METHOD FOR TRANSMITTING AND RECEIVING QUADRATURE AMPLITUDE MODULATION SIGNALS Russian patent published in 2023 - IPC H04L27/34 

FIELD: electronics.

SUBSTANCE: methods for transmitting and receiving quadrature amplitude modulation signals. On the transmitting side a harmonic signal is formed and branched into two channels; the signal of the first channel is modulated, converted by the first boost mixer to the radiation frequency and radiated with power P_s in horizontal polarization, and the non-modulated harmonic signal of the second channel is converted by the second boost mixer to the radiation frequency and radiated with power P_s/n in vertical polarization, while the common signal of the transmitter local oscillator is fed to the first and second boost mixers. On the receiving side, the modulated signal of the first channel is received in horizontal polarization, converted using the first down mixer to an intermediate frequency, subjected to bandpass filtering in the В_c band, and the non-modulated harmonic signal of the second channel is received in vertical polarization, converted using the second down mixer to an intermediate frequency, is subjected to band-pass filtering in the band В_car equal to В_с/m, and is used for synchronous demodulation of the modulated signal of the first channel, while the common signal of the receiver local oscillator is fed to the first and second down mixers, and the value of the number m is chosen greater than the value of the number n.

EFFECT: reduction of the demodulation threshold by providing a low carrier frequency synchronization threshold.

1 cl, 1 dwg