Abstract: This application relates to an apparatus and method for generating a jamming signal, and a communication system. In one aspect, the method may include converting binary bits of a first communication signal to be transmitted and obtaining at least one codeword matched previously to the binary bits. The method may also include generating a second communication signal by superimposing a first conversion signal being obtained by converting the first communication signal to an up-chirp signal and a second conversion signal being obtained by converting the first communication signal to a down-chirp signal. The method further include generating a pseudo jamming signal by computing the second communication signal and the codeword.