LTE Antennas

Subject: 4G LTE
Category: Radio
Duration: 3 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 (V-BLAST)
● 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 SC-FDMA

● OFDMA and SC-FDMA as the key transmission techniques in the LTE specs
● 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

E-UTRA Release 8 MIMO Processing

● Downlink and uplink scenarios for Rel. 8 MIMO
● Pilot patterns for 1, 2 and 4 antenna ports at the eNB
● Signal processing chain for MIMO including eNB transmitter and UE receiver
● MIMO mapping including transport blocks, codewords and layers
● MIMO operation for SFBC, spatial multiplexing and beamforming
● MIMO modes and feedback (PMI, RI)

E-UTRA Release 10 and Beyond MIMO Enhancements

● 8×8 spatial multiplexing in downlink and new reference signals
● 4×4 spatial multiplexing in uplink
● SU-MIMO for PUSCH and transmit diversity for PUCCH
● Coordinated multipoint transmission in downlink
● Coordinated multipoint reception in uplink

LTE MIMO in Network Deployment

● Antenna system elements and site configurations
● Practical realization of MIMO configurations
● MIMO impact on coverage, capacity, reliability and interference
● Influence on link budgets and capacity budgets
● Typical design trade-offs in application of MIMO

Numerical Experiments (tool-based)

● MIMO processing at eNB transmitter (including SISO, TX Diversity, Spatial Multiplexing)
● MIMO related reference signals
● Channel correlation influence on spatial stream separation

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