The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 28, 1980
Filed:
Oct. 11, 1978
Andre E Desblache, Nice, FR;
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method and device for measuring the slope of the envelope delay characteristic of a transmission channel and deriving the phase intercept value therefrom. A measurment signal having a frequency spectrum including three rays at frequencies f.sub.o, f.sub.1 and f.sub.2 is sent over the transmission channel. Frequency f.sub.o is the carrier frequency and frequencies f.sub.1 and f.sub.2 are defined as f.sub.1 =f.sub.o -1/2T and f.sub.2 =f.sub.o +1/2T, where 1/T is the signaling rate. At the output of the channel, the three components at frequencies f.sub.o, f.sub.1 and f.sub.2 are extracted from the received measurement signal, and the instantaneous phases .psi..sub.o, .psi..sub.1 and .psi..sub.2 of these three components are then measured. The value of the slope S of the envelope delay characteristic is obtained in accordance with the relation ##EQU1## where .phi..sub.o.sup.', .phi..sub.1' and .phi..sub.2' are the phases of the three rays at frequencies f.sub.o, f.sub.1 and f.sub.2 of the measurement signal sent over the channel. The value of the phase intercept .phi..sub.i for a given sampling phase .phi..sub.s is determined in accordance with the relation