M-ary suprathreshold stochastic resonance in multilevel threshold systems with signal-dependent noise

We investigate multilevel threshold systems with signal-dependent noise that transmit a common random input signal. We demonstrate the occurrence of M-ary suprathreshold stochastic resonance caused by the signal-dependent noise, and quantify the information enhancement that results relative to the absence of noise. We also find that in the case of M-ary threshold systems, the values of mutual information and signal-to-quantization-noise ratio are larger than the corresponding values in the case of binary threshold systems. These results are potentially useful for understanding the encoding mechanism of inner-ear hair cells and other biological sensory systems.