Uplink Channel State Information Multiplexing in LTE
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Solution Overview
Problem
Current LTE specifications do not support simultaneous transmission of multiple periodic channel state information reports in uplink, leading to limitations in channel state information reporting capacity and overhead, particularly in carrier aggregation scenarios with asymmetrical downlink-uplink combinations and time division duplex (TDD) frame structures.
Innovation Solution
The solution involves multiplexing periodic channel state information reports into the same subframe using rules for selecting reports based on a periodic control information cap value, prioritizing reports, and allowing for transmission of multiple reports within a defined cap, thereby avoiding the need to drop all reports except one, and utilizing larger bandwidth or physical uplink shared channels for enhanced reporting capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple periodic channel state information reports are transmitted simultaneously in uplink, then channel state information reporting capacity is improved, but uplink overhead increases
Solution Approach 1:
The patent merges multiple periodic channel state information reports into a single uplink transmission by multiplexing them on the physical uplink shared channel (PUSCH). This combining approach allows multiple reports to be transmitted simultaneously without requiring separate dedicated resources for each report, thereby improving reporting capacity while managing overhead through shared channel utilization.
Solution Approach 2:
The physical uplink shared channel (PUSCH) is utilized to serve multiple functions: it carries both data transmissions and multiplexed channel state information reports. This multi-functionality allows the same uplink resources to support both user data and channel state feedback, improving reporting capacity without proportionally increasing dedicated overhead resources.
2Reliability
If periodic channel state information reports are prioritized and selected based on predetermined rules, then transmission reliability is improved, but reporting completeness deteriorates
Solution Approach 1:
The patent introduces dynamic resource allocation and multiplexing mechanisms that adapt to varying channel conditions and traffic requirements. Instead of rigid predetermined priority rules, the system dynamically selects which reports to transmit and how to multiplex them, allowing flexibility to maintain reliability for critical reports while preserving completeness by including additional reports when resources permit.
Solution Approach 2:
The system changes key parameters such as the number of reports multiplexed, the priority thresholds, and the available uplink resources based on current channel conditions and network state. This parameter adaptation allows the system to balance reliability and completeness dynamically, transmitting more reports when conditions allow and maintaining priority-based selection when resources are constrained.
3Productivity
If channel state information reports are multiplexed into the same subframe, then reporting efficiency is improved, but collision-related issues increase
Solution Approach 1:
The patent introduces the physical uplink shared channel (PUSCH) as an intermediary carrier for multiplexing multiple channel state information reports. This intermediary channel provides a structured framework with defined multiplexing rules and resource allocation mechanisms, allowing multiple reports to share the same subframe while maintaining organizational structure and reducing collision-related issues through standardized handling procedures.
Data Source
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AI summary
Communication systems, for example, wireless communication systems such as long term evolution (LTE) release 11 (Rel-11) may use methods for multiplexing of periodic channel state information reports. Such methods may support the support heavy reliance on channel state information signaling in uplink to provide improved downlink performance. A method can include multiplexing a plurality of channel state information reports into a same subframe. The plurality of channel state information reports can correspond to a user equipment. The method can further include prioritizing a set of channel state information reports including the plurality of channel state information reports.