Development of an FM multiplex broadcasting system having a large transmission capacity

In Japan, it has been absolutely essential that both additional sound and data are simultaneously serviced in FM multiplex broadcasting. Accordingly, the FM multiplex broadcasting system, which has had a large transmission capacity of 48 kbit/s has been developed. An outline of the development is described and the characteristics of this transmission channel are made clear, by using a computer simulation program which has been newly developed and which can simulate various transmission characteristics. In particular, the effect of multipath interferences with FM multiplex broadcasting signals, is explained by means of spectrum and eye patterns which are outputs of this simulation program. In addition, various kinds of receivers for FM multiplex broadcasting are introduced along with their applications and future developments.<>