Weak BPSK Signal Reception Based On Chaotic Synchronization

In the field of digital modulation technology, BPSK (Binary Phase ShiftKeying) modulation is one of the most commonly used modulation technologies.Signal is inevitably affected by strong noise because of the complex transmissionenvironment. The traditional receiving technology for BPSK signal can onlydemodulate the signal which SNR (signal-to-noise ratio) is above0dB. Therefore,the traditional method can't satisfy the requirement of today's communicationtransmission.The purpose of research for low SNR BPSK signal reception technology is todemodulate the BPSK signal from strong noise background. This paper embarksfrom the concept of chaotic theory to study the basic characteristic of the chaoticsystem and list several classical chaotic models. Especially for the Duffing system,this paper studies its noise immunity and its influence from the phase and frequencyof the additional signals. Then we verify the demodulation method of low SNRBPSK signal based on Duffing system. However, we find this method has itsoutstanding shortcomings. On this basis, this paper combines synchronous controlalgorithm and the chaotic system to put forward one demodulation method of lowSNR BPSK signal based on chaotic synchronization algorithm. This method ismainly divided into two parts, the first part is to use of Duffing equation and SG(speed gradient) method to recover the waveform of low SNR BPSK signal, toimprove the SNR of the signal waveform; The second part is to use the traditionalcoherent demodulation to demodulate the code element from the recovery waveform.In this paper, we use Matlab/Simulink to build the model of chaotic synchronizationsystem, and then take the simulation analysis to verify this method's feasibility.Among them, the second part (waveform recovery part) is the core of this paper.According to chaotic synchronization algorithm, this paper will not only use Matlabto make the simulation analysis, but also write the Verilog HDL program to makethe hardware behavior simulation. So we can have a further validation for thefeasibility of low SNR BPSK signal's reception based on chaotic synchronizationmethod.