Multicarrier CQI Grouping Reduces Uplink Overhead
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Solution Overview
Problem
Existing multicarrier communication systems face challenges in reducing Channel Quality Indicator (CQI) report overhead, especially for communication terminals with high transmission rates and low allocation priority, as they require reporting CQI for multiple resource blocks, increasing the amount of information needed.
Innovation Solution
The system divides channel quality indicators into groups based on received quality and selects a group to report, using group selection information and channel quality indicator selection information, reducing the amount of CQI report by limiting the number of alternatives and reporting only necessary bits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the number of resource blocks is increased to achieve finer frequency scheduling granularity, then time-frequency scheduling effectiveness is improved, but the amount of CQI report increases and uplink overhead becomes large
Solution Approach 1:
The patent segments the CQI report into two parts: a first CQI report containing CQI values for selected resource blocks (most important ones), and a second CQI report containing CQI values for remaining resource blocks. This segmentation allows the system to report essential scheduling information with minimal overhead while retaining the ability to provide complete CQI data when needed.
Solution Approach 2:
The patent applies partial action by requiring communication terminals to report CQI values only for a subset of resource blocks in the first CQI report, rather than all resource blocks. The terminal selects resource blocks based on received quality, reporting only the most relevant CQI values (e.g., top N resource blocks) to reduce uplink overhead while maintaining scheduling effectiveness.
2Measurement precision
If CQI report is required for all resource blocks to maintain scheduling accuracy, then scheduling precision is improved, but uplink overhead increases
Solution Approach 1:
The patent divides the CQI reporting process into two segments: a first CQI report for selected resource blocks and a second CQI report for remaining resource blocks. This segmentation enables the system to achieve sufficient scheduling precision through the first report while minimizing uplink overhead, with the option to supplement with the second report only when necessary.
Solution Approach 2:
The patent applies local quality by differentiating the reporting requirements for different resource blocks based on their received quality. High-quality resource blocks are included in the first CQI report for precise scheduling, while lower-quality resource blocks may be omitted or reported separately, allowing the system to allocate reporting resources efficiently based on local channel conditions.
3Measurement precision
If communication terminals report CQI for all allocated resource blocks, then scheduling accuracy is maintained, but the proportion of CQI in uplink signal increases
Solution Approach 1:
The patent implements partial action by having communication terminals report CQI values only for a selected subset of resource blocks in the first CQI report, rather than all allocated resource blocks. This partial reporting maintains scheduling accuracy for the most critical resource blocks while significantly reducing the proportion of uplink signal occupied by CQI information.
Solution Approach 2:
The patent extracts only the essential CQI information needed for scheduling decisions from the complete set of resource block CQI values. By selecting and reporting only the most important CQI values (e.g., for resource blocks with highest received quality), the system extracts sufficient scheduling information while minimizing the overall CQI report size and uplink overhead.
Data Source
AI summary
Provided is a multicarrier communication apparatus by which information quantity of CQI reporting can be reduced. In the apparatus, each CQI is recorded in a CQI table section (122) by being classified into a plurality of CQI groups by following a certain rule. A CQI selecting section (123) estimates fluctuation range and variance of reception qualities of the entire resource block to be reported, based on an SINR value outputted from a quality level calculating section (121). Then, based on the estimated values, the CQI selecting section selects a suitable CQI group in a first step, selects a suitable CQI value from among the CQIs included in the selected CQI group in a second step, and outputs the ID of the selected CQI group and the selected CQI value to a CQI generating section (124). Based on such information, the CQI generating section (124) generates a CQI frame to be transmitted to a base station.