Methodology and Results of Synthesis and Analysis of Potential Resilience for Noise Immunity Compensator of an Asynchronous Intermittent Interference Similar to a Useful Phase-Manipulated Signal

Abstract

In telecommunication radio systems with random multiple-access (RMA), user signals are characterized by a random intermittent radiation mode and the occurrence of their collisions in the propagation medium, i.e. conflicts at the physical level. Practical interest belongs to the situations when the useful and interfering (intermittent) signals are asynchronous at clock points. It should also be noted that when there are intermittent mutually non-orthogonal signals along the length of the information error more than two, the detection-separation algorithms that are optimal in terms of the minimum probability of error in estimating the discrete parameter of the useful signal are too complex. Therefore, the simplest case is investigated here, when the interfering signal is the only one. An algorithm for demodulation of a binary phase-manipulated signal is observed, which is observed at the background of a similar asynchronous clock noise, which is characterized by a random intermittent radiation mode. The minimum probability of error in the discrete information parameter estimation of the useful signal is chosen as the criterion of optimum for the synthesis. It is also assumed that all non-information parameters of the useful signal and similar interference are precisely known. The distribution medium is considered to be stationary in time. These initial data for the synthesis allow obtaining in the analysis the potential limits of the noise immunity of the digital signal demodulation, which is observed at the background of a similar intermittent noise. The result is a «framework» of the demodulation-separation procedure, which should be subsequently supplemented with nodes (blocks) of continuous parameters estimation that are not informational - frequencies, initial phases, amplitudes, shapes of bending, clock points, etc. The algorithm for demodulating a digital signal under the influence of such an asynchronous intermittent interference turns out to be about twice as complicated in comparison with the previously known one, when the signal and the interference at the clock points were assumed to be synchronous. A characteristic feature of the obtained compensation algorithm is the absence of feedback - the compensation procedure is performed forward, at the outputs of the signal correlators and interference. The result is generalized to the case when the clock frequencies of the signal and interference differ by an arbitrary value. A simplified approximation of the obtained algorithm is proposed.