Adaptation of Algebraic Space Time Codes to Frequency Selective Channel

Background

Despite the attractive features of both OFDM and ASTC they are very sensitive to the transmitter and receiver synchronization imperfections (A. Bannour M. A., 2010) (A. Bannour M. A., 2011). Thus, the synchronization is crucial for ASTC-MIMO-OFDM-based systems. Frequency synchronization errors destroy the orthogonality among the subcarriers which results in inter-carrier interference (ICI) (Renfors, 2007) (B.Swami, 2005) (Schlegel, 2002) (Peeters, 2002). Therefore an accurate CFO estimation is essential for OFDM receiver design. Various carrier synchronization schemes have been proposed for SISO OFDM systems. Some schemes rely on pilot or preamble data (Moose, 1994) (Cox, 2007) (Santella, 2002) (Mengali, An improved frequency offset estimator for OFDM applications, 2002) (S. Hyoung-Kyu, 2000) (Reggiannini, 2005) and some use the inherent structure of the OFDM symbol in either frequency (U. Tureli H. L., 1997) or time domain (J. J. van de Beek, 2002). For multiple antenna OFDM, data-aided schemes are proposed for receiver diversity and MIMO in (Czylwik, p. 1999) and (Stuber, 2001), respectively. A blind method for receiver diversity combined with OFDM is proposed in (U. Tureli D. K., 2001).