Robust 2D+1D adaptive channel estimation scheme in OFDM systems

Linear pilot-aided channel estimation in orthogonal-frequency division multiplexing (OFDM) systems is carried out optimally via 2D Wiener filters. The standard approach employed in conventional receivers is based on cascaded 2×1D Wiener filtering, which has a lower complexity but also suboptimal performance. The 2D+1D filtering scheme proposed in this paper combines the benefits of the two other schemes and is not affected by some restrictions of 2×1D filtering as shown by theoretical analysis of such schemes. For comparison, the mean-squared error (MSE) performance of the different channel estimation schemes is evaluated. Based on this analysis, results from full link-level simulations w.r.t. the digital video broadcasting standard for satellite services to handheld devices (DVB-SH) are presented applying adaptive channel estimation algorithms instead of the Wiener filters. The novel 2D+1D scheme shows enhanced bit error rate (BER) performance since it provides more accurate channel estimates in high Doppler channel conditions compared to the conventional cascaded 2×1D schemes.