• Coherent Demodulation for Orthogonal Sideband and Carrier Tracking

      Udalov, Sergei; Axiomatix (International Foundation for Telemetering, 1978-11)
      A demodulation technique which permits simultaneous coherent and orthogonal tracking of a suppressed carrier and of the associated sidebands is described. The performance of a demodulator based on such a technique is defined for a general case and for a specific case of two-channel FM multiplexing. Experimental data supporting the analysis of the FM multiplexing mode of the demodulator is presented and discussed.
    • A Coherent Receiver for QPSK and SQPSK Signals

      Alem, W. K.; Weber, C. L.; Axiomatix; University of Southern California (International Foundation for Telemetering, 1978-11)
      A demod-remod type of coherent tracking loop for conventional QPSK and staggered QPSK (SQPSK) is presented. The phase detector characteristic (S-curve) is determined. The effects of power unbalance and arm gain unbalance on the S-curve are presented. The steady state rms phase error is shown as a function of the signal-to-noise ratio at the output of the arm filters.