CJT Codebook Parameter Signaling for Lower CSI Feedback Overhead
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Solution Overview
Problem
In frequency division duplexing systems with coherent joint transmission, configuring CJT codebook-related parameters and restriction information for terminal devices is challenging, leading to increased complexity and overheads in channel state information feedback.
Innovation Solution
A network device generates and sends indication information to a terminal device, configuring K first parameter combinations and a target second parameter combination to reduce the number of preconfigured candidate parameter combinations, thereby reducing indication overheads and complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple preconfigured candidate parameter combinations are used for CJT codebook configuration, then the terminal device can achieve accurate channel state information feedback, but the indication overheads and configuration complexity increase significantly
Solution Approach 1:
The patent segments the parameter configuration into two distinct parts: first parameter combinations (K combinations) that are individually configured for each reference signal resource, and a second parameter combination that is shared across all resources. This segmentation allows the terminal device to determine spatial domain basis vectors and port quantities per resource while sharing frequency domain basis vectors and non-zero coefficient quantities, thereby reducing overall configuration complexity while maintaining feedback accuracy.
Solution Approach 2:
The patent makes the second parameter combination universal across multiple reference signal resources. The same second parameter combination (including frequency domain basis vector quantity and non-zero coefficient quantity) is applied to all N reference signal resources, reducing the need for separate configurations for each resource and thereby reducing indication overheads while still enabling accurate channel state information feedback for coherent joint transmission.
2Adaptability or versatility
If multiple preconfigured candidate parameter combinations are provided for terminal device selection, then codebook configuration flexibility is improved, but the indication overheads increase
Solution Approach 1:
The patent divides the parameter combinations into first parameter combinations (K different combinations) and a second parameter combination. The first parameter combinations provide flexibility for spatial domain configuration per reference signal resource, while the second parameter combination provides shared frequency domain configuration. This segmented approach maintains codebook configuration flexibility while reducing indication overheads by avoiding the need to provide multiple complete parameter combination sets.
Solution Approach 2:
Instead of providing multiple complete parameter combination sets (which would be excessive), the patent provides K first parameter combinations plus one second parameter combination that is shared across all resources. This partial provision of parameter combinations is sufficient to achieve codebook configuration flexibility for coherent joint transmission while significantly reducing indication overheads compared to providing multiple full parameter combination sets.
3Manufacturing precision
If separate parameter configurations are provided for each reference signal resource, then resource-specific optimization is achieved, but the configuration complexity and overheads increase
Solution Approach 1:
The patent segments the parameter configuration approach by applying first parameter combinations individually to each reference signal resource for spatial domain basis vector and port quantity determination, while applying a shared second parameter combination for frequency domain basis vector and non-zero coefficient quantity across all resources. This segmented configuration achieves resource-specific optimization where needed while simplifying the overall configuration process through sharing common parameters.
Solution Approach 2:
The patent merges the configuration of the second parameter combination across all N reference signal resources. The same second parameter combination (frequency domain basis vector quantity and non-zero coefficient quantity) is combined and applied to all resources, reducing configuration complexity and ease of operation by eliminating the need to separately configure these parameters for each resource, while still allowing resource-specific optimization through the first parameter combinations.
Data Source
AI summary
Embodiments of this application provide a communication method and apparatus, applicable to a CJT communication system, to resolve a parameter configuration problem of a CJT codebook. The method includes: A network device generates first indication information and second indication information, and sends the first indication information and the second indication information to a terminal device, where the first indication information indicates K first parameter combinations, the second indication information indicates a target second parameter combination determined from multiple candidate second parameter combinations, each of the multiple candidate second parameter combinations corresponds to one target value, a target value corresponding to the target second parameter combination is greater than or equal to a largest value in K values determined based on the K first parameter combinations.