Design of adaptive modulation and coding system using ideal performance codes

A major issue in feedback systems is to use the feedback bits most efficiently. In this paper, we use information theory to get an upper limit on the value of feedback bits in an optimum AMC system. The AMC optimization problem is simplified by using ideal error performance (i. e. a step function like performance curve) characteristic of capacity-reaching codes. Given a strong enough code such as turbo code similar step function based approximation can be used. The results show nice match between the solution sets from the ideal error performance approximation and the real error performance.