Iteratively decoded space-time trellis codes without channel estimation

The iteratively decoded space-time trellis codes (ISTTC) have been introduced in Junghoon Suh and Mostofa K. Howlader (March 2004). In this article, we propose to combine a differential space-time block code (DSTBC) scheme with ISTTC, and show that an acceptable performance can be achieved over flat fading channels without channel estimation and error correction codes. When the space-time trellis code (STTC) is combined with space-time block codes (STTC-STBC), it provides an improved BER over the system with STTC only. Here, we also present an iteratively decoded STTC-STBC (ISTTC-STBC) to improve the BER performance, and compare the performance of ISTTC-STBC with ISTTC-DSTBC. The design methodologies of ISTTC-DSTBC and ISTTC-STBC are described in detail, where the extrinsic information shared between two constituent decoders and computing branch metrics using soft-outputs out of DSTBC or STBC are studied thoroughly. The performance of these proposed schemes are shown via simulation.