Evaluation of HSDPA and LTE

Dr. Sebastian Caban, University of Technology Vienna, AustriaSebastian Caban finished his PhD with summa cum laude in October 2009 and is now post doctoral fellow at this institute. Christian Mehlführer, University of Technology Vienna, AustriaChristian Mehlführer received his Dipl.-Ing. degree in electrical engineering from the Vienna University of Technology. In 2009, he finished his PhD about measurement-based performance evaluation of WiMAX and HSDPA with summa cum laude. Professor Markus Rupp, University of Technology Vienna, AustriaMarkus Rupp received his Dipl.-Ing. degree in 1988 at the University of Saarbrücken, Germany and his Dr.-Ing. degree in 1993 at the Technische Universität Darmstadt, Germany, where he worked with Eberhardt Hänsler on designing new algorithms for acoustical and electrical echo compensation. Martin Wrulich, University of Technology Vienna, AustriaMartin Wrulich received his Dipl.-Ing. degree from Vienna University of Technology in March 2006 (diploma thesis: "Capacity Analysis of MIMO systems").

• About the Authors xiii About the Contributors xvPreface xviiAcknowledgments xxiiiList of Abbreviations xxvPart I CELLULAR WIRELESS STANDARDSIntroduction 3References 41 UMTS High-Speed Downlink Packet Access 51.1 Standardization and Current Deployment of HSDPA 51.2 HSDPA Principles 61.2.1 Network Architecture 71.2.2 Physical Layer 91.2.3 MAC Layer 131.2.4 Radio Resource Management 141.2.5 Quality of Service Management 161.3 MIMO Enhancements of HSDPA 171.3.1 Physical Layer Changes for MIMO 191.3.2 Precoding 211.3.3 MAC Layer Changes for MIMO 251.3.4 Simplifications of the Core Network 26References 262 UMTS Long-Term Evolution 29Contributed by Josep Colom Ikuno2.1 LTE Overview 292.1.1 Requirements 292.2 Network Architecture 312.3 LTE Physical Layer 332.3.1 LTE Frame Structure 342.3.2 Reference and Synchronization Symbols 362.3.3 MIMO Transmission 372.3.4 Modulation and Layer Mapping 392.3.5 Channel Coding 412.3.6 Channel Adaptive Feedback 452.4 MAC Layer 462.4.1 Hybrid Automatic Repeat Request 462.4.2 Scheduling 472.5 Physical, Transport, and Logical Channels 48References 51Part II TESTBEDS FOR MEASUREMENTSIntroduction 57Reference 583 On Building Testbeds 593.1 Basic Idea 603.2 Transmitter 613.3 Receiver 633.4 Synchronization 653.5 Possible Pitfalls 673.5.1 Digital Baseband Hardware 673.5.2 Tool and Component Selection 683.5.3 Analog RF Front Ends 693.5.4 Cost 703.5.5 Matlab® Code and Testbeds 703.6 Summary 71References 724 Quasi-Real-Time Testbedding 754.1 Basic Idea 754.2 Problem Formulation 774.3 Employing the Basic Idea 784.4 Data Collection 804.4.1 More Sophisticated Sampling Techniques 814.4.2 Variance Reduction Techniques 844.4.3 Bias 854.4.4 Outliers 864.4.5 Parameter Estimation 874.5 Evaluating and Summarizing the Data 884.6 Statistical Inference 904.6.1 Inferring the Population Mean 904.6.2 Precision and Sample Size 914.6.3 Reproducibility and Repeatability 924.7 Measurement Automation 954.8 Dealing with Feedback and Retransmissions 96References 97Part III EXPERIMENTAL LINK-LEVEL EVALUATIONIntroduction 1015 HSDPA Performance Measurements 1035.1 Mathematical Model of the Physical Layer 1045.1.1 System Model for the Channel Estimation 1065.1.2 System Model for the Equalizer Calculation 1065.2 Receiver 1075.2.1 Channel Estimation 1075.2.2 Equalizer 1125.2.3 Further Receiver Processing 1135.3 Quantized Precoding 1135.4 CQI and PCI Calculation 1155.4.1 HS-PDSCH Interference 1155.4.2 Pilot Interference 1165.4.3 Synchronization and Control Channel Interference 1165.4.4 Post-equalization Noise and SINR 1185.4.5 SINR to CQI Mapping 1195.5 Achievable Mutual Information 1215.6 Measurement Results 1245.6.1 Alpine Scenario 1255.6.2 Urban Scenario 1285.6.3 Discussion of the Implementation Loss 1305.7 Summary 131References 1326 HSDPA Antenna Selection Techniques 139Contributed by Jos´e Antonio Garc´ıa-Naya6.1 Existing Research 1416.2 Receive Antenna Selection 1426.2.1 Antenna Selection Based on System Throughput 1436.2.2 Hardware Aspects of Antenna Selection 1436.3 An Exemplary Measurement and its Results 1446.3.1 Urban Scenario 1446.3.2 Experimental Assessment of Antenna Selection in HSDPA 1456.3.3 Measurement Results and Discussion 1476.4 Summary 148References 1497 HSDPA Antenna Spacing Measurements 1537.1 Problem Formulation 1537.2 Existing Research 1547.3 Experimental Setup 1557.4 Measurement Methodology 1577.4.1 Inferring the Mean Scenario Throughput 1577.4.2 Issues Requiring Special Attention 1587.5 Measurement Results and Discussion 1607.5.1 Equal Polarization Versus Cross-Polarization 1607.5.2 Channel Capacity 1607.5.3 Channel Capacity Versus Mutual