Patent ID: 7516373

Claim:
A method for testing a bit error ratio (BER) of a device against a maximal allowable Error Ratio BER limit with an early pass criterion, whereby the early pass criterion is allowed to be wrong only by a small probability F 1 for the entire test, comprising the following steps: measuring ns bits of the output of the device, thereby detecting ne erroneous bits of these ns bits; assuming that a likelihood distribution giving the distribution of the number of erroneous bits ni in a fixed number of samples of bits is PD(NE,ni), wherein NE is an average number of erroneous bits, obtaining PD high from D 1 = ∫ 0 ne ⁢ PD high ⁡ ( NE high , ni ) ⁢ ⁢ ⅆ ni wherein PD high is the worst possible likelihood distribution containing the measured ne erroneous bits with a single step wrong decision probability D 1 for a preliminary Error Ratio BER stage, whereby using a single step wrong decision probability D 1 smaller than the probability F 1 for the entire test; obtaining the average number of erroneous bits NE high for the worst possible likelihood distribution PD high ; comparing NE high with NE limit =BER limit ns; if NE limit is higher than NE high stopping the test and deciding that the device has early passed the test; and if NE limit is smaller than NE high continuing the test, thereby increasing ns.