METHOD FOR VOICE SIGNAL PROCESSING AND DEVICE WHICH IMPLEMENTS SAID METHOD Russian patent published in 1998 - IPC

FIELD: communications. SUBSTANCE: time-base encrypting method involves splitting voice signal into sequence of time intervals, splitting resulted intervals into sequence of sub-intervals, their random permutation. Duration of said intervals is, number and duration of sub-intervals are random. Direction for reading signal from sub-intervals produced by splitting is random. Sub-intervals which are randomly selected is subjected to reading of converted signal with speed is greater than speed of their storing. Pauses caused by this difference in speed are located in time interval in random position and are filled with background noise which characteristics depend on current pseudorandom sequence. Corresponding device has unit for interface to channel of voice signal to be transmitted, which is connected to first band-pass filter, unit for interface to channel of voice signal to be received, which is connected to second band-pass filter. Outputs of first and second band-pass filters are connected to input of analog-to-digital converter. In addition device has digital-to-analog converter which output is connected to second commutator, which one output is connected to third band-pass filter which output is connected to input of unit for interface to output encoded voice signal. Second output of second commutator is connected to fourth band-pass filter, which output is connected to unit for interface to output decoded voice signal. In addition device has processor which serves as unit for synchronization of communication between users and pseudorandom sequence generator which restores spectrum of noise signal, performs pseudorandom processing of sequences of digital samples of voice signal, controls device operations and runs self tests. EFFECT: decreased probability of surveillance decoding, simplified design, increased functional capabilities.