Search Space Segmentation for Low Latency DCI Detection
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Solution Overview
Problem
Current wireless communications systems, such as LTE, face high scheduling latency due to the 1 ms transmission time interval of downlink control information (DCI), which fails to meet the low-latency requirements of emerging services like Internet of Vehicles, leading to increased blind detections and processing times.
Innovation Solution
The method involves defining a smaller search space with fewer blind detections, allowing for rapid acquisition of scheduling information by differentiating between first-type and second-type DCI within the search space, where the first-type DCI schedules data with a shorter time length than the standard 1 ms, thereby improving data processing speed without increasing the number of candidate control channels or information bit quantities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the transmission time interval for DCI is reduced to meet low-latency requirements, then scheduling latency is reduced, but the complexity of blind detection increases
Solution Approach 1:
The patent segments the search space into multiple candidate control channel sets with different aggregation levels (AL=1, AL=2, AL=4, AL=8). By dividing the search space into structured segments with hierarchical aggregation levels, the terminal can efficiently search through organized groups rather than individual channels, reducing overall blind detection complexity while enabling shorter TTI for low-latency services
Solution Approach 2:
The patent dynamically adjusts the number of candidate control channels at each aggregation level based on the short TTI configuration. For example, it configures specific numbers of candidates (1, 2, 4, or 8) at different AL levels according to service requirements, allowing flexible adaptation between latency reduction and detection complexity management
2Adaptability or versatility
If the number of candidate control channels is increased to improve scheduling flexibility, then scheduling adaptability is improved, but the number of blind detections increases
Solution Approach 1:
The patent changes key parameters of the control channel structure by defining specific aggregation levels (1, 2, 4, 8) and configuring a predetermined number of candidates at each level. This parameter-based configuration enables scheduling flexibility for different service types while controlling the total number of blind detections through structured parameter selection rather than arbitrary channel multiplication
3Adaptability or versatility
If the search space is expanded to cover more candidate control channels, then scheduling coverage is improved, but the data processing speed decreases
Solution Approach 1:
The patent segments the expanded search space into organized candidate sets grouped by aggregation levels. This segmentation allows the terminal to process channels in structured groups rather than examining all channels individually, maintaining comprehensive scheduling coverage while improving processing speed through organized search patterns and efficient candidate evaluation
Data Source
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AI summary
This application provides a control information detection method, a control information sending method, and a device. The detection method includes: determining, by a terminal device, a first search space and a second search space, where the first search space is a part of the second search space; detecting, by the terminal device, at least one piece of first-type downlink control information (DCI) in the first search space; and detecting, by the terminal device, at least one piece of second-type DCI in the second search space, where the first-type DCI is used to schedule data transmission with a first time length, the second-type DCI is used to schedule data transmission with a second time length, and the first time length is less than the second time length. According to the method or device described in this application, for data transmission with a low latency requirement, a search space is relatively small, and there is a small quantity of blind detections, so that scheduling information can be rapidly obtained, thereby improving a data processing speed.