1.8.4 Microcell Zone... 1.28 Expected University Questions with Answers... 1.31-1.32 UNIT - II [MOBILE RADIO PROPAGA GATION : LARGE-SCALE PATH LOSS OSS]... 2.1-2.46 2.1 INTRODUCTION TO O RADIO WAVE VE PROPAGA GATION TION... 2.2 2.2 FREE SPACE CE PROPAGA GATION MODEL... 2.2 2.3 RELATING POWER TO O ELECTRIC FIELD... 2.6 2.4 THE THREE BASIC PROPAGA GATION MECHANISMS... 2.9 2.5 REFLECTION... 2.10 2.5.1 Reflection from Dielectrics... 2.10 2.5.2 Reflection from Perfect Conductors... 2.13 2.5.3 Ground Reflection (Two wo-r -Ray) ay) Model... 2.13 2.6 DIFFRACTION... 2.19 2.6.1 Fresnel Zone Geometry... 2.19 2.6.2 Knife-Edge Diffraction Model... 2.23 2.6.3 Multiple Knife-Edge Diffraction... 2.24 2.7 SCATTERING... 2.25 2.7.1 Radar Cross-Section Model... 2.26
iii 2.8 OUTDOOR PROPAGA GATION MODELS... 2.27 2.8.1 Longley-Rice Model... 2.28 2.8.2 Okumura Model... 2.29 2.8.3 Hata Model... 2.32 2.8.4 PCS Extension to Hata Model... 2.33 2.8.5 Walfisch and Bertoni Model... 2.33 2.8.6 Wideband PCS Microcell Model... 2.35 2.9 INDOOR PROPAGA GATION MODELS... 2.36 2.9.1 Partition Losses (Same Floor)... 2.37 2.9.2 Partition Losses between Floors... 2.37 2.9.3 Log og-distance Path ath Loss Model... 2.38 2.9.4 Ericsson Multiple Breakpoint Model... 2.39 2.9.5 Attenuation Factor Model... 2.39 2.10 SIGNAL PENETRATION TION INTO O BUILDINGS... 2.42 2.11 RAY Y TRACING AND SITE SPECIFIC MODELING... 2.43 Expected University Questions with Answers... 2.45-2.46 UNIT - III [MOBILE RADIO PROPAGATION : SMALL-SCALE FADING AND MULTIPATH]... 3.1-3.38 3.1 INTRODUCTION... 3.2 3.2 SMALL-SCALE SCALE MULTIP TIPATH TH PROPAGA GATION... 3.2 3.2.1 Factors Influencing Small-Scale Fading... 3.2 3.2.2 Doppler Shift... 3.3 3.3 IMPULSE RESPONSE MODEL OF A MULTIP TIPATH TH CHANNEL... 3.5 3.3.1 Relationship between Bandwidth and Received Power... 3.8 3.4 SMALL-SCALE SCALE MULTIP TIPATH TH MEASUREMENTS... 3.9 3.4.1 Direct RF Pulse System... 3.10 3.4.2 Spread Spectrum Sliding Correlator Channel Sounding... 3.11 3.4.3 Frequency Domain Channel Sounding... 3.15
iv 3.5 PARAMETERS OF MOBILE MULTIP TIPATH TH CHANNELS... 3.16 3.5.1 Time Dispersion Parameter... 3.17 3.5.2 Coherence Bandwidth... 3.20 3.5.3 Doppler Spread and Coherence Time... 3.20 3.6 TYPES OF SMALL-SCALE SCALE FADING... 3.23 3.6.1 Fading Effects Due to Multipath Time Delay Spread... 3.23 3.6.1.1 Flat Fading... 3.23 3.6.1.2 Frequency Selective Fading... 3.24 3.6.2 Fading Effects due to Doppler Spread... 3.27 3.6.2.1 Fast Fading... 3.27 3.6.2.2 Slow Fading... 3.28 3.7 STATISTICAL TISTICAL MODELS FOR MULTIP TIPATH TH FADING CHANNELS... 3.28 3.7.1 Clarke s Model for Flat Fading... 3.28 3.7.2 Spectral Shape due to Doppler Spread in the Clarke s Model... 3.30 3.7.3 Simulation of Clarke and Gans Fading Models... 3.31 3.7.4 Level Crossing and Fading Statistics... 3.34 3.7.5 Two wo-r -Ray ay Rayleigh Fading Model... 3.36 Expected University Questions with Answers... 3.37-3.38 UNIT - IV [EQUALIZATION AND DIVERSITY]... 4.1-4.32 4.1 INTRODUCTION... 4.2 4.2 FUNDAMENT AMENTALS ALS OF EQUALIZA ALIZATION TION... 4.3 4.3 TRAINING A GENERIC ADAPTIVE EQUALIZER... 4.5 4.4 EQUALIZERS IN A COMMUNICATION RECEIVER... 4.7 4.5 CLASSIFICATION OF EQUALIZA ALIZATION TECHNIQUES... 4.8 4.6 LINEAR EQUALIZERS... 4.10 4.6.1 FIR (or) Transversal Equalizers (Filters)... 4.10 4.6.2 Lattice Equalizer... 4.11
