General Interplex Technique for Signal Combining

Abstract

Several methods have been developed for the combining of various navigation signals onto a common radio frequency carrier. Modern techniques have focused on the use of constant envelope combining to enable efficiencies in spaceborne transmitters. Typically, these techniques are developed in the phase domain, and most recently, results have been transformed to the amplitude domain. The objective of this paper is to provide a full development of the general problem in the amplitude domain. For constant envelope composite signals, constraints in the amplitude domain are established and lead, in general, to a nonlinear optimization. Within the general formulation, special cases are highlighted, which enable simplification of the signal combining design equations and the optimization problem. Various design cases are examined as well as optimization strategies and implications for the spectrum of the resultant composite waveforms. Copyright © 2017 Institute of Navigation