METHOD AND DEVICE FOR MEASURING PHASE-JITTER OF A TRANSMISSION CANAL

摘要

A sinusoidal test signal of a given frequency is applied by the generator 12 to the transmission channel 10. The output signal from the channel is sampled at 16 and fed to a Hilbert transformer 20 through an ADC 18. The sampled outputs from the Hilbert transformer are fed to a device 26 which derives therefrom the phase of the received signal. The phase of the test signal generated at 30-34 is subtracted from that of the output signal from device 26 and the resultant signal is fed to a phase filter 36, which removes therefrom the phase intercept and frequency shift components. The output from filter 36 is fed to a predictive filter 40 which removes the residual noise therefrom. A detector 42 measures the variations of the phase jitter values provided by predictive filter 40.