Method and apparatus for generating a timing signal in a time-of-arrival

Abstract

A noise pulse rejection circuit for use in a pulse type time-of-arrival detection system is described. Preferably, the pulse type time-of-arrival detection system includes a precision distance measuring equipment (DME/P) receiver having a delay-attenuate-compare (DAC) detector. The DAC detector produces first time-of-arrival detector outputs due to receiver noise, and a second time-of-arrival detector output upon detection of a received DME pulse having a leading edge, each of the first time-of-arrival detector outputs having a substantially shorter period than the period of the second time-of-arrival detector output. The noise pulse rejection circuit preferably includes a monostable multivibrator, which is triggered by the first and second time-of-arrival detector outputs to generate a timing signal having first and second logic states, the timing signal normally changing from a first logic state to a second logic state after a predetermined time period 'T'. Because the output of the monostable multivibrator has a longer period than the period of each time-of-arrival detector output, the monostable multivibrator can only 'time-out' upon reception of the desired pulse.