HARQ-ACK Codebook Determination With C-DAI and T-DAI
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Solution Overview
Problem
Existing 5G wireless communication systems face high overhead and require stringent coordination among cells for HARQ-ACK codebook determination, especially in scenarios with multiple cells, which can be inefficient and complex.
Innovation Solution
The proposed techniques introduce counter downlink assignment indicator (C-DAI) and total downlink assignment indicator (T-DAI) to optimize HARQ-ACK codebook determination, reducing overhead and minimizing the need for frequent inter-cell coordination through various ordering and grouping methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing HARQ-ACK codebook determination methods are used in 5G systems with multiple cells, then HARQ-ACK feedback can be transmitted, but overhead increases and coordination complexity among cells increases
Solution Approach 1:
The patent segments the HARQ-ACK codebook determination into cell-specific components using C-DAI for each scheduled cell and T-DAI for the scheduling cell. This segmentation allows independent determination of HARQ-ACK bits per cell, reducing the need for complex inter-cell coordination while maintaining reliable feedback transmission across multiple cells
Solution Approach 2:
The patent introduces C-DAI and T-DAI as intermediary indicators that mediate between the scheduling cell and scheduled cells. These indicators carry necessary information for HARQ-ACK codebook determination without requiring direct complex coordination between all cells, thus reducing overall system complexity while ensuring reliable feedback
2Reliability
If existing HARQ-ACK codebook determination methods are used in 5G systems with multiple cells, then HARQ-ACK feedback can be transmitted, but overhead increases
Solution Approach 1:
The patent extracts the essential information needed for HARQ-ACK codebook determination into compact C-DAI and T-DAI fields within DCI messages. By taking out only the necessary counter and total indicators rather than transmitting complete codebook information, the patent reduces overhead while maintaining the reliability of HARQ-ACK feedback transmission
Solution Approach 2:
The patent changes the parameter representation from transmitting full codebook information to transmitting condensed counter (C-DAI) and total (T-DAI) indicators. This parameter transformation reduces the quantity of data transmitted while preserving the essential information needed for accurate HARQ-ACK feedback across multiple cells
Data Source
AI summary
Techniques are described to determine HARQ-ACK codebook. An example wireless communication method includes receiving, by a communication device from a cell, control information that includes a field comprising a value, where the value indicates a current number of a control channel monitoring occasion that is associated with the cell and is to be monitored by the communication device, and where the current number of the control channel monitoring occasion is part of a series of numbers associated with a set of control channel monitoring occasions where control channels are received or are to be received from the cell; and transmitting one or more hybrid automatic repeat request acknowledgement (HARQ-ACK) information bits indicating whether a shared channel associated with the control channel monitoring occasion is received by the communication device or indicating that the communication device received the control information.