LTE-A Codebook Segmentation for 8-Antenna Feedback
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Solution Overview
Problem
The LTE system's codebook for 4 antennae is inadequate for channel information feedback in the LTE-Advanced (LTE-A) system using 8 antennae, leading to suboptimal transmission performance.
Innovation Solution
A method for acquiring and sending a Rank Indicator (RI) and Precoding Matrix Indicator (PMI) in a modified codebook space, allowing for effective channel information feedback from mobile terminals to base stations in LTE-A systems, even with 8 antennae, by constructing a codebook space using specific matrix sets and transformations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the LTE system's codebook for 4 antennae is used, then the system structure is simple and easy to implement, but the channel information feedback accuracy deteriorates when using 8 antennae in LTE-A
Solution Approach 1:
The codebook for 8 antennae is segmented into multiple sub-codebooks, each corresponding to different antenna configurations. This allows the system to select appropriate sub-codebooks based on the actual antenna setup, maintaining implementation simplicity while improving feedback accuracy for 8-antenna scenarios.
Solution Approach 2:
The invention extends the codebook structure from 4-antenna dimension to 8-antenna dimension by introducing additional codebook layers and indicators. This dimensional expansion enables accurate channel feedback for 8-antenna MIMO while preserving the original codebook's simplicity through hierarchical organization.
2Measurement precision
If the codebook space is expanded to support 8 antennae, then the channel information feedback accuracy improves, but the codebook complexity and storage requirements increase
Solution Approach 1:
The large 8-antenna codebook is divided into multiple smaller sub-codebooks, each handling specific antenna configurations. This segmentation reduces the complexity of managing the entire codebook while maintaining comprehensive coverage for accurate channel feedback.
Solution Approach 2:
The codebook is pre-organized into structured sub-codebooks with defined relationships and selection criteria. This preliminary organization enables efficient codebook management and selection during operation, reducing real-time processing complexity while supporting accurate 8-antenna feedback.
3Reliability
If more code words are stored in the codebook for 8 antennae, then the precoding performance improves, but the feedback overhead and processing time increase
Solution Approach 1:
The codebook is segmented into sub-codebooks that can be selectively activated based on channel conditions and antenna configurations. This segmentation allows the system to use only the necessary portion of the codebook for each transmission, improving precoding performance while reducing feedback processing time.
Solution Approach 2:
Instead of using the complete expanded codebook for all scenarios, the system applies partial codebook usage by selecting appropriate sub-codebooks based on actual channel conditions. This partial action approach maintains high precoding performance when needed while reducing processing overhead in other cases.
Data Source
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AI summary
The present invention discloses a method for sending channel information, and a terminal, a base station and an LTE-A system. The method comprises: a mobile terminal acquiring channel information; determining, in a codebook space, an RI and a PMI corresponding to the channel information according to the channel information; and sending the RI and the PMI to a base station. By way of the present invention, the effects of improving the throughput of an LTE-A system and the frequency spectrum efficiency thereof are achieved.