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

Kenan Altun,Enis Günay

doi:10.3906/elk-1904-186

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 carrier signals. The objective of the proposed adaptive method is to increase the low BER versus SNR performance caused by the constant threshold voltage level. In the proposed method, the communication signal received by the receiver circuits was defined as a Dirac delta function and a comparison signal was obtained from this signal. Then the BER versus SNR performance was analyzed and compared with that of various chaotic generator structures by using an instantaneous adaptive signal instead of a constant threshold voltage in the receiver circuit decision block. Both the simulation results and the experiments show the efficiency of the proposed method.

Highlights

In the last century, chaos theory was applied in many different fields of science
A novel decision block was proposed for distributed spectrum Direct chaotic communication (DCC) systems with the present study
A decision block with an adaptive threshold voltage level was realized for noncoherent structures with the proposed method

Summary

Introduction

Chaos theory was applied in many different fields of science. It is noteworthy due to its approaches in introducing system behavior and problem solving. The most important problem in chaos-based communication systems is the necessity of recovering the carrier signals in the receiver circuit. Digital noncoherent communication systems that do not require continuous synchronization have begun to gain importance [3, 4] It is valid for systems where both the chaotic and the periodic signals are used as carriers [5]. The information signal is obtained through a decision block in the receiver circuits of these communication systems. The decision is made with constant threshold voltage level at the comparator input of the decision blocks It complicates the recovery of the transmitted information signals at the receiver circuits. The proposed study aims to decrease the bit error rate by determining an adaptive threshold voltage level in the decision blocks of the DCC systems’ receiver circuits.

Proposed method ATL-COOK

Experimental realization of the proposed ATL-COOK on FPAA

Findings

Conclusion