Analysis and comparison of four signal processing schemes for noise reduction in chaotic communication systems and application of LDPC code

Noise, as a form of destructive signal interference, brings challenges of varying degrees in the field of wireless communications. In order to reduce the impact of noise on the communication system, this paper combines four kinds of noise reduction schemes to compare and analyze the anti-noise performance in the communication system. In this paper, a chaotic keying system based on carrier modulation is firstly proposed as the basis, which can implicitly propagate an extra part of bits to improve the transmission rate. The system is compared with other systems through formula derivation and simulation analysis to analyze the advantages brought by carrier modulation. Next, four noise reduction schemes, namely, moving average (MA) noise reduction, autocorrelation (AC) noise reduction, variational modal decomposition (VMD) and wavelet packet decomposition (WPD), are combined to compare and analyze the performance of each scheme. By improving or balancing the advantages of some of the schemes, the overall performance is more obviously improved. Finally, LDPC channel coding is introduced, and the anti-noise performance of the communication system after the introduction of LDPC coding is analyzed through Monte Carlo simulation. After all the above simulations, the carrier modulation can efficiently improve the system transmission rate, which is the best choice for today's high-speed communication. The four noise reduction schemes can effectively improve the anti-noise performance of the system, each has its own advantages and disadvantages, and the performance is better after improvement and balancing. After the introduction of the LDPC coding, the performance of the system has a qualitative leap, which provides a reference for the future research. All the above schemes have good theoretical value and can provide good reference for practical engineering applications.