| 摘要 |
A measuring or security system (1) for detecting the distance between an object (2) or a person (2) from a given point of reference, comprising a first transmitter/receiver device (10) enabling production of a nd wireless transmission of a control signal to a separate second transmitter/receiver device (30) and reception of an acknowledgement signal transmitted by the second transmitter/receiver device (30) on receiving control signal. Both transmitter/receiver devices (10,30) have a signal source (24,24,25,26) producing pulses as a control signal or an acknowledgement signal. Said pulses have a monotonously decreasing or increasing frequency during pulse duration or are made of overlapping pairs of like pulses. The other transmitter/receiver (10,30) has at least one dispersion filter (11) with a given frequency dependent signal transit time on its receive side so that received pulses ca n be time-compressed. Transit time is adapted to the modulation on transmit side in such a way that spectral signal components of the contro l or acknowledgement signal coincide substantially at dispersion filter output (11) as a result of varying frequency-dependent signal transit - times through said filter and appear thus with slight temporal imprecision.
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