HARQ-ACK Feedback for Carrier Aggregation with Mixed Modes
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Solution Overview
Problem
Current LTE systems do not support the case where bit quantities of HARQ-ACKs need to be fed back for downlink subframes on different aggregated carriers, which may have different PDSCH transmission modes, leading to inconsistent feedback requirements.
Innovation Solution
A terminal and access network device system that divides preconfigured downlink subframes into subsets, allowing for different bit quantities of HARQ-ACKs to be fed back for each subset, with a receiving module, processing module, and sending module to generate and send uplink control information based on the specific bit quantities and scheduling information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If carrier aggregation is used to improve data rate, then system capacity and throughput are improved, but the complexity of HARQ-ACK feedback management increases when different carriers have different PDSCH transmission modes
Solution Approach 1:
The patent segments the HARQ-ACK feedback into multiple codebooks, where each codebook corresponds to a specific PDSCH transmission mode. This segmentation allows the system to manage HARQ-ACK feedback for different transmission modes separately, reducing the overall complexity while supporting carrier aggregation with diverse transmission modes.
Solution Approach 2:
The patent applies different HARQ-ACK feedback mechanisms locally according to the specific PDSCH transmission mode of each carrier. Instead of using a uniform feedback approach for all carriers, the system tailors the feedback method to match the local characteristics of each transmission mode, thereby simplifying management while maintaining high data rates.
2Adaptability or versatility
If multiple PDSCH transmission modes are supported on aggregated carriers, then system versatility is improved, but the inconsistency in HARQ-ACK bit quantities across carriers creates feedback management difficulties
Solution Approach 1:
The patent divides HARQ-ACK feedback into multiple codebooks, with each codebook dedicated to a specific PDSCH transmission mode. This segmentation ensures that each transmission mode has its own standardized feedback structure, maintaining operational ease while supporting diverse transmission modes across aggregated carriers.
Solution Approach 2:
The patent changes the parameter of HARQ-ACK feedback organization from a unified bit sequence to multiple codebooks with distinct structures. Each codebook is designed with parameters tailored to its corresponding transmission mode, resolving the inconsistency issue while preserving versatility.
3Productivity
If carrier aggregation with up to 32 carriers is supported, then system capacity is improved, but the uniform HARQ-ACK feedback structure becomes inadequate for carriers with different transmission modes
Solution Approach 1:
The patent segments HARQ-ACK feedback into multiple codebooks that can be scaled to support a large number of carriers. Each codebook handles a specific transmission mode, allowing the system to accommodate up to 32 carriers with diverse transmission modes while maintaining structured and manageable feedback.
Solution Approach 2:
The patent creates a universal HARQ-ACK feedback framework using multiple codebooks that can adapt to different transmission modes and carrier configurations. This multi-functional structure enables the system to handle various scenarios including single-carrier, multi-carrier, single-mode, and multi-mode configurations within a unified architecture.
Data Source
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AI summary
The present invention relates to the field of wireless communications technologies, and in particular, to a terminal, an access network device, a wireless communications system, and an uplink control information transmission method. In the terminal, a receiving module receives downlink scheduling information of a downlink subframe F(i, j), where a set M of preconfigured downlink subframes in which the downlink subframe F(i, j) is located is divided into N subsets of preconfigured downlink subframes, a bit quantity of a hybrid automatic repeat request-acknowledgement HARQ-ACK that needs to be fed back for each downlink subframe in one subset of preconfigured downlink subframes is a predetermined value, and bit quantities of HARQ-ACKs that need to be fed back for any downlink subframes in different subsets of preconfigured downlink subframes are different; a processing module generates a HARQ-ACK codebook according to a receiving status of downlink data, and generates uplink control information after encoding the HARQ-ACK codebook; and a sending module sends the uplink control information. Therefore, a case in which bit quantities of HARQ-ACKs that need to be fed back for downlink subframes on different to-be-aggregated carriers are different is supported.