Control Channel Detection Using Virtual CRC and NDI Checks
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Solution Overview
Problem
In wireless communication systems, existing methods for detecting control information are prone to errors, particularly in semi-persistent scheduling, leading to inefficient use of radio resources and reduced reliability due to incorrect CRC error detection.
Innovation Solution
A method that utilizes a specific value in an error check field as a virtual CRC for accurate detection of control information, enhancing CRC error checking accuracy and effectively utilizing radio resources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the UE monitors the control channel through CRC error detection, then the UE can identify control information, but false positive detections occur leading to incorrect decoding results and waste of radio resources
Solution Approach 1:
The patent segments the error detection process into two independent parts: CRC checking and new data indicator (NDI) verification. Instead of relying solely on CRC, the UE now performs separate NDI value comparison to determine whether received control information is new or retransmission. This segmentation prevents false positive detections where CRC passes but the control information is not actually for the UE.
Solution Approach 2:
The patent introduces the new data indicator (NDI) field as an intermediary verification mechanism between the UE and the control information. The NDI value acts as a mediator that provides additional confirmation beyond CRC checking, allowing the UE to verify whether the control information is genuinely intended for it before proceeding with decoding.
2Ease of operation
If the UE decodes all pieces of control information in blind detection, then the UE can find its control information, but radio resources are wasted due to incorrect decoding of other UEs' control information
Solution Approach 1:
The patent applies preliminary action by performing NDI value verification before committing to full decoding of control information. The UE first checks the NDI field to confirm the control information is intended for it, and only then proceeds with resource-intensive decoding operations. This preliminary check prevents wasting radio resources and energy on decoding control information belonging to other UEs.
Solution Approach 2:
The patent implements feedback through the NDI mechanism where the UE compares the received NDI value with its expected NDI value. This feedback loop allows the UE to immediately determine whether to continue processing or discard the control information, reducing unnecessary decoding operations and optimizing radio resource utilization.
3Productivity
If the BS multiplexes control information of multiple UEs on control channels, then service to multiple UEs is provided, but the UE may incorrectly identify control information belonging to other UEs
Solution Approach 1:
The patent applies local quality by making the error detection process UE-specific through the NDI field. Each UE has its own NDI value associated with its control information, allowing precise local identification at the UE level. This UE-specific NDI verification complements the general CRC checking and enables accurate differentiation between control information intended for different UEs in a multiplexed environment.
Data Source
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AI summary
A method for detecting control information in a wireless communication system is provided. The method includes checking a cyclic redundancy check (CRC) error by monitoring control channels, determining whether a value of an error check field is equal to a specific value, and, if the value of the error check field is equal to the specific value, detecting the control information on the control channel.