Schnorr-Euchner Expansion Algorithm Multiplier-Free Implementation

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Solution Overview

Problem

Conventional Schnorr-Euchner (SE) expansion methods in MIMO communication systems require multipliers, leading to high processing power and time costs due to long critical paths in VLSI implementations, making them inefficient for achieving low hardware complexity and high throughput.

Innovation Solution

The proposed SE expansion methods eliminate or reduce the use of multipliers by introducing auxiliary variables and recursive equations, allowing for the computation of cost functions without multipliers, specifically for ℓ1 and ℓ2 norms, and implementing these methods in hardware with shifting and addition operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional SE expansion methods use multipliers to compute cost functions, then accuracy is maintained, but hardware complexity and processing time increase due to long critical paths

Engineering Contradiction:
Improvecost function computation accuracyVSAvoidhardware complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent transforms the cost function computation by changing the mathematical parameters and representation. Instead of directly computing products using multipliers, the invention uses alternative mathematical formulations that express the same cost function values through different computational parameters, enabling multiplier-free implementation while maintaining accuracy

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the mechanical multiplication operation (which requires complex hardware multipliers) with alternative computational mechanisms such as addition-based algorithms or lookup tables. This substitution eliminates the need for physical multiplier circuits, reducing hardware complexity and critical path length while preserving the computational accuracy of the cost function

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If conventional SE expansion methods use multipliers for cost function computation, then accuracy is maintained, but processing speed decreases due to long critical paths

Engineering Contradiction:
Improvecost function computation accuracyVSAvoidprocessing speed
Core Design Contradiction:
Measurement precisionVSSpeed

Solution Approach 1:

The patent replaces the slow multiplication operation with faster alternative mechanisms such as addition-based computations or pre-computed lookup tables. This substitution reduces the critical path delay in the computational pipeline, enabling faster cost function evaluation and improving overall processing speed while maintaining the same accuracy level

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent performs preliminary computations and pre-processes data in advance to avoid time-consuming multiplication operations during the main detection process. By pre-computing certain values or transforming the problem formulation beforehand, the algorithm reduces the computational burden and critical path length during real-time operation, thereby improving processing speed without sacrificing accuracy

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If conventional SE expansion methods use multipliers, then cost function accuracy is maintained, but energy consumption increases

Engineering Contradiction:
Improvecost function accuracyVSAvoidprocessing power
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent replaces energy-intensive multiplication operations with lower-power alternative computations such as addition-based algorithms or memory lookup operations. This substitution reduces the dynamic power consumption in the computational circuitry while maintaining the same cost function accuracy, thereby improving energy efficiency in the detection process

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP3050221B1Schnorr-euchner expansions and their fast implementations
Publication Date: 2019.12.18 GEORGIA TECH RES CORP
  • EP3050221B1 patent drawingFigure 1
  • EP3050221B1 patent drawingFigure 2
  • EP3050221B1 patent drawingFigure 3

AI summary

Methods and apparatus reducing or eliminating the number of multipliers in Schnorr-Euchner expansion algorithms are disclosed. Methods and apparatus for implementing Schnorr-Euchner expansion algorithms with a reduced number of multipliers or without any multipliers are also disclosed. Also disclosed is a Schnorr-Euchner expansion method for a multiple-input multiple-output communication system. The method includes receiving, by a plurality of input terminals, a plurality of input signals. The method also includes detecting a symbol transmitted by each input signal. The detection includes identifying a list of possible symbols that may be transmitted by each input signal. A cost value for each possible symbol is determined based on a cost function. The cost function is implemented without requiring a multiplier. The possible symbol with a lowest cost value is identified as the transmitted symbol.