Recently, some works have shown that it was possible to obtain quite good bit error rate performances over an additive white Gaussian noise channels with chaotic systems. In this research field, this paper proposes new insights for the chaos-coded modulation (CCM) schemes originally proposed by Kozic et al. (2003; IEEE Trans Circuits Syst Regul Pap 53:2048–2059, 2006). A detailed study of the distance spectrum of such schemes is proposed and an approximation of its distribution by means of Gaussian or Rayleigh mixtures is given. Furthermore, using these approximate distributions, a complete study of the performances of these CCM schemes when they are concatenated with a space–time block code is proposed. Accurate bounds are obtained even in the case of time-selective channels.