Time-frequency interferometry for OFDM

In OFDM systems, the pilot signal averaging channel estimation is generally used to identify the channel state information (CSI). In this case, large pilot symbols are required for obtaining an accurate CSI. As a result, the total transmission rate is degraded due to large number of pilot symbols transmission. To reduce this problem, in this paper, we propose time-frequency interferometry (TFI) for OFDM to achieve an accurate CSI. TFIOFDM can multiplex the same impulse responses in twice on the time domain without overlapping to each other. By averaging of these impulse responses, we can obtain the accurate channel impulse response.