Communications system using radio - has transmitter which produces conventionally coded frequency modulated binary data words of N bits

摘要

The receiver accepts and decodes these data words. In order to determine the carrier signal and measure its Doppler shift, a first code converter is provided in the sender before the modulator, it converts the conventionally coded binary data words into binary data words with M bits with equal number of "1" and "0" bits, called for short(M/2 from M); a second code converter is provided in the receiver behind the demodulator for conversion of the (M/2) from (M) binary data words into conventionally coded data words with (N) bits; a measuring device determines the Doppler shift of the carrier signal from the received modulated signal.