A novel chaos-based modulation scheme: adaptive threshold level chaotic on–off keying for increased BER performance

Abstract

A novel modulation scheme called adaptive threshold level-chaotic on–off keying (ATL-COOK) is proposed.This scheme is applied to direct chaotic communication (DCC) systems where the chaotic signals are used as carriersignals. The objective of the proposed adaptive method is to increase the low BER versus SNR performance caused bythe constant threshold voltage level. In the proposed method, the communication signal received by the receiver circuitswas defined as a Dirac delta function and a comparison signal was obtained from this signal. Then the BER versus SNRperformance was analyzed and compared with that of various chaotic generator structures by using an instantaneousadaptive signal instead of a constant threshold voltage in the receiver circuit decision block. Both the simulation resultsand the experiments show the efficiency of the proposed method.