Channel Estimation and Equalization for SS-OOFDM System With High Mobility

摘要

When orthogonal frequency-division multiplexing (OFDM) is used in high-speed mobile scenarios, the traditional implementation of the OFDM receiver causes significant performance degradation. This letter proposes a subband superposed oversampled OFDM (SS-OOFDM) scheme for accommodating the diverse scenarios, including the scenarios with high mobility. To track the fast-varying mobile channel, a time-domain channel estimation method is developed to first obtain the channel impulse response (CIR) values at pilots by means of the basis expansion model. Subsequently, by utilizing Slepian sequences-based interpolation, the CIR values at data symbols are reconstructed. Furthermore, we design a subband decision feedback and feedforward equalizer for exploiting the Doppler and multipath diversity gains. Simulation results show that the SS-OOFDM, especially in high-speed mobile channels, outperforms the traditional OFDM receiver in terms of the bit-error-rate performance.