PUCCH Transmission Power Control Using DAI Modulo in TDD Systems
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Solution Overview
Problem
Existing wireless communication systems face inefficiencies in transmitting uplink control information in Time Division Duplex (TDD) systems, particularly in determining accurate transmission power for the Physical Uplink Control Channel (PUCCH), which affects resource management and can lead to errors in ACK/NACK signaling.
Innovation Solution
A method for determining the transmission power of the PUCCH using a specific equation that takes into account the number of configured cells, downlink assignment indices, and received PDCCHs, along with modulo operations to accurately reflect the number of HARQ-ACK bits and PDCCHs, ensuring correct power adjustment for efficient control information transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a general power control approach is used for HARQ-ACK transmission, then the transmission can be performed, but the transmission power may be inaccurate leading to decoding errors
Solution Approach 1:
The patent modifies the power control parameters by introducing a specific offset value (ΔP) that is determined based on the Downlink Assignment Index (DAI). This parameter change allows the transmission power to be dynamically adjusted according to the actual downlink scheduling situation, improving both power accuracy and decoding reliability.
Solution Approach 2:
The patent utilizes the DAI field in downlink grants as feedback information to adjust the uplink transmission power. The DAI provides information about the cumulative number of downlink assignments, which is fed back into the power control calculation to determine the appropriate power level for HARQ-ACK transmission.
2Productivity
If the number of HARQ-ACK bits is not accurately determined, then resource allocation may be inefficient, but increasing the number of bits for DAI to resolve ambiguities increases overhead
Solution Approach 1:
The patent changes the interpretation and usage of the existing 2-bit DAI parameter by applying modulo operations and specific mapping rules. Instead of increasing the DAI bit length, the patent modifies how the DAI value is processed and used to determine both the power control offset and the number of HARQ-ACK bits, thereby maintaining overhead efficiency while improving resource management.
3Productivity
If spatial bundling is applied to reduce HARQ-ACK bits, then uplink resource usage is improved, but the ability to provide detailed feedback is reduced
Solution Approach 1:
The patent introduces a configurable parameter that allows the system to dynamically adjust the level of spatial bundling based on channel conditions and traffic requirements. When channel conditions are good or traffic is light, spatial bundling can be relaxed or disabled to provide more detailed feedback. When conditions are poor or traffic is heavy, spatial bundling is applied to improve uplink resource efficiency. This parameter change enables flexible trade-off management.
Data Source
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AI summary
The present invention relates to a wireless communication system. In more detail, the present invention relates to a method for transmitting uplink control information in a wireless communication system operating in TDD, and a device for same. The method includes transmitting Hybrid Automatic Repeat request - Acknowledgement (HARQ) in a subframe n through Physical Uplink Control Channel (PUCCH), and a transmission power of the PUCCH relates to a method determined using a specific equation, and a device for same. The specific equation includes applying a modulo-4 operation to a difference between a downlink assignment index, DAI, number and a number of physical downlink control channels, PDCCHs, the DAI number corresponding to a value of a DAI in a PDCCH lastly detected within at least one subframe associated with the UL subframe in the cell according to a specifc UL-DL configuration, and the number of PDCCHs corresponding to a total number of scheduling-related PDCCHs detected within the at least one subframe associated with the UL subframe in the cell according to the specific UL-DL configuration.