Uplink Control Channel Resource Mapping for LTE ACK/NACK Detection
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Solution Overview
Problem
In 3GPP LTE systems, the accuracy of detecting uplink control information in base stations is compromised due to differences in channel states between PCell and SCell, leading to inconsistent recognition of the number of configured component carriers, which affects the detection of ACK/NACK signals.
Innovation Solution
A terminal apparatus generates response signals based on error detection results and transmits them using an uplink control channel according to a mapping rule that associates specific error detection patterns with resources, ensuring that a first resource is allocated for the PCell when communicating with the base station, and all other error detection results are NACK or DTX, thereby reducing the detection across multiple uplink component carriers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the base station uses multiple uplink component carriers to transmit control information, then the reliability of control information transmission is improved, but the detection accuracy deteriorates due to channel state differences between carriers
Solution Approach 1:
The patent segments the uplink control information transmission by allocating different component carriers for different purposes: PCell carries ACK/NACK signals while SCell carries other uplink control information. This segmentation prevents the base station from having to detect multiple types of control information on the same carrier, thereby avoiding detection accuracy deterioration while maintaining transmission reliability through diverse carrier usage.
Solution Approach 2:
The patent applies local quality by assigning specific functions to specific carriers based on their channel characteristics. The PCell, which typically has more stable channel conditions, is designated for critical ACK/NACK detection, while SCell handles other control information. This localized optimization ensures that each carrier's transmission quality matches its assigned function, resolving the contradiction between reliability and detection accuracy.
2Adaptability or versatility
If the base station switches uplink component carriers for transmitting uplink control information, then the adaptability of the system is improved, but the consistency of component carrier recognition deteriorates
Solution Approach 1:
The patent applies preliminary action by pre-configuring the terminal with information about which component carrier to use for specific uplink control information types before actual transmission occurs. The base station provides configuration information indicating that PCell should be used for ACK/NACK signals, allowing the terminal to consistently select the appropriate carrier without real-time switching decisions, thereby maintaining recognition consistency while preserving adaptability.
3Reliability
If the terminal transmits response signals on multiple uplink component carriers, then the robustness of response signal transmission is improved, but the complexity of resource management increases
Solution Approach 1:
The patent simplifies resource management by changing the parameter of carrier selection from a dynamic, complex decision process to a rule-based determination. The terminal uses clear parameters: if the control information is ACK/NACK, use PCell; otherwise, use SCell. This parameter-based approach maintains robustness through multi-carrier transmission while dramatically reducing the complexity of resource management by eliminating the need for complex algorithms to determine carrier selection.
Data Source
AI summary
A control unit (208) transmits a response signal on an uplink control channel on the basis of a rule. In the rule, error detection result pattern candidates are associated with multiple resources of the uplink control channel used in the transmission of the response signal and with phase points within each resource, and at least a specific pattern candidate, wherein the pattern for a specific error detection result with respect to downlink data of a first unit band is identical to the error detection result pattern when communication with the base station (100) occurs using only the first unit band, and the error detection results other than the specific error detection result are all NACK or DTX, is associated with the first resource of the multiple resources. In addition, at least the first resource of the multiple resources is arranged within the first unit band.