DOUBLE RELATIVE PHASE MODULATION METHOD Russian patent published in 2023 - IPC H04L27/20 H04L27/227 H04B10/556 

FIELD: radio engineering.

SUBSTANCE: double relative phase modulation method in which one of the quadratures of the signal is further manipulated at the time corresponding to the middle of the element, in phase by 180° meander. Message elements from the first and second message sources arrive at the inputs of the modulator synchronously. The square wave has a period equal to the duration of the transmitted message element. The odd or even fronts of the meander coincide with the fronts of the elements of the transmitted message. The even or odd fronts of the meander coincide with the centers of the elements of the transmitted message. On the receiving side of the communication channel, the signal is branched. In one branch of the demodulator, a narrow-band filter of the main selectivity is included, which passes to its output only a quadrature that is not additionally manipulated in phase, which, after the filter, is fed to the input of any of the known demodulators of signals with relative phase modulation. A phase demanipulator is installed at the input of the second branch, which levels out the phase change by 180 produced by the meander in the modulator at the transmitting end of the communication channel.° in the second quadrature. In the second branch, after the phase demanipulator, a narrow-band filter is switched on, to the output of which only the second quadrature passes, in which the additional phase change produced by the meander at the transmitting end of the radio link is eliminated. The first quadrature after the demanipulator acquires a phase change in the center of the message elements by 180°. The second quadrature after phase demanipulation and after the narrow band filter is fed to the input of the signal demodulator with relative phase modulation.

EFFECT: simplifying the circuit implementation of the modem with double relative phase modulation.

1 cl, 2 dwg