ENHANCED PERFORMANCE OF THE MIMO CHANNEL BY USING THE BEAMFORMING TECHNIQUE AND THE RACK RECEIVER A Thesis Presented to the Faculty of California State University, Fullerton ____________________________________ In Partial Fulfillment of the Requirements for the Degree Master of Science in Electrical Engineering ____________________________________ By Mohanad Saleh Mohammedhasan Alaamer Thesis Committee Approval: Hamidian, Karim, Department of Electrical Engineering, Chair Chaudhry, Maqsood, Department of Electrical Engineering Shiva, Mostafa, Department of Electrical Engineering Summer, 2018 ABSTRACT In recent years, the demands for high data rate and reliable transmission have increased in wireless communications systems due to the wide use of web applications. The key technology that achieves these requirements is the application of Multiple Input Multiple Output (MIMO). The MIMO system exploits the multipath propagation by using multiple transmitted antennas to send the signal to multiple received The MIMO system classification depends on whether the focus of the MIMO processing is on improving reliability, by creating spatial diversity, or on maximizing throughput, by performing spatial multiplexing. There are different ways to achieve spatial multiplexing, which are Layered Space Time coding and beamforming technique. In this thesis, I will investigate and analyze the performance of the MIMO channel by creating the combination of using the beamforming technique and the rack receiver to achieve both spatial multiplexing, which improves the data rate, and the diversity, which increases the reliability of the MIMO channel. The proposed technique uses DSSS-CDMA with-BPSK and QPSK modulation in a Slow Rayleigh flat fading environment. To apply the beamforming, I assume the transmitter has knowledge of the channel state information, that will decouple the MIMO channel to sub-independent parallel channels. It is shown that by using the combination of the beamforming and the rack receiver at each sub-channel, the signal-to-noise ratio for each sub-channel will increase, so the reliability of the MIMO channel will improve. Also, the capacity of the MIMO channel will increase. ii TABLE OF CONTENTS ABSTRACT ................................................................................................................... ii LIST OF TABLES ......................................................................................................... vi LIST OF FIGURES ....................................................................................................... vii ACKNOWLEDGMENTS ............................................................................................. x Chapter 1. INTRODUCTION ................................................................................................ 1 2. WIRELESS COMMUNICATION ....................................................................... 5 Introduction to Wireless Communication ............................................................. 5 Application of Wireless Communication ............................................................. 5 RF Propagation ..................................................................................................... 6 Impulse Response of Wireless Communication Channel ..................................... 8 Multipath Channel Parameter ............................................................................... 9 Delay Spread (Tm) ......................................................................................... 10 Coherent Bandwidth (Bc) .............................................................................. 10 Doppler Spread (Bd) ...................................................................................... 11 Coherent Time (Tc) ....................................................................................... 11 Type of Small-Scale Fading ................................................................................. 12 Flat Fading ..................................................................................................... 12 Frequency Selective Fading ........................................................................... 12 Fast Fading ..................................................................................................... 13 Slow Fading ................................................................................................... 13 Statistic of Small- Scale Fading ............................................................................ 14 Rayleigh Fading ............................................................................................. 14 Rician Fading ................................................................................................. 14 3. MIMO COMMUNCATION SYSTEM ................................................................ 16 Introduction ........................................................................................................... 16 SISO, MISO, and SIMO Antenna Configuration ................................................. 18 Single - User and Multi - User of The MIMO System ......................................... 21 The Concept of Diversity ...................................................................................... 22 Diversity Order and Diversity Gain ...................................................................... 23 iii The Concept of Spatial Multiplexing.................................................................... 23 Capacity of The MIMO System ........................................................................... 25 Diversity – Multiplexing Tradeoff ........................................................................ 30 4. MIMO BEAMFORMING TECHNIQIE .............................................................. 32 Introduction ........................................................................................................... 32 Singular Value Decomposition (SVD) ................................................................. 34 Precoding of The MIMO Channel ........................................................................ 36 The Input-Shaping Matrix ............................................................................. 37 The Beamforming Matrix .............................................................................. 38 Spatial Multiplexing by Beamforming Technique ............................................... 38 Optimal Allocated of Power (Waterfilling Algorithm) ........................................ 42 Maximal Ratio Receive Combining (MRC) ......................................................... 45 Maximal Ratio Transmit (MRT)........................................................................... 48 Maximum Likelihood Detection with MRRC ...................................................... 49 Single – Mode Beamforming ................................................................................ 51 5. SPARATE SPECTRAM MOUDLATION .......................................................... 56 Introduction ........................................................................................................... 56 Direct Sequence Spread Spectrum (DSSS) .......................................................... 57 Pseudo - Noise Sequence PN ................................................................................ 61 Partial Correlation of PN Sequence ............................................................... 62 PN Signal ....................................................................................................... 63 Multipath Channel Model ..................................................................................... 66 The Rack Receiver ................................................................................................ 68 Performance of The Rack Receiver with MIMO Beamforming Technique ........ 72 6. ANALYSIS THE RESULT OF USING BEAMFORMING TECHNIQUE WITH THE RACK RECIEVER........................................................................... 75 (N×N) DSSS-BPSK MIMO Communication System Preform Result ................. 75 (2×2) MIMO Communication System Performance Result of DSSS-BPSK 78 (3×3) MIMO Communication System Performance Result of DSSS-BPSK 94 (N×N) DSSS-QPSK MIMO Communication System Performance Result ......... 99 (2×2) MIMO Communication System Performance Result of DSSS-QPSK 99 (3×3) MIMO Communication System Performance Result of DSSS-QPSK 103 (2×Nr) DSSS-BPSK MIMO Communication System ......................................... 105 (2×3) MIMO Communication System Performance Result of DSSS-BPSK 106 (2×4) MIMO Communication System Performance Result of DSSS-BPSK 110 (3×4) MIMO Communication System Performance Result of DSSS-BPSK ....... 114 iv 7. CONCLUSION AND FUTURE WORK ............................................................. 120 Conclusion ............................................................................................................ 120 Future Work .......................................................................................................... 122 APPENDICES ............................................................................................................... 123 A. NORMALIZ THE SYSTEM EQUATION OF THE MIMO SYSTEM ....... 123 B. MEAN AND VARIANCE OF THE CORRELATION PROCESS AT THE RACK RECEIVER ............................................................................... 126 REFERENCES .............................................................................................................