In this paper, we investigate the performance of serially concatenated space-time coding systems on quasi-static and ideally-interleaved (rapid) Rayleigh fading channels. The considered system uses rate-1/2 repetition or nonrecursive convolutional codes as the outer code and conventional or super-orthogonal space-time QPSK trellis codes as the inner code. We consider the cases of two transmit and one or two receive antennas with iterative decoding based on the maximum a posteriori (MA-P) algorithm. We introduce new low-complexity component code combinations for serially concatenated space-time coding systems providing full diversity and good error performance. (c) 2006 Elsevier GmbH. All rights reserved.