Pilot Tone Insertion and Utilization in Unique Word OFDM

Unique word-orthogonal frequency division multiplexing (UW-OFDM) provides several performance benefits over conventional cyclic prefix (CP) based OFDM, such as excellent spectral sidelobe suppression properties and an outstanding bit error ratio performance. Aside from idealized assumptions, each communication system faces challenges in conducting various system parameter estimation tasks. This work extends the current UW-OFDM signaling scheme by optimally including pilots tones in the frequency domain. Pilot tone based estimation of a carrier frequency offset (CFO) is conducted as a practical estimation example. Simulation results in a multipath environment demonstrate a significantly increased estimation accuracy in UW-OFDM over CP-OFDM, a result predicated on the inherent redundancy present in an UW-OFDM signal. The difference in estimation quality gets even more dominant with increasing CFO.