Noise suppression method for sensor arrangement using transmitter and receiver - modulating random signal generated at transmitter and correlating received signal in evaluating circuit with random signal

摘要

The noise suppression method uses a random generated signal (7) for the transmitter (1). The signal obtained at the receiver (2) is correlated with the random signal (7) in an evaluation circuit (6) to extract the transmitted signal from the accompanying noise. Pref. the transmitter is coupled to a pseudo-random signal generator (3) providing a signal (7) modulated by superimposing different frequencies which is also fed to the valuation circuit (6) coupled to the receiver (2). The correlation of the received signal with the modulation signal delivers the statistically most probable evaluation valvue for the interference-free signal, namely, the value at which, derived from the measuring period, the quadrant of the different between the received and estimated signals is at a min., achieving an optimal process. USE/ADVANTAGE - Light barrier. Good noise suppression within short measuring interval.