A REDUCED-COMPLEXITY FREQUENCY DETECTOR DERIVED FROM THE MAXIMUM-LIKELIHOOD PRINCIPLE

In addition to the conventional matched filter, implementation of Gard ner's frequency detector (GFD) based on the maximum-likelihood princip le also involves a frequency-matched filter. In this paper, we present a reduced-complexity frequency detector (RCFD) derived from Gardner's detector through a simple approximation to the frequency-matched filt er. We analyze its steady-state jitter properties and frequency acquis ition performance and compare it to the original GFD as well as to the well-known balanced quadricorrelator. Our results show that performan ce of the RCFD is close to that of the original GFD and that this dete ctor significantly outperforms the balanced quadricorrelator which inv olves a similar hardware complexity. Another contribution of this pape r is the analysis of GFD and RCFD when their outputs are computed at t wice the symbol rate.