Access Node DTX Cause Determination via Combined Energy Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In LTE networks, distinguishing between DL and UL problems causing DTX (Discontinuous Transmission) is challenging due to independent signaling of UL grants and DL assignments, leading to inefficiencies and robustness issues, especially with the introduction of skipPadding in Rel-13, which complicates differentiating between true DTX and error cases.
Innovation Solution
A method where the access node transmits both UL grants and DL assignments in the same DL subframe, employing a combined energy detection scheme using feedback from UL data and HARQ ACK/NACK to determine the cause of DTX, thereby improving DTX robustness and resource utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If UL grant and DL assignment are signaled independently through PDCCH/EPDCCH, then the signaling flexibility is improved, but the DTX cause differentiation capability deteriorates
Solution Approach 1:
The patent combines the independent UL grant and DL assignment signaling into a unified signaling structure where both are transmitted together in the same DL subframe. This merging allows the access node to detect DTX conditions and differentiate between DL and UL problems more effectively, as the combined signaling creates a reference relationship that was missing in independent signaling.
2Reliability
If separate energy detection schemes are applied for UL grant and DL assignment, then the detection robustness is improved, but the resource utilization efficiency deteriorates
Solution Approach 1:
The patent merges the separate energy detection schemes into a combined detection approach. By detecting the presence of both UL grant and DL assignment together in the same DL subframe, the system maintains detection robustness while reducing the total number of separate detection operations required, thereby improving resource utilization efficiency.
3Speed
If UL grant re-transmission is scheduled without accurate DTX cause identification, then the system responsiveness is improved, but the resource wastage increases
Solution Approach 1:
The patent implements a feedback mechanism where the access node uses the combined detection results of UL grant and DL assignment to identify the DTX cause accurately. This feedback information guides the scheduling of UL grant re-transmissions, ensuring that re-transmissions are only scheduled when necessary (reducing resource wastage) while maintaining quick response times to DTX events.
Data Source
Figure 1
Figure 2~3
AI summary
The present disclosure provides a method of determining a DTX cause at an access node, comprising: transmitting, to a UE, an UL grant and a DL assignment in a same DL subframe; detecting whether DTX of at least one of (1) UL data to be transmitted in response to the UL grant received by the UE and (2) HARQ ACK/NACK to be transmitted in response to DL data related to the DL assignment received by the UE occurs; and determining a cause of the DTX based on a result of the DTX detection. The present disclosure further provides an access node using the method and a computer program product.