The performance of noncoherent orthogonal M-FSK in the presence of timing and frequency errors

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 error probability performance of the system. Exact expressions for these various error probability performances are derived and evaluated numerically for system parameters of interest. Also presented are upper bounds on average symbol error probability for the case of frequency error alone which are useful in assessing the absolute and relative performance of the system. Both continuous and discontinuous phase M-FSK cases are considered when timing error is present, the latter being much less robust to this type of offset.<>