METHOD OF PROBABILITY DETECTION INCREASE OF RADIATION COUPLING FROM OPTICAL FIBER Russian patent published in 2009 - IPC H04B10/12 

FIELD: physics, communication.

SUBSTANCE: invention concerns methods of detection of infringement of working capacity of the protected fiber-optical systems of transmission (FOTS) information of restricted access and can be used as an expedient of the constant control of a fiber-optical transmission line (FOTL) from leakage on the optical channel. In the method, consisting in reception, detection of optical signals from a fiber-optical line, amplification, integration and analogue-digital transformation of the gained analogue electrical signals which in the numeral shape are compared to control value in such a manner that in case of decrease in amplitude of a signal below control value on the given quantity the alarm signal is shaped. That through each quantity of readout N making a j-th cycle set by the timer, medial sampling value which is calculated is new the gained quantity Faugh is remembered and used in the subsequent cycles for evaluation of a control signal under the formula after the termination of each j cycles remembered and subtracted from the value calculated in the j-7, j-k1, j-k2...j-km cycles, the gained difference is compared to in advance given thresholds of detection Φ_d and alarms Φ_a and in case one of requirements that is carried out the alarm signal is shaped, in a case if one of requirements that for quantity of medial sampling value in a j+1 cycle is carried out quantity calculated either in j-k1-1, or in j-k2-1 is accepted, either in j-k3-7 or ... in j-km - depending on what of requirements (4) is carried out, otherwise the value is accepted, used in y cycle, and k1/k2, k12/k...km-1/km≥Φ_a/Φ_d.

EFFECT: increase of the signal/noise relation at decision-making for signals pickup of any shape, amplitude and duration, and also an error exception at decision-making at the expense of the account of slow changes of a signal in definition of control value.

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