MIMO In-depth

Subject: 4G LTE
Category: Key Techniques
Duration: 2 days

Course outline:

Radio Propagation Overview and Antenna Fundamentals

● Propagation in dispersive multipath channels
● Basic antenna characteristics (time, frequency and angular spread)
● Vertical, horizontal and circular polarization of electromagnetic wave
● Basic antenna structures (isotropic and dipole), their characteristics and parameters
● Sector antenna pattern, influence of down-tilting
● Line-of-sight and non-line-of-sight propagation

Spatial Diversity Methods

● Three domains for providing diversity (time, frequency and space)
● Diversity combining schemes: MRC for receive diversity, Alamouti for transmit diversity and selection combining for both
● Combination of spatial diversity (RAKE receiver and cyclic delay diversity)
● Use of space time coding (STBC, STTC)

Beamforming

● Fundamentals of creating adaptive antenna patterns
● Transmit and receive beamforming (DoD and DoA)
● Physical vs. mathematical beamforming
● Switched multibeam vs. adaptive antenna array
● Optimal usage of beamforming (desired signal
● enforcement, interference suppression or cancellation)
● Combination of beamforming with spatial diversity or spatial multiplexing
● Practical examples of range increase

Spatial Multiplexing

● Basic idea of creating independent spatial channels
● General mathematical model for spatially multiplexed channels
● Encoder and decoder for Horizontal Layered Space (H-BLAST)
● Encoder and decoder for Vertical Layered Space (VBLAST)
● Encoder and decoder for Diagonal Layered Space (D-BLAST)
● Spatial multiplexing with feedback (closed loop)
● Water-filling concept in closed loop MIMO
● Zero-forcing receiver and singular value decomposition (SVD)

MIMO in Multiple-user Scenario

● Extension of spatial multiplexing concept to multiple-user scenarios
● Classification of multiple-user scenarios for MIMO usage
● 3-dimensional scheduling in LTE system
● Coordinated MIMO transmission from more than one base station

Combination of MIMO with OFDMA and SCFDMA

● OFDMA and SC-FDMA as the key transmission techniques for current broadband systems
● MIMO-related synchronization and channel estimation aspects
● Combination of STBC and OFDMA
● Combination of SM/BF and OFDMA
● Possible allocations of transmit diversity and spatial multiplexing
● Receive beamforming with SC-FDMA

MIMO Applied in the Major Standards

● MIMO in 3GPP Rel. 8, Rel. 9 and Rel. 10 E-UTRAN
● MIMO in IEEE 802.16e
● MIMO in eHSPA

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