HARQ-ACK Codebook Bundling for Multi-Slot PDSCH Scheduling
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Solution Overview
Problem
The existing 3GPP LTE(-A) wireless communication system faces challenges in efficiently transmitting and receiving signals due to limited resource allocation for downlink control channels, leading to high energy consumption and long decoding times for user equipment, which is exacerbated by the need for improved 5G systems to support higher data rates and lower latency.
Innovation Solution
The proposed method and apparatus optimize the transmission of HARQ-ACK codebooks in 3GPP-based wireless communication systems, such as 3GPP NR, by implementing time domain bundling and efficient resource allocation strategies to reduce decoding time and energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple user equipments share limited PDCCH resources through CCE combinations, then resource utilization is improved, but decoding time and energy consumption increase
Solution Approach 1:
The patent segments the HARQ-ACK codebook into multiple parts, where each part corresponds to a specific PDSCH reception occasion. This segmentation allows the UE to process and report HARQ-ACK information for different PDSCHs in an organized manner, reducing the complexity of decoding multiple PDCCH candidates simultaneously and thereby reducing overall decoding time while maintaining efficient resource utilization.
Solution Approach 2:
The patent introduces dynamic determination of the number of HARQ-ACK bits based on the actual number of PDSCH reception occasions within a bundling window. This dynamic approach allows the system to adapt the codebook size to the actual traffic conditions, optimizing the balance between resource utilization and processing complexity, thus reducing unnecessary decoding operations and energy consumption.
2Reliability
If the HARQ-ACK codebook includes all possible PDSCH reception occasions, then reliability is improved, but codebook size and processing complexity increase
Solution Approach 1:
The patent applies local quality by assigning different HARQ-ACK reporting behaviors to different PDSCH reception occasions within the bundling window. Specifically, PDSCHs received in certain slots are grouped together, and the number of HARQ-ACK bits is determined based on the actual reception occasions rather than all possible occasions. This localized approach maintains reliability for actual receptions while reducing overall codebook complexity.
Solution Approach 2:
The patent changes the parameter of codebook size dynamically based on the number of actual PDSCH reception occasions. Instead of using a fixed maximum codebook size, the system adjusts the codebook size according to actual traffic conditions, thereby maintaining reliability when needed while reducing processing complexity when the number of receptions is lower.
3Length of stationary object
If beamforming and massive MIMO are used to reduce path loss in mmWave band, then transfer distance is improved, but system complexity increases
Solution Approach 1:
The patent segments the HARQ-ACK feedback process into multiple reporting occasions corresponding to different PDSCH receptions. This segmentation simplifies the processing of control information in complex mmWave systems by breaking down the feedback mechanism into manageable units, thereby reducing the overall system complexity while maintaining the benefits of beamforming and massive MIMO for extended transfer distance.
Solution Approach 2:
The patent enables the UE to autonomously determine the number of HARQ-ACK bits based on the actual number of PDSCH reception occasions without requiring explicit signaling from the base station. This self-service approach reduces the signaling overhead and processing complexity in mmWave systems, allowing the system to maintain extended transfer distance through beamforming and massive MIMO while minimizing the additional complexity introduced by these technologies.
Data Source
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AI summary
The present invention relates to a wireless communication system and, more particularly, to a method comprising the steps of: receiving a PDCCH for multi-slot scheduling; determining a PDSCH candidate for each slot on the basis of information in the PDCCH; and transmitting a semi-static HARQ-ACK codebook on the basis of the determined PDSCH candidate of each slot, and to an apparatus therefor.