Turbo coded unitary space-time modulation (USTM) can provide large coding gain as compare to uncoded USTM. Concatenated with a low-density parity-check code, pilot symbol-assisted modulation (PSAM) was shown to have better error performance than USTM. Because the noncoherent space-time maximum a posteriori demodulator is very complicated especially for long block length, the noncoherernt iterative channel-quantization demodulator and iterative decision-feedback demodulator with lower complexity were proposed. In this thesis, we focus on noncoherent iterative space-time demodulators for turbo coding systems. We generalize Noncoherent iterative channel-quantization demodulator and iterative decision-feedback demodulator. We also investigate the error performance of various noncoherent iterative demodulators for turbo coded PSAM.