Performance enhancement of TFI-OFDM with path selection based channel identification

Recently time-frequency interferometry (TFI)-OFDM has been proposed as a channel identification scheme. TFI-OFDM system can multiplex the same impulse response in twice on the time domain without overlapping each other. In this case, the required pilot signal is only one. Moreover, by averaging these impulse responses, the accurated channel impulse responses are obtained. However, if the total channel paths are reduced, the performance might be degraded. This is because the channel identification of TFI-OFDM is operated with averaging the selected spectrum signals from the time windows. For the case with reduced channel paths, the selected time spectrum signals include the noise terms. By applying the FFT operation, these noise terms are spread in the frequency domain. In this case, the channel identification is poorly operated due to the noise. To reduce this problem, in the paper, we propose the channel identification method with path selection for performance enhancement of TFI-OFDM.