DRX-Based Downlink Control Channel Detection in Carrier Aggregation
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Solution Overview
Problem
In carrier aggregation wireless communication systems, existing methods face challenges in efficiently detecting and receiving downlink control channels, particularly in dynamic radio resource configurations, which affects channel state information measurement and HARQ timing continuity.
Innovation Solution
A method for a user equipment to configure downlink control channel detection subframes in TDD primary and FDD secondary cells based on specific uplink/downlink subframe configurations, using a DRX timer to detect the downlink control channel and receive data, while allowing for dynamic changes in resource usage and HARQ timing adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If carrier aggregation is applied to increase bandwidth and data rate, then system capacity and throughput are improved, but downlink control channel detection complexity and reliability degradation increase
Solution Approach 1:
The patent segments the control channel detection process into multiple candidate subframes with different detection probabilities. Instead of uniformly detecting in all subframes, the system divides subframes into categories (e.g., first candidate subframes with higher detection probability, second candidate subframes with lower detection probability) based on downlink data presence, enabling differentiated detection strategies that reduce overall complexity while maintaining reliability.
Solution Approach 2:
The patent implements dynamic adaptation of detection behavior based on channel conditions and data patterns. The user equipment dynamically adjusts which candidate subframes to monitor and with what detection probability, rather than using a static detection scheme. This dynamic approach allows the system to optimize control channel detection reliability adaptively while reducing unnecessary detection operations.
2Reliability
If continuous monitoring of downlink control channel is performed to ensure reliable data reception, then data reception reliability is improved, but power consumption increases
Solution Approach 1:
The patent implements periodic discontinuous reception (DRX) cycles where the user equipment alternates between active monitoring periods and sleep periods. During active periods, the UE monitors downlink control channels in candidate subframes; during sleep periods, monitoring is suspended. This periodic action pattern reduces average power consumption while maintaining data reception reliability through timely wake-up and detection when data is likely present.
Solution Approach 2:
The patent applies partial monitoring action by selectively monitoring only certain candidate subframes rather than all subframes. The user equipment identifies a subset of candidate subframes based on downlink data patterns and monitors only those, performing partial detection actions. This reduces the total number of detection operations and associated power consumption while still capturing the necessary control information for reliable data reception.
3Loss of information
If downlink control channel detection is performed in all subframes to capture all scheduling information, then scheduling information completeness is improved, but detection complexity and processing overhead increase
Solution Approach 1:
The patent extracts and identifies a specific subset of candidate subframes from the complete set of all subframes where downlink control channels are likely to be present. By extracting only the relevant candidate subframes based on downlink data patterns and scheduling behavior, the system reduces the detection search space from all subframes to a manageable subset, thereby reducing processing complexity while maintaining scheduling information completeness.
Solution Approach 2:
The patent applies different detection qualities and probabilities to different candidate subframes based on their local characteristics. First candidate subframes (where downlink data is more likely present) receive higher detection probability and more thorough monitoring, while second candidate subframes receive lower detection probability. This local quality differentiation ensures scheduling information is captured where most needed while reducing unnecessary detection complexity in other subframes.
Data Source
AI summary
Disclosed in the present application is a method for detecting a downlink control channel by a terminal in DRX mode in a wireless communication system applying carrier aggregation technique. Specifically, the method comprises the steps of: setting downlink control channel detection sub-frames in a TDD primary cell and an FDD secondary cell on the basis of a specific uplink/downlink sub-frame setting related to the TDD primary cell; detecting the downlink control channel in one of the downlink control channel detection sub-frames through the TDD primary cell or the FDD secondary cell while a preset DRX related timer defined by the number of sub-frames operates: and receiving a downlink data signal on the basis of the detected downlink control channel, wherein the downlink control channel detection sub-frames in the FDD secondary cell are sub-frames on the FDD secondary cell, conforming to the location of downlink sub-frames in the specific uplink/downlink sub-frame setting or the location of special sub-frames including a downlink resource having the length identical to or greater than a preset length.