Accession Number:

AD0767714

Title:

Nonlinear Analysis of Angle Demodulation,

Descriptive Note:

Corporate Author:

CALIFORNIA UNIV IRVINE SCHOOL OF ENGINEERING

Personal Author(s):

Report Date:

1972-09-01

Pagination or Media Count:

46.0

Abstract:

The angle-demodulation problem is investigated from the viewpoint of nonlinear filtering theory. The mean square error criterion and state-variable representation of Kushners classical nonlinear approach are adopted. The relationship between the optimum nonlinear filter and certain decoupled implementations is shown. The decoupled implementations are subsequently analyzed and nonlinear effects such as thresholding, cycle skipping, and phase locking are investigated by Fokker-Planck methods. The mean square estimation error is obtained exactly for the first-order signal-to-noise ratios SNR and demodulator gains. Linear methods of analysis are shown to lead to erroneous results even when the SNR is large. Since solutions to the Fokker-Planck equation for angle-modulation problems are usually difficult to obtain, an orthogonal projection technique is presented for obtaining approximate solutions. The approximate solutions are shown to compare favorably with simulations above and below threshold for the frequency demodulation of a message with a first-order spectrum. Author

Subject Categories:

  • Cybernetics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE