An extended form of multi-hop communication systems has been introduced recently which allows the application of multiple-input-multiple-output (MIMO) capacity enhancement techniques over spatially separated relaying mobile terminals. It was further shown that such deployment yields significant capacity gains over direct communication or traditional single-input-single-output (SISO) relaying networks. The contribution of this paper is the derivation of the end-to-end bit-error rates (BER) for space-time block encoded M-PSK and M-QAM, assuming full and partial cooperation at each relaying stage. The theoretical analysis is corroborated by simulation results.