DMRS Antenna Port Grouping for CoMP Signal Demodulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In coordinated multipoint transmission/reception (CoMP) systems, accurately indicating antenna port information is challenging, particularly for demodulation reference signal (DMRS) antenna ports, due to the lack of a clear method to distinguish between different quasi-co-located (QCL) antenna ports, which hinders correct signal reception and demodulation by terminal devices.
Innovation Solution
The proposed solution involves establishing a correspondence between indication information in downlink control information (DCI) and DMRS antenna port groups, allowing terminal devices to determine the specific DMRS antenna port used for downlink data transmission by utilizing preconfigured or prestored mapping relationships, and enabling network devices to configure DMRS port grouping through higher layer signaling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple QCL information groups are configured for different transmission points, then the ability to support coordinated multipoint transmission is improved, but the complexity of indicating antenna port information increases
Solution Approach 1:
The patent segments antenna ports into multiple QCL information groups (first QCL information group, second QCL information group, etc.), where each group corresponds to a specific transmission point. This segmentation allows the terminal to clearly identify which antenna port belongs to which transmission point, resolving the indication complexity while maintaining support for multiple transmission points.
Solution Approach 2:
The patent introduces a new dimension of QCL information group indexing to differentiate antenna ports from multiple transmission points. By adding this dimensional distinction (group indices), the system can indicate antenna port information more clearly without increasing overall system complexity, as the terminal can now distinguish between ports from different TPs using the group index parameter.
2Loss of information
If antenna port information is indicated without clear QCL distinction, then signaling overhead is reduced, but signal reception and demodulation accuracy deteriorates
Solution Approach 1:
The patent applies preliminary action by pre-configuring multiple QCL information groups through higher-layer signaling before data transmission. The terminal stores these pre-configured groups and their corresponding antenna ports. During actual transmission, the network only needs to indicate which pre-configured group to use, significantly reducing real-time signaling overhead while ensuring the terminal has the necessary QCL information for accurate demodulation.
3Adaptability or versatility
If multiple DMRS configurations are used for different transmission points, then non-coherent joint transmission capability is improved, but the difficulty of determining antenna port relationships increases
Solution Approach 1:
The patent applies local quality by assigning specific QCL characteristics to different QCL information groups. Each group has its own QCL parameters (QCL-TypeA, QCL-TypeB, etc.) that are locally optimized for its corresponding transmission point. This allows the terminal to determine antenna port relationships more easily by referring to the specific QCL characteristics of each group, rather than trying to analyze complex inter-port relationships across multiple transmission points.
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
This application provides an information transmission method and a communications apparatus. The method includes: receiving downlink control information DCI, where the DCI includes indication information, the indication information indicates at least one demodulation reference signal DMRS antenna port group and layer information of downlink data, the at least one DMRS antenna port group is one or more of a plurality of DMRS antenna port groups, and DMRS antenna ports in a same DMRS antenna port group satisfy a quasi co-location QCL relationship; and determining, based on the indication information, a DMRS antenna port occupied by the downlink data. According to embodiments of this application, a DMRS antenna port can be indicated when DMRS antenna ports are grouped.