Integer Carrier Frequency Offset Estimation in OFDM with Zadoff-Chu Sequences

Millimeter-wave spectra combined with the goal of supporting high velocity communications such as high speed trains and low earth orbit non-terrestrial networks increase the need for a robust method to address severe Doppler effects. To date, most cellular applications require management of a link where the effective Doppler is less than a subcarrier spacing; however, with emerging applications we can expect to see far larger distortion. To address this, we present a Zadoff-Chu sequence-based approach to overcome the ambiguity associated with estimating very high levels of integer Doppler. This algorithm enables certain niche applications of 5G and affords flexibility when choosing waveform subcarrier spacing.