MIMO WIRELESS COMMUNICATION SYSTEMS

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MIMO WIRELESS COMMUNICATION SYSTEMS

• Bhaskar D. Rao
• University of California, San Diego
• La Jolla, CA 92093-0407

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Textbooks

• Introduction to Space-Time Wireless
  Communications, A. Paulraj, R. Nabar and D. Gore,
  Cambridge University Press
• Fundamentals of Wireless Communications, D. Tse
  and P. Vishwanath
• Space-Time Block Coding for Wireless
  Communications, E. G. Larsson and P. Stoica
• MIMO Wireless Communications, Edited by E.
  Biglieri, R. Calderbank .

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Prerequistive Classes

• Digital Communication (ECE 258A,B)
• Channel Coding (ECE 259A,B)
• Information Theory (ECE 255A)
• Statistical Signal Processing (ECE 251A)
• Array Processing (ECE 251D)
• Estimation Theory (ECE 275A,B)

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Prerequisites
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Course Grading

• Homeworks 40
• Theory and Matlab
• Project 25
• Presentation on day of Finals
• Exam 35

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Wireless Channel Characteristics

• Fading Multiple Paths with different phases add
  up at the receiver resulting in a random path
  gain
• ISI Paths with different delays causing
  intersymbol interference (Frequency Selective
  Channels)
• CCI Co-Channel users create interference
• Noise Thermal noise from electronics
• Doppler Channel varies over time (mobility)
• Bandwidth Bandwidth limited and so data rates
  can grow only as log(1 SNR)

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Space-Time Processing for Wireless Communications
Goal Exploit the spatial dimension to improve
capacity and quality of network
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Variants of Multiple Antenna Systems
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Terminology
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Benefits of Space-Time Processing

• Increased Capacity
• Improved Signal Quality
• Increased Coverage
• Lower Power Consumption
• Higher Data Rates

These requirements are often conflicting. Need
balancing to maximize system performance
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Technical Rationale

• Spatial Diversity to Combat Fading
• Spatial Signature for Interference Suppression
• Array Gain enables Lower Power Consumption
• Multiple Transmit Antennas provide Transmit
  Diversity
• Capacity Improvements using Spatial Multiplexing

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Scenarios

• Base Station or Mobile
• Receive versus Transmit Antennas
• MIMO systems
• Choice of Multiple Access Scheme (CDMA or TDMA)
• Microcell versus Macrocell
• Mobility versus Fixed

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Beamforming
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Multi-Input Multi-Output System
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Capacity of MIMO systems
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Role of Diversity
Two Fading Channels combined to improve SNR
Diversity gain
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Spatial Diversity to Combat Fading