Error Probability Bounds for Unbalanced QAM Over the Gaussian Phase-Jittered, Dispersive Channel

The purpose of this paper is to present an analysis concerned with a hybrid QAM system capable of simultaneously handling digital as well as analog data. Upper bounds are computed for the error probability in two- and four-level digital data streams as a function of the noise power, linear distortion, and phase jitter of the channel and of the relative power of the analog and digital signals.We show that the digital error probability is less than 10
^-5
if the noise and intersymbol interference in the digital channel are more than 24 dB below the signal level, the power of the analog signal appearing in the quadrature channel differs by no more than 3 dB from that of the in-phase digital signal, the crosstalk from the analog into the digital channel is more than 40 dB down, and rms phase jitter is at most 1 degree for the four-level and 2 degrees for the two-level digital signal.