PDCCH Link Adaptation via Outer-Loop Compensation
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Solution Overview
Problem
Current PDCCH link adaptation methods in LTE networks are inefficient due to aggressive or conservative resource allocation, leading to decoding failures and reduced throughput, especially in VoIP applications, as they do not accurately account for interference and varying channel conditions.
Innovation Solution
A method that classifies different types of PDCCH commands by their robustness and uses a weighted average of success rates to adjust the outer-loop compensation factor, distinguishing between DL assignments and UL grants to optimize resource usage and reduce errors in PDCCH link adaptation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If PDCCH link adaptation uses aggressive resource allocation (small number of CCEs and low transmit power), then resource efficiency is improved, but PDCCH decoding failure rate increases
Solution Approach 1:
The patent dynamically adjusts the outer-loop compensation factor based on the actual PDCCH success rate, which modifies the link adaptation parameters (CCE aggregation level and transmit power) to resolve the contradiction between resource efficiency and decoding reliability
Solution Approach 2:
The patent implements a feedback mechanism where the network node receives PDCCH success rate information from the wireless device and uses this feedback to adjust the outer-loop compensation factor, enabling adaptive optimization of the contradiction between resource usage and decoding success
2Reliability
If PDCCH link adaptation uses conservative resource allocation (large number of CCEs and high transmit power), then PDCCH decoding success rate is improved, but network capacity decreases
Solution Approach 1:
The patent dynamically adjusts the outer-loop compensation factor based on actual PDCCH success rate measurements, enabling the system to transition from conservative fixed allocations to adaptive parameter selection that maintains reliability while optimizing network capacity
Solution Approach 2:
The patent transforms the static PDCCH link adaptation into a dynamic system that continuously adjusts CCE aggregation level and transmit power based on real-time success rate feedback, allowing the network to adapt to varying channel conditions and maximize capacity
3Quantity of substance
If CQI reporting interval is limited, then uplink resource usage is reduced, but PDCCH link adaptation accuracy deteriorates
Solution Approach 1:
The wireless device autonomously measures and reports PDCCH success rate directly to the network node, eliminating the need for frequent CQI reports while providing accurate link quality information for PDCCH link adaptation
Data Source
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AI summary
The present disclosure relates to a method for a wireless device configured to perform outer-loop control of a Physical Downlink Control Channel, PDCCH, link. The method comprises obtaining, based on reporting from a UE, actual PDCCH success rate values indicative of the transmission success on a PDCCH for two or more of respective downlink control information, DCI, formats among several DCI formats, obtaining expected PDCCH success probability values indicative of DCI format success probabilities for the two or more DCI formats, obtaining discrepant values for respective of the two or more of said DCI formats by comparing the actual PDCCH success rate values to the expected PDCCH success probability values, determining a PDCCH link outer loop compensation factor by suppressing a higher among the discrepant values, and performing a PDCCH link transmission using the PDCCH link outer loop compensation factor.