DEVICE FOR HIGH-ORDER QUADRATURE AMPLITUDE SHIFT KEYING SIGNAL DEMODULATOR RECOVERY

摘要

FIELD: communication equipment.;SUBSTANCE: invention relates to communication engineering and can be used in digital demodulators of radio relay links operating in decimetre frequency range for demodulation of quadrature amplitude-shift keying (QASK) signals. Device for recovery of carrier frequency of high-order quadrature amplitude shift keying demodulator comprises quadrature amplitude-shift keying, decision unit on received symbol, loop filter, sine and cosine count generator, connected by its output to quadrature multiplier input, which is connected by an output to the input of the decision unit on the received symbol, and an amplitude detector. Device is also equipped with a unit for selecting a weight coefficient, a multiplier, a unit for calculating the accurate error, which together with the quadrature multiplier, a decision unit on the received symbol, a loop filter, a sine and cosine count generator and an amplitude detector, a circuit for accurate frequency estimation, and a coarse frequency estimation circuit comprising a quadrature multiplier, a unit for rough estimation of frequency offset, a loop filter and a sine and cosine count generator.;EFFECT: high accuracy of capturing a phase of a received signal when using high-order constellations QASK64-QASK256, without changing the band of the loop filter, and shorter time for capturing frequency tuning.;1 cl, 3 dwg