Simulation and analysis of a STBC-DSQPSK-CDMA scheme with image transferring experiments

Space-Time Code is one of the most practical techniques for a MIMO system. In case of other diversity techniques are not available (e.g., for a quasi-static fading channel), it is still a simple and efficient way to apply. Alamouti scheme is the earliest implementation of the Space-Time Code. It is easier to extend to multi-antenna case and further to perform transmitter diversity and receiver diversity as well. The decoding process of the scheme could be carried out with a linear complexity, so it is easier for the terminal to perform the decoding process within limited resources. An Alamouti scheme is integrated with a DS-QPSK-CDMA system and images are transferred through the simulation system with different SNR. It shows the simulation system works well, and the quality of image after transferring by the system is consistent with the BER performance simulation and analysis results of the simulation system. In addition, a typical MIMO simulation system usually suppose that the multiple antenna channels are synchronized by default, however, a different simulation result is given in this paper, in which the sub-streams are not synchronized. It shows synchronization of the parallel channels has great effect on the performance of a multiple antenna system.