METHOD FOR DIGITAL DATA TRANSFER IN PSEUDORANDOM OPERATING FREQUENCY TUNED LINK Russian patent published in 2004 - IPC

FIELD: electrical communications and computer engineering. SUBSTANCE: proposed method and device are designed for data transfer in computer network over radio link incorporating provision for tuning pseudorandom operating frequency. On sending end of radio link input signal is divided into blocks produced in the form of n-bit binary vectors in compliance with number of p = 2ⁿ, frequency channels used; two pseudorandom-sequence binary vectors are generated by simultaneously and concurrently taking data off different places of shift register; in the process length of each pseudorandom-sequence binary vector is chosen to equal that of binary vector of input-signal block; binary vector of input signal block is coded by modulo two addition of its bits to those of first pseudorandom-sequence binary vector; transmitter is tuned to desired frequencies in compliance with codes generated in the form of second pseudorandom-sequence binary vector, transmitter frequency is modulated followed by signal radiation into space. On receiving end of radio link signal is received simultaneously at all frequencies, converted to intermediate frequency, amplified, and demodulated; binary vector of demodulated signals is generated; two pseudorandom-sequence binary vectors are produced in same manner as on sending end; signal is decoded by modulo two addition of two bits of first pseudorandom-sequence binary vector to bits of demodulated-signal binary vector, and signal is supplied to terminal device; transmitter frequencies are modulated by noiseimmune code and transmitter tuning is effected to several frequencies simultaneously; in the process first frequency is chosen for frequency channel whose number corresponds to code of second pseudorandom-sequence binary vector and all other frequencies are selected by sequential search in compliance with symbol 1 meaning in respective bit of coded binary vector of input signal; on receiving end of radio link binary vector whose bits acquire 1 meaning is generated upon demodulation of signals in presence of signal in respective frequency channels whose numbers follow that of frequency channel found by code of second pseudorandom-sequence binary vector. EFFECT: enhanced noise immunity and security of communications. 1 cl, 2 dwg