RADIO SIGNAL TRANSMISSION SYSTEM INCLUDING A PLURALITY OF TRANSMITTERS FOR TRANSMITTING A COMMON SIGNAL

摘要

A radio communication system of the type where two or more transmit stations transmit a common signal using substantially identical frequency carrier waves is described. Where the zones of the two stations overlap interference between the two waves occurs if the frequencies or phases of the two carriers are not the same. The invention minimizes the effect of this interference by conveying the common signal directly from a signal generator to the first station but providing a delayed common signal to the second station. Preferably the phase difference between the undelayed and the delayed signals is between 20.degree. and 40.degree. . The substantially identical carrier waves which are generated in the two stations are modulated, in the case of the first station, by the undelayed common signal and, in the case of the second station, by the delayed common signal. The type of modulation used is frequency or phase modulation. It is provable mathematically and practically that the code error rate in the overlapping zone is reduced using this technique.