PUCCH Resource Indexing for ePDCCH-Based HARQ-ACK Signaling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless communication systems face inefficiencies in determining PUCCH resource indices, leading to increased overhead and reduced throughput in coordinated multipoint (CoMP) scenarios, particularly in heterogeneous networks with low-power RRHs, due to the need for additional resources and potential underutilization of PUCCH resources.
Innovation Solution
A method for determining at least part of a PUCCH resource index that reduces overhead by implicitly linking PUCCH resources to ePDCCH CCEs, allowing flexible assignment of HARQ-ACK signals and optimizing resource utilization through dynamic or RRC-configured offsets, thereby supporting both orthogonal and non-orthogonal DMRS-assisted MU-MIMO operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additional PUCCH resources are allocated for CoMP scenarios, then reliability of HARQ-ACK transmission is improved, but overhead increases by 6%-10%
Solution Approach 1:
The patent merges the determination of PUCCH resource index with the ePDCCH CCE indexing mechanism. By using the same indexing logic for both PDCCH CCEs and ePDCCH CCEs, the system eliminates the need for separate PUCCH resource allocation mechanisms, thereby reducing overhead while maintaining reliable HARQ-ACK transmission in CoMP scenarios.
Solution Approach 2:
The patent makes the PUCCH resource index determination universal by applying the same formula and indexing method for both traditional PDCCH and enhanced PDCCH (ePDCCH). This multi-functional approach allows a single mechanism to serve multiple purposes: resource allocation for different downlink control channels and support for various MIMO operations, eliminating redundant resource allocations.
2Adaptability or versatility
If PUCCH resources are allocated for all possible scenarios, then adaptability is improved, but device complexity increases
Solution Approach 1:
The patent uses parameter changes by introducing an offset value (offsetPUCCH) that can be configured based on network conditions and scenario requirements. This parameter allows the system to adapt to different operational modes (orthogonal and non-orthogonal DMRS-assisted MU-MIMO) without requiring complex resource determination logic, thereby maintaining scheduler flexibility while reducing device complexity.
3Measurement precision
If explicit PUCCH resource signaling is used, then measurement precision is improved, but loss of information increases due to additional signaling overhead
Solution Approach 1:
The patent implements self-service by enabling the UE to autonomously determine the PUCCH resource index based on the received ePDCCH CCE indexing. The UE uses the same indexing information already available from the downlink control channel to automatically derive the uplink resource, eliminating the need for separate explicit resource signaling and reducing information loss while maintaining precise resource allocation.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method and a wireless network (100) determining at least part of a PUCCH resource index nPUCCH1 (PUCCH format 1a/1b) associated with an ePDCCH PRB set. The PUCCH resource index nPUCCH1 is determined depending on whether a localized or distributed ePDCCH is used.