An estimation algorithm for fast fading channel in MIMO-OFDM system

A combining of Multiple Input Multiple Output (MIMO) signal processing with Orthogonal Frequency Division Multiplexing (OFDM) is regarded as a promising solution the performance enhancement of next generation wireless system. In this paper, we proposed a trellis coded MIMO-OFDM system with a channel estimation algorithm for fast fading time-varying channels. In our system, we put more information in the cyclic prefix (CP) of each OFDM symbol by implementing this CP as a training sequence (TS). One TS is repeatedly transmitted from each transmit antenna for the MIMO channel estimation at the receiver. By properly designing each TS for multiple antennas to be orthogonal in the time domain, the channel estimation can be executed based on semi-blind processing in the case of more than two transmit antennas. The approach has brought higher spectral efficiency and convenient implementation at the expense of one extra FFT at the receiver. In the simulations, the normalized mean square error (NMSE) performance of MIMO-OFDM systems is compared with the pilot based algorithm. The bit error rate (BER) performance using this approach is also provided.