NOISE SUPPRESSION CIRCUIT AND CYCLOCONVERTER Russian patent published in 2004 - IPC

FIELD: communications engineering; noise suppression circuits and cycloconverters.

SUBSTANCE: noise suppression circuit has at least one decimating device in passband and adding device; each decimating device has error elimination filter, band filter, and decimator; transfer functions of error elimination filter and band filter are convoluted to obtain transfer function of passband decimator; filtered-off signal is then decimated by N value; N-value decimation can be also effected within passband in decimator so that the latter operates in passband at 1/N of sampling synchronizer frequency of analog-to-digital converter; signals arriving from all decimators are added in passband and intermediate-frequency samples obtained are conveyed to two multiplying devices which convert intermediate-frequency samples into I and Q samples, at the same time reducing their frequency, in modulating-signal frequency band with in-phase and quadrature sine wave; samples are filtered with aid of low-pass filter in modulating-signal frequency band.

EFFECT: simplified design, reduced power requirement.

26 cl, 17 dwg