Low probability of intercept communication schemes are crucial in scenarios where transmitter covertness must be maintained. Popular efforts to improve covertness are known to employ or enhance featureless qualities of wideband spread spectrum waveforms. The authors implement the strategy of modulating an already featureless wideband waveform - average white Gaussian noise - such that the modulation waveform remains featureless while transmitting binary data. The technique employed is adapted directly from the theoretical description given by Cooper at MILCOM '82. A working hardware model for a featureless wideband Gaussian noise signaling binary data modem has been prepared using standard ACT programmable transversal filters (PTFs). A transmitted reference modulation scheme is employed which enables decoding at the receiver without phase locked carrier recovery or code synchronization. ACT PTFs are used at the receiver to recorrelate the reference signal with the modulated signal. Correlation sequences are fully programmable.
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