Sigma shift keying (SSK): A paradigm shift in digital modulation techniques

A new digital modulation technique, named Sigma Shift Keying (SSK), is introduced with minimal transmitter power output (TPO) and very low probability of intercept (POI). Standard deviations (or variances, respectively) of zero mean Gaussian noise signals are being digitally modulated instead of shift keying of sinusoidal carrier signals. Following a theoretical analysis of achievable bit error rate performances and calculation of optimal detection thresholds, experimental results are presented of a prototype 2-level SSK modem (i.e., a communication system with two distinguishable noise power levels).