A.A. Agafonov, A.E. Kaunov, A.E. Kondratenko, K.Yu. Lozhkin, V.N. Poddubny
Despite of the big number of the jobs devoted to various questions of use MSK of signals, now are far from end of research on synthesis and an estimation of a noise stability of non-coherent receivers of such signals. So, absence of results of synthesis of non-coherent receivers MSK of signals complicates revealing interrelation and essential distinctions of known schemes of such receivers.
In clause on the basis of criterion of a maximum of the attitude of credibility the structure of the optimum receiver for white noise of the frequency-manipulated signals with the minimal shift keying (MSK signals) which are formed quadrature by way is synthesized.
As a result of synthesis it is established, that for simple MSK signals with a unknown initial phase the four-channel correlation receiver which is carrying out calculation under formulas (19) projections neighbouring elements accepted signal on corresponding coordinate functions, formation from these projections of scalar product which moves on threshold devices where the decision on the passed binary elements is passed is optimum.
It is shown, that if the condition the optimum four-channel correlation receiver can be transformed to the autocorrelation receiver equivalent on a noise stability realizing algorithm (23) is satisfied.
In the synthesized four-channel correlation receiver at calculation of scalar product elements MSK a signal it is not required, unlike the autocorrelation receiver, the high-frequency block of a delay of an received signal for a while equal to duration element a signal that facilitates practical realization of the given receiver.
By replacement of integrators with dump on passive filters, or by use of harmonious oscillation and instead of more complex basic oscillation accepted during synthesis the synthesized optimum receiver can be transformed to known quasi-optimal to receivers.
The revealed features of construction and functioning of various non coherent receivers of the frequency-manipulated signals with are minimal shift keying can to appear useful to the experts, engaged system engineering of transfer of the information and a substantiation of requirements to technics of their radiosuppression.
The interrelation and essential distinctions synthesized and known non-coherent receivers MSK of signals is revealed.