LTE DM-IM Resource Patterns for Dense-Cell Interference Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing LTE systems face challenges in managing high interference levels, particularly in dense cell deployments, which affect signal quality and throughput, despite advancements in CSI feedback and interference cancellation techniques.
Innovation Solution
Implementing Demodulation Interference Measurement (DM-IM) resources to measure and suppress interference, using a pattern of DM-IM resources located in Physical Resource Blocks (PRBs) within LTE subframes, adjusted based on frame numbers, subframe numbers, and RB indices, and utilizing co-scheduling indicators to identify and suppress interfering signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If DM-IM resources are deployed in dense cell deployments to measure and suppress interference, then signal-to-interference-plus-noise ratio is enhanced and downlink throughput is improved, but device complexity and processing requirements increase
Solution Approach 1:
The patent applies preliminary action by deploying DM-IM resources in advance within the resource grid before actual data transmission occurs. These pre-configured reference signals enable the UE to perform interference measurements and generate cancellation signals ahead of time, reducing the computational burden during real-time decoding operations.
Solution Approach 2:
The patent introduces DM-IM resources as an intermediary element that mediates between the transmitted signal and the received signal. These reference signals serve as a bridge that enables the UE to separately measure and characterize interference components, which are then used to construct cancellation signals that subtract interference from the received signal before decoding.
2Productivity
If advanced interference cancellation techniques are implemented at the UE, then network capacity and performance in high-interference environments are boosted, but ease of operation and implementation difficulty increase
Solution Approach 1:
The patent implements self-service by enabling the UE to autonomously perform interference measurement, cancellation signal generation, and interference subtraction operations using the deployed DM-IM resources. The UE independently estimates interference characteristics from the reference signals and applies cancellation without requiring complex network coordination or manual configuration, simplifying deployment while enhancing network capacity.
3Measurement precision
If multiple DM-IM resources are allocated across different PRBs and subframes for comprehensive interference measurement, then interference suppression accuracy is improved, but loss of time and signaling overhead increase
Solution Approach 1:
The patent applies segmentation by dividing the interference measurement process across multiple DM-IM resources distributed in different physical resource blocks and subframes. This segmented approach allows the UE to measure interference characteristics from multiple spatial and temporal perspectives, improving measurement accuracy while distributing the measurement burden over time rather than requiring all measurements to occur simultaneously.
Solution Approach 2:
The patent implements periodic action by allocating DM-IM resources periodically across subframes and resource blocks according to configured patterns. This periodic deployment allows the UE to perform repeated interference measurements at regular intervals, capturing interference variations over time while maintaining a predictable measurement schedule that optimizes the balance between measurement accuracy and time efficiency.
Data Source
AI summary
A method implemented by a Wireless Transmit/Receive Unit (WTRU) includes receiving a DeModulation Interference Measurement (DM-IM) resource, determining an interference measurement based on the DM-IM resource, and demodulating a received signal based on the interference measurement. An interference is suppressed based on the interference measurement. At least one DM-IM resource is located in a Physical Resource Block (PRB). The DM-IM resource is located in a PRB allocated for the WTRU. The DM-IM resource is a plurality of DM-IM resources which form a DM-IM pattern, and the DM-IM pattern is located on a Physical Downlink Shared Channel (PDSCH) and/or an enhanced Physical Downlink Shared Channel (E-PDSCH) of at least one Long Term Evolution (LTE) subframe. The DM-IM resources are different for different Physical Resource Blocks (PRB) in the LTE subframe. The DM-IM is located in a Long Term Evolution (LTE) Resource Block (RB), and the DM-IM pattern is adjusted.