Research On BER Of 2FSK Signal Based On Stochastic Resonance Theory Under Levy Noise Excitation

Based on the fact that the noise in the real environment is more impulsive,and its distribution does not conform to the Gaussian distribution characteristics,the more impulsive Levy noise is selected,and the traditional incoherent demodulation model is used to solve the problem of lower signal quality of the 2FSK signal in the Levy noise background.,A new method based on the adaptive three-stable stochastic resonance theory to improve the output bit error rate of the traditional incoherent demodulation model of 2FSK signal is proposed.The 2FSK signal adaptive ternary stochastic resonance system model and the 2FSK signal adaptive cascade ternary stochastic resonance system model are theoretically deduced and established,and the MATLAB software is used for numerical simulation.The simulation results show:(1)Compared with the traditional incoherent demodulation model,the built-up 2FSK signal adaptive tri-stable stochastic resonance system model increases the amplitude of the upper branch spectrum by 62.2%,and the signal-to-noise ratio increases by 7.654dB;corresponding to the lower branch the channel spectrum amplitude has increased by 30%,the signal-to-noise ratio has increased by 6.018dB,and the bit error rate has been reduced by 7%.(2)Compared with the traditional incoherent demodulation model,the constructed 2FSK signal adaptive cascaded three-stable stochastic resonance system model has increased the amplitude of the upper branch spectrum by 165.2%,and the signal-to-noise ratio has increased by 13.672dB;corresponding to the lower branch spectrum The amplitude has increased by 70.9%,the signal-to-noise ratio has increased by 12.939dB,and the bit error rate has been reduced by 10%.The results show that the 2FSK signal adaptive ternary stochastic resonance system model can effectively reduce the error rate of the traditional incoherent demodulation model,and the 2FSK signal adaptive cascaded ternary stochastic resonance system model can further improve the 2FSK signal adaptive ternary stability The output performance of the state stochastic resonance system model is better than the formerThis paper further studies the changes between the output error rate of the two models and the Levy noise parameters and the three-stable system parameters.Research shows:(1)There is an optimal noise intensity interval,in which stochastic resonance occurs in the system and there is an optimal stochastic resonance noise intensity value;(2)When the Levy noise parameter a is greater than 1.5,the output error rate of the two models is significantly lower than that of the traditional incoherent demodulation model,indicating that weak impact noise will be more conducive to the occurrence of stochastic resonance;(3)The symmetric parameter ? of Levy noise basically has no effect on the output error rate of the two models;(4)When the value range of the three-stable system parameter w is approximately between[0.2,2],the two models output The bit error rate is significantly lower than that of the traditional incoherent demodulation model.The lowest value of the output bit error rate of the non-cascaded model and the cascaded model is obtained at w=0.5 and w=0.7 respectively.At this time,the two models have the highest value.Good stochastic resonance;(5)The value of the three-stable system parameter a should be greater than 0.14.At this time,both models have stochastic resonance,and the output error rate of the cascade model is lower than that of the non-cascade model.After this condition is met,the value of a is not It will have a greater impact on the output bit error rate of the two models;(6)When the value interval of the parameter b of the three-stable system is approximately(0,1.05],the output error rate of the two models is lower than that of the traditional incoherent model,indicating that this interval is the best value interval of the parameter b.