An improved signal detection method for high mobility SC-OSTBC system

The Alamouti orthogonal space time block code (OSTBC) scheme assumes that the channel remain constant during the length of the code word period. However, in time selective channel, this assumption does not hold good and leads to inter transmit antenna interferences (ITAI). To combat the ITAI effects, we have analyzed various conventional signal detection methods which include diagonalized maximum likelihood decoder (DMLD), decision feedback (DF) and maximum likelihood (ML) decoders. The DF method is the trade off between performance and computational complexity but it experiences error floor. Hence, in this paper, we have proposed an order iterative decision feedback (OIDF) decoder which eliminates the error floor of the conventional DF method by applying order iterative double decision feedback scheme according to the difference in diversity gain term to recover the desired transmitted signal. The theory and simulation results show that our proposed OIDF method achieves performance close to the optimal ML method with very low computational complexity.