摘要 |
A method, apparatus and computer program for detecting an echo signal including interpolating at least one fast Fourier transformed OFDM signal received in the time-domain, interpolating the at least one signal generated by the time-domain interpolation in the frequency-domain, using a time-domain varying bandwidth low pass filter (LPF), with bandwidth that varies in response to a bandwidth control signal, measuring at least one signal to power ratio between a scattered pilot signal of the at least one signal generated by the time-domain interpolation and another scattered pilot signal of the at least one signal generated by the frequency-domain interpolation, and comparing the signal to power ratio to a threshold value to determine a state of an echo signal, and providing the bandwidth control signal with the determined echo state information to adjust the bandwidth of the time-domain LPF, based on the bandwidth control signal.
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