  Traditional molecular communications via diffusion (MCvD) systems have used
baseband modulation techniques by varying properties of molecular pulses such
as the amplitude, the frequency of the transversal wave of the pulse, and the
time delay between subsequent pulses. In this letter, we propose and implement
passband modulation with molecules that exhibit longitudinal carrier wave
properties. This is achieved through the oscillation of the transmitter.
Frequency division multiplexing is employed to allow different molecular
information streams to co-exist in the same space and time channel, creating an
effective bandwidth for MCvD.