Information 1627.5.4 Mutual Information Versus Achievable Mutual Information 1627.5.5 Achievable Mutual Information Versus Throughput 1637.5.6 Throughput 1637.6 Different Transmit Power Levels and Scenarios 163References 1648 Throughput Performance Comparisons 1678.1 Introduction 1678.2 Cellular Systems Investigated: WiMAX and HSDPA 1688.2.1 WiMAX and HSDPA 1688.2.2 Throughput Bounds and System Losses 1698.3 Measurement Methodology and Setup 1728.4 Measurement Results 1738.4.1 WiMAX Results 1738.4.2 HSDPA Results in Standard-Compliant Setting 1778.4.3 HSDPA Results in Advanced Setting 1798.5 Summary 179References 1829 Frequency Synchronization in LTE 183Contributed by Qi Wang9.1 Mathematical Model 1849.2 Carrier Frequency Offset Estimation in LTE 1869.2.1 Standardized Training Symbols in LTE 1869.2.2 Maximum Likelihood Estimators 1889.3 Performance Evaluation 1919.3.1 Estimation Performance 1929.3.2 Post-FFT SINR 1949.3.3 Post-equalization SINR and Throughput 195References 19910 LTE Performance Evaluation 201Contributed by Stefan Schwarz10.1 Mathematical Model of the Physical Layer 20210.2 Receiver 20310.2.1 Channel Estimation 20410.2.2 Data Detection 20510.2.3 Further Receiver Processing 20610.3 Physical Layer Modeling 20610.3.1 Post-equalization SINR 20710.3.2 SINR Averaging 20710.4 User Equipment Feedback Calculation 20810.4.1 User Equipment Feedback Indicators 20810.4.2 Calculation of the CQI, PMI, and RI 21010.5 Practical Throughput Bounds 21610.5.1 Channel Capacity 21610.5.2 Open-Loop Mutual Information 21710.5.3 Closed-Loop Mutual Information 21810.5.4 BICM Bounds 21910.5.5 Achievable Throughput Bounds 22210.5.6 Prediction of the Optimal Performance 22310.6 Simulation Results 22410.6.1 SISO Transmission 22510.6.2 OLSM Transmission 22710.6.3 CLSM Transmission 229References 230Part IV SIMULATORS FOR WIRELESS SYSTEMSIntroduction 237References 24011 LTE Link- and System-Level Simulation 243Contributed by Josep Colom Ikuno11.1 The Vienna LTE Link Level Simulator 24511.1.1 Structure of the Simulator 24511.1.2 Complexity 24711.2 The Vienna LTE System Level Simulator 25011.2.1 Structure of the Simulator 25011.2.2 Simulator Implementation 25211.2.3 Complexity 25311.3 Validation of the Simulators 25511.3.1 3GPP Minimum Performance Requirements 25711.3.2 Link- and System-Level Cross-Comparison 25711.4 Exemplary Results 25911.4.1 Link-Level Throughput 25911.4.2 LTE Scheduling 262References 26512 System-Level Modeling for MIMO-Enhanced HSDPA 27112.1 Concept of System-Level Modeling 27112.2 Computationally Efficient Link-Measurement Model 27312.2.1 Receive Filter 27412.2.2 WCDMA MIMO in the Network Context 27612.2.3 Equivalent Fading Parameters Description 27812.2.4 Generation of the Equivalent Fading Parameters 28412.2.5 Influence of Non-Data Channels 28612.2.6 Resulting SINR Description 28712.3 Link-Performance Model 28812.3.1 Link-Performance Model Concept 28912.3.2 Training and Validation of the Model 293References 296Part V SIMULATION-BASED EVALUATION FOR WIRELESS SYSTEMSIntroduction 30113 Optimization of MIMO-Enhanced HSDPA 30313.1 Network Performance Prediction 30313.1.1 Simulation Setup 30313.1.2 Single Network Scenario Investigation 30413.1.3 Average Network Performance 30613.2 RLC-Based Stream Number Decision 31013.2.1 UE Decision 31013.2.2 RLC Decision 31113.2.3 System-Level Simulation Results 31113.3 Content-Aware Scheduling 31313.3.1 Video Packet Prioritization in HSDPA 31313.3.2 Content-Aware Scheduler 31413.3.3 Simulation Results 31513.4 CPICH Power Optimization 31613.4.1 System-Level Modeling of the CPICH Influence 31713.4.2 CPICH Optimization in the Cellular Context 318References 32114 Optimal Multi-User MMSE Equalizer 32514.1 System Model 32614.2 Intra-Cell Interference Aware MMSE Equalization 33014.2.1 Interference Suppression Capability 33214.3 The Cell Precoding State 33414.3.1 Training-Sequence-Based Precoding State Estimation 33614.3.2 Blind Precoding State Estimation 33714.3.3 Estimator Performance 33914.4 Performance Evaluation 34014.4.1 Physical-Layer Simulation Results 34014.4.2 System-Level Simulation Results 341References 34315 LTE Advanced Versus LTE 347Contributed by Stefan Schwarz15.1 IMT-Advanced and 3GPP Performance Targets 34815.2 Radio Interface Enhancements 34915.2.1 Bandwidth Extension 34915.2.2 Enhanced MIMO 35015.2.3 Uplink Improvements 35115.2.4 Beyond Release 10 35215.3 MIMO in LTE Advanced 35415.3.1 Codebook-Based Precoding 35415.3.2 Non-Codebook-Based Precoding 35615.4 Physical-Layer Throughput Simulation Results 35915.4.1 Eight-Antenna Transmission 35915.4.2 Comparison between LTE and LTE Advanced 36315.4.3 Comparison of SU-MIMO and MU-MIMO 363References 366Index 369