Turbo processing in transmit antenna diversity systems

We consider turbo-trellis-coded transmission over,fading multiple-input-mul tiple-output (MIMO) channels with transmit diversity using space-time block codes. We give a new view on space-time block codes as a transformation of the fading MIMO channel towards a Gaussian single-input-single-output (sis o) channel and provide analytical results on the BER of space-time block co des. Furthermore, we describe the concatenation of Turbo-Tcm with a space-t ime block code and show that in addition to the transmit diversity substant ial benefits can be obtained by turbo iterations as long as the channel is time-varying during transmission of a coded block or frequency hopping is a pplied. Finally, a double iterative scheme for turbo equalization and turbo decoding of the concatenation of Turbo-Tcm and space-time block code in fr equency-selective mimo channels is described.