Precoded space-time block coded GMSK system with soft-output demodulation

In this paper, a soft output precoded space-time block coded (STBC) Gaussian minimum shift-keying (GMSK) system with two transmit antennas and one receive antenna is proposed. The memory of the continuous phase modulation (CPM) signal is eliminated by precoding, but it will result in inter-symbol interference (ISI). The turbo detection and decoding receiver with a linear SISO detector based on MMSE criterion is used to reduce the inherent ISI. The iterative principle is applied and a good performance is achieved.