SEARCH METHOD OF NOISE-LIKE SIGNALS WITH MINIMUM FREQUENCY-SHIFT MODULATION Russian patent published in 2009 - IPC H04L27/14 

FIELD: radio-engineering.

SUBSTANCE: invention refers to radio-engineering, and can be used in radio navigation systems and radio communication systems for receiving noise-like signals with minimum frequency-shift modulation. For that purpose in each search cycle there performed is division of input noise-like signal into quadrature components, discretisation, digitalisation and integration of quadrature components at clock intervals that are m times shorter than durability of code sequence element. Integration results are stored for the period equal to durability of code sequence element, during which they are multiplied by readings of the appropriate reference noise-like signals generated with frequency that is M times bigger than clock frequency of input signal code sequence. At that during the period equal to one repetition period of code sequence, there formed is M of values of cross-correlation function modulus, which then are stored at the interval equal to a fixed number of repetition periods of code sequence. Decision on the value of delay time of input signal is taken by choosing maximum value of M of values of stored cross-correlation function moduli, by storing maximum value, its address and cycle number, and by repeating search procedure for a fixed number of times with a shift for M of elements of sequence when changing over to each next search cycle.

EFFECT: reducing signal search time at high interference resistance of reception and at low equipment costs.

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