It has been recently recognized by Zehavi that the performance of code
d modulation over a Rayleigh fading channel can be improved by bit-wis
e interleaving at the encoder output, and by using an appropriate soft
-decision metric as an input to a Viterbi decoder. The goal of this pa
per is to present in a comprehensive fashion the theory underlying bit
-interleaved coded modulation, to provide tools for evaluating its per
formance, and to give guidelines for its design.