Channel Estimation for Resource Elements

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Solution Overview

Problem

Current channel estimation techniques in wireless communication systems are computationally expensive and often result in poor estimates, especially in situations with high frequency selectivity or Doppler spread, which can degrade the performance of modern transmission techniques like FDMA.

Innovation Solution

A method that dynamically selects a subset of Resource Elements for complex estimation filters based on the channel condition, allowing for more accurate interpolation without increasing computational complexity, by optimizing the subset to fit the channel transfer function and fading structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If complex estimation filters are applied to all Resource Elements, then channel estimation accuracy is improved, but computational complexity increases

Engineering Contradiction:
Improvechannel estimation accuracyVSAvoidcomputational complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent divides the Resource Elements into two subsets: a first subset where complex estimation filters are applied, and a second subset where simpler interpolation methods are used. This segmentation allows the system to achieve good channel estimation accuracy at critical Resource Elements while avoiding the high computational cost of applying complex filters to all Resource Elements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different estimation quality levels to different subsets of Resource Elements. The first subset receives high-quality complex filter estimation, while the second subset uses lower-complexity interpolation. This local differentiation optimizes the trade-off between accuracy and computational load by concentrating resources where they are most needed.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If complex estimation filters are applied to all Resource Elements, then channel estimation accuracy is improved, but processing time increases

Engineering Contradiction:
Improvechannel estimation accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent segments Resource Elements into two groups, applying computationally intensive complex filters only to the first subset and simpler interpolation to the second subset. This reduces the total processing time while maintaining adequate estimation accuracy for all Resource Elements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of applying complex filters to all Resource Elements (excessive action), the patent applies them only to the first subset (partial action), which is sufficient to achieve good overall channel estimation performance when combined with interpolation for the remaining elements.

Inventive Principle:
Principle #16Partial or excessive action

3Device complexity

If simple interpolation is used for all Resource Elements, then computational complexity is reduced, but channel estimation accuracy deteriorates

Engineering Contradiction:
Improvecomputational complexityVSAvoidchannel estimation accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent divides Resource Elements into two subsets, applying simple interpolation to the second subset while using complex filters for the first subset. This ensures that computational simplicity does not compromise overall accuracy, as the complex-filtered elements provide anchor points for the interpolation process.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent merges two different estimation approaches (complex filtering and simple interpolation) into a unified channel estimation process. By combining the results from both methods across different Resource Element subsets, the system achieves both computational efficiency and adequate estimation accuracy.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentUS9860764B2Channel estimation for a subset of resource elements of a resource block
Publication Date: 2018.01.02 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • US9860764B2 patent drawing
  • US9860764B2 patent drawing
  • US9860764B2 patent drawing

AI summary

A technique for performing channel estimation for a wireless communication channel is provided. A determining circuit determines a channel condition for the wireless communication channel. A filtering circuit applies an estimation filter to reference signals transmitted on the wireless communication channel. The filter estimates coefficients for a subset of Resource Elements transmitted on the wireless communication channel. The subset is chosen depending on the determined channel condition. An interpolating circuit interpolates the estimated coefficients for Resource Elements that are not included in the subset.