In this paper, the achievable performance of a turbo coded system adapted to a block fading channel model is evaluated. This model is suitable for analyzing, for instance, frequency-hopped multiple access (FHMA) systems that operate in a mobile satellite environment characterized by frequency-nonselective slow Rician fading, provided that the spacing between carriers is larger than the coherence bandwidth, resulting in basically uncorrelated blocks. In such systems, coded information is transmitted over a small number of fading channels in order to achieve diversity. The best coded information allocations over a certain number of fading channels are evaluated. Bounds on the achievable performance due to coding are derived using information-theoretic techniques. Moreover, simulation results are obtained and compared with the theoretical ones.