Sub-carrier Selection for Channel Quality Reporting
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Solution Overview
Problem
Conventional wireless communication systems face challenges in high-speed packet transmission due to the large quantity of control signals required for channel quality reporting, leading to reduced data capacity, increased interference, and higher power consumption.
Innovation Solution
A wireless communication apparatus and method that measures and reports reception quality of sub-carriers, selecting only those with superior conditions for adaptive modulation and scheduling, thereby reducing the amount of control signals transmitted and improving system capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If CQI reporting is performed for all sub-carriers, then channel quality information completeness is improved, but the quantity of control signals increases leading to reduced data capacity
Solution Approach 1:
The patent segments the 64 sub-carriers into multiple groups (e.g., 4 groups of 16 sub-carriers each). Instead of reporting CQI for all 64 sub-carriers individually, the mobile station selects one representative sub-carrier from each group and reports CQI only for those selected representatives. This segmentation reduces the control signal quantity from 64 CQI reports to approximately 4 CQI reports per frame, significantly increasing data capacity while maintaining channel quality assessment capability.
Solution Approach 2:
The patent extracts only the essential channel quality information by selecting representative sub-carriers that best indicate the propagation conditions. Rather than transmitting all 64 CQI values, the system extracts and transmits only the CQI values for selected representative sub-carriers, removing redundant information while preserving the ability to determine appropriate modulation and coding schemes.
2Measurement precision
If CQI reporting is performed for all sub-carriers, then channel quality information completeness is improved, but interference with other data channels and cells increases
Solution Approach 1:
By segmenting sub-carriers into groups and selecting only representative sub-carriers for CQI reporting, the patent reduces the total number of control signals transmitted in the uplink. This reduction in control signal quantity directly decreases interference with other data channels and other cellular systems, while the grouped approach ensures that channel quality information remains sufficiently complete for effective scheduling decisions.
3Measurement precision
If CQI reporting is performed for all sub-carriers, then channel quality information completeness is improved, but power consumption of mobile station increases
Solution Approach 1:
The patent reduces power consumption by segmenting the CQI reporting process into grouped sub-carrier selections. Instead of measuring and reporting CQI for all 64 sub-carriers, the mobile station only needs to identify and report CQI for representative sub-carriers from each group. This reduces the processing load and transmission energy required, extending battery life while maintaining sufficient channel quality information for adaptive modulation and scheduling.
Solution Approach 2:
The patent extracts only the necessary CQI information from the full set of sub-carrier measurements. By identifying and reporting CQI values only for selected representative sub-carriers rather than all sub-carriers, the mobile station reduces the energy consumed in both the measurement processing and the uplink transmission, directly addressing the power consumption issue.
Data Source
AI summary
A wireless communication apparatus is provided including: a radio receiver configured to acquire, from a base station, a first information indicating a fixed number identifying quantity of sub-carrier bands to be selected for channel quality reporting; a reception quality measurer configured to measure channel quality of each of a plurality of sub-carrier bands within a communication band; a subcarrier selector configured to select sub-carrier bands from the plurality of sub-carrier bands based on the measured channel quality, wherein quantity of the selected sub-carrier bands matches the quantity of sub-carrier bands identified by the fixed number; a modulator configured to modulate a second information indicating channel quality of the selected sub-carrier bands and a third information indicating positions of the selected sub-carrier bands according to a modulation scheme; and a radio transmitter configured to report to the base station the second and third modulated information.