Non-cooperative denial of communication after synchronizing with repeating sequences

In this paper, a novel and non-cooperative data analysis approach has been developed to track the intervals of repeating sequences in a communication link and subsequently disrupt it without using conventional methods of high power jamming. The presence of repeating sequence, which may be preambles or training sequences, in the transmitted signal, is detected and a modified form of it is sent to the receiver´s end. Since the receiver is dependent on these sequences for channel estimation and frame synchronization purposes, reception of interfered sequences results in improper equalization of original data samples, thus making the communication erroneous. A cross-correlation based algorithm has been laid here to blindly trace the repeating sequence even when the sequence bits and its periodicity are unknown. The advantages over using autocorrelation for the same purpose are also shown. To get finer synchronization, a carrier frequency offset estimation method has also been instilled into this work. Insusceptibility to noisy bit errors and effectively avoiding being detected as an external jammer reflect the major strengths of our methodology.