A novel channel estimation method for SC-FDE over fast fading channels

Single carrier frequency domain equalization (SC-FDE) is an attractive technique for broadband wireless communications because it does not have the problems of OFDM systems such as large peak-to-average power ratio and the sensitivity to carrier frequency offsets. However, channel variations within an SC-FDE block destroy orthogonality in frequency domain, resulting in interference, which increases an error floor in proportional to normalized Doppler frequency. To mitigate the effects of channel variations, this paper first provides an interference analysis in both time- and frequency-domain. With this analysis, an interpolation and unique word (UW) based scheme for estimating the time varying channel parameters at each sampling time is proposed. Theoretical analysis and simulation results show that the proposed interference suppression method and channel estimation scheme have low computational complexity and good performance dealing with changes in channel characteristics.