Clear Channel Assessment Method for Multi-Carrier Interference
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Solution Overview
Problem
In multi-carrier communication scenarios, signal leakage from one carrier can lead to incorrect busy channel assessments on neighboring carriers, causing CCA blocking and wastage of channel resources.
Innovation Solution
The method involves sending downlink information with indication of idle symbols on a carrier, allowing CCA to be performed on neighboring carriers during idle times, thereby preventing interference and reserving channel resources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If CCA is performed on neighboring carriers during data transmission on a carrier, then channel resource utilization is improved, but measurement precision deteriorates due to signal leakage causing false busy channel assessment
Solution Approach 1:
The patent segments the channel assessment process by separating CCA operations into distinct time intervals: first CCA before data transmission, second CCA after data transmission. This temporal segmentation prevents signal leakage from interfering with the assessment process, as the assessment occurs when no data is being transmitted on the primary carrier.
Solution Approach 2:
The patent performs preliminary CCA assessment before allowing data transmission to occur. By completing the channel assessment in advance (first CCA), the system ensures that no data transmission has yet occurred to create interfering signals, thereby maintaining assessment accuracy while still enabling subsequent efficient channel utilization.
2Productivity
If data transmission occurs on a carrier without reserving idle time, then productivity is improved, but harmful factors increase due to signal leakage causing CCA blocking
Solution Approach 1:
The system performs preliminary CCA assessment before data transmission begins. This preliminary action allows the system to determine channel status accurately before any data is transmitted, preventing the harmful effect of signal leakage from corrupting subsequent CCA assessments on neighboring carriers.
Solution Approach 2:
The patent maintains continuous channel utilization by implementing a two-stage process: first CCA for initial assessment, then data transmission, followed by second CCA for re-assessment. This continuous approach ensures channels are efficiently utilized without interruption while preventing signal leakage interference through proper timing.
3Reliability
If CCA is performed continuously on all carriers, then reliability is improved, but loss of time increases due to CCA blocking between carriers
Solution Approach 1:
The patent segments the CCA process into distinct phases: first CCA before data transmission and second CCA after data transmission. This segmentation allows reliable channel assessment without continuous blocking, as the assessment occurs at specific intervals rather than continuously, reducing time loss while maintaining reliability.
Solution Approach 2:
The system dynamically adjusts the CCA timing based on data transmission status. When data is being transmitted on one carrier, the system performs CCA on other carriers at appropriate intervals rather than continuously, creating a dynamic scheduling mechanism that reduces CCA blocking time while maintaining channel access reliability.
Data Source
AI summary
Embodiments of the present application disclose a clear channel assessment (CCA) method, an information receiving method, and apparatuses thereof. The CCA method comprises: sending downlink information on a first carrier, wherein the downlink information comprises first indication information, and the first indication information is used to indicate that at least one part of at least one symbol of at least one subframe is idle; and performing CCA on at least one neighboring carrier of the first carrier in at least a time of the at least one part that is idle. According to the methods and the apparatuses in the embodiments of the present application, a part of channel resources can be reserved when downlink information is transmitted on a carrier, so as to prevent interference caused by local leakage of the carrier to CCA on a neighboring carrier, thereby preventing CCA blocking between carriers.