A matched filter detection system for complicated Doppler shifted signals

Abstract

A matched filter system is described which was designed to detect complicated signals subject to a wide range of possible Doppler shifts. A 100 tap band-pass delay line was used in conjunction with a resistor weighting matrix to synthesize signals and filter characteristics. The system could handle a signal with a duration-bandwidth product of 100 over a range of Doppler frequency shifts 17 times the reciprocal of the signal duration. A theoretical discussion of the Doppler effect is given, making use of conjugate functions or Hilbert Transforms. Various engineering compromises which simplify the construction of matched filters are suggested. The performance of the resulting signal detection system was within 5 db of that of an ideal theoretical model.