DMRS QCL Association for Channel Estimation in Wireless Control Channels
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Solution Overview
Problem
In next-generation wireless communications, the lack of support for CRS reference signals leads to excessive time-frequency resource occupation, hindering proper channel estimation and degrading DCI detection performance due to the inability to learn reference signals with QCL associations, especially in communal and user-specific search sections.
Innovation Solution
The implementation of different types of pilot signals with quasi-co-location QCL associations in communal and user-specific search sections allows for channel estimation interpolation during blind detection, using synchronization signals, demodulation pilots of broadcast channels, and CSI-RSs to associate DMRSs with pilot signals, enabling effective channel estimation without CRS.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If CRS reference signal is used for channel estimation, then channel estimation accuracy is improved, but time-frequency resource occupation increases excessively
Solution Approach 1:
The patent extracts the channel estimation function from the CRS reference signal and relocates it to DMRS-based mechanisms. By removing the dependency on CRS for channel estimation in search sections, the solution eliminates the excessive time-frequency resource occupation while preserving estimation capability through alternative reference signals.
Solution Approach 2:
The patent introduces DMRS (demodulation reference signal) as an intermediary to enable channel estimation without requiring CRS. The DMRS serves as a mediator that provides the necessary reference information for channel estimation in both communal and user-specific search sections, replacing the CRS function.
2Productivity
If blind detection is performed in communal and user-specific search sections, then DCI detection capability is improved, but channel estimation performance degrades due to lack of QCL association
Solution Approach 1:
The patent applies multi-functionality to the DMRS signal, enabling it to serve both as a demodulation reference and as a QCL indicator. The DMRS in both communal and user-specific search sections is configured to provide channel estimation capabilities, making it a universal reference signal that supports both detection and estimation functions.
Solution Approach 2:
The patent creates a copying mechanism where DMRS signals in search sections are configured with QCL associations that replicate the channel estimation functionality previously provided by CRS. By copying the reference signal function to DMRS, the system maintains channel estimation performance while enabling blind detection in multiple search sections.
3Adaptability or versatility
If multiple search sections are supported for blind detection, then detection flexibility is improved, but system complexity increases due to multiple pilot signal types
Solution Approach 1:
The patent segments the search sections into communal and user-specific categories, with each segment having its own DMRS-based QCL configuration. This segmentation allows independent optimization of channel estimation for different detection scenarios while maintaining overall system manageability through structured organization of reference signals.
Data Source
AI summary
This application provides a wireless communication method, a terminal device, and a network device. The method includes: determining, by a terminal device, a pilot signal corresponding to at least one of a plurality of search sections of a control channel; and detecting, by the terminal device, a control channel candidate in the at least one search section based on a quasi-co-location (QCL) association between the pilot signal corresponding to each search section and the demodulation pilot of the control channel candidate in each search section.