Estimation of the Spectral Efficiency and Noise Immunity of the Coherent Reception of an Unfading QBL–MSK Signal

. The mathematical model of an unfading QBL–MSK signal, as well as the algorithms for its formation and reception are substantiated in the article. The energy spectrum of the QBL–MSK signal is found, and a methodical apparatus is developed in the form of analytical techniques and mathematical models for estimating the effectiveness of the Gaussian noise interference on a coherent receiver of this signal. A distinctive feature of the proposed methodologies and models is the consideration of intersymbol interference, which is specially introduced into the signal on the transmitting side in the process of leading edge smoothing of the transmitted packages. It is shown that the smoothing by a QBL-pulse provides a significant narrowing of the signal spectrum and some improvement in noise immunity of its reception.