An OFDM-based channel sounder system

In this paper we have presented an OFDM-based channel sounder system. We can use commercial VSG (with arbitrary waveform generator) and real time VSA to conduct channel measurements. The requirement is that both VSG and VSA should have stable oscillator during the time of measurement and the frequency offset between these two equipments can be known in advance. Because the time offset was not calibrated, the power delay profile (PDP) measured does not give the absolute time delay but the relative time delay of multipath components. The frequency offset between the VSA and VSG has little effect on the measurement of single PDP, but will give a constant frequency offset for the Doppler measurement. If the frequency offset is known in advance, the offset can be compensated and the Doppler spectrum can be obtained.