#equation378#
Using the estimated values for noise, and assuming a transmitter
voltage on the order of 10 V, a channel capacity can be calculated for
a foot-to-foot configuration or as a function of receiver height. For
the height dependent case, the channel capacity decreases roughly
linearly with height.
Using the most current experimental hardware (not a low noise op-amp)
with a front end low pass filter to limit the bandwidth to 1.2 kHz, and
an interference estimate of white noise at 50 #tex2html_wrap_inline1372#, the channel capacity is roughly 30.8 kilobits per
second (kbps). A low noise op-amp would increase this to roughly 33.9
kbps. The thermal noise has almost no impact -- less than 10 bits per
second decrease relative to an ideal system without thermal noise.
Using a wider bandwidth is the most effective for increasing channel
capacity. Spreading the signal to a 10 kHz band, with a low noise
op-amp yields a channel capacity of 252 kbps. At 100kHz, the capacity
is in excess of 2000 kbps.