1/135 TABLE OF CONTENTS 1. BACKGROUND AND SCOPE OF WHITEPAPER ........................................................................................... 14 2. BASE STATION ANTENNA EVOLUTION ........................................................................................................ 19 2.1. EARLY TECHNOLOGY ........................................................................................................................................... 19 2.2. CURRENT TECHNOLOGY ....................................................................................................................................... 20 2.2.1. Extensive Usage ................................................................................................................................. 20 2.2.2. Moderate Usage ................................................................................................................................. 21 2.2.3. Advanced Antenna Technology .......................................................................................................... 22 2.2.4. MIMO Systems ................................................................................................................................... 23 2.2.5. Reconfigurable Beam Antenna ........................................................................................................... 24 2.2.6. Active Antenna .................................................................................................................................... 25 2.3. COMPARISON TABLE—ANTENNA TYPES SUPPLIED – ONE VENDOR ....................................................................... 25 2.4. ANTENNAS FOR MIMO ......................................................................................................................................... 26 3. ADAPTATIVE ARRAY (AA) BEAMFORMING ANTENNAS ............................................................................ 28 3.1. INTRODUCTION ..................................................................................................................................................... 28 3.1.1. Individual Antenna Column Characteristics ........................................................................................ 30 3.2. BEAMFORMING ..................................................................................................................................................... 35 3.2.1. Beamforming Antenna Calibration Requirements .............................................................................. 38 3.3. FIXED MULTI-BEAM ARRAY ANTENNAS ................................................................................................................. 41 4. RECONFIGURABLE BEAM ANTENNAS ........................................................................................................ 44 4.1. HOW RECONFIGURABLE BEAM ANTENNAS WORK ................................................................................................. 44 4.2. USE CASES OF RECONFIGURABLE BEAM ANTENNAS IN 3G NETWORKS ................................................................. 44 4.3. COMPARISON OF RET, 2D, AND 3D RECONFIGURABLE BEAM ANTENNAS .............................................................. 46 4.3.1. Measurement of Coverage, Interference, and Load Balancing with Reconfigurable Beam Antennas46 4.3.2. Network Optimization Versus Load Balancing.................................................................................... 47 4.3.3. Antenna Beam width Distribution ........................................................................................................ 49 4.4. RECONFIGURABLE BEAM ANTENNAS--CYCLICAL TRAFFIC PATTERN MANAGEMENT................................................ 51 4.5. RECONFIGURABLE BEAM ANTENNA SUMMARY ...................................................................................................... 51 5. ACTIVE ANTENNA ARRAYS ........................................................................................................................... 53 6. ADDITIONAL SIMULATIONS AND COMPARISONS OF LTE TRANSMISSION SCHEMES / ANTENNA CONFIGURATIONS .......................................................................................................................................... 58 6.1. COMPARABLE DOWNLINK SPECTRAL EFFICIENCY ................................................................................................. 58 6.2. AN ANALYSIS OF ANTENNA CONFIGURATIONS FOR 4X2 AND 4X4 MIMO................................................................ 59 2/135 7. DEPLOYMENT SCENARIOS ............................................................................................................................ 63 7.1. TYPICAL CELL SITE ARCHITECTURE ...................................................................................................................... 63 7.2. CURRENT DEPLOYMENTS ..................................................................................................................................... 64 7.2.1. Typical Tower Top Deployment .......................................................................................................... 65 7.2.2. Typical Mast Deployment.................................................................................................................... 67 7.2.3. Typical RooF TOP Deployment .......................................................................................................... 69 8. MISCELLANEOUS COMMERCIAL AND DEPLOYMENT ISSUES ................................................................. 72 8.1. CONSTRAINTS ON THE ANTENNA DEPLOYMENTS DUE TO COMMERCIAL CONSIDERATIONS ....................................... 72 8.2. ELECTRICAL AND MECHANICAL TILTING OF ANTENNAS .......................................................................................... 73 8.2.1. Effects of Mechanical Downtilt on Sector Antenna Horizontal Patterns ............................................. 73 8.2.2. Effects of Incorrect Antenna Installation ............................................................................................. 87 8.3. PASSIVE INTERMODULATION (PIM) SITE CONSIDERATIONS .................................................................................... 88 8.4. INDEPENDENT ANTENNA TILT OPTIMIZATION BY AIR INTERFACE ............................................................................. 89 8.5. REMOTE RADIO HEADS FOR MIMO ....................................................................................................................... 90 8.5.1. Remote Radio Heads and Transmitter-Receiver Duplexer Units ....................................................... 90 8.5.2. Remote Radio Head Advantages and Considerations ....................................................................... 92 8.5.3. Remote Radio Configurations ............................................................................................................. 92 8.6. FEEDER CABLE FOR REMOTE RADIO HEADS ......................................................................................................... 94 8.6.1. Hybrid Fiber/Copper Remote Fiber Feeders ...................................................................................... 97 8.6.2. Assemblies .......................................................................................................................................... 98 8.6.3. Lightning Protection ............................................................................................................................ 99 8.6.4. Accessories ......................................................................................................................................... 99 8.6.5. Advantages of Remote Fiber Feeders .............................................................................................. 100 8.7. CO-SITING OF MULTIPLE BASE STATIONS AND TECHNOLOGIES ............................................................................ 101 8.7.1. Separate Feeders for Each System .................................................................................................. 101 8.7.2. Shared Feeders—Frequency Multiplexing ....................................................................................... 102 8.7.3. Shared Antennas .............................................................................................................................. 103 8.7.4. Shared Feeders and Antennas—Same Band Combining ................................................................ 104 8.7.5. Hybrid Combining ............................................................................................................................. 104 8.7.6. Low Loss Combiner—Multiplexer ..................................................................................................... 105 8.7.7. Single Carrier Power Amplifiers (SCPA) ........................................................................................... 105 8.7.8. Multi-Carrier Power Amplifier (MCPA) .............................................................................................. 106 8.7.9. Receiver Multicoupler ....................................................................................................................... 107 8.7.10. Integrated Devices—Same Band Combiner ..................................................................................... 107 3/135 8.7.11. Tower Mounted Amplifiers ...............................................................................................................