Performance Analysis of MSK Modulation Under a Single-Tone Jamming

In the existing literatures, researchers naturally believe that single-tone jamming (STJ) targeting at the central frequency of minimum frequency shift keying (MSK) modulation shall be the optimal jamming strategy. However, it is not the truth. In this paper, the bit error rate (BER) performance of the MSK signaling under different STJ distribution is derived. Interestingly, it is found that STJ at the central frequency of MSK signaling is not necessarily optimal. In some conditions, STJ at the carrier frequency has a better jamming effect. In addition, for STJ targeting at the central frequency, the influence of phase discrepancy between jamming signal and legitimate signal on BER performance of MSK is also analyzed. It is demonstrated that when this phase discrepancy happens to be $\boldsymbol{0.25}\boldsymbol{\pi}+\boldsymbol{0.5 k}\boldsymbol{\pi}(\boldsymbol{k}=\boldsymbol{0,1,2,3})$ , the BER of MSK modulation is minimum. Therefore, the transmit power of the jamming signal should have some redundancy to remain its jamming effect even encountering the particular phase difference case.