CSI Bit Ordering in UCI for Resource-Constrained Uplink
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing mechanisms for CSI omission in NR wireless communication systems face challenges in efficiently handling varying CSI reports and resource allocations, leading to potential CSI loss and inaccurate channel state estimation due to insufficient resource allocation for CSI payloads.
Innovation Solution
An efficient CSI omission scheme is implemented by defining an ordering for mapping CSI bits to UCI, where the least significant bits are truncated if the PUSCH resource allocation is smaller than the CSI payload, ensuring that wideband CSI parameters have higher priority and are included in full, while subband CSI parameters are omitted last, allowing the gNB to interpolate omitted CSI and minimize loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If PUSCH resource allocation is reduced to accommodate other uplink data, then uplink data transmission efficiency is improved, but CSI payload capacity deteriorates leading to CSI loss
Solution Approach 1:
The CSI payload is segmented into multiple parts with different priorities. Part 1 contains critical wideband CSI parameters (RI, CQI, PMI) that are always transmitted, while Part 2 contains less critical subband CSI parameters that can be omitted when resources are limited. This segmentation allows the system to maintain essential CSI feedback even when PUSCH resources are reduced.
Solution Approach 2:
Different portions of the CSI payload are assigned different quality levels based on their importance. Wideband CSI parameters receive higher priority and are protected from omission, while subband CSI parameters receive lower priority and can be truncated. This local quality differentiation ensures that the most important channel state information is preserved under resource constraints.
2Adaptability or versatility
If arbitrary resource allocation is applied to PUSCH, then resource utilization flexibility is improved, but CSI transmission reliability deteriorates due to insufficient resources
Solution Approach 1:
The system dynamically adjusts the CSI transmission strategy based on the allocated PUSCH resources. When resources are sufficient, the complete CSI payload is transmitted. When resources are limited, the system dynamically truncates the payload by omitting less critical parts while ensuring critical parts are transmitted. This dynamic adaptation maintains reliability across varying resource conditions.
Solution Approach 2:
The invention changes the transmission parameters of CSI based on resource availability. The payload size, composition, and priority weighting are adjusted according to the allocated resources. This parameter adaptation allows the system to maintain reliable CSI transmission even with arbitrary resource allocations by optimizing the transmitted information content to match available capacity.
3Measurement precision
If subband CSI parameters are transmitted in full, then channel state estimation accuracy is improved, but uplink resource consumption increases
Solution Approach 1:
The invention extracts and separates the essential wideband CSI parameters from the less essential subband CSI parameters. By taking out the critical information (Part 1) and transmitting it separately with higher priority, the system ensures accurate channel state estimation with reduced resource consumption. The subband details (Part 2) are omitted when resources are constrained, achieving a balance between accuracy and resource usage.
Data Source
AI summary
Methods and systems for reporting Channel State Information (CSI), including ordering of CSI in Uplink Control Information (UCI), are provided herein. According to one embodiment, a method performed in a wireless device for reporting CSI comprises at least one of: receiving an indication of a resource allocation for an UL transmission; determining, from the indication, a maximum container size for a CSI report; mapping the one or more information bits of a CSI report to a bitstream, optionally such that a first CSI subset is mapped to more significant bits than a second CSI subset; and omitting the one or more least significant bits of the bitstream.