1. Introduction to Key LTE TDD Features: Beamforming
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Introduction to Key LTE TDD Features: Beamforming
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2. Introduction to Key LTE TDD Features: Beamforming
Definition
Benefits
Basic principles
Beamforming features and their characteristics
When to use beamforming
How to deploy beamforming
Beamforming Feature Parameter Description

3. Definition
With traffic beamforming, an eNodeB weights downlink data before transmission to form a narrow beam toward target UEs, thereby increasing the SINR for demodulation and improving CEU experience.

4. Gains Offered By Beamforming
Beamforming offers array gains and multiplexing gains.
Array gains indicate an increase in the SINR at the receiver and the improvements of cell coverage. When channel quality is poor, an increase of the array gain indicates that user experience improves.
When channel quality is satisfactory, an eNodeB uses the same time-frequency resource to process two data streams related to one user or the data streams related to two users, increasing cell throughputs and peak cell capacity.

5. Basic principles
In an LTE TDD system, the eNodeB measures uplink channel quality using SRSs and estimates the downlink channel characteristics based on channel reciprocity between the uplink and downlink.
Based on the measurement and estimation results, the eNodeB calculates the weight and then applies it to downlink signals to form a narrow beam toward target UEs.
Weighting

6. Beamforming Features and Their Characteristics
Beamforming covers the following features:
Characteristics of Beamforming Features

7. When to Use Beamforming
Adaptive selection between beamforming and MIMO in low-speed scenarios
Adaptive selection between beamforming and MIMO in low-speed scenarios

8. How to Deploy Beamforming
Beamforming Feature Parameter Description describes how to deploy beamforming features and adaptation between beamforming and MIMO in the following chapters.

9. How to Obtain Beamforming Feature Parameter Description
Log in to and obtain Beamforming Feature Parameter Description from eRAN TDD 6.1 Feature Documentation 01(HDX).