Application Of Tristable Stochastic Resonance In Weak OFDM Signal Detection

Orthogonal Frequency Division Multiplexing(OFDM)technology,as a high-speed transmission method of multi-carrier modulation,has a series of advantages such as high spectrum utilization and anti-multipath fading,and it is widely used in various fields.In order to solve the performance degradation problem of traditional OFDM signal demodulation method under the condition of low signal-to-noise ratio,this paper combines Stochastic Resonance(SR)theory with weak OFDM signal enhancement and demodulation process,and proposes a tristable-based the weak OFDM signal detection method of stochastic resonance enhances the weak OFDM signal by utilizing the characteristic that stochastic resonance will transfer noise energy to signal energy.The main contents of the paper are:(1)This paper introduces the research status and basic principles of tri-stable stochastic resonance and OFDM technology,expounds the great significance of applying tri-stable stochastic resonance to weak OFDM signal detection,and proposes a weak OFDM signal enhancement detection method based on tri-stable stochastic resonance.(2)The tri-stable stochastic resonance Langevin equation and the Fokker-Planck equation are deduced in detail,the tri-stable stochastic resonance model is established,and the switching law of the tri-stable stochastic resonance system between different steady states is studied.A complete transmitting and receiving model of OFDM system is built,the modulation and demodulation principle of OFDM technology is fully explained,and all the changing processes of OFDM system from transmitting end to receiving end are analyzed in detail..(3)The influence of different noise intensities and system parameters on the output effect of the stochastic resonance system is studied and analyzed,the numerical solution algorithm of the tri-stable stochastic resonance system is deduced,and the tri-stable stochastic resonance under different noise environments(Gaussian noise,stable noise)is studied and analyzed.system.Combined with the simulation experiments,the detection enhancement effect of the in-well stochastic resonance system on the weak signal under the input signal of single carrier and multicarrier is explored.(4)An OFDM signal enhancement and demodulation method based on stochastic resonance in tri-stable wells is proposed,and the system model and mathematical equations of stochastic resonance in tri-stable wells driven by OFDM signals are given.The expression of the transient response time required by the stochastic resonance system in the tri-stable well under the excitation of multi-carrier signals and the analytical expression of the steady-state output of the nonlinear system are derived.The DC component problem is analyzed in detail.Combined with simulation experiments,the influence of the stochastic resonance system in the tri-stable well on the demodulation performance of weak OFDM signals under different noise intensities and different system parameters is explored.The research results show that the OFDM signal enhancement and demodulation method based on the stochastic resonance in the tri-stable well proposed in this paper can indeed enhance the weak OFDM signal,effectively solve the problem of the deterioration of the reception performance of the weak OFDM signal under low signal-to-noise ratio,and improve the OFDM signal.Noise immunity of the system.