Patent · US Expired

Process for transmitting digital signals which combines advantages of OQPSK and .pi./4-QPSK

US5615230A · kind A · utility

11Cited by

4References

2Claims

0Family size

Assignee

Ascom Tech AG · CH

Inventors

Christoph Günther · Weßling, DE
Joachim Habermann · Wetzlar, DE

Key dates

Filing date	Feb 23, 1995
Grant date	Mar 25, 1997
Priority date	—
Expiry date	Feb 23, 2015

Classification

Technology area (CPC H)Electricity
CPC primaryH04L27/233
WIPO fieldDigital communication
WIPO sectorElectrical engineering

Abstract

A process for transmitting digital signals, in which the digital data are coded differentially in symbols of a symbol period T.sub.s (2.1, 2.2), the symbols transmitted with the Q component being delayed by T.sub.s /2, relative to those of the I component, to achieve a time-staggering. A cross interference of the I and Q components, occurring on the receiver end and caused by the differential coding nd the time staggering, is resolved with a trellis decoder (10), for example. As a result, a differential offset QPSK process achieved on this basis combines the advantages of DQPSK and OQPSK procedures.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.