Method for testing the error ratio of BER of a device according to confidence level, test time and selectivity

Abstract

A method for testing the error ratio BER of a device under test against a specified allowable error ratio comprises the steps: measuring ns samples of the output of the device, thereby detecting ne erroneous samples of these ns samples, defining BER(ne)=ne / ns as the preliminary error ratio and deciding to pass the device, if the preliminary error ratio BER(ne) is smaller than an early pass limit EPL(ne). The early pass limit is constructed by using an empirically or analytically derived distribution for a specific number of devices each having the specified allowable error ratio by separatinga specific portion DD of the best devices from the distribution for a specific number of erroneous samples ne and proceeding further with the remaining part of the distribution for an incremented number of erroneous samples.

Description

technical field The present invention relates to a method of testing the bit error rate (BER) error rate of a device under test relative to a specific allowable error ratio. Background technique Statistical testing is an example of testing a device under test (DUT) such as a digital receiver for a cellular phone. The test will determine whether the DUT meets a specified bit error rate (BER). True BER is not the goal of this test. The purpose of the present invention is to design an optimal test. The present invention derives and discovers the knowledge that testing is controlled by the three parameters mentioned above, confidence level, testing time and selectivity. In the prior art, the test has actually been optimized according to only the two parameters of test time and confidence, without considering selectivity. In WO 02 / 089390A1 tests found known properties of the distribution. If the errors occur independently, this situation can be mathematically described by...

AI Technical Summary

Problems solved by technology

This situation has the disadvantage that the test has two different qualities

-In the prior art, the early pass and early fail bounds are only based on the following definition: a bad DUT may pass falsely with false decision probability F, and a good DUT may falsely fail with false decision probability F

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