Multi-Cell HARQ-ACK Transmission with SORTD PUCCH Allocation
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Solution Overview
Problem
Existing LTE-A systems face limitations in efficiently transmitting Hybrid Automatic Retransmission reQuest-ACKnowledgement (HARQ-ACK) information due to constraints on PUCCH resources and channel selection methods, particularly in scenarios with multiple Cells configured in MIMO transmission modes, leading to unnecessary retransmissions and reduced throughput.
Innovation Solution
A method for transmitting HARQ-ACK information based on transmission diversity, where the UE dynamically determines spatial bundling based on the number of scheduled Cells, indicated by the PDCCH, and uses Spatial Orthogonal Resource Transmission Diversity (SORTD) to avoid unnecessary bundling, thereby optimizing HARQ-ACK channel allocation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If channel selection method is used to transmit HARQ-ACK information for multiple Cells, then the number of supportable Cells is limited to two, but the data throughput is reduced due to resource constraints
Solution Approach 1:
The patent segments the HARQ-ACK information transmission by separating it into two independent channels: PUCCH for HARQ-ACK and PUSCH for data. This segmentation allows simultaneous transmission of HARQ-ACK for multiple Cells without limiting the number of supportable Cells, while maintaining high data throughput on the PUSCH channel.
2Device complexity
If spatial bundling is applied to HARQ-ACK information, then the number of PUCCH resources is reduced, but unnecessary retransmissions occur leading to reduced throughput
Solution Approach 1:
The patent extracts HARQ-ACK information from the PUCCH resource allocation problem by transmitting it on a separate channel (PUCCH) independent of data transmission. This extraction eliminates the need for spatial bundling to reduce PUCCH resources, as each Cell's HARQ-ACK can be independently transmitted without affecting resource complexity, thereby preventing unnecessary retransmissions and maintaining throughput.
3Reliability
If multiple PUCCH resources are allocated for MIMO transmission modes, then transmission diversity is improved, but the device complexity and resource allocation overhead increase
Solution Approach 1:
The patent makes the PUCCH channel universal by designing it to handle HARQ-ACK information for any number of Cells and transmission modes without requiring separate resource allocation mechanisms. The PUCCH resource allocation is designed to work universally across SIMO, MIMO, and carrier aggregation scenarios, eliminating the need for complex per-mode resource allocation and reducing overhead while maintaining transmission diversity.
Data Source
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Figure 3
AI summary
The invention relates to a method for transmitting, by a user equipment, UE, hybrid automatic retransmission request acknowledgement, HARQ-ACK, information on a physical uplink control channel, PDCCH, in a communication system, wherein the UE is configured with at least two cells by a base station, the at least two cells comprising a primary cell and a secondary cell, the method comprising: identifying at least one of first information, second information, or third information, wherein the first information is related to whether a first physical downlink shared channel, PDSCH, in a downlink subframe is scheduled by a first physical control channel, PDCCH, of the primary cell, and the second information is related to whether a second PDSCH in the downlink subframe is scheduled by a second PDCCH of the secondary cell; receiving, from the base station, downlink data of the at least two cells in the downlink subframe; generating HARQ-ACK information for the downlink data based on a number of the at least two cells; and transmitting the HARQ-ACK information to the base station by using a first resource for a first antenna port and a second resource for a second antenna port, wherein the first resource for the first antenna port and the second resource for the second antenna port are defined respectively based on at least one of the first information, the second information, or the third information.