Reception and detection of a wide‐band OFDM signal in a Doppler spreading channel

This study focuses on the reception strategy and the detection method of a wideband orthogonal frequency‐division multiplexing (OFDM) signal, which is passing through a Doppler channel. Most prior works regarded the Doppler effect as a reason of interchannel interference due to its destruction of the subcarrier orthogonality. Distinguishing from those works, the authors point out that the wideband OFDM signal is still an OFDM signal with subcarrier orthogonality after passing the channel with single Doppler scaling factor. Thus, the received OFDM signal passing the Doppler spreading channel is a linear superposition of a set of transmitted OFDM signals associated with different parameters. To make full use of the diversity gain offered by the superposition, the authors propose a strategy of diversity reception and a belief propagation detection method for the received wideband OFDM signal. The simulation results show that the proposed strategy improves the performance obviously with increase of the diversity order in a Doppler spreading channel. It offers different options for system demands. Furthermore, the proposed detection method can offer an acceptable performance even it combined with the conventional sampling process. It makes the conventional structure replacing the common resampling structure possible in a wideband OFDM system.