CQI Reporting for Virtual Carrier Scheduling Under Uplink Overhead Limits
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Solution Overview
Problem
Existing wireless telecommunications systems supporting virtual carrier operations face challenges in reporting radio channel conditions effectively, leading to suboptimal scheduling decisions and increased uplink signaling overhead.
Innovation Solution
A method for terminal devices to measure channel conditions across the system frequency bandwidth and transmit measurement reports with varying resolutions, where resources within the restricted bandwidth downlink channel have higher frequency and time resolution than those outside it, allowing for optimized resource allocation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high-resolution CQI reporting is implemented for all transmission resources, then scheduling accuracy is improved, but uplink signaling overhead increases
Solution Approach 1:
The patent applies local quality by differentiating the reporting resolution based on the transmission resource type. For transmission resources comprising the restricted bandwidth downlink channel, high-resolution CQI reporting is implemented to enable accurate scheduling decisions. For transmission resources not comprising the restricted bandwidth downlink channel, low-resolution or no CQI reporting is used, reducing signaling overhead. This selective approach ensures that measurement precision is optimized only where necessary for the virtual carrier operation.
2Measurement precision
If CQI reporting for transmission resources not comprising restricted bandwidth downlink channel is provided with high resolution, then scheduling accuracy for potential virtual carrier allocation is improved, but uplink signaling overhead increases
Solution Approach 1:
The patent implements local quality by applying different reporting resolutions to different transmission resource regions. High-resolution reporting is applied only to the restricted bandwidth downlink channel where the terminal device actually receives communications, while low-resolution or no reporting is applied to other transmission resources. This reduces the processing complexity for terminal devices by limiting the scope of detailed measurements to only where needed.
3Adaptability or versatility
If the terminal device measures and reports channel conditions for the full system frequency bandwidth, then the base station can make informed scheduling decisions for virtual carrier configuration, but the measurement and reporting complexity increases
Solution Approach 1:
The patent applies local quality by restricting detailed channel condition measurements and reporting to only the restricted bandwidth downlink channel that the terminal device actually uses for communications. While the base station maintains flexibility to consider full bandwidth for virtual carrier configuration, the terminal device performs high-precision measurements only where required, reducing its measurement and reporting complexity while still enabling informed scheduling decisions.
Data Source
AI summary
A wireless telecommunications system including a base station and terminal device, supporting a virtual carrier mode with downlink communications made by the base station using a radio interface spanning a system frequency bandwidth while the terminal device can receive at least some communications from the base station within a restricted subset of transmission resources selected from within the system frequency bandwidth providing a restricted bandwidth downlink. The terminal device can measure channel conditions across the system frequency bandwidth and transmit corresponding measurement reports to the base station. Measurement reports for transmission resources not including the restricted bandwidth downlink channel may be aperiodic while measurement reports for transmission resources including the restricted bandwidth downlink channel may be periodic. Measurement reports for transmission resources not including the restricted bandwidth downlink channel may be based on a subset of the channel condition measurements selected because they are associated with relatively poor channel conditions.