Channel Estimation for the Chinese DTTB System Based on a Novel Iterative PN Sequence Reconstruction

Digital television/terrestrial multimedia broadcasting (DTMB), announced as the Chinese digital television terrestrial broadcasting (DTTB) standard in August, 2006, recommends three PN padding modes as guard intervals (GI) and training sequences for both multi- and single-carrier block transmissions. The conventional channel estimation methods can be performed through either the subtraction of the pseudo-noise (PN) sequence or the cancellation of residual inter-symbol interference, which are quite complex. In this paper, a simple method is introduced to separate the PN sequence from the OFDM symbol and the channel impulse response (CIR) estimation can be obtained and updated via the reconstruction of the PN sequence in an iterative manner. Analysis shows that the proposed algorithm achieves low-complexity channel estimation and can be applied to the DTMB receiver directly. Simulation shows that the proposed algorithm works well under slow-fading broadcast channel even with long delay spread.