Terminal Uplink Control Information Transmission via PUCCH Format Selection
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Solution Overview
Problem
The existing radio communication systems, particularly in LTE, lack an efficient method for transmitting uplink control information, which is crucial for effective communication in cellular networks with multiple serving cells.
Innovation Solution
The proposed solution involves a terminal apparatus and base station apparatus that utilize specific communication methods and formats, such as PUCCH cell groups and various PUCCH formats, to efficiently transmit uplink control information, including HARQ-ACK, CSI, and scheduling requests, by determining the appropriate PUCCH resource and format based on downlink assignment indices and the number of serving cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the terminal apparatus transmits uplink control information on multiple serving cells simultaneously, then the communication capacity is improved, but the complexity of determining HARQ-ACK codebook size and PUCCH resource allocation increases
Solution Approach 1:
The patent segments the serving cells into two groups: a first group where the terminal transmits PUCCH and a second group where the terminal receives PDCCH. This segmentation allows the terminal to determine HARQ-ACK codebook size based on the second group (PDCCH-receiving cells) while maintaining efficient uplink control information transmission across multiple cells. The segmentation resolves the complexity by providing a clear division of responsibilities between different cell groups.
Solution Approach 2:
The patent introduces PDCCH (Physical Downlink Control Channel) as an intermediary mechanism to carry Downlink Assignment Index (DAI) information. The DAI in the PDCCH serves as a mediator that enables the terminal to accurately determine the HARQ-ACK codebook size without complex calculations. The PDCCH acts as an intermediary carrier that conveys necessary control information efficiently, simplifying the overall system complexity.
2Ease of manufacture
If the terminal apparatus uses traditional PUCCH resource allocation methods, then the implementation is simple, but the HARQ-ACK codebook size becomes inconsistent between terminal and base station in carrier aggregation scenarios
Solution Approach 1:
The patent implements a feedback mechanism where the base station transmits Downlink Assignment Index (DAI) information through PDCCH to the terminal. The terminal uses this feedback information to determine the correct HARQ-ACK codebook size. This feedback loop ensures that both terminal and base station agree on the codebook size, resolving the inconsistency problem while maintaining implementation simplicity through standardized feedback procedures.
Solution Approach 2:
The patent changes the parameter used for PUCCH resource determination from traditional methods to a new approach based on DAI values from PDCCH. By changing the determining parameter to DAI-based calculations, the system achieves consistent HARQ-ACK codebook size determination across carrier aggregation scenarios. This parameter change resolves the reliability issue while keeping the implementation process straightforward.
3Ease of manufacture
If the terminal apparatus transmits control information on FDD cells only, then the method is simple, but it cannot efficiently handle TDD carrier aggregation configurations
Solution Approach 1:
The patent creates a universal method that works for both FDD and TDD carrier aggregation configurations. By using PDCCH from any serving cell (regardless of FDD or TDD mode) to transmit DAI information, and by allowing the terminal to select PUCCH transmission based on the determined codebook size, the system achieves multi-functionality. This universal approach enables efficient handling of TDD carrier aggregation while maintaining the simplicity of FDD operations.
Solution Approach 2:
The patent introduces dynamic adaptability by allowing the terminal to determine HARQ-ACK codebook size based on DAI values received from PDCCH, and to dynamically select appropriate PUCCH resources for transmission. This dynamic mechanism enables the system to adapt to different carrier aggregation configurations (FDD or TDD) without requiring separate dedicated methods, thereby achieving versatility while maintaining operational simplicity.
Data Source
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AI summary
Uplink control information is efficiently transmitted. In a terminal apparatus, HARQ-ACK is transmitted by using a first PUCCH format in a case that first information is received, a PDCCH used for scheduling of a PDSCH transmission only on a primary cell is detected in a CSS on the primary cell, and a counter DAI value included in a downlink assignment is set to 1, and HARQ-ACK is transmitted by using the first PUCCH format in a case that the first information is received, a PDCCH used for scheduling of a PDSCH transmission only on the primary cell is detected in a USS on the primary cell, and both a counter DAI value and a total DAI value included in a downlink assignment are set to 1.