The paper presents a further development of the theoretical analysis that has been devoted to the terrestrial or satellite system with Gaussian noise and one cochannel intereference per link. The specific aims of the paper are to simplify the performance analysis of the multilink system by introducing an estimate on the upper and lower bound of the symbol error rate, and to present in analytical form the impact of some imperfections (noise of preamplifier, internal interference of cochannel type, internal noise, jitter produced by the first and second local oscaillators) that exist in each repeater as well as in the receiver of anm-ary CPSK or DCPSK system. It is assumed that the repeater output amplifier is a bandpass hard-limiter type (the BPHL type), and that noise and interference act independently on each link of the system.