Space-time trellis coded OFDM system with added pilot semi-blind iterative channel estimation

Various channel estimation methods for multiple-input multiple-output (MIMO) systems have been proposed. In this paper, to prevent performance degradation for the space-time trellis coded OFDM (STTC-OFDM) system in fast fading channels, we propose a system that applies the added pilot semi-blind (APSB) channel estimation to all the OFDM data symbols except the preamble of a frame. We also propose a simplified system that applies the APSB channel estimation to the last OFDM symbol of a frame. We show that the proposed systems can track the channel variations without additional bandwidth because of the use of the APSB channel estimation and improve the word error rate (WER) performance compared to the conventional system that uses only DDCE.