Pulse compression applied to the detection of F.S.K. and P.S.K. signals

Abstract

The matched filter detector is well known as the optimum detector for use in communication, as well as in radar systems for signals corrupted by
Additive White Gaussian Noise (A.W.G.N.).
Non-coherent F.S.K. and differentially coherent P.S.K. (D.P.S.K.) detection schemes, which employ a new approach in realizing the matched filter processor, are investigated. The new approach utilizes pulse
compression techniques, well known in radar systems, to facilitate the
implementation of the matched filter in the form of the Pulse Compressor
Matched Filter (P.C.M.F.). Both detection schemes feature a mixer- P.C.M.F.
Compound as their predetector processor. The Compound is utilized to convert
F.S.K. modulation into pulse position modulation, and P.S.K. modulation into
pulse polarity modulation. The mechanisms of both detection schemes are
studied through examining the properties of the Autocorrelation function
(A.C.F.) at the output of the P.C.M.F.. The effects produced by time delay,
and carrier interference on the output A.C.F. are determined.
Work related to the F.S.K. detection scheme is mostly confined to verifying its validity, whereas the D.P.S.K. detection scheme has not been reported before. Consequently, an experimental system was constructed, which
utilized combined hardware and software, and operated under the supervision
of a microprocessor system. The experimental system was used to develop
error-rate models for both detection schemes under investigation.
Performances of both F. S. K. and D.P. S. K. detection schemes were
established in the presence of A. W. G. N. , practical imperfections, time delay,
and carrier interference. The results highlight the candidacy of both detection schemes for use in the field of digital data communication and, in
particular, the D.P.S.K. detection scheme, which performed very close to
optimum in a background of A.W.G.N.

Date of Award	Sept 1980
Original language	English
Supervisor	R.L. Brewster (Supervisor)