Error Performance of M-ary Noncoherent FSK in the Presence of CW Tone Interference

The error probability performance of
M
-ary noncoherent frequency-shift-keying (NCFSK) digital systems when under the influence of continuous wave (CW) interference is determined. Exact expressions are derived in terms of the signal-to-noise and the signal-to-interference ratios. Numerical results are given for quarternary and octonary NCFSK with the signal-signal-to-interference ratio as a parameter.