SSMA Data transmission system

US4134071A · kind A · utility

Assignee

• Licentia Patent-Verwaltungs-GmbH · DE

Inventor

• Horst Ohnsorge · Freiberg, DE

Key dates

• Filing date: Jul 19, 1971
• Grant date: Jan 9, 1979
• Expiry date: Jul 19, 1991

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04B1/707
• WIPO field: Telecommunications
• WIPO sector: Electrical engineering

Abstract

In an SSMA data transmission system in which each binary information signal (k.sub.ij) is multiplied with a binary address a.sub.i (t-j T) having Z binary digits and is transmitted after being modulated onto a carrier oscillation signal cos (.omega..sub.i t), the effective signal-to-noise ratio for the desired received signal is improved by providing each receiver station, e. g., the m.sup.th receiver station, with means for reproducing the transmitted data-functions k.sub.i (t) by k.sub.i *(t) of at least one of the stations i.noteq. m by correlation of the received total signal f.sub.e (t) by EQU g*a.sub.i (t) =a.sub.i * (t-j T-.tau..sub.i *) cos (.omega..sub.i * t-.phi..sub.i *) and forming EQU f.sub.i *(t) = K.sub.i *(t) .multidot. a.sub.i *(t-jT-.tau..sub.i. * ) cos (.omega..sub.i *t-.phi..sub.i *); means for subtracting each of the thus reproduced transmitting functions from the received mixture signal f.sub.e (t) to produce a derived received signal f.sub.e *(t); and means for determining the desired data sequence K.sub.m *(t) by correlating only the signal f.sub.e *(t) with the address g*a.sub.m (t) for the m.sup.th station.