Robust Pilot Design for Consistent Carrier Frequency Offset Estimation

Consistent pilot designs for carrier frequency offset (CFO) estimation eliminate ambiguity in the noise-free estimation metric trajectory regardless of the channel impulse response. Their importance is more pronounced in emergency and disaster situations since an inconsistent CFO estimate will result in a link failure. The CFO estimation performances of distinct consistent pilot designs can be quite different at moderate or low SNR due to different statistics of outlier which also yields a link failure. In this paper, we develop novel pilot designs that provide both consistency and robustness against outliers. We also propose new generalized pilot designs that yield consistency over any arbitrary but fixed CFO estimation range and that include our previous consistent pilot designs in H. Minn et al. (2006) as a special case which provides consistency over the maximum CFO estimation range (half of the sampling rate). Our new consistent pilot designs facilitate more flexible and economical implementation while our robust pilot designs enable wireless links with less outage and better resilience