]>

Figure 3: Receiver structure for the proposed P-STCs in cooperative communications. The Viterbi decoder is the same as for the single convolutional code adopted in transmission, but the metric on the generic branch is, for example, for $n=2$ and $R=1,{\sum }_{s=1}^m|r_s^{(t\mathrm{,1})}-\sqrt{E_s}(h_{\mathrm{0,1,}s}^{(t)}{\tilde{c}}_{\mathrm{0,1}}+h_{\mathrm{0,2,}s}^{(t)}{\tilde{c}}_{\mathrm{0,2}}){|}^2+|r_s^{(t\mathrm{,2})}-\sqrt{E_s}(h_{\mathrm{1,1,}s}^{(t)}{\tilde{c}}_{\mathrm{1,1}}+h_{\mathrm{1,2,}s}^{(t)}{\tilde{c}}_{\mathrm{1,2}}){|}^2,$ where ${\tilde{c}}_{\mathrm{0,1}}\mathrm{,}{\tilde{c}}_{\mathrm{0,2}}\mathrm{,}{\tilde{c}}_{\mathrm{1,1}}\mathrm{,}{\tilde{c}}_{\mathrm{1,2}}$, are the four symbols associated to the branch. Note that $r_s^{(t\mathrm{,1})}$ is received at time $t_1+t$ whereas $r_s^{(t\mathrm{,2})}$ is received at time $t_2+t$.