Coherent receiver for angle-modulated data signals.

摘要

A receiver for angle-modulated signals of the form a sin((ω))t + 0°(t)), comprising a frequency transposition stage (3) incorporating a local oscillator (3 1). A frequency shift Δω of the local oscillator relative to the carrier frequency ω may cause the angle modulation signal 0(t) to become faded. An argument detector (4) produces the signal [0(t) + (Δω)t] which is differentiated by a differentiator (6) to provide the signal [d 0(t) /dt + Δω]. A DC-shift detector (7) determines the DC-component Δω of this signal. This component is integrated by an integrator (8) to provide the signal (Δω)t, which is thereafter subtracted by difference producer (5) from the output signal of the argument detector (4) to provide a clear angle modulation signal. This receiver is suitable for use in systems for the radio transmission of data signals, Figure 1.