Precoded Reference Signals for 3D MIMO Cell Selection
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Solution Overview
Problem
Current 3D MIMO systems face challenges in cell selection due to the use of non-precoded reference signals, leading to inefficient beam formation and frequent handovers, especially with the increasing complexity of antenna arrangements in future wireless communication systems.
Innovation Solution
Implementing a 3D MIMO system where user equipment receives and measures the quality of precoded reference signals from multiple antenna ports, selecting the best directional beam for communication and feeding back the beam index to the base station, which adjusts handover parameters to minimize frequent beam selection and handovers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If non-precoded reference signals are used for cell selection in 3D MIMO systems, then the system can support basic beam formation, but cell selection efficiency deteriorates and handover frequency increases
Solution Approach 1:
The patent applies preliminary action by pre-coding reference signals with beamforming weights before transmission. The base station performs beamforming processing on reference signals in advance, creating precoded reference signals that carry directional information. This preliminary beamforming action enables user equipment to directly measure and compare beam qualities without requiring subsequent complex beam selection procedures, thereby improving cell selection efficiency and reducing handover frequency.
Solution Approach 2:
The patent implements feedback mechanisms where user equipment measures the quality of precoded reference signals from multiple base stations and feeds back measurement results. The network uses this feedback information to make informed cell selection and handover decisions. This feedback loop enables optimized handover timing and target cell selection, reducing unnecessary handovers and improving overall system efficiency.
2Adaptability or versatility
If multiple antenna ports are arranged two-dimensionally for 3D MIMO, then beam forming capability in vertical and horizontal directions is improved, but system complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the two-dimensional antenna array into separate horizontal and vertical subsets. Each subset is independently controlled for beamforming, allowing the system to form beams in both horizontal and vertical directions through coordinated operation of segmented antenna groups. This segmentation simplifies the control architecture while maintaining full 3D beamforming capability.
Solution Approach 2:
The patent implements multi-functionality by designing the precoding mechanism to simultaneously handle both horizontal and vertical beamforming using the same signal processing framework. The reference signals are precoded to carry information for both directional dimensions, allowing the system to perform multiple beamforming functions (horizontal beam selection, vertical beam selection, and cell selection) through a unified approach, thereby managing complexity while maintaining versatility.
3Measurement precision
If user equipment measures reception quality of precoded reference signals from multiple base stations, then optimal beam selection is improved, but measurement and processing time increases
Solution Approach 1:
The patent applies periodic action by configuring user equipment to measure precoded reference signals at specific periodic intervals rather than continuously. The network configures measurement timing and resources periodically, allowing UE to efficiently sample beam qualities from multiple base stations at optimized moments. This periodic measurement approach maintains measurement accuracy for handover decisions while significantly reducing overall measurement and processing time compared to continuous monitoring.
Data Source
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AI summary
A user equipment that comprises a transmission and reception unit configured to receive a reference signal list including precoded reference signals associated with cell indices and collocation information, a measurement unit configured to measure reception quality of the precoded reference signals included in the received reference signal list and a selection unit configured to select a precoded reference signal based on the measured reception quality.