Example 2.2


Question 2.10
Question 2.11


Channel capacity restriction due to noise – the Shannon–Hartley theorem (cont)

 

The Shannon–Hartley theorem states that if the required information transfer is less than the Shannon capacity limit (C), then error-free communication is possible. If information transfer at a rate greater than C is attempted, then errors in transmission will always occur no matter how well the equipment is designed.

The Shannon–Hartley capacity equation is a very good first step for evaluating the feasibility of any digital communication system design. It immediately provides the engineer with an 'upper bound' on channel capacity because it assumes a perfectly flat, distortion and interference free communications link, with the noise taking the form of Additive White Gaussian Noise (AWGN). It also is a theoretical bound with the implication that infinite signal processing power is available in both TX and RX units. In practice, we will of course not be able to achieve data rates quite as good as those suggested by the Shannon–Hartley equation, but it is a good starting point in a design.