The ShannonHartley Theorem: Graphical representation
The ShannonHartley theorem clearly shows that bandwidth efficiency can be traded
for power efficiency, and vice-versa.
It is important to note that the Shannon Capacity theorem assumes that the noise present
with the signal is Additive White Gaussian Noise.
This is often a valid assumption, particularly if the operating bandwidth is small
compared with the channel center frequency.
In practice, no implementation of a digital communication system can reach the
performance suggested by the Shannon equation, and most fall short by 3 dB or more.
Results for some common modem types are given in Chapter 6.