Low Probability of Detection Communication via Polarization Diversity: An Experimental Study

In this paper, we experimentally investigate the performance of diversity-based Low Probability of Detection (LPD) wireless communication using a custom Software-Defined Radio (SDR) system. We illustrate that polarization diversity can dramatically reduce a key metric for LPD against feature detection schemes: the Degree of Cyclostationarity (DCS) of the received signal. This reduces the probability of signal detection at an adversarial receiver. Moreover, random sequence selection and time-dithering are both proven to be potent methods for reducing cyclic correlations and can combine to provide a 94.6% reduction in DCS at the receiver. To facilitate communication with asynchronous SDRs several post-correction measures are described which enable demodulation of the received data. These are tested and shown to be effective even in the absence of an explicit preamble, which is critical to maintain the LPD nature of the communication signal.