Radio communication system

TLDR: In this paper, a cellular mobile-radio system with radio stations and transmission facilities remote therefrom, the radio stations send out radio signals and receive radio signals which, in each case, contain information signals.

Abstract: In a cellular mobile-radio system with radio stations and transmission facilities remote therefrom, the radio stations send out radio signals and receive radio signals which, in each case, contain information signals. According to the invention, as many as possible of the processing functions are shifted from the radio stations to the transmission facilities. The radio signal to be sent out by the radio station is easily generated in the radio station because in the transmission facility, an unmodulated carrier and a carrier modulated with the information signal is produced, in which case the carriers differ in frequency by the amount of the carrier frequency of the radio signal. These two optical carriers are transmitted to the radio station and are mixed there in an optical receiver, so that the radio signal containing the information signal is generated. A radio signal that is received in a radio station is transmitted optically to a the transmission facility and is processed further there. This transmission is carried out by the fact that an optical transmitter present in the transmission facility generates an unmodulated optical carrier and transmits it to an optical modulator located in the radio station. In the optical modulator, the light, modulated with the received radio signals, is sent back and the radio signal is recovered by optical heterodyne reception of the unmodulated and modulated carrier.