Emulated Interference Injection for CSI Reporting

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Solution Overview

Problem

Current wireless communication systems face challenges in accurately estimating and reporting Channel State Information (CSI) for Coordinated Multipoint (CoMP) transmission, leading to inefficient interference management and increased overhead, especially in large coordination clusters.

Innovation Solution

A method where User Equipment (UE) measures interference on configured time-frequency resources, injects emulated interference signals, and reports modified Channel State Information to the eNodeB, allowing for flexible interference hypotheses and reduced overhead by implicitly accounting for frequency selectivity and spatial characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional interference measurement methods are used in CoMP systems, then interference estimation can be performed, but overhead increases and measurement accuracy deteriorates in large coordination clusters

Engineering Contradiction:
Improveinterference estimation accuracyVSAvoidoverhead
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent creates virtual copies of interference signals by injecting emulated interference signals that replicate the statistical characteristics and spatial properties of actual interference from coordinated transmission points. This allows the UE to measure interference without requiring actual transmissions from all TPs, reducing overhead while maintaining measurement accuracy.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent transforms the interference measurement approach by changing the parameter representation from direct physical interference measurement to statistical characterization through emulated signals. The emulated interference signals are configured with matching covariance matrices and spatial characteristics, allowing accurate interference estimation with reduced overhead.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If separate interference measurement resources are allocated for each UE in CoMP, then accurate per-UE interference measurement is achieved, but resource overhead increases significantly

Engineering Contradiction:
Improveper-UE interference measurement accuracyVSAvoidmeasurement resources
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent enables shared interference measurement resources to serve multiple UEs simultaneously. By configuring emulated interference signals with UE-specific spatial characteristics and covariance matrices, the same physical resources can provide accurate interference measurements for different UEs, eliminating the need for dedicated per-UE measurement resources.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent applies local quality by customizing the emulated interference signals for each UE based on their specific spatial characteristics, channel conditions, and coordinated TP configurations. Each UE receives interference measurements tailored to its local environment while sharing the same physical measurement resources.

Inventive Principle:
Principle #3Local quality

3Measurement precision

If emulated interference signals are injected to match actual interference characteristics, then CSI reporting accuracy improves, but signal processing complexity increases

Engineering Contradiction:
ImproveCSI reporting accuracyVSAvoidsignal processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent performs preliminary configuration of emulated interference signals by pre-computing covariance matrices and spatial characteristics based on available channel state information and coordinated TP configurations. This preliminary setup reduces the real-time processing complexity at the UE while maintaining accurate interference characterization for CSI reporting.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2828984B1Artificial interference injection for channel state information reporting
Publication Date: 2018.11.14 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP2828984B1 patent drawingFigure 1
  • EP2828984B1 patent drawingFigure 2
  • EP2828984B1 patent drawingFigure 3

AI summary

A system and method for improving the link adaptation in a wireless communication system (10) is disclosed. User Equipment (UE) (20) forms an interference hypothesis by amending a measured interference and noise by artificially injecting, to the measured interference and noise, interference corresponding to at least one emulated interfering isotropic signal that is virtually transmitted over an associated estimated effective channel. The UE (20) further determines at least one channel state information (CSI) report based on the interference hypothesis, and transmits the CSI report to the network (10).