Inner code rate selection for serial concatenated block codes

Typically, appropriate code rates for the constituent codes in a concatenated coding system have been found through the means of heuristic methods and simulations. Herro et al. (see IEEE Trans. Inform. Theory, vol.4, p.212-22, Mar. 1988) first employed information-theoretic techniques to conclude that there is an optimum rate for the inner code of a concatenated block coding system. In this work we expand upon the results of Herro et al. to present a tractable method for determining appropriate code rates as a function of selected system constraints, such as coder block length.