A Low Complexity SFBC-OFDM Channel Estimation in Fast Fading Channel

The space frequency block code based orthogonal frequency division multiplexing (SFBC-OFDM) system is very attractive for fast fading channel. Thus, the channel state information (CSI) is required to perform signal detection. However, in multiple transmitting antenna system, the pilot symbols are superimposed and which leads to inter transmitting antenna interference (ITAI). In this paper, a special comb-type pilot design is proposed which cancels the ITAI effects. Moreover, due to special pilot design, the channel estimation technique requires only arithmetic operations at pilot subcarrier followed by low pass interpolation (LPI) or Discrete Fourier Transformation (DFT) based interpolation method at data subcarrier to obtain the channel accurately. The performance of the DFT and LPI based interpolation are compared for SFBC-OFDM system on the basis of symbol error rate (SER) over multipath fast fading channel. From the results, it is observed that the DFT based interpolation outperforms the LPI method and achieves performance close to perfect channel estimation.