Negotiated CQI Feedback Tables for Wireless Systems
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Solution Overview
Problem
Existing CQI feedback schemes in wireless communication systems are complex due to varying user capabilities and deployment scenarios, particularly in MIMO systems, which require different gradations of CQI quantization, making it challenging to optimize feedback effectively.
Innovation Solution
A method for optimizing CQI feedback by selecting and transmitting appropriate feedback tables based on indicators such as system loading, access terminal capability, and reverse link capacity, which include information for determining packet formats and signal-to-noise ratios, allowing for dynamic adaptation to different scenarios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple feedback tables with different CQI quantization schemes are supported to accommodate diverse user capabilities and deployment scenarios, then the adaptability and versatility of the system is improved, but the device complexity and feedback overhead increase significantly
Solution Approach 1:
The patent implements dynamic selection of feedback tables based on current system conditions. The access terminal and access point negotiate to determine which feedback table to use at different times, allowing the system to adapt its CQI quantization scheme dynamically rather than supporting all schemes simultaneously. This reduces device complexity while maintaining adaptability across different scenarios.
Solution Approach 2:
The patent changes the parameter of CQI quantization by selecting different feedback tables with different quantization levels. Instead of maintaining multiple fixed feedback schemes, the system dynamically adjusts the quantization parameter based on system loading, user capability, and deployment scenario, thereby achieving versatility without proportionally increasing complexity.
2Measurement precision
If comprehensive CQI feedback with fine-grained quantization is used to improve channel quality assessment accuracy, then the measurement precision is improved, but the loss of reverse link capacity increases
Solution Approach 1:
The patent applies partial action by selecting feedback tables that provide sufficient but not excessive CQI quantization precision. Instead of always using the finest quantization, the system chooses the appropriate level of precision based on current needs, thereby maintaining adequate measurement accuracy while conserving reverse link capacity for other purposes.
Solution Approach 2:
The system dynamically adjusts the CQI feedback precision by negotiating and selecting different feedback tables based on current system conditions. When high precision is needed, finer quantization is used; when capacity is constrained, coarser quantization is selected. This dynamic approach balances measurement precision against reverse link capacity consumption.
3Adaptability or versatility
If negotiation mechanisms are implemented between access terminal and access point to select feedback tables, then the adaptability to different scenarios is improved, but the loss of time for feedback establishment increases
Solution Approach 1:
The patent implements preliminary action by pre-defining multiple feedback tables with different CQI quantization schemes before actual operation. During negotiation, the access terminal and access point only need to select from these pre-configured options rather than creating custom schemes, significantly reducing the time required for feedback establishment while maintaining adaptability to different scenarios.
4Measurement precision
If feedback tables with more entries are used to provide finer CQI quantization, then the measurement precision is improved, but the device complexity and processing requirements increase
Solution Approach 1:
The patent employs dynamic selection of feedback table size based on current system requirements. Instead of always using the largest feedback table with finest quantization, the system negotiates and selects an appropriate table size that provides sufficient precision for current conditions. This reduces processing complexity and memory requirements while maintaining adequate measurement precision when needed.
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AI summary
Techniques to enhance the performance in a wireless communication system using CQI feedback optimized to support different scenarios. According to one aspect, an access terminal may select a CQI feedback table based on the access terminals capability. According to another aspect, an access point may select a CQI feedback table based on an access terminals capability, system loading and the type of service provided by the access point. An access point which provides services that require high data rates may select a larger CQI feedback table to support the high data rates for access terminals which support the larger CQI feedback table. The same access point may select a smaller CQI feedback table for access terminals which do not have the capability or need for the high data rate services.