This paper investigates the problem of tone interference within the ve
ry small aperture terminal (VSAT) binary phase-shift keying (BPSK) sig
nal spectrum. The degree of performance degradation of a VSAT link in
the presence of a tone interference is discussed. A simple theoretical
analysis is derived, and its validity is verified by experimental mea
surements performed using a standard commercial VSAT modem measurement
setup.