One of the most important equations in wireless communications, if not the most important, is the Shannon–Hartley theorem.
It states that the channel capacity, C, equals the bandwidth, B, multiplied by the base-two logarithm of one plus the signal-to-noise ratio.
C=B\log_2(1+S/N)
In simple terms, this equation tells us the theoretical maximum rate at which information can be transmitted reliably over a communication channel of a given bandwidth and signal-to-noise ratio.
What makes this equation so important is that it establishes a fundamental limit. No matter how sophisticated our modulation, coding, or communication system becomes, for a given bandwidth and signal-to-noise ratio, there is a theoretical limit to how much information that channel can reliably carry.
