Slicing List Detector for MIMO Symbol Detection

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Solution Overview

Problem

MIMO communication systems face increasing complexity and processing delays as the number of antennas and alphabet size increase, making real-time symbol detection impractical due to high computational complexity, especially in next-generation wireless standards like 5G.

Innovation Solution

The slicing list detector method reduces complexity by defining decision regions in the complex plane with horizontal and vertical threshold lines, allowing for a lookup table-based detection process that replaces metric computations and sorting, significantly reducing the number of candidates and computations required.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional K-best detection is used to maintain detection accuracy, then symbol detection performance is preserved, but computational complexity increases exponentially with the number of antennas and alphabet size

Engineering Contradiction:
Improvesymbol detection accuracyVSAvoidcomputational complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the complex plane into multiple decision regions, each associated with a subset of K symbols. This segmentation allows the detector to divide the search space into manageable regions, evaluating only K candidates per region rather than all M possible symbols, thereby reducing computational complexity while maintaining detection accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies partial action by considering only a subset (K < M) of candidate symbols in each decision region rather than exhaustively evaluating all possible symbols. This partial evaluation approach reduces the number of metric computations from O(M) to O(K) per decision region, significantly lowering complexity while preserving sufficient detection performance.

Inventive Principle:
Principle #16Partial or excessive action

2Measurement precision

If exhaustive search maximum-likelihood detection is used to achieve optimal performance, then detection accuracy is maximized, but processing time becomes prohibitively long for real-time systems

Engineering Contradiction:
Improvedetection accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent evaluates only a partial set of K candidate symbols in each decision region rather than performing exhaustive search over all M symbols. This reduces the number of metric computations and sorting operations required, decreasing processing time to meet real-time requirements while maintaining sufficient detection accuracy through the structured selection of candidate subsets.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent performs preliminary organization of the complex plane into decision regions with pre-defined threshold lines before detection. This preliminary structuring allows for efficient candidate selection and metric computation during actual detection, avoiding the need for exhaustive real-time evaluation and enabling real-time processing.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If the number of antennas and alphabet size are increased to improve spectral efficiency, then data rate increases, but the complexity of the MIMO detector grows rapidly

Engineering Contradiction:
Improvespectral efficiencyVSAvoidMIMO detector complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the symbol alphabet into multiple decision regions in the complex plane, each containing K candidate symbols. This segmentation allows the detector to handle large alphabet sizes (e.g., 64-QAM, 256-QAM) and multiple antennas by dividing the search space into manageable regions, preventing detector complexity from growing exponentially with spectral efficiency improvements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent evaluates only K candidate symbols per decision region rather than all M symbols in the alphabet. This partial evaluation approach ensures that detector complexity grows linearly with the number of decision regions rather than exponentially with alphabet size, enabling support for high spectral efficiency standards while maintaining manageable detector complexity.

Inventive Principle:
Principle #16Partial or excessive action

4Measurement precision

If traditional metric computation and sorting methods are used in K-best detection, then accurate candidate selection is achieved, but the number of computations and processing delay increase

Engineering Contradiction:
Improvecandidate selection accuracyVSAvoidnumber of computations
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the candidate selection process into multiple decision regions with threshold lines. This segmentation allows the detector to compute metrics and select candidates within each region independently, reducing the total number of computations required compared to global metric computation and sorting over all M symbols, while maintaining accurate candidate selection through structured regional evaluation.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentUS10374772B2Method for slicing K-best detection in multiple-input multiple-output wireless communications system
Publication Date: 2019.08.06 GEORGIA TECH RES CORP
  • US10374772B2 patent drawing
  • US10374772B2 patent drawing
  • US10374772B2 patent drawing

AI summary

In a MIMO detector, a slicing list detection scheme employs a complex plane to represent symbols in an alphabet, in which all decision regions are bounded by either vertical lines or horizontal lines. A K-best scheme accesses the complex plane and an offline-generated lookup table to detect elements of a received vector. At each level, the system prunes all but the K-best candidates from each surviving node through the slicing list detector.