초록 ▼

A method and circuit for accurately determining the leading edge timing of a pulse of high frequency carrier signal at a receiver which substantially simultaneously receives the same pulse over multiple transmission paths resulting in distortion of the pulse envelope. The amplitude of the pulse enve

A method and circuit for accurately determining the leading edge timing of a pulse of high frequency carrier signal at a receiver which substantially simultaneously receives the same pulse over multiple transmission paths resulting in distortion of the pulse envelope. The amplitude of the pulse envelope is compared with the amplitude of the derivative of the pulse envelope and with a reference threshold amplitude. The leading edge of a pulse is indicated when the amplitude of the pulse envelope exceeds both the amplitude of the derivative and the reference threshold.

대표청구항 ▼

A circuit for determining a timing of a leading edge of a pulse signal within a received signal which may have a poorly defined leading edge as a result of effects introduced by the path over which the received signal is transmitted, the circuit including a first and second operational amplifiers, o

A circuit for determining a timing of a leading edge of a pulse signal within a received signal which may have a poorly defined leading edge as a result of effects introduced by the path over which the received signal is transmitted, the circuit including a first and second operational amplifiers, of which the first is connected to receive a threshold voltage at its inverting input terminal, the circuit further comprising: an envelope rectifier circuit operable to produce an envelope signal corresponding to the envelope of the received signal; first connecting means for supplying the envelope signal from said envelope rectifier circuit to the noninverting input terminals of the first and second operational amplifiers; a differentiating circuit connected to receive the envelope signal from said envelope rectifier circuit, and operable to produce a derivative signal corresponding to the time dependent first derivative of the envelope signal; second connecting means for supplying the derivative signal from said differentiating circuit to the inverting input terminal of the second operational amplifier; and an AND logic circuit connected to receive an output signals of the first and second operational amplifiers, and operable to indicate presence of the leading edge of a pulse when the output signals of the first and second operational amplifiers indicate that the amplitude of the envelope signal simultaneously exceeds both the time derivative of the envelope signal and the threshold voltage.