PDCCH Decoding Aggregation Level Adaptation
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Solution Overview
Problem
LTE mobile terminals face challenges in efficiently decoding Physical Downlink Control Channel (PDCCH) messages due to the need to search through multiple aggregation levels and perform blind decodes, which consumes time and power, especially in varying radio conditions.
Innovation Solution
Mobile terminals can exploit the rate-matching procedure used by LTE cells to encode PDCCH messages, allowing for reduced decoding aggregation levels when radio conditions are strong, thereby decoding only part of the encoded data to conserve time and power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If mobile terminals perform blind decoding at multiple aggregation levels to ensure reliable PDCCH message reception, then decoding reliability is improved, but time consumption and power consumption increase
Solution Approach 1:
The patent applies dynamics by making the decoding aggregation level adjustable rather than fixed. The terminal device dynamically selects between first aggregation level and second aggregation level based on channel conditions, allowing the system to adapt between reliability-focused mode (first aggregation level) and efficiency-focused mode (second aggregation level), thus resolving the contradiction between decoding reliability and time consumption
Solution Approach 2:
The patent changes the aggregation level parameter based on channel quality indicators. When channel conditions are good, the system switches to lower aggregation level (second aggregation level) to reduce decoding time and power consumption. When channel conditions deteriorate, it switches to higher aggregation level (first aggregation level) to maintain decoding reliability, thereby dynamically adjusting the parameter to balance reliability and time consumption
2Reliability
If mobile terminals perform blind decoding at multiple aggregation levels to ensure reliable PDCCH message reception, then decoding reliability is improved, but power consumption increases
Solution Approach 1:
The system dynamically adjusts the decoding aggregation level based on real-time channel conditions. Under good channel conditions, it uses the second aggregation level which consumes less power. Under poor channel conditions, it switches to the first aggregation level to maintain reliability, thus dynamically optimizing the balance between decoding reliability and power consumption
Solution Approach 2:
The aggregation level parameter is changed according to channel quality feedback. When the channel is favorable, the system reduces the aggregation level parameter to decrease power consumption while maintaining sufficient reliability. When the channel deteriorates, it increases the aggregation level parameter to ensure reliable decoding, effectively managing the trade-off between reliability and power usage
3Measurement precision
If mobile terminals decode all CCEs in a PDCCH candidate to ensure complete message recovery, then decoding accuracy is improved, but processing efficiency decreases
Solution Approach 1:
The patent extracts only the necessary portion of CCEs for decoding based on channel conditions. Instead of always decoding all CCEs in a PDCCH candidate, the system intelligently determines the minimum required aggregation level (first or second aggregation level) based on channel quality, extracting and decoding only that necessary subset. This maintains decoding accuracy when needed while improving processing efficiency when channel conditions permit
Solution Approach 2:
The system applies partial action by decoding fewer CCEs than the maximum possible when channel conditions are good. Instead of performing excessive decoding on all potential CCEs, it performs partial decoding at the appropriate aggregation level, which maintains sufficient decoding accuracy under good channel conditions while significantly improving processing efficiency
4Productivity
If mobile terminals use reduced decoding aggregation level to save time and power, then processing efficiency is improved, but decoding reliability may deteriorate
Solution Approach 1:
The patent makes the aggregation level selection dynamic rather than static. The terminal device continuously monitors channel conditions and dynamically switches between first aggregation level (higher reliability) and second aggregation level (higher efficiency). This dynamic adaptation ensures that processing efficiency is maximized when channel conditions allow, while decoding reliability is automatically restored when channel conditions deteriorate
Solution Approach 2:
The system implements feedback-based aggregation level selection where channel quality indicators feed into the aggregation level determination logic. Based on this feedback, the system adjusts the aggregation level to maintain an optimal balance between processing efficiency and decoding reliability, ensuring that reduced aggregation level is only used when channel conditions support it
Data Source
AI summary
A circuit arrangement includes a control circuit configured to identify a candidate message in received control data that indicates a potential location of an encoded message in the received control data, the candidate message having a predefined message bit length, a measurement circuit configured to perform a radio measurement, the control circuit further configured to compare the radio measurement to a predefined threshold, and a decoding circuit further configured to, if the radio measurement satisfies the predefined threshold, search for the encoded message in the received control data by decoding the candidate message from the received control data with a reduced message bit length less than the predefined bit length.