This email address is being protected from spambots. You need JavaScript enabled to view it.
 
+7 (4912) 72-03-73
 
Интернет-портал РГРТУ: http://rsreu.ru

UDC 621.391

PHASE DISCRIMINATOR WITH SOLVING FEEDBACK FOR RADIO SIGNAL WITH CONTROLLED COUPLING BETWEEN QUADRATURE COMPONENTS

P. S. Pokrovskij, PhD (technical sciences), associate professor, RSREU, Ryazan; This email address is being protected from spambots. You need JavaScript enabled to view it.
S. N. Kirillov, PhD (technical sciences), full professor, Head of the Department, RSREU, Ryazan; This email address is being protected from spambots. You need JavaScript enabled to view it.

For the case of prior known transmitted data, the task of initial phase evaluation of bandwidth-efficient radio signals by likelihood function maximization is described. The aim of the article is the development of phase discriminator with solving feedback for radio signals shaped by controlled coupling between in-phase and quadrature components. To simplify the evaluation algorithm in a receiver, a radio signal model that does not include interaction between quadrature components was chosen. The interaction is appropriate for bandwidth-efficient modulations (such as GMSK, FQPSK, TFM). On the basis of the model a phase discriminator was developed, two (two- and three- channel) functional schemes for practical implementation of this discriminator were proposed. Analytical equations to calculate S-curve, its slope, as well as correlation characteristics of output signal were received. Computer simulation showed the validity of the introduced equations and the efficiency of using this phase discriminator for synchronization circuits with solving feedback. It is shown that the use of the developed phase discriminator in comparison with the known discriminator of OQPSK-like radio signals provides the gain of not less than 12 percent for bandwidth-efficient radio signals that are realized in the class of signals with controlled coupling between quadrature components.

Key words: phase discriminator, bandwidth-efficient modulations, radio signals with controlled coupling between quadrature components, S-curve.

 Download