Research on the application of intrawell stochastic resonance of tri-stable system in weak OFDM signal detection

Abstract

Aiming at the performance deterioration of traditional OFDM signal demodulation methods under the condition of low signal-to-noise ratio, this paper proposes an OFDM signal enhancement and demodulation method based on intrawell stochastic resonance of tri-stable system. Firstly, the OFDM baseband complex signal model and the mathematical model of the stochastic resonance system in the tri-stable well are given; then, the transient response process and the steady-state response process of the stochastic resonance in the tri-stable well are analyzed, and the system from zero state to the expression of the transient time required for the resonance equilibrium state, and the analytical expression of the steady-state output signal of the stochastic resonance system in the trap is derived. Finally, the OFDM baseband complex signal enhancement and demodulation processing model of the stochastic resonance in the tri-stable trap is given, the received OFDM baseband complex signal is segmented according to the symbol period, the in-phase component and the quadrature component of the two-way signal are processed by in-well stochastic resonance at the same time, and the simulation is carried out. The simulation results show that by choosing appropriate noise intensity and system parameters, the stochastic resonance in the tri-stable well can effectively improve the detection performance of weak OFDM signals.