ePDCCH Transmission via CSI-RS Removal in LTE
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for transmitting enhanced physical downlink control channel (ePDCCH) signals in LTE systems face inefficiencies due to high overhead from reference signals, particularly CSI-RS, which complicates demodulation and leads to reduced transmission efficiency and increased errors, especially when CSI-RS overhead is considerable, impacting the ability to use lower aggregation levels and causing false detections.
Innovation Solution
The method involves puncturing CSI-RS reference signals in PRB pairs scheduled for ePDCCH transmission, allowing ePDCCH to be mapped without CSI-RS, thereby maximizing available resources and enabling correct demodulation without CSI-RS bitmap information, especially at the initial communication stage, and maintaining transmission efficiency by fixing the number of resource elements in eCCEs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If CSI-RS reference signals are transmitted in PRB pairs for ePDCCH transmission, then channel estimation and measurement capabilities are improved, but overhead increases and transmission efficiency decreases
Solution Approach 1:
The patent extracts and removes CSI-RS reference signals from PRB pairs that are scheduled for ePDCCH transmission. This extraction eliminates the conflict between CSI-RS and ePDCCH resources, allowing ePDCCH to be mapped to all resource elements in the PRB pair without puncturing, thereby maximizing transmission efficiency while channel estimation is performed using alternative reference signals.
2Measurement precision
If CSI-RS overhead is considerable, then measurement resolution is improved, but demodulation accuracy deteriorates due to resource conflicts
Solution Approach 1:
The patent removes CSI-RS from PRB pairs allocated for ePDCCH, eliminating the resource conflict that causes demodulation errors. By extracting CSI-RS from these specific resource blocks, the patent ensures that ePDCCH can be transmitted without puncturing while maintaining accurate demodulation through alternative reference signal mechanisms.
Solution Approach 2:
The patent applies different resource allocation strategies to different PRB pairs. PRB pairs scheduled for ePDCCH have CSI-RS removed to ensure reliable control channel transmission, while other PRB pairs may retain CSI-RS for measurement purposes. This local differentiation optimizes both demodulation accuracy and measurement capabilities.
3Productivity
If resource elements are maximized for ePDCCH mapping, then transmission capacity is improved, but reference signal overhead increases
Solution Approach 1:
The patent extracts CSI-RS from PRB pairs designated for ePDCCH transmission, thereby eliminating reference signal overhead in these critical resource blocks. This allows all resource elements in the PRB pair to be utilized for ePDCCH mapping, maximizing transmission capacity while reducing redundant reference signal transmissions.
Data Source
Figure 1~2
AI summary
The present invention relates to a method in a network control node for transmission of control channel signals in a wireless communication system, said wireless communication system employing scheduling of physical resource blocks (PRBs) used for each new transmission of a control channel signal, wherein each control channel signal is related to one or more control channel elements (CCEs); said method comprising the steps of: removing user specific reference signals in associated physical resource blocks (PRBs) if said associated physical resource blocks (PRBs) comprises at least one control channel signal; inserting control channel signals in said associated physical resource blocks (PRBs); and transmitting said associated physical resource blocks (PRBs). Furthermore, the invention also relates to a computer program, a computer program product, and a network control node device thereof.