Joint CSI-RS Transmission for Channel State Feedback
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Solution Overview
Problem
Legacy wireless communication devices are unable to support multi-point transmissions using multiple channel state information reference signals (CSI-RS), limiting their ability to provide effective channel state feedback for transmission point selection in wireless communication networks.
Innovation Solution
The technique involves configuring a single CSI-RS for legacy devices to enable multi-point transmissions by allowing joint transmission of CSI-RS from multiple transmission points, enabling channel state feedback for transmission point selection and supporting legacy UEs in mixed systems with newer devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple CSI-RS are transmitted from different transmission points, then channel state feedback for transmission point selection is improved, but device complexity increases and legacy devices cannot support the functionality
Solution Approach 1:
The patent merges multiple CSI-RS transmissions from different transmission points into a single joint transmission. Instead of transmitting separate CSI-RS from each transmission point, the system combines them into one unified CSI-RS signal that carries information about multiple transmission points, allowing legacy devices to receive and process the combined signal for transmission point selection.
Solution Approach 2:
The single CSI-RS signal serves multiple functions simultaneously: it provides channel state information for multiple transmission points, enables transmission point selection, and maintains compatibility with legacy devices. This multi-functional design allows the system to support both legacy and advanced devices without requiring separate reference signals for each function.
2Reliability
If multiple transmission points transmit separately, then transmission diversity is improved, but signal interference and resource allocation complexity increase
Solution Approach 1:
The patent combines signals from multiple transmission points into a single joint transmission. By merging the transmissions and using a unified CSI-RS signal, the system reduces signal interference that would occur with separate transmissions while maintaining the diversity benefits of multiple transmission points through the combined signal structure.
Data Source
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AI summary
Certain example embodiments of the present disclosure provide techniques for joint transmission of channel state information reference signals (CSI-RS) from multiple transmission points (TPs) for channel state feedback and/or TP selection. An example method generally includes coordinating with one or more other TPs to jointly transmit a channel state information reference signal (CSI-RS) to a user equipment (UE); signaling a reporting restriction to the UE; receiving precoding matrix indicator (PMI) feedback from the UE based on the jointly transmitted CSI-RS and subject to the reporting restriction; and selecting one or more of the TPs to serve based on the PMI feedback.