CQI Accuracy Measurement in HSDPA Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for measuring the accuracy of channel quality reports in radio communication systems, such as those using HSDPA, are flawed as they do not account for varying reception performance among communication apparatuses, leading to invalidity in reported CQI accuracy measurements and potential errors in packet transmission rates and system throughput.
Innovation Solution
An accuracy measurement apparatus and method that transmits test data for a fixed period to determine the most frequently reported CQI, using this value as a fixed CQI for subsequent accuracy measurement, and calculates the error rate of accuracy measurement signals to assess the accuracy of reported CQI values, thereby isolating the influence of reception performance and detecting divergent CQI reports.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If packets are continuously transmitted for a fixed period at a transmission rate corresponding to a fixed CQI to measure reported CQI accuracy, then the measurement process can be standardized and automated, but the measurement becomes invalid for communication apparatuses with advanced receivers that report CQI values higher than the fixed CQI
Solution Approach 1:
The patent makes the transmission rate dynamic by adapting it to the reported CQI value rather than using a fixed CQI for all measurements. The base station selects transmission parameters (modulation scheme, coding rate, transport block size) based on the actual CQI reported by the communication apparatus, allowing the measurement system to accommodate different receiver capabilities and propagation environments.
Solution Approach 2:
The patent changes the measurement approach by using multiple CQI values and corresponding transmission rates instead of a single fixed CQI. The system measures PER and throughput for each reported CQI value against its corresponding optimal transmission rate, creating a comprehensive accuracy assessment that accounts for varying receiver performance.
2Reliability
If a communication apparatus with advanced receivers reports CQI values higher than the fixed CQI, then the receiver performance is better, but the reported CQI accuracy measurement test becomes invalid
Solution Approach 1:
The patent applies local quality by tailoring the transmission parameters to each specific CQI value reported by the communication apparatus. Instead of using a uniform fixed CQI for all measurements, the system selects transmission rates locally optimized for each reported CQI level, allowing accurate measurement of CQI reporting accuracy across different performance levels.
Solution Approach 2:
The measurement system dynamically adapts to the reported CQI values by adjusting transmission parameters accordingly. This allows the system to validly measure CQI accuracy for communication apparatuses with varying receiver capabilities, including those with advanced receivers that report higher CQI values.
3Reliability
If the reported CQI is lower than the actual propagation environment quality, then the PER decreases, but the overall system throughput decreases due to suboptimal transmission rates
Solution Approach 1:
The patent uses feedback mechanisms to measure and evaluate CQI reporting accuracy. By comparing the reported CQI values with the actual PER and throughput performance at corresponding transmission rates, the system can identify when CQI reports are inaccurate and provide feedback for improving CQI measurement validity.
Solution Approach 2:
The patent performs measurements for multiple CQI values and transmission rate combinations, which is more comprehensive than a single fixed CQI measurement. This excessive measurement approach ensures that even if some CQI reports are inaccurate, the overall accuracy can be assessed across the full range of operating conditions.
Data Source
AI summary
A channel quality report accuracy measurement apparatus and accuracy measurement method are provided that correctly measure the accuracy of channel quality reported from a communication apparatus. A scheme control section (140) stores coding rates and modulation schemes corresponding to CQIs, and specifies the transmission scheme corresponding to a fixed CQI reported from a CQI statistical processing section (230). A CQI decoding section (220) decodes a reported CQI contained in a received signal. The CQI statistical processing section (230) performs statistical processing of reported CQIs corresponding to test data transmitted prior to an accuracy measurement test, and reports the most frequently reported CQI to the scheme control section (140) as a fixed CQI. A PER calculation section (260) calculates the PER in the communication apparatus from the reported CQI and Ack/Nack corresponding to test data transmitted in accordance with the fixed CQI. A determination section (270) performs threshold value determination for the PER for each reported CQI value, and outputs the reported CQI scheme determination result.