On Apr 27, 2014 10:19 AM, "David Woolley" <david@ex.djwhome.demon.invalid> wrote: > > On 27/04/14 17:28, Rob wrote: >> >> We are setting up a co-channel diversity network. That means multiple >> FM transmitters that are transmitting the same signal on the same >> frequency on different sites, where the receive areas partly overlap. > > > This problem has already been solved using COFDM (aka DAB) and it is much more tolerant of fading that is inevitable with co-channel transmitters than your system.
DAB is a nice system but unfortunately there are parts of the world where DAB receivers are unheard-of. > Your transmitters will have to be contained within a circle of 3.6km, reduced by the timing errors in the modulation at 0.3km/microsecond. Only the distance between the receiver and all transmitters strong enough for it to receive need be < 4 km. The overall network can be bigger if each transmitter is weak enough not to be heard too far away. Of course there will still be multipath issues with destructive interference at the carrier frequency even at much shorter distances. Henry _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
