Rate-Splitting MU-MIMO DM-RS Configuration for Stream Separation
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Solution Overview
Problem
There is a need for further improvements in wireless communications, particularly in LTE and NR systems, to enhance spectral efficiency and support multiple access technologies, especially in multi-user multiple-input multiple-output (MU-MIMO) communication.
Innovation Solution
The implementation of a rate-splitting multiple access scheme in wireless communication systems, utilizing demodulation reference signals (DM-RS) for both common and private streams, to optimize downlink transmissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If rate-splitting multiple access scheme is implemented with separate DM-RS for common and private streams, then spectral efficiency and wireless communication capacity are enhanced, but system complexity and configuration management difficulty increase
Solution Approach 1:
The patent segments the DM-RS configuration into separate configurations for common streams and private streams. The network entity determines and signals distinct DM-RS parameters (such as port indices, scrambling identities, and resource element mappings) for common PDSCH and dedicated PDSCH, allowing independent optimization of reference signals for each stream type while maintaining overall system performance
Solution Approach 2:
The network entity performs preliminary determination of DM-RS configurations before downlink transmission. By pre-determining and signaling the DM-RS configuration through DCI or higher-layer parameters, the system prepares the UE in advance with the necessary reference signal parameters, enabling efficient demodulation without real-time computation overhead during transmission
2Reliability
If separate DM-RS configurations are used for common and private streams, then signal processing and interference management are improved, but downlink control information overhead increases
Solution Approach 1:
The patent employs a unified DM-RS configuration framework that can serve both common and private streams. The same DM-RS parameter structure (port indices, scrambling identities, resource element patterns) is reused across different PDSCH types, allowing the system to maintain separate configurations when needed while falling back to shared configurations to minimize overhead
Solution Approach 2:
The system dynamically changes DM-RS parameters based on transmission requirements. Through DCI format 1_1 or 1_2, the network entity adjusts specific parameters such as dmrs-DownlinkConfigIndicator, scramblingIdentity, and nSCID to match the current transmission mode, balancing the need for separate configurations with overhead constraints
Data Source
AI summary
Disclosed is a method of wireless communication. The method is performed at a user equipment (UE). The method comprises receiving, from a network entity, downlink control information (DCI) for a downlink transmission, wherein the downlink transmission is based on a rate-splitting multiple access scheme, and wherein the downlink transmission comprises a common stream, a demodulation reference signal (DM-RS) for the common stream, a private stream and a DM-RS for the private stream, determining, based on the DCI, a DM-RS configuration for the DM-RS for the common stream and for the DM-RS for the private stream, and receiving, based on the DM-RS configuration, the downlink transmission.