v 4.7 NON-LINEAR EQUALIZA ALIZATION... 4.12 4.7.1 Decision Feedback Equalization (DFE)... 4.12 4.7.2 Maximum Likelihood Sequence Estimation (MLSE) Equalizer... 4.14 4.8 ALGORITHMS FOR ADAPTIVE APTIVE EQUALIZA ALIZATION... 4.15 4.8.1 Zero Forcing Algorithm... 4.16 4.8.2 Least Mean Square Algorithm... 4.17 4.8.3 Recursive Least Squares Algorithm... 4.19 4.8.4 Comparison of Various Algorithms for Adaptive Equalization... 4.20 4.9 DIVERSITY TECHNIQUES... 4.21 4.9.1 Derivation of Selection Diversity Improvement... 4.22 4.9.2 Derivation of Maximal Ratio Combining Improvement... 4.23 4.9.3 Practical Space Diversity Considerations... 4.24 4.9.3.1 Selection Diversity... 4.24 4.9.3.2 Feedback (or) Scanning Diversity... 4.25 4.9.3.3 Maximal Ratio (Combining) Diversity... 4.25 4.9.3.4 Equal Gain Combining... 4.26 4.9.4 Polarization Diversity... 4.26 4.9.5 Frequency Diversity... 4.28 4.9.6 Time Diversity... 4.28 4.10 RAKE RECEIVER... 4.28 Expected University Questions with Answers... 4.31-4.32 UNIT - V [WIRELESS NETWORKS]... 5.1-5.52 5.1 INTRODUCTION TO WIRELESS NETWORKS... 5.2 5.2 TYPES OF WIRELESS NETWORKS... 5.3 5.2.1 Wireless Local Area Networks (WLANs)... 5.4 5.2.2 Wireless Wide Area Networks (WWANs)... 5.4 5.2.3 Wireless Personal Area Networks (WPANs)... 5.4 5.2.4 Wireless Metropolitan Area Networks (WMANs)... 5.5
vi 5.3 INTRODUCTION TO WIRELESS LOCAL AREA NETWORK... 5.5 5.4 ADVANT ANTAGES AND DISADVANT ANTAGES OF WIRELESS LOCAL AREA NETWORK... 5.5 5.5 WIRELESS LOCAL AREA NETWORK APPLICATIONS TIONS... 5.6 5.6 WLAN TOPOL OPOLOGIES OGIES... 5.7 5.6.1 Ad-hoc Network Topology... 5.8 5.6.2 Infrastructure Network Topology... 5.8 5.6.3 Comparison of Infrastructure and Ad-hoc Network Topologies... 5.9 5.7 WLAN STAND ANDARD ARD IEEE 802.11... 5.10 5.7.1 IEEE 802.11 Architecture... 5.11 5.7.1.1 IEEE 802.11 Architecture and Services... 5.13 5.7.1.1.1 Station Services... 5.13 5.7.1.1.2 Distribution Services... 5.13 5.7.2 IEEE 802.11 Family and its Standards... 5.14 5.7.2.1 IEEE 802.11 a, b, g AND n STAND ANDARDS ARDS... 5.15 5.7.2.2 IEEE 802.11 Physical Layer... 5.16 5.8 IEEE 802.11 MEDIUM ACCESS CONTROL... 5.25 5.8.1 Reliable Data Delivery... 5.25 5.8.2 Access Control... 5.26 5.8.3 DCF and PCF... 5.26 5.8.3.1 Distributed Co-ordination Function (DCF)... 5.26 5.8.3.2 Point Co-ordination ordination Function (PCF)... 5.28 5.8.4 Frame Formats ormats... 5.29 5.9 COMPARISON OF IEEE 802.11 a, b, g AND n STAND ANDARDS ARDS... 5.30
vii 5.10 IEEE 802.16 AND ITS ENHANCEMENTS... 5.31 5.10.1 Properties of IEEE 802.16... 5.31 5.10.2 IEEE 802.16 Standards... 5.31 5.10.3 Advantages of IEEE 802.16...... 5.32 5.10.4 Comparison of IEEE 802.16 Standards... 5.33 5.11 IEEE 802.16 VS. IEEE 802.11...... 5.34 5.12 WIRELESS PANS... 5.35 5.12.1 Bluetooth... 5.35 5.12.2 Applications of Bluetooth... 5.40 5.13 HIPERLAN... 5.41 5.13.1 Architecture of HIPERLAN-1... 5.42 5.13.1.1 Similarities between the HIPERLAN-1 and IEEE 802.11...... 5.42 5.13.1.2 Differences between the HIPERLAN-1 and IEEE 802.11...... 5.43 5.13.2 Architecture of HIPERLAN-2... 5.43 5.13.2.1 Similarities between the HIPERLAN-1 and HIPERLAN-2... 5.44 5.13.2.2 Basic Differences between the Medium Access Control Layer of the HIPERLAN-2 and IEEE 802.11...... 5.45 5.13.2.3 Differences between IEEE 802.11a and HIPERLAN-2... 5.45 5.14 WIRELESS LOCAL LOOP (WLL)... 5.46 Expected University Questions with Answers... 5.50-5.52
viii STUDENT NOTES