Flexible CRC Lengths for Downlink Control Channels
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication systems face inefficiencies due to fixed cyclic redundancy check (CRC) lengths for downlink control channels, which lead to increased overhead, processing, and false alarms, as they do not optimally balance payload size and error detection for varying DCI message formats and attributes.
Innovation Solution
Implementing flexible CRC lengths for downlink control information (DCI) messages based on attributes such as DCI format, component carriers, bandwidth parts, subcarrier spacing, and payload size, allowing the network entity to dynamically adjust CRC lengths via configuration messages or RRC signaling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fixed CRC lengths are used for downlink control channels, then error detection capability is maintained, but overhead and processing complexity increase
Solution Approach 1:
The patent implements dynamic CRC length selection where the CRC length is adjusted based on transmission characteristics such as DCI format, payload size, and channel conditions. This allows the system to adapt the error detection capability to match the actual transmission requirements, avoiding unnecessary processing complexity while maintaining reliability.
Solution Approach 2:
The patent changes the CRC length parameter based on different transmission scenarios. By varying the CRC length according to payload size and DCI format, the system optimizes the balance between error detection capability and processing overhead, resolving the contradiction between reliability and complexity.
2Ease of manufacture
If fixed CRC lengths are used for downlink control channels, then implementation is simple, but overhead increases
Solution Approach 1:
The system dynamically adjusts CRC length based on transmission characteristics, reducing the overhead when shorter CRCs are sufficient while maintaining the ability to use longer CRCs when higher reliability is needed. This resolves the contradiction between implementation simplicity and overhead reduction.
Solution Approach 2:
By changing the CRC length parameter according to transmission requirements, the system reduces the average overhead compared to fixed long CRCs, while still providing adequate error detection capability for different DCI formats and payload sizes.
3Reliability
If longer CRC lengths are used, then false alarm frequency decreases, but overhead and processing increase
Solution Approach 1:
The patent adjusts the CRC length parameter based on transmission characteristics such as payload size and DCI format. By matching the CRC length to the actual transmission requirements, the system achieves appropriate false alarm rates without the excessive overhead that would result from uniformly using longer CRCs for all transmissions.
Data Source
AI summary
Methods, systems, and devices for wireless communications are described. The described techniques provide for flexible cyclic redundancy check (CRC) lengths for downlink control information (DCI) message. For example, a network entity may determine a length of a CRC applied to a DCI message based on an attribute of the DCI message. In some examples, relationships between attributes of the DCI message and CRC lengths may be stored or configured at a user equipment (UE) or may be indicated to the UE via additional control signaling from the network entity. In some examples, the UE may transmit, to the network entity, a capability of the UE to support flexible CRC lengths for DCI messages. Varying the length of the CRC applied to the DCI message based on one or more attributes of the DCI message may enable the network entity to effectively balance overhead, payload size, and frequency of false alarms.