Terminal Beamforming Vector Selection for High-Speed Multipath Diversity
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Solution Overview
Problem
In high-speed movement scenarios, existing LTE technologies struggle to effectively perform beamforming due to limitations in channel estimation and feedback procedures, leading to suboptimal use of multipath characteristics, which hampers communication robustness.
Innovation Solution
A beamforming-based transmission method where a terminal selects and feeds back multiple beamforming vectors based on downlink channel states, allowing for optimal channel quality determination and utilization of multipath diversity, enhancing communication robustness in high-speed environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single beamforming codeword is selected from the codebook for beamforming transmission, then the feedback procedure is simplified and codebook size is reduced, but the multipath characteristics of the channel cannot be fully utilized and communication robustness deteriorates
Solution Approach 1:
The patent segments the single beamforming codeword selection into multiple independent codeword selections (first beamforming codeword, second beamforming codeword, etc.). Each codeword corresponds to a different beamforming vector that can be independently selected from the codebook. This segmentation allows the system to exploit multiple independent beamforming directions simultaneously, thereby utilizing multipath characteristics while keeping each individual codeword selection simple.
Solution Approach 2:
The patent merges multiple beamforming codewords (first beamforming codeword, second beamforming codeword, etc.) into a unified transmission scheme. The base station combines the signals from multiple antenna ports using these codewords, and the terminal combines the corresponding received signals. This merging enables the system to leverage multipath diversity and improve communication robustness while maintaining manageable feedback complexity through independent codeword selection.
2Reliability
If multiple beamforming codewords are selected and fed back to utilize multipath characteristics, then communication robustness is improved, but the feedback procedure becomes more complex and codebook size increases
Solution Approach 1:
The patent divides the feedback process into separate, independent selections of beamforming codewords (first beamforming codeword, second beamforming codeword, etc.). Each codeword is selected independently based on channel state information, and each selection can be processed and fed back separately. This segmentation reduces the overall feedback complexity compared to selecting and processing a single complex multi-codeword solution, while still achieving robust communication through multiple codewords.
3Device complexity
If traditional transmission modes (TM2, TM3) are used for high-speed movement scenarios, then the feedback procedure remains simple, but beamforming cannot be effectively performed and cell capacity is limited
Solution Approach 1:
The patent introduces dynamic beamforming capabilities by enabling the selection of multiple beamforming codewords from an enhanced codebook. This dynamic selection allows the system to adapt to high-speed movement scenarios by exploiting multipath characteristics that change over time. The base station can dynamically adjust the beamforming vectors based on current channel conditions, thereby increasing cell capacity while maintaining manageable feedback complexity through independent codeword selection.
Solution Approach 2:
The patent changes the parameters of the beamforming system by introducing multiple beamforming codewords with different spatial directions and characteristics. This parameter expansion allows the system to exploit multipath diversity in high-speed scenarios, transforming the limited single-codeword approach into a multi-codeword system that can adapt to changing channel conditions and increase cell capacity.
Data Source
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AI summary
A beamforming-based transmission method and apparatus are disclosed. The method includes: obtaining, by a terminal, a quantity M of beamforming vectors needing to be reported by the terminal and a first reference signal that are sent by a base station; estimating downlink channel states on N dual-polarized antenna ports based on the first reference signal; selecting m first beamforming codewords based on the downlink channel states and the quantity M of beamforming vectors needing to be reported that is sent by the base station; and feeding back the m selected first beamforming codewords and ranks of the downlink channel states to the base station. The terminal selects the m first beamforming codewords based on the downlink channel states and the quantity M of beamforming vectors needing to be reported that is sent by the base station, and feeds back the m first beamforming codewords to the base station, so that a multipath characteristic of a channel can be fully used, and communication robustness can be maintained in a high-speed movement scenario based on multipath diversity of the channel.