Shown here are the BER curves for M-ary orthogonal FSK. As predicted,
as the number of symbol states is increased, the BER performance improves (at the expense
of bandwidth) but never crosses the -1.6 dB performance bound.
For digital communications applications where the optimum performance in noise is
required, for example in deep space missions where the path loss is so great, M-ary FSK is
a very effective modulation technique.