NYU WIRELESS TR 2014-002 Technical Report Antenna Diversity Combining and Beamforming at Millimeter Wave Frequencies Shu Sun, Theodore S. Rappaport [email protected], [email protected] NYU WIRELESS NYU Polytechnic School of Engineering 2 MetroTech Center Brooklyn, NY 11201 June 10, 2014 © 2015 NYU ABSTRACT Antenna Diversity Combining and Beamforming at Millimeter Wave Frequencies Shu Sun, Theodore S. Rappaport New York University, 2014 This thesis focuses on antenna diversity combining and beamforming at millimeter wave (mmWave) frequencies. Extensive outdoor channel propagation measurement campaigns have been conducted in downtown dense urban environments of New York City at 28 GHz and 73 GHz, from which huge amount of data were acquired and post-processed to obtain various channel parameters and statistics for the next generation wireless communications. Using the measured data, theoretical analysis of antenna diversity combining has been performed to investigate its effect on improving the received signal quality and extending coverage range. Various broadband mmWave beamforming algorithms and hardware architectures have also been reviewed and investigated in this thesis, with an emphasis on the design and characterization of optically addressed phased array antennas. ii Table of Contents ABSTRACT .............................................................................................................................................................. II LIST OF TABLES ..................................................................................................................................................... IV CHAPTER 1 INTRODUCTION ................................................................................................................................... 1 1.1 PROJECT PURPOSE ................................................................................................................................... 1 1.2 PROJECT GOALS ...................................................................................................................................... 3 1.3 LITERATURE REVIEW OF MIMO SYSTEMS ................................................................................................................ 5 A. ADAPTIVE ARRAYS ......................................................................................................................................... 24 B. ADAPTIVE BEAMFORMING ALGORITHMS ............................................................................................................. 26 C. NON-BLIND ADAPTIVE ALGORITHMS .................................................................................................................. 27 D. BLIND ADAPTIVE ALGORITHMS ......................................................................................................................... 29 CHAPTER 2 CHANNEL SOUNDING SYSTEM ........................................................................................................... 59 2.1 CHANNEL SOUNDING METHODS .......................................................................................................................... 59 2.2 SPREAD SPECTRUM MODULATION ....................................................................................................................... 62 2.3 PSEUDO-NOISE SEQUENCES ............................................................................................................................... 63 2.4 SLIDING CORRELATOR DESCRIPTION ..................................................................................................................... 63 2.5 CHANNEL SOUNDING SYSTEM FOR 28 GHZ OUTDOOR PROPAGATION MEASUREMENTS.................................................... 72 2.6 CHANNEL SOUNDING SYSTEM FOR 73 GHZ OUTDOOR PROPAGATION MEASUREMENTS.................................................... 72 CHAPTER 3 MEASUREMENT PROCEDURE AND RESULTS AT 28 GHZ AND 73 GHZ ................................................. 86 3.1 28 GHZ MEASUREMENT PROCEDURE ................................................................................................................... 86 3.2 73 GHZ MEASUREMENT PROCEDURE ................................................................................................................... 91 3.3 OUTDOOR CELLULAR PROPAGATION MEASUREMENTS RESULTS AT 28 GHZ ................................................................. 102 3.4 OUTDOOR CELLULAR PROPAGATION MEASUREMENTS RESULTS AT 73 GHZ ................................................................. 112 CHAPTER 4 BEAM COMBINING AT 28 GHZ AND 73 GHZ ..................................................................................... 126 4.1 CONCEPT OF BEAM COMBINING ........................................................................................................................ 126 4.2 BEAM COMBINING PROCEDURE ........................................................................................................................ 129 4.3 PATH LOSS MODELS ....................................................................................................................................... 131 4.4 BEAM COMBINING RESULTS AT 28 GHZ .............................................................................................................. 133 4.5 BEAM COMBINING RESULTS AT 73 GHZ .............................................................................................................. 142 4.6 COMPARISON OF 28 GHZ AND 73 GHZ BEAM COMBINING RESULTS ......................................................................... 150 4.7 BEAM COMBINING RESULTS USING MEASURED DATA DEFINED IN A OMNI MODEL ....................................................... 153 CHAPTER 5 MIMO SYSTEMS AND BEAMFORMING............................................................................................. 165 5.1 ANTENNA ARRAY ........................................................................................................................................... 165 5.2 MIMO SYSTEMS ........................................................................................................................................... 173 5.3 MASSIVE MIMO VERSUS SMALL CELL ................................................................................................................ 186 5.4 BEAMFORMING CATEGORIES ............................................................................................................................ 187 5.5 DOA ESTIMATION ALGORITHMS ....................................................................................................................... 191 5.6 OPTICAL BEAMFORMING HARDWARE ARCHITECTURE ............................................................................................. 205 CHAPTER 6 CONCLUSION AND FUTURE WORK ................................................................................................... 221 6.1 CONCLUSION ................................................................................................................................................ 221 6.2 FUTURE WORK ............................................................................................................................................. 221 BIBLIOGRAPHY ............................................................................................................................................ 223 iii List of Tables Table 1. List and comparison among different adaptive array algorithms for beamforming. ...... 31 Table 2 Comparison of various channel sounding techniques. ................................................... 67 Table 3 Noise sources and the corresponding methods of mitigating them. ................................ 71 Table 4 Spread spectrum channel sounder specifications at 28 GHz and 73 GHz. ...................... 84 Table 5 The different antenna pointing angle combinations used for all outdoor Manhattan measurements at 28 GHz. “Narrow” and “Wide” mean 24.5 dBi horn antenna (with 10.9° beamwidth) and 15 dBi horn antenna (with 28.8° beamwidth), respectively. The Elevation column represents the number of beam widths above or below horizon. The TX Azimuth column represents the number of beam widths left or right from boresight where boresight is the angle with the strongest multipath link found during the initial cursory sweep. Positive beamwidths correspond to a counterclockwise increasing direction about the antenna boresight. .................. 89 Table 6 The different antenna pointing angle combinations used for all outdoor Brooklyn measurements at 28 GHz. “Narrow” means 24.5 dBi horn antenna with 10.9° beamwidth and “Wide” means 15 dBi with 28.8º beamwidth. The Elevation column represents the number of beam widths above or below horizon. ........................................................................................ 90 Table 7 TX and RX locations and the corresponding TX-RX distances for the mobile scenario. 97 Table 8 TX and RX locations and the corresponding TX-RX distances for the backhaul scenario. ................................................................................................................................................. 99 Table 9. TX-RX separation, average received power (Pav), received power of the best single signal – i.e. from the single best antenna pointing angle (PC1 or PNC1), received power of the best two, three, and four signals combined noncoherently (denoted by PNC2, PNC3, PNC4 respectively), received power of the best two, three, and four