Optimal Reception of Pulse-Time-Modulated Signals in Asynchronous-Address Communication Systems

The Markov theory of optimal nonlinear filtering in the Gaussian approximation is used to solve the optimal reception problem for pulse-time-modulated signals in asynchronous-address communication systems with frequency-time coding. The useful signal is analyzed in the presence of additive fluctuation noise approximated by white noise and of nonadditive temporal and phase distortions corresponding to time shifts of the reference and working user-address pulses, instability of the sender carrier frequencies, and influence of the Doppler effect. A transmitted speech message is approximated by the model of a component of a continuous bivariate Markov process. Expressions are derived and graphs plotted for the relative filtering errors, making it possible to estimate the receiver errors of asynchronous-address systems.