Multi-TRP PDSCH Scheme Indication via DM-RS Port Mapping
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Solution Overview
Problem
Existing wireless communication systems face challenges in dynamically indicating the use of multi-Transmission/Reception Point (TRP) Physical Downlink Shared Channel (PDSCH) transmission schemes, such as Single Frequency Network (SFN), Spatial Division Multiplexing (SDM), Frequency Domain Multiplexing (FDM), and Time Domain Multiplexing (TDM), without increasing Downlink Control Information (DCI) overhead.
Innovation Solution
A method is proposed to use an antenna port field in DCI to jointly indicate both the Demodulation Reference Signal (DM-RS) ports and the transmission scheme, allowing flexible PDSCH scheduling by linking DM-RS port allocation to transmission schemes, even when multiple Transmission Configuration Indicator (TCI) states are indicated.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple TCI states are indicated in DCI to enable multi-TRP PDSCH transmission, then transmission reliability is improved, but DCI overhead increases
Solution Approach 1:
The patent merges the transmission scheme indication into the existing antenna port field by defining multiple DM-RS port tables that encode both port indices and transmission scheme information. This allows the antenna port field to simultaneously indicate both the DM-RS ports and the transmission scheme (SFN, SDM, FDM, or TDM), eliminating the need for separate indication fields while maintaining multi-TRP transmission reliability
Solution Approach 2:
The antenna port field is given multiple functions: it not only indicates DM-RS port allocation but also encodes the transmission scheme through the selection of different DM-RS port tables. The TCI field simultaneously indicates multiple TCI states and their associated TRPs. This multi-functionality reduces overall DCI overhead while preserving the ability to indicate complex multi-TRP transmission configurations
2Adaptability or versatility
If additional DCI fields are added to indicate transmission scheme, then transmission scheme flexibility is improved, but DCI size increases
Solution Approach 1:
The patent segments the transmission scheme indication into different DM-RS port tables, where each table corresponds to a specific transmission scheme (SFN, SDM, FDM, or TDM). The UE is configured with multiple tables through higher layer signaling, and the appropriate table is selected based on the antenna port field value. This segmentation allows flexible transmission scheme indication without requiring additional DCI fields, as the scheme information is embedded in the table selection mechanism
Data Source
AI summary
Dynamic indication of multi-Transmission/Reception Point (TRP) Physical Downlink Shared Channel (PDSCH) transmission is provided. A solution is proposed to use an antenna port field (e.g., a Demodulation Reference Signal (DM-RS) port indication field) in Downlink Control Information (DCI) to jointly indicate both the DM-RS ports and the scheme used for a PDSCH transmission. When more than one Transmission Configuration Indicator (TCI) state is indicated in a DCI, a new DM-RS table is used in which a DM-RS port allocation is also linked to a transmission scheme. The solution enables flexible PDSCH scheduling without introducing additional DCI overhead.