Compact DCI Format for PDSCH Beamforming in LTE
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Solution Overview
Problem
Current wireless communication systems face inefficiencies in scheduling physical downlink shared channel (PDSCH) transmissions with downlink control information (DCI) format, particularly in managing beamforming parameters and control overhead, which affects data transmission efficiency and power consumption.
Innovation Solution
The method involves generating and transmitting DCI in a compact format that includes indications for beamforming parameters, allowing for efficient scheduling of PDSCH transmissions and reducing control overhead, specifically using a compact DCI format like DCI format 1A' that supports both closed-loop and open-loop beamforming, and dynamically adjusting DM-RS REs based on transmission modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional DCI format is used for scheduling PDSCH transmissions, then complete control information can be provided, but control overhead increases and data transmission efficiency decreases
Solution Approach 1:
The patent extracts and removes unnecessary control information fields from the conventional DCI format to create a compact DCI format. Specifically, fields such as redundancy version, new data indicator, and TPC commands for PUCCH/PUSCH are removed when not required, thereby reducing control overhead while maintaining essential scheduling information for PDSCH transmissions
Solution Approach 2:
The patent changes the parameter structure of DCI by dynamically adjusting the number of DM-RS resource elements based on transmission modes and beamforming configurations. This allows the DCI format to adapt its size and content according to actual transmission requirements, optimizing the balance between control information completeness and overhead reduction
2Adaptability or versatility
If beamforming parameters are explicitly indicated in DCI, then beamforming flexibility improves, but DCI size and control overhead increase
Solution Approach 1:
The patent implements dynamic beamforming parameter indication where the DCI format adapts its content based on transmission mode and beamforming configuration. The beamforming parameters are only included when needed, and their presence/absence is dynamically determined by the scheduling requirements and channel conditions, thereby maintaining flexibility without permanently increasing DCI size
Solution Approach 2:
The compact DCI format is designed to support multiple transmission modes and beamforming types (closed-loop and open-loop) using a unified structure. By using a single DCI format that can adapt to different beamforming requirements rather than having separate formats for each mode, the patent achieves beamforming flexibility without the overhead of maintaining multiple specialized DCI formats
3Reliability
If DM-RS resource elements are increased for better channel estimation, then transmission reliability improves, but power consumption increases
Solution Approach 1:
The patent dynamically changes the number of DM-RS resource elements based on transmission mode, beamforming configuration, and channel conditions. Rather than using a fixed high number of DM-RS REs, the system adjusts this parameter to match actual requirements, thereby maintaining reliable channel estimation while minimizing unnecessary power consumption from excessive reference signals
Data Source
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AI summary
Certain aspects of the present disclosure relate to physical downlink shared channel (PDSCH) transmission schemes with compact downlink control information (DCI) format in new carrier type (NCT) in long term evolution (LTE).