S. Hinedi et al., THE PERFORMANCE OF NONCOHERENT ORTHOGONAL M-FSK IN THE PRESENCE OF TIMING AND FREQUENCY ERRORS, IEEE transactions on communications, 43(2-4), 1995, pp. 922-933
Practical M-FSK systems experience a combination of time and frequency
offsets (errors). This paper assesses the deleterious effect of these
offsets, first individually and then combined, on the average bit err
or probability performance of the system. Exact expressions for these
various error probability performances are derived and evaluated numer
ically for system parameters of interest. Also presented are upper bou
nds on average symbol error probability for the case of frequency erro
r alone which are useful in assessing the absolute and relative perfor
mance of the system. Both continuous and discontinuous phase M-FSK cas
es are considered when timing error is present, the latter being much
less robust to this type of offset.