PUCCH Resource Assignment for Carrier Aggregation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional PUCCH resource assignment methods in LTE Rel-8 are inadequate for LTE-Advanced, particularly with carrier aggregation, as they fail to efficiently manage the increased UCI transmission requirements for multiple component carriers.
Innovation Solution
A communication system and method where a base station transmits four indices for physical uplink control channel resources to a user equipment, using higher layer signaling, and includes a transmission power control command in downlink control information to schedule HARQ-ACK/NACK on non-primary component carriers, allowing flexible resource assignment and efficient transmission control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional PUCCH resource assignment methods from LTE Rel-8 are used, then the system maintains backward compatibility and simple resource management, but it fails to efficiently manage the increased UCI transmission requirements for multiple component carriers in LTE-Advanced with carrier aggregation
Solution Approach 1:
The PUCCH resource indices are segmented into multiple candidate indices (e.g., four indices: 0, 1, 2, 3) that are separately configured and stored in the UE. Each index corresponds to a specific PUCCH resource, allowing the system to select appropriate resources based on carrier aggregation scenarios without managing all resources simultaneously, thus reducing complexity while improving adaptability.
Solution Approach 2:
The PUCCH resource assignment becomes dynamic through the introduction of TPC commands that can indicate different index values. Instead of static resource allocation, the system dynamically selects from pre-configured candidate indices based on current transmission requirements, enabling flexible adaptation to carrier aggregation while maintaining manageable resource configuration.
2Adaptability or versatility
If four PUCCH resource indices are configured and stored in the UE, then the system enables flexible PUCCH resource assignment for carrier aggregation, but it increases the signaling overhead and memory requirements in the UE
Solution Approach 1:
The four PUCCH resource indices are pre-configured and stored in the UE through higher layer signaling before actual PUCCH transmission occurs. This preliminary configuration allows the UE to have ready-access candidate resources without requiring real-time signaling for each PUCCH assignment, reducing signaling overhead while maintaining flexibility in resource selection.
Solution Approach 2:
The same set of four PUCCH resource indices serves multiple functions: they can be used for different component carriers, different HARQ-ACK scenarios, and different PUCCH formats. This multi-functionality reduces the need for separate resource configurations for each scenario, minimizing signaling overhead while providing comprehensive coverage for various transmission requirements.
3Productivity
If TPC commands are used to indicate PUCCH resource indices, then the system achieves efficient dynamic resource selection, but it requires reusing existing TPC fields which limits the range of resource selections
Solution Approach 1:
Different TPC command values are assigned different local meanings based on the PUCCH resource configuration scenario. For example, TPC values may indicate specific index offsets or direct index selections depending on the configured resource set. This localized interpretation allows the same TPC field to provide fine-grained control over resource selection without requiring additional signaling bits.
Solution Approach 2:
The system extends the resource selection capability by using the TPC command not just to select from a small fixed set of resources, but to indicate offsets or selections across a broader range of pre-configured resources. This dimensional extension allows limited TPC field values to control a larger effective resource space through mathematical relationships or configured mappings.
Data Source
AI summary
A communication system in which a base station apparatus and a user equipment communicate on multiple component carriers comprising primary component carrier and non-primary component carrier, the base station apparatus, transmits, to the user equipment, four indices for physical uplink control channel resource using higher layer signaling, transmits, to the user equipment, an index indicator using transmission power control command for physical uplink control channel field, the user equipment, determines an index among the four indices according to the index indicator, transmits, to the base station apparatus, HARQ-ACK/NACK using physical uplink control channel resource the index, wherein the transmission power control command for physical uplink control channel field is included in a downlink control information format, which is used to schedule a physical downlink shared channel on the non-primary component carrier.