Multi-TRP Uplink Channel Measurement Using CSI-RS Matrix Reconstruction
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Solution Overview
Problem
Existing technologies are unable to perform complete uplink channel measurement in a multi-Transmission Reception Point (TRP) scene due to the limitation of CSI-RS resources being transmitted by a single TRP, preventing the acquisition of a complete downlink and uplink channel matrix, which is necessary for non-codebook based uplink channel measurement.
Innovation Solution
The method involves receiving SRS scheduling information, associating it with multiple CSI-RS resources to measure the downlink channel state of multiple TRPs, performing time-frequency offset compensation and channel estimation to obtain a complete downlink channel matrix, and transforming this matrix to acquire a complete uplink channel matrix, allowing for the determination and transmission of precoded SRS resources based on the number of SRS resources in the set.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If CSI-RS resources are transmitted by a single TRP, then the transmission structure is simple, but complete downlink and uplink channel matrix acquisition is prevented
Solution Approach 1:
The patent segments the channel measurement process by associating different CSI-RS resources with different TRPs. Each CSI-RS resource measures the downlink channel of a specific TRP, and multiple segmented measurements are combined to form a complete channel matrix for multi-TRP scenarios.
Solution Approach 2:
The patent extends the universal application of CSI-RS resources to multi-TRP scenarios. The same CSI-RS resource configuration mechanism is made multi-functional by associating it with multiple TRPs, allowing a single measurement framework to handle both single-TRP and multi-TRP cases.
2Loss of information
If multiple CSI-RS resources are associated with SRS resource set for multi-TRP measurement, then complete downlink channel matrix can be obtained, but the resource configuration complexity increases
Solution Approach 1:
The patent implements feedback mechanisms where the UE reports channel state information based on multiple CSI-RS resources. The base station uses this feedback to determine appropriate precoding matrices, creating a closed-loop system that optimizes uplink transmission while managing configuration complexity through intelligent resource selection.
Solution Approach 2:
The patent performs preliminary downlink channel measurement using multiple CSI-RS resources before uplink transmission. By pre-acquiring complete downlink channel matrices from multiple TRPs, the system prepares necessary channel state information in advance, enabling efficient precoding calculation without real-time complexity.
3Productivity
If non-codebook based uplink transmission is used, then uplink data transmission efficiency is improved, but complete uplink channel measurement is required which is currently unachievable in multi-TRP scenes
Solution Approach 1:
The patent uses downlink channel measurements as copies to represent uplink channel characteristics. By measuring downlink channels from multiple TRPs and applying reciprocity, the system creates accurate copies of uplink channel state information without requiring direct uplink measurement, enabling non-codebook based transmission in multi-TRP scenarios.
Data Source
AI summary
Uplink channel measurement method and apparatus for multi-TRP scene, storage medium, terminal, and base station are provided. The method includes: receiving SRS scheduling information indicating an SRS resource set triggered by current uplink channel measurement; receiving an CSI-RS resource associated with the SRS resource set, and performing time-frequency offset compensation and channel estimation to obtain a complete downlink channel matrix, wherein the CSI-RS resource is used to measure downlink channel state of a plurality of TRPs, and the complete downlink channel matrix includes downlink channel matrixes of the TRPs; acquiring a complete uplink channel matrix by transforming the complete downlink channel matrix, wherein the complete uplink channel matrix includes uplink channel matrixes of the TRPs; determining and transmitting preset number of precoded SRS resources based on the complete uplink channel matrix, wherein the preset number is determined based on a number of SRS resources included in the SRS resource set.