Multicast PDSCH Reception via Segmented HARQ-ACK Resources
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Solution Overview
Problem
In future radio communication systems like NR, the methods for receiving downlink control information (DCI) for scheduling Physical Downlink Shared Channel (PDSCH) using multicast and transmitting Hybrid Automatic Repeat Request Acknowledgement (HARQ-ACK) are not adequately considered, leading to potential degradation in system performance such as throughput.
Innovation Solution
The proposed solution involves a method for a terminal to appropriately receive PDSCH using multicast by configuring the receiving process through higher layer signaling and interpreting specific fields in the DCI as multicast parameters, while also transmitting HARQ-ACK corresponding to the multicast PDSCH using orthogonal or non-orthogonal uplink resources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple UEs simultaneously receive the same PDSCH using multicast in ultra-high density environment, then system capacity and spectral efficiency are improved, but system performance degrades due to insufficient consideration of DCI receiving methods and HARQ-ACK transmitting methods
Solution Approach 1:
The patent segments the HARQ-ACK transmission resources by introducing multiple PUCCH resources with different orthogonal cover codes (OCC). UEs are divided into different groups based on their reception outcomes, with each group using specific OCC sequences for ACK/NACK transmission. This segmentation allows simultaneous multicast reception by multiple UEs while maintaining distinguishable feedback channels, resolving the contradiction between system capacity and performance reliability.
2Device complexity
If DCI field for PUSCH resource indication uses minimum bits to reduce overhead, then control channel efficiency is improved, but the ability to indicate multiple PUCCH resources is limited
Solution Approach 1:
The patent makes the existing DCI field serve multiple functions: it simultaneously indicates both the PUSCH resource allocation and the PUCCH resource type (first or second type). By interpreting the same bit field differently based on the indicated PUSCH resource type, the system achieves versatile PUCCH resource indication without increasing DCI overhead, thus resolving the contradiction between control channel efficiency and adaptability.
Data Source
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AI summary
A terminal according to one aspect of the present disclosure includes a receiving section that receives downlink control information (DCI) for scheduling a downlink shared channel of a multicast; and a control section that controls transmission of Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK) with respect to the downlink shared channel based on the DCI. According to one aspect of the present disclosure, a PDSCH using the multicast can be appropriately received.