PDCCH Candidate Determination for Carrier Aggregation with Mixed Subcarrier Spacings
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Solution Overview
Problem
In carrier aggregation scenarios, existing technologies face challenges in determining the maximum number of PDCCH candidates that a terminal can monitor in a unit time, especially when carriers have different subcarrier spacings, limiting communication flexibility and efficiency.
Innovation Solution
A method where a network device configures serving cells with different subcarrier spacings and determines the maximum number of PDCCH candidates based on these spacings, allowing for flexible and efficient monitoring by the terminal, either by considering individual serving cells or aggregating carriers with different numerologies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If carriers are considered to have the same configuration parameters in carrier aggregation, then the maximum number of PDCCH candidates can be simply calculated as a product, but this approach cannot accommodate scenarios where carriers have different subcarrier spacings
Solution Approach 1:
The patent segments the carrier aggregation scenario into multiple groups based on subcarrier spacing configurations. Carriers with the same subcarrier spacing are grouped together, allowing the system to handle different subcarrier spacings (e.g., 15kHz, 30kHz, 60kHz) separately. This segmentation enables the terminal to determine maximum PDCCH candidates for each group independently, then aggregate the results, thus accommodating diverse subcarrier spacings without excessive complexity.
Solution Approach 2:
The patent introduces parameter changes by allowing different subcarrier spacing values (Δf) to be assigned to different carriers in the aggregation. The maximum number of PDCCH candidates is then determined based on these varying parameters, where each carrier group's contribution is calculated according to its specific subcarrier spacing characteristics. This parameter-based approach provides flexibility to adapt to different numerical configurations while maintaining a systematic determination method.
2Reliability
If the terminal performs PDCCH blind detection without knowing the DCI format or PDCCH candidate, then the terminal can receive scheduled data, but the terminal's blind detection capability is limited
Solution Approach 1:
The patent applies preliminary action by pre-configuring search spaces and determining the maximum number of PDCCH candidates before the actual blind detection process. The network device configures multiple search spaces with specific parameters (monitoring occasions, aggregation levels, candidate numbers) in advance. The terminal uses these pre-configured parameters to limit its blind detection scope, performing detection only within the predetermined search space boundaries rather than exhaustively searching all possible PDCCH locations.
Solution Approach 2:
The patent implements partial action by having the terminal perform blind detection only on a subset of possible PDCCH candidates within configured search spaces, rather than attempting to detect all possible candidates. The maximum number of candidates per search space and total across all search spaces is carefully controlled to match the terminal's blind detection capability, allowing the terminal to handle the task with limited capability while still achieving reliable data reception.
3Reliability
If a maximum number of PDCCH candidates is defined to ensure it does not exceed the terminal's blind detection capability, then the terminal's capability is protected, but communication flexibility is reduced
Solution Approach 1:
The patent introduces dynamics by allowing the maximum number of PDCCH candidates to be flexibly determined based on multiple factors including the terminal's reported capability, the number and configuration of search spaces, and the subcarrier spacing of aggregated carriers. Rather than using a fixed limit, the system dynamically adjusts the maximum candidate number within reasonable bounds, enabling better utilization of terminal capability while maintaining protection against excessive detection requirements.
Solution Approach 2:
The patent achieves universality by creating a determination method that works across multiple scenarios: single-carrier and multi-carrier aggregation, different subcarrier spacing configurations (15kHz, 30kHz, 60kHz), and various terminal capabilities. The same framework can accommodate different numbers of aggregated carriers (2, 3, 4, or more) and different search space configurations, providing a universal solution that maintains both capability protection and communication flexibility across diverse deployment scenarios.
Data Source
AI summary
This application provides a parameter determining method, a monitoring method, and a communications apparatus. The method includes: configuring, by a network device, a plurality of serving cells for a terminal, where at least two of the plurality of serving cells have different subcarrier spacings; and determining, by the network device based on at least one of subcarrier spacings of the plurality of serving cells, a maximum number of physical downlink control channel PDCCH candidates monitored by the terminal in a unit time. According to this application, a maximum number of PDCCH candidates monitored by a terminal in one time unit can be determined when carriers for carrier aggregation correspond to different subcarrier spacings.