The invention provides an apparatus and procedure for radio transmission of
information using a middle channel, a first side channel and a second side
channel. The transmitted middle channel is FM-modulated by a suitable
frequency. A signal symmetrically amplitude-modulated with respect to the
center frequency of the middle channel is generated, and a first
amplitude-modulated single side band (LSB) and a second
amplitude-modulated single side band (USB) are formed from the
amplitude-modulated signal. The first single side band (LSB) is modulated
by the information in the first side channel to form two side bands for
the first single side band, and the second single side band (USB) is
modulated by the information in the second side channel to form two side
bands for the second single side band. The middle channel FM signal, the
modulated first single side band (SSB) and the second modulated single
side band (SSB) are then combined in a combiner for simultaneous
transmission of all three channels.
