Semi-Static HARQ-ACK Codebook Optimization for Unicast Multicast
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Solution Overview
Problem
Existing methods struggle to determine a semi-static HARQ-ACK codebook when user equipment supports simultaneous service transmission of two types of PDSCHs, leading to an unnecessarily large codebook size.
Innovation Solution
A method for determining a semi-static HARQ-ACK codebook by using a K 1 set associated with an active UL BWP, considering TDRA tables for both PDSCHs, and employing a union or subset approach to identify candidate PDSCH reception occasions, thereby optimizing the codebook determination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate TDRA tables and K1 sets are configured for unicast and multicast PDSCHs, then the system supports simultaneous service transmission of two types of PDSCHs, but the semi-static HARQ-ACK codebook size becomes unnecessarily large
Solution Approach 1:
The patent merges the determination of candidate PDSCH reception occasions for unicast and multicast PDSCHs by using a unified K1 set associated with the active UL BWP. Instead of maintaining separate K1 sets and TDRA tables for unicast and multicast services, the invention combines their determination processes, using the union of candidate occasions from both services to generate the semi-static HARQ-ACK codebook. This merging approach reduces codebook size while preserving support for simultaneous transmission of both PDSCH types.
2Reliability
If a semi-static HARQ-ACK codebook is generated based on all candidate PDSCH reception occasions from both unicast and multicast services, then all possible PDSCHs are covered, but the codebook size increases unnecessarily when both services are not simultaneously active
Solution Approach 1:
The patent introduces dynamic adaptation into the semi-static HARQ-ACK codebook generation process. While the codebook itself is semi-static, the determination of candidate PDSCH reception occasions dynamically considers the actual service configuration and active state. The method adapts the codebook content based on whether unicast and multicast PDSCHs are simultaneously configured and active, allowing the system to maintain reliable coverage only when necessary while reducing complexity when services are not simultaneously active.
3Ease of manufacture
If the K1 set is determined separately for unicast and multicast PDSCHs, then each service type can be optimized independently, but the union of both K1 sets leads to redundant HARQ-ACK bits
Solution Approach 1:
The patent extracts and removes redundant elements from the HARQ-ACK codebook generation process. By determining candidate PDSCH reception occasions based on the union of unicast and multicast opportunities using a unified K1 set, the invention identifies and eliminates duplicate HARQ-ACK bit positions that would arise from separate K1 set determinations. This extraction of redundancy maintains the ease of independent configuration for each service type while preventing information loss due to redundant feedback bits.
Data Source
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AI summary
This application discloses a method and terminal for generating a semi-static HARQ-ACK codebook, where the generation method includes: determining, based on at least one of K1 sets corresponding to a first PDSCH and a second PDSCH, a K1 set associated with an active UL BWP; determining, for each K1,k value in the K1 set associated with the active UL BWP, based on at least one of TDRA tables corresponding to the first PDSCH and the second PDSCH, a candidate PDSCH reception occasion in a slot corresponding to each K1,k value; and determining, based on the candidate PDSCH reception occasion, the semi-static HARQ-ACK codebook.