Performance of turbo-coded QO-STBC schemes

This paper analyzes the relationship between soft decision detected values and the performance of turbo codes. Proper utilization of channel quality information is one of the important factors affects on the performance of turbo codes. If a space time block coding (STBC) scheme is used with turbo codes, the output of the STBC decoder should be fed into a decoder of turbo codes in the form of soft decision information. In this case, the channel quality information is contained in this soft decision information. Therefore, the performance of turbo codes is subject to how the STBC scheme generates soft decision information from its detection process. In this paper, we investigate a number of STBC schemes, and present suitable soft decision information for turbo codes. Simulation results show that a conventional QO-STBC scheme can highly degrade the performance of the turbo codes unless its soft detection information is carefully modified.