Eye Diagram BER Calculation Without Sender-Receiver Control

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Solution Overview

Problem

Existing methods for calculating the bit error rate (BER) in eye diagrams require controlling both the sender and receiver, limiting their applicability when the equipment does not have access to both, as they rely on partial eye information that cannot be calculated without this control.

Innovation Solution

A method to calculate the BER for a mask in an eye diagram without using partial eye PDFs P0 and P1, by assuming no appreciable probability of bits exceeding mask boundaries and maximizing BER at either the top or bottom of the mask, allowing for BER calculation using minimum and maximum voltages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If partial eye information is used to calculate BER, then BER calculation is possible with controlled sender and receiver, but the method cannot be applied when equipment does not control both sender and receiver

Engineering Contradiction:
Improveapplicability of BER calculationVSAvoidcontrol requirement
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent extracts the essential information needed for BER calculation from the eye diagram itself, specifically using the probability distribution function (PDF) that can be obtained from the eye diagram without requiring access to partial eye information. This allows BER calculation to be performed using only the eye diagram data, removing the dependency on controlled sender-receiver pairs.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces the probability distribution function (PDF) as an intermediary that bridges the gap between the eye diagram and BER calculation. By using the PDF derived from the eye diagram as the basis for BER calculation, the method enables BER determination without direct access to transmitted and received bit sequences, thus working around the limitation of not controlling both sender and receiver.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If conservative BER estimation is used to ensure accuracy, then error impact is minimized, but the estimate may be off by a factor of 2

Engineering Contradiction:
ImproveBER calculation accuracyVSAvoiderror margin
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent applies a conservative estimation approach that cushions against potential errors by assuming the worst-case scenario within the mask boundaries. By calculating BER based on the assumption that all samples within the mask region represent errors, the method provides a conservative upper bound that ensures accuracy is not overestimated, even though it may overestimate by a factor of 2 in some cases.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent changes the approach from using precise partial eye information to using the overall PDF from the eye diagram with conservative assumptions. This parameter change in the calculation methodology trades some precision for broader applicability and conservative reliability, accepting a potential factor of 2 error margin in exchange for being able to calculate BER in uncontrolled environments.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3012639B1Method to determine BER (bit error rate) from an eye diagram
Publication Date: 2017.12.06 TEKTRONIX INC
  • EP3012639B1 patent drawingFigure 1~2
  • EP3012639B1 patent drawingFigure 3A~3B
  • EP3012639B1 patent drawingFigure 4~5

AI summary

A system and method for calculating a bit error rate for a mask is described. For each time during the time duration of the mask, the minimum and maximum voltages of the mask at that time are determined. The maximum bit error rate can be calculated for each time by integrating between those voltages. The maximum bit error rate for all times during the time duration of the mask can be selected as the maximum bit error rate for the mask.