Capacity estimation of communication channel with PSK-n-signals in the presence of intersymbol interference

The paper presents a new method for estimating capacity of real communication channel in the absence of noise when PSK-n signals are used under conditions of strong intersymbol distortion caused by transient processes in selective systems of a linear radio path. The presented method has high accuracy and low computational complexity, which does not depend on the number of discrete states of the PSK-n signal. The verification of the method carried out in the work showed that the error in estimating of capacity does not exceed 2.71% for the number of discrete states 8 and an increase in the number of discrete states leads to a decrease in the error, which on the average corresponds to 0.16%. The paper estimates the unity capacity for a filter with coupled circuits.