: As technology becomes increasingly able to meet the requirements, interest in faster, noncoherent, frequency hopping rates to reduce the jamming of communication has heightened. The focus of this paper is on the performance of the fast frequency hopping spread spectrum system operating in the presence of partial band noise jamming. In this paper we consider a communication system that transmits binary data sequence or M frequency shift keying over a channel. With noncoherent detection, the MFSK tones on a given hop must be separated in frequency by an integer multiple of chip rate to provide orthogonality. The worst case partial-band noise jammer chooses fraction ( ) to maximize the bit error probability (Pb) for a given M and signal to noise ratio. It has been observed from the simulation results that increases with K, illustrating the effectiveness of worst-case jamming ( wc ) against FH/MFSK signals at typical operating points. It may be noted that wc decreases as Eb/NJ gets lar...