PDCCH Joint Channel Estimation with HARQ-ACK Timing Offsets
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Solution Overview
Problem
Current wireless communication systems face challenges in improving channel estimation accuracy for physical downlink control channels (PDCCH), which affects performance and efficiency, especially when hybrid automatic repeat request (HARQ) acknowledgments are requested without corresponding physical downlink shared channel grants, leading to increased latency and reduced efficiency.
Innovation Solution
Implementing joint channel estimation (JCE) using demodulation reference signals (DMRS) bundling across multiple PDCCH monitoring occasions, allowing for the identification and selection of timing offsets based on processing capabilities to enhance HARQ-ACK transmission timing, thereby improving channel estimation accuracy and reducing latency and increasing spectrum efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If joint channel estimation using DMRS bundling is implemented across multiple PDCCH monitoring occasions, then channel estimation accuracy is improved, but device complexity increases
Solution Approach 1:
The patent segments the channel estimation process by introducing separate offset values for different timing scenarios. A first offset value is used when HARQ-ACK is transmitted in response to a PDCCH without corresponding PDSCH, while a second offset value is used for other cases. This segmentation allows the system to improve channel estimation accuracy for specific scenarios without requiring complete redesign of the entire estimation process, thereby managing complexity.
Solution Approach 2:
The patent applies preliminary action by pre-configuring multiple offset values (first offset and second offset) in advance based on different transmission scenarios. The UE is configured with these offset values through RRC signaling before actual transmission occurs. This preliminary configuration enables the system to quickly select the appropriate offset without real-time complex calculations, improving channel estimation accuracy while maintaining manageable processing complexity.
2Loss of time
If HARQ-ACK requests are transmitted without corresponding PDSCH grants, then latency is reduced, but reliability deteriorates
Solution Approach 1:
The patent changes the timing parameter by introducing different offset values based on the transmission scenario. When a PDCCH without corresponding PDSCH is received, the system uses a first offset value that allows earlier HARQ-ACK transmission, reducing latency. For other scenarios, a second offset value is used to ensure adequate processing time and maintain reliability. This parameter change approach enables flexible timing adjustment to balance latency and reliability requirements.
Solution Approach 2:
The patent implements feedback mechanisms where the base station configures the UE with specific offset values based on observed transmission patterns and channel conditions. The network can adjust the first and second offset values based on feedback about transmission success rates and latency requirements, enabling continuous optimization of the balance between latency reduction and reliability maintenance.
3Productivity
If processing time capability is increased to handle multiple PDCCH monitoring occasions, then productivity is improved, but loss of time increases
Solution Approach 1:
The patent applies dynamics by making the processing time adaptive rather than fixed. The system dynamically selects between a first offset value and a second offset value based on the specific transmission scenario and UE processing capability. When the UE has sufficient processing capability, the system can use the first offset value for faster transmission. When processing capability is limited, the second offset value provides adequate time, ensuring reliable operation while optimizing productivity.
Data Source
AI summary
Example aspects include a method, apparatus, and computer-readable medium for wireless communication at a user equipment (UE) of a wireless communication network, comprising receiving, from a base station, configuration information indicating that physical downlink control channel (PDCCH) joint channel estimation (JCE) is enabled for a plurality of PDCCH monitoring occasions. The aspects further include receiving, from the base station, a plurality of PDCCH transmissions. At least one PDCCH transmission comprises a hybrid automatic repeat request (HARD) acknowledgement (ACK) request without a corresponding physical downlink shared channel (PDSCH) grant. Additionally, the aspects further include identifying a base offset according to the at least one PDCCH transmission. Additionally, the aspects further include selecting an additional offset according to a processing time capability of the UE. Additionally, the aspects further include transmitting, at a timing offset in relation to the plurality of PDCCH transmissions, a HARQ-ACK.