Separation of zero/constant modulus signals

Abstract

Zero/constant modulus (ZCM) signals are complex signals for which every sample is either zero or has modulus 1. Such signals arise after imprecise carrier-to-baseband conversion of binary {0,1}-modulated signals, or with intermittent phase-modulated signals. We consider the separation of linear superpositions of such signals using analytic techniques. An application is the separation of multiple partly coinciding aircraft transponder signals (secondary surveillance radar reply signals).