Frequency Estimation and Tracking Based on DFT-Domain NLMS Filters

Carrier tracking is a very well-known and widely-present problem in telecommunications, to which many solutions exist. However, these solutions still have many drawbacks, especially in low SNR scenarios. In this paper, a new approach is proposed, where estimates are extracted from the state of a normalized least-mean square adaptive predictor, improved using novel delay compensation technique coupled with a new frequency filtering stage based in phasor embedding, that avoids lock-in issues, achieving performance comparable to that of a traditional PLLs, without most of its main drawbacks, such as long transient responses and the need to rely on the presence of an explicit narrow-band carrier in the signal being tracked.