Information transmission in parallel threshold arrays: suprathreshold stochastic resonance.

The information transmitted through a parallel summing array of noisy threshold elements with a common threshold is considered. In particular, using theoretical and numerical analysis, a recently reported [N. G. Stocks, Phys. Rev. Lett. 84, 2310 (2000)] form of stochastic resonance, termed suprathreshold stochastic resonance (SSR), is studied in detail. SSR is observed to occur in arrays with two or more elements and, unlike stochastic resonance (SR) in a single element, gives rise to noise-induced information gains that occur independent of the setting of the threshold or the size of the signal. The transmitted information is maximized when all thresholds are set to coincide with the signal mean. In this situation, and for large arrays, the noise can enhance performance up to approximately half the theoretical noiseless channel capacity. The theory is tested against digital simulation.