Method and device for determining the phase intercept in a system employing phase-shift keying modulation
US4231094A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 11, 1978 |
| Grant date | Oct 28, 1980 |
| Priority date | — |
| Expiry date | Oct 11, 1998 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/227
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
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 EQU .phi..sub.i =.phi..su…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